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 #include <linux/kmod.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/ctype.h>
  15 #include <linux/major.h>
  16 #include <linux/slab.h>
  17 #include <linux/hdreg.h>
  18 #include <linux/async.h>
  19 #include <linux/mutex.h>
  20 #include <linux/debugfs.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/vmalloc.h>
  23
  24 #include <asm/ccwdev.h>
  25 #include <asm/ebcdic.h>
  26 #include <asm/idals.h>
  27 #include <asm/itcw.h>
  28 #include <asm/diag.h>
  29
  30 #include "dasd_int.h"
  31 /*
  32  * SECTION: Constant definitions to be used within this file
  33  */
  34 #define DASD_CHANQ_MAX_SIZE 4
  35
  36 #define DASD_DIAG_MOD           "dasd_diag_mod"
  37
  38 /*
  39  * SECTION: exported variables of dasd.c
  40  */
  41 debug_info_t *dasd_debug_area;
  42 EXPORT_SYMBOL(dasd_debug_area);
  43 static struct dentry *dasd_debugfs_root_entry;
  44 struct dasd_discipline *dasd_diag_discipline_pointer;
  45 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  46 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  47
  48 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  49 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  50                    " Copyright IBM Corp. 2000");
  51 MODULE_LICENSE("GPL");
  52
  53 /*
  54  * SECTION: prototypes for static functions of dasd.c
  55  */
  56 static int dasd_flush_block_queue(struct dasd_block *);
  57 static void dasd_device_tasklet(unsigned long);
  58 static void dasd_block_tasklet(unsigned long);
  59 static void do_kick_device(struct work_struct *);
  60 static void do_reload_device(struct work_struct *);
  61 static void do_requeue_requests(struct work_struct *);
  62 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  63 static void dasd_device_timeout(struct timer_list *);
  64 static void dasd_block_timeout(struct timer_list *);
  65 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  66 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  67 static void dasd_profile_exit(struct dasd_profile *);
  68 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  69 static void dasd_hosts_exit(struct dasd_device *);
  70 static int dasd_handle_autoquiesce(struct dasd_device *, struct dasd_ccw_req *,
  71                                    unsigned int);
  72 /*
  73  * SECTION: Operations on the device structure.
  74  */
  75 static wait_queue_head_t dasd_init_waitq;
  76 static wait_queue_head_t dasd_flush_wq;
  77 static wait_queue_head_t generic_waitq;
  78 static wait_queue_head_t shutdown_waitq;
  79
  80 /*
  81  * Allocate memory for a new device structure.
  82  */
  83 struct dasd_device *dasd_alloc_device(void)
  84 {
  85         struct dasd_device *device;
  86
  87         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  88         if (!device)
  89                 return ERR_PTR(-ENOMEM);
  90
  91         /* Get two pages for normal block device operations. */
  92         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  93         if (!device->ccw_mem) {
  94                 kfree(device);
  95                 return ERR_PTR(-ENOMEM);
  96         }
  97         /* Get one page for error recovery. */
  98         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
  99         if (!device->erp_mem) {
 100                 free_pages((unsigned long) device->ccw_mem, 1);
 101                 kfree(device);
 102                 return ERR_PTR(-ENOMEM);
 103         }
 104         /* Get two pages for ese format. */
 105         device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 106         if (!device->ese_mem) {
 107                 free_page((unsigned long) device->erp_mem);
 108                 free_pages((unsigned long) device->ccw_mem, 1);
 109                 kfree(device);
 110                 return ERR_PTR(-ENOMEM);
 111         }
 112
 113         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 114         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 115         dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 116         spin_lock_init(&device->mem_lock);
 117         atomic_set(&device->tasklet_scheduled, 0);
 118         tasklet_init(&device->tasklet, dasd_device_tasklet,
 119                      (unsigned long) device);
 120         INIT_LIST_HEAD(&device->ccw_queue);
 121         timer_setup(&device->timer, dasd_device_timeout, 0);
 122         INIT_WORK(&device->kick_work, do_kick_device);
 123         INIT_WORK(&device->reload_device, do_reload_device);
 124         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 125         device->state = DASD_STATE_NEW;
 126         device->target = DASD_STATE_NEW;
 127         mutex_init(&device->state_mutex);
 128         spin_lock_init(&device->profile.lock);
 129         return device;
 130 }
 131
 132 /*
 133  * Free memory of a device structure.
 134  */
 135 void dasd_free_device(struct dasd_device *device)
 136 {
 137         kfree(device->private);
 138         free_pages((unsigned long) device->ese_mem, 1);
 139         free_page((unsigned long) device->erp_mem);
 140         free_pages((unsigned long) device->ccw_mem, 1);
 141         kfree(device);
 142 }
 143
 144 /*
 145  * Allocate memory for a new device structure.
 146  */
 147 struct dasd_block *dasd_alloc_block(void)
 148 {
 149         struct dasd_block *block;
 150
 151         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 152         if (!block)
 153                 return ERR_PTR(-ENOMEM);
 154         /* open_count = 0 means device online but not in use */
 155         atomic_set(&block->open_count, -1);
 156
 157         atomic_set(&block->tasklet_scheduled, 0);
 158         tasklet_init(&block->tasklet, dasd_block_tasklet,
 159                      (unsigned long) block);
 160         INIT_LIST_HEAD(&block->ccw_queue);
 161         spin_lock_init(&block->queue_lock);
 162         INIT_LIST_HEAD(&block->format_list);
 163         spin_lock_init(&block->format_lock);
 164         timer_setup(&block->timer, dasd_block_timeout, 0);
 165         spin_lock_init(&block->profile.lock);
 166
 167         return block;
 168 }
 169 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 170
 171 /*
 172  * Free memory of a device structure.
 173  */
 174 void dasd_free_block(struct dasd_block *block)
 175 {
 176         kfree(block);
 177 }
 178 EXPORT_SYMBOL_GPL(dasd_free_block);
 179
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         /*
 186          * As long as the device is not in state DASD_STATE_NEW we want to
 187          * keep the reference count > 0.
 188          */
 189         dasd_get_device(device);
 190         device->state = DASD_STATE_KNOWN;
 191         return 0;
 192 }
 193
 194 /*
 195  * Let the system forget about a device.
 196  */
 197 static int dasd_state_known_to_new(struct dasd_device *device)
 198 {
 199         /* Disable extended error reporting for this device. */
 200         dasd_eer_disable(device);
 201         device->state = DASD_STATE_NEW;
 202
 203         /* Give up reference we took in dasd_state_new_to_known. */
 204         dasd_put_device(device);
 205         return 0;
 206 }
 207
 208 static struct dentry *dasd_debugfs_setup(const char *name,
 209                                          struct dentry *base_dentry)
 210 {
 211         struct dentry *pde;
 212
 213         if (!base_dentry)
 214                 return NULL;
 215         pde = debugfs_create_dir(name, base_dentry);
 216         if (!pde || IS_ERR(pde))
 217                 return NULL;
 218         return pde;
 219 }
 220
 221 /*
 222  * Request the irq line for the device.
 223  */
 224 static int dasd_state_known_to_basic(struct dasd_device *device)
 225 {
 226         struct dasd_block *block = device->block;
 227         int rc = 0;
 228
 229         /* Allocate and register gendisk structure. */
 230         if (block) {
 231                 rc = dasd_gendisk_alloc(block);
 232                 if (rc)
 233                         return rc;
 234                 block->debugfs_dentry =
 235                         dasd_debugfs_setup(block->gdp->disk_name,
 236                                            dasd_debugfs_root_entry);
 237                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 238                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 239                         dasd_profile_on(&device->block->profile);
 240         }
 241         device->debugfs_dentry =
 242                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 243                                    dasd_debugfs_root_entry);
 244         dasd_profile_init(&device->profile, device->debugfs_dentry);
 245         dasd_hosts_init(device->debugfs_dentry, device);
 246
 247         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 248         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 249                                             8 * sizeof(long));
 250         debug_register_view(device->debug_area, &debug_sprintf_view);
 251         debug_set_level(device->debug_area, DBF_WARNING);
 252         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 253
 254         device->state = DASD_STATE_BASIC;
 255
 256         return rc;
 257 }
 258
 259 /*
 260  * Release the irq line for the device. Terminate any running i/o.
 261  */
 262 static int dasd_state_basic_to_known(struct dasd_device *device)
 263 {
 264         int rc;
 265
 266         if (device->discipline->basic_to_known) {
 267                 rc = device->discipline->basic_to_known(device);
 268                 if (rc)
 269                         return rc;
 270         }
 271
 272         if (device->block) {
 273                 dasd_profile_exit(&device->block->profile);
 274                 debugfs_remove(device->block->debugfs_dentry);
 275                 dasd_gendisk_free(device->block);
 276                 dasd_block_clear_timer(device->block);
 277         }
 278         rc = dasd_flush_device_queue(device);
 279         if (rc)
 280                 return rc;
 281         dasd_device_clear_timer(device);
 282         dasd_profile_exit(&device->profile);
 283         dasd_hosts_exit(device);
 284         debugfs_remove(device->debugfs_dentry);
 285         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 286         if (device->debug_area != NULL) {
 287                 debug_unregister(device->debug_area);
 288                 device->debug_area = NULL;
 289         }
 290         device->state = DASD_STATE_KNOWN;
 291         return 0;
 292 }
 293
 294 /*
 295  * Do the initial analysis. The do_analysis function may return
 296  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 297  * until the discipline decides to continue the startup sequence
 298  * by calling the function dasd_change_state. The eckd disciplines
 299  * uses this to start a ccw that detects the format. The completion
 300  * interrupt for this detection ccw uses the kernel event daemon to
 301  * trigger the call to dasd_change_state. All this is done in the
 302  * discipline code, see dasd_eckd.c.
 303  * After the analysis ccw is done (do_analysis returned 0) the block
 304  * device is setup.
 305  * In case the analysis returns an error, the device setup is stopped
 306  * (a fake disk was already added to allow formatting).
 307  */
 308 static int dasd_state_basic_to_ready(struct dasd_device *device)
 309 {
 310         struct dasd_block *block = device->block;
 311         struct queue_limits lim;
 312         int rc = 0;
 313
 314         /* make disk known with correct capacity */
 315         if (!block) {
 316                 device->state = DASD_STATE_READY;
 317                 goto out;
 318         }
 319
 320         if (block->base->discipline->do_analysis != NULL)
 321                 rc = block->base->discipline->do_analysis(block);
 322         if (rc) {
 323                 if (rc == -EAGAIN)
 324                         return rc;
 325                 device->state = DASD_STATE_UNFMT;
 326                 kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
 327                                KOBJ_CHANGE);
 328                 goto out;
 329         }
 330
 331         lim = queue_limits_start_update(block->gdp->queue);
 332         lim.max_dev_sectors = device->discipline->max_sectors(block);
 333         lim.max_hw_sectors = lim.max_dev_sectors;
 334         lim.logical_block_size = block->bp_block;
 335
 336         if (device->discipline->has_discard) {
 337                 unsigned int max_bytes;
 338
 339                 lim.discard_granularity = block->bp_block;
 340
 341                 /* Calculate max_discard_sectors and make it PAGE aligned */
 342                 max_bytes = USHRT_MAX * block->bp_block;
 343                 max_bytes = ALIGN_DOWN(max_bytes, PAGE_SIZE);
 344
 345                 lim.max_hw_discard_sectors = max_bytes / block->bp_block;
 346                 lim.max_write_zeroes_sectors = lim.max_hw_discard_sectors;
 347         }
 348         rc = queue_limits_commit_update(block->gdp->queue, &lim);
 349         if (rc)
 350                 return rc;
 351
 352         set_capacity(block->gdp, block->blocks << block->s2b_shift);
 353         device->state = DASD_STATE_READY;
 354
 355         rc = dasd_scan_partitions(block);
 356         if (rc) {
 357                 device->state = DASD_STATE_BASIC;
 358                 return rc;
 359         }
 360
 361 out:
 362         if (device->discipline->basic_to_ready)
 363                 rc = device->discipline->basic_to_ready(device);
 364         return rc;
 365 }
 366
 367 static inline
 368 int _wait_for_empty_queues(struct dasd_device *device)
 369 {
 370         if (device->block)
 371                 return list_empty(&device->ccw_queue) &&
 372                         list_empty(&device->block->ccw_queue);
 373         else
 374                 return list_empty(&device->ccw_queue);
 375 }
 376
 377 /*
 378  * Remove device from block device layer. Destroy dirty buffers.
 379  * Forget format information. Check if the target level is basic
 380  * and if it is create fake disk for formatting.
 381  */
 382 static int dasd_state_ready_to_basic(struct dasd_device *device)
 383 {
 384         int rc;
 385
 386         device->state = DASD_STATE_BASIC;
 387         if (device->block) {
 388                 struct dasd_block *block = device->block;
 389                 rc = dasd_flush_block_queue(block);
 390                 if (rc) {
 391                         device->state = DASD_STATE_READY;
 392                         return rc;
 393                 }
 394                 dasd_destroy_partitions(block);
 395                 block->blocks = 0;
 396                 block->bp_block = 0;
 397                 block->s2b_shift = 0;
 398         }
 399         return 0;
 400 }
 401
 402 /*
 403  * Back to basic.
 404  */
 405 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 406 {
 407         device->state = DASD_STATE_BASIC;
 408         return 0;
 409 }
 410
 411 /*
 412  * Make the device online and schedule the bottom half to start
 413  * the requeueing of requests from the linux request queue to the
 414  * ccw queue.
 415  */
 416 static int
 417 dasd_state_ready_to_online(struct dasd_device * device)
 418 {
 419         device->state = DASD_STATE_ONLINE;
 420         if (device->block) {
 421                 dasd_schedule_block_bh(device->block);
 422                 if ((device->features & DASD_FEATURE_USERAW)) {
 423                         kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
 424                                         KOBJ_CHANGE);
 425                         return 0;
 426                 }
 427                 disk_uevent(file_bdev(device->block->bdev_file)->bd_disk,
 428                             KOBJ_CHANGE);
 429         }
 430         return 0;
 431 }
 432
 433 /*
 434  * Stop the requeueing of requests again.
 435  */
 436 static int dasd_state_online_to_ready(struct dasd_device *device)
 437 {
 438         int rc;
 439
 440         if (device->discipline->online_to_ready) {
 441                 rc = device->discipline->online_to_ready(device);
 442                 if (rc)
 443                         return rc;
 444         }
 445
 446         device->state = DASD_STATE_READY;
 447         if (device->block && !(device->features & DASD_FEATURE_USERAW))
 448                 disk_uevent(file_bdev(device->block->bdev_file)->bd_disk,
 449                             KOBJ_CHANGE);
 450         return 0;
 451 }
 452
 453 /*
 454  * Device startup state changes.
 455  */
 456 static int dasd_increase_state(struct dasd_device *device)
 457 {
 458         int rc;
 459
 460         rc = 0;
 461         if (device->state == DASD_STATE_NEW &&
 462             device->target >= DASD_STATE_KNOWN)
 463                 rc = dasd_state_new_to_known(device);
 464
 465         if (!rc &&
 466             device->state == DASD_STATE_KNOWN &&
 467             device->target >= DASD_STATE_BASIC)
 468                 rc = dasd_state_known_to_basic(device);
 469
 470         if (!rc &&
 471             device->state == DASD_STATE_BASIC &&
 472             device->target >= DASD_STATE_READY)
 473                 rc = dasd_state_basic_to_ready(device);
 474
 475         if (!rc &&
 476             device->state == DASD_STATE_UNFMT &&
 477             device->target > DASD_STATE_UNFMT)
 478                 rc = -EPERM;
 479
 480         if (!rc &&
 481             device->state == DASD_STATE_READY &&
 482             device->target >= DASD_STATE_ONLINE)
 483                 rc = dasd_state_ready_to_online(device);
 484
 485         return rc;
 486 }
 487
 488 /*
 489  * Device shutdown state changes.
 490  */
 491 static int dasd_decrease_state(struct dasd_device *device)
 492 {
 493         int rc;
 494
 495         rc = 0;
 496         if (device->state == DASD_STATE_ONLINE &&
 497             device->target <= DASD_STATE_READY)
 498                 rc = dasd_state_online_to_ready(device);
 499
 500         if (!rc &&
 501             device->state == DASD_STATE_READY &&
 502             device->target <= DASD_STATE_BASIC)
 503                 rc = dasd_state_ready_to_basic(device);
 504
 505         if (!rc &&
 506             device->state == DASD_STATE_UNFMT &&
 507             device->target <= DASD_STATE_BASIC)
 508                 rc = dasd_state_unfmt_to_basic(device);
 509
 510         if (!rc &&
 511             device->state == DASD_STATE_BASIC &&
 512             device->target <= DASD_STATE_KNOWN)
 513                 rc = dasd_state_basic_to_known(device);
 514
 515         if (!rc &&
 516             device->state == DASD_STATE_KNOWN &&
 517             device->target <= DASD_STATE_NEW)
 518                 rc = dasd_state_known_to_new(device);
 519
 520         return rc;
 521 }
 522
 523 /*
 524  * This is the main startup/shutdown routine.
 525  */
 526 static void dasd_change_state(struct dasd_device *device)
 527 {
 528         int rc;
 529
 530         if (device->state == device->target)
 531                 /* Already where we want to go today... */
 532                 return;
 533         if (device->state < device->target)
 534                 rc = dasd_increase_state(device);
 535         else
 536                 rc = dasd_decrease_state(device);
 537         if (rc == -EAGAIN)
 538                 return;
 539         if (rc)
 540                 device->target = device->state;
 541
 542         /* let user-space know that the device status changed */
 543         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 544
 545         if (device->state == device->target)
 546                 wake_up(&dasd_init_waitq);
 547 }
 548
 549 /*
 550  * Kick starter for devices that did not complete the startup/shutdown
 551  * procedure or were sleeping because of a pending state.
 552  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 553  * event daemon.
 554  */
 555 static void do_kick_device(struct work_struct *work)
 556 {
 557         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 558         mutex_lock(&device->state_mutex);
 559         dasd_change_state(device);
 560         mutex_unlock(&device->state_mutex);
 561         dasd_schedule_device_bh(device);
 562         dasd_put_device(device);
 563 }
 564
 565 void dasd_kick_device(struct dasd_device *device)
 566 {
 567         dasd_get_device(device);
 568         /* queue call to dasd_kick_device to the kernel event daemon. */
 569         if (!schedule_work(&device->kick_work))
 570                 dasd_put_device(device);
 571 }
 572 EXPORT_SYMBOL(dasd_kick_device);
 573
 574 /*
 575  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 576  * event daemon.
 577  */
 578 static void do_reload_device(struct work_struct *work)
 579 {
 580         struct dasd_device *device = container_of(work, struct dasd_device,
 581                                                   reload_device);
 582         device->discipline->reload(device);
 583         dasd_put_device(device);
 584 }
 585
 586 void dasd_reload_device(struct dasd_device *device)
 587 {
 588         dasd_get_device(device);
 589         /* queue call to dasd_reload_device to the kernel event daemon. */
 590         if (!schedule_work(&device->reload_device))
 591                 dasd_put_device(device);
 592 }
 593 EXPORT_SYMBOL(dasd_reload_device);
 594
 595 /*
 596  * Set the target state for a device and starts the state change.
 597  */
 598 void dasd_set_target_state(struct dasd_device *device, int target)
 599 {
 600         dasd_get_device(device);
 601         mutex_lock(&device->state_mutex);
 602         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 603         if (dasd_probeonly && target > DASD_STATE_READY)
 604                 target = DASD_STATE_READY;
 605         if (device->target != target) {
 606                 if (device->state == target)
 607                         wake_up(&dasd_init_waitq);
 608                 device->target = target;
 609         }
 610         if (device->state != device->target)
 611                 dasd_change_state(device);
 612         mutex_unlock(&device->state_mutex);
 613         dasd_put_device(device);
 614 }
 615
 616 /*
 617  * Enable devices with device numbers in [from..to].
 618  */
 619 static inline int _wait_for_device(struct dasd_device *device)
 620 {
 621         return (device->state == device->target);
 622 }
 623
 624 void dasd_enable_device(struct dasd_device *device)
 625 {
 626         dasd_set_target_state(device, DASD_STATE_ONLINE);
 627         if (device->state <= DASD_STATE_KNOWN)
 628                 /* No discipline for device found. */
 629                 dasd_set_target_state(device, DASD_STATE_NEW);
 630         /* Now wait for the devices to come up. */
 631         wait_event(dasd_init_waitq, _wait_for_device(device));
 632
 633         dasd_reload_device(device);
 634         if (device->discipline->kick_validate)
 635                 device->discipline->kick_validate(device);
 636 }
 637 EXPORT_SYMBOL(dasd_enable_device);
 638
 639 /*
 640  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 641  */
 642
 643 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 644
 645 #ifdef CONFIG_DASD_PROFILE
 646 struct dasd_profile dasd_global_profile = {
 647         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 648 };
 649 static struct dentry *dasd_debugfs_global_entry;
 650
 651 /*
 652  * Add profiling information for cqr before execution.
 653  */
 654 static void dasd_profile_start(struct dasd_block *block,
 655                                struct dasd_ccw_req *cqr,
 656                                struct request *req)
 657 {
 658         struct list_head *l;
 659         unsigned int counter;
 660         struct dasd_device *device;
 661
 662         /* count the length of the chanq for statistics */
 663         counter = 0;
 664         if (dasd_global_profile_level || block->profile.data)
 665                 list_for_each(l, &block->ccw_queue)
 666                         if (++counter >= 31)
 667                                 break;
 668
 669         spin_lock(&dasd_global_profile.lock);
 670         if (dasd_global_profile.data) {
 671                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 672                 if (rq_data_dir(req) == READ)
 673                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 674         }
 675         spin_unlock(&dasd_global_profile.lock);
 676
 677         spin_lock(&block->profile.lock);
 678         if (block->profile.data) {
 679                 block->profile.data->dasd_io_nr_req[counter]++;
 680                 if (rq_data_dir(req) == READ)
 681                         block->profile.data->dasd_read_nr_req[counter]++;
 682         }
 683         spin_unlock(&block->profile.lock);
 684
 685         /*
 686          * We count the request for the start device, even though it may run on
 687          * some other device due to error recovery. This way we make sure that
 688          * we count each request only once.
 689          */
 690         device = cqr->startdev;
 691         if (!device->profile.data)
 692                 return;
 693
 694         spin_lock(get_ccwdev_lock(device->cdev));
 695         counter = 1; /* request is not yet queued on the start device */
 696         list_for_each(l, &device->ccw_queue)
 697                 if (++counter >= 31)
 698                         break;
 699         spin_unlock(get_ccwdev_lock(device->cdev));
 700
 701         spin_lock(&device->profile.lock);
 702         device->profile.data->dasd_io_nr_req[counter]++;
 703         if (rq_data_dir(req) == READ)
 704                 device->profile.data->dasd_read_nr_req[counter]++;
 705         spin_unlock(&device->profile.lock);
 706 }
 707
 708 /*
 709  * Add profiling information for cqr after execution.
 710  */
 711
 712 #define dasd_profile_counter(value, index)                         \
 713 {                                                                  \
 714         for (index = 0; index < 31 && value >> (2+index); index++) \
 715                 ;                                                  \
 716 }
 717
 718 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 719                                       int is_alias,
 720                                       int is_tpm,
 721                                       int is_read,
 722                                       long sectors,
 723                                       int sectors_ind,
 724                                       int tottime_ind,
 725                                       int tottimeps_ind,
 726                                       int strtime_ind,
 727                                       int irqtime_ind,
 728                                       int irqtimeps_ind,
 729                                       int endtime_ind)
 730 {
 731         /* in case of an overflow, reset the whole profile */
 732         if (data->dasd_io_reqs == UINT_MAX) {
 733                         memset(data, 0, sizeof(*data));
 734                         ktime_get_real_ts64(&data->starttod);
 735         }
 736         data->dasd_io_reqs++;
 737         data->dasd_io_sects += sectors;
 738         if (is_alias)
 739                 data->dasd_io_alias++;
 740         if (is_tpm)
 741                 data->dasd_io_tpm++;
 742
 743         data->dasd_io_secs[sectors_ind]++;
 744         data->dasd_io_times[tottime_ind]++;
 745         data->dasd_io_timps[tottimeps_ind]++;
 746         data->dasd_io_time1[strtime_ind]++;
 747         data->dasd_io_time2[irqtime_ind]++;
 748         data->dasd_io_time2ps[irqtimeps_ind]++;
 749         data->dasd_io_time3[endtime_ind]++;
 750
 751         if (is_read) {
 752                 data->dasd_read_reqs++;
 753                 data->dasd_read_sects += sectors;
 754                 if (is_alias)
 755                         data->dasd_read_alias++;
 756                 if (is_tpm)
 757                         data->dasd_read_tpm++;
 758                 data->dasd_read_secs[sectors_ind]++;
 759                 data->dasd_read_times[tottime_ind]++;
 760                 data->dasd_read_time1[strtime_ind]++;
 761                 data->dasd_read_time2[irqtime_ind]++;
 762                 data->dasd_read_time3[endtime_ind]++;
 763         }
 764 }
 765
 766 static void dasd_profile_end(struct dasd_block *block,
 767                              struct dasd_ccw_req *cqr,
 768                              struct request *req)
 769 {
 770         unsigned long strtime, irqtime, endtime, tottime;
 771         unsigned long tottimeps, sectors;
 772         struct dasd_device *device;
 773         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 774         int irqtime_ind, irqtimeps_ind, endtime_ind;
 775         struct dasd_profile_info *data;
 776
 777         device = cqr->startdev;
 778         if (!(dasd_global_profile_level ||
 779               block->profile.data ||
 780               device->profile.data))
 781                 return;
 782
 783         sectors = blk_rq_sectors(req);
 784         if (!cqr->buildclk || !cqr->startclk ||
 785             !cqr->stopclk || !cqr->endclk ||
 786             !sectors)
 787                 return;
 788
 789         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 790         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 791         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 792         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 793         tottimeps = tottime / sectors;
 794
 795         dasd_profile_counter(sectors, sectors_ind);
 796         dasd_profile_counter(tottime, tottime_ind);
 797         dasd_profile_counter(tottimeps, tottimeps_ind);
 798         dasd_profile_counter(strtime, strtime_ind);
 799         dasd_profile_counter(irqtime, irqtime_ind);
 800         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 801         dasd_profile_counter(endtime, endtime_ind);
 802
 803         spin_lock(&dasd_global_profile.lock);
 804         if (dasd_global_profile.data) {
 805                 data = dasd_global_profile.data;
 806                 data->dasd_sum_times += tottime;
 807                 data->dasd_sum_time_str += strtime;
 808                 data->dasd_sum_time_irq += irqtime;
 809                 data->dasd_sum_time_end += endtime;
 810                 dasd_profile_end_add_data(dasd_global_profile.data,
 811                                           cqr->startdev != block->base,
 812                                           cqr->cpmode == 1,
 813                                           rq_data_dir(req) == READ,
 814                                           sectors, sectors_ind, tottime_ind,
 815                                           tottimeps_ind, strtime_ind,
 816                                           irqtime_ind, irqtimeps_ind,
 817                                           endtime_ind);
 818         }
 819         spin_unlock(&dasd_global_profile.lock);
 820
 821         spin_lock(&block->profile.lock);
 822         if (block->profile.data) {
 823                 data = block->profile.data;
 824                 data->dasd_sum_times += tottime;
 825                 data->dasd_sum_time_str += strtime;
 826                 data->dasd_sum_time_irq += irqtime;
 827                 data->dasd_sum_time_end += endtime;
 828                 dasd_profile_end_add_data(block->profile.data,
 829                                           cqr->startdev != block->base,
 830                                           cqr->cpmode == 1,
 831                                           rq_data_dir(req) == READ,
 832                                           sectors, sectors_ind, tottime_ind,
 833                                           tottimeps_ind, strtime_ind,
 834                                           irqtime_ind, irqtimeps_ind,
 835                                           endtime_ind);
 836         }
 837         spin_unlock(&block->profile.lock);
 838
 839         spin_lock(&device->profile.lock);
 840         if (device->profile.data) {
 841                 data = device->profile.data;
 842                 data->dasd_sum_times += tottime;
 843                 data->dasd_sum_time_str += strtime;
 844                 data->dasd_sum_time_irq += irqtime;
 845                 data->dasd_sum_time_end += endtime;
 846                 dasd_profile_end_add_data(device->profile.data,
 847                                           cqr->startdev != block->base,
 848                                           cqr->cpmode == 1,
 849                                           rq_data_dir(req) == READ,
 850                                           sectors, sectors_ind, tottime_ind,
 851                                           tottimeps_ind, strtime_ind,
 852                                           irqtime_ind, irqtimeps_ind,
 853                                           endtime_ind);
 854         }
 855         spin_unlock(&device->profile.lock);
 856 }
 857
 858 void dasd_profile_reset(struct dasd_profile *profile)
 859 {
 860         struct dasd_profile_info *data;
 861
 862         spin_lock_bh(&profile->lock);
 863         data = profile->data;
 864         if (!data) {
 865                 spin_unlock_bh(&profile->lock);
 866                 return;
 867         }
 868         memset(data, 0, sizeof(*data));
 869         ktime_get_real_ts64(&data->starttod);
 870         spin_unlock_bh(&profile->lock);
 871 }
 872
 873 int dasd_profile_on(struct dasd_profile *profile)
 874 {
 875         struct dasd_profile_info *data;
 876
 877         data = kzalloc(sizeof(*data), GFP_KERNEL);
 878         if (!data)
 879                 return -ENOMEM;
 880         spin_lock_bh(&profile->lock);
 881         if (profile->data) {
 882                 spin_unlock_bh(&profile->lock);
 883                 kfree(data);
 884                 return 0;
 885         }
 886         ktime_get_real_ts64(&data->starttod);
 887         profile->data = data;
 888         spin_unlock_bh(&profile->lock);
 889         return 0;
 890 }
 891
 892 void dasd_profile_off(struct dasd_profile *profile)
 893 {
 894         spin_lock_bh(&profile->lock);
 895         kfree(profile->data);
 896         profile->data = NULL;
 897         spin_unlock_bh(&profile->lock);
 898 }
 899
 900 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 901 {
 902         char *buffer;
 903
 904         buffer = vmalloc(user_len + 1);
 905         if (buffer == NULL)
 906                 return ERR_PTR(-ENOMEM);
 907         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 908                 vfree(buffer);
 909                 return ERR_PTR(-EFAULT);
 910         }
 911         /* got the string, now strip linefeed. */
 912         if (buffer[user_len - 1] == '\n')
 913                 buffer[user_len - 1] = 0;
 914         else
 915                 buffer[user_len] = 0;
 916         return buffer;
 917 }
 918
 919 static ssize_t dasd_stats_write(struct file *file,
 920                                 const char __user *user_buf,
 921                                 size_t user_len, loff_t *pos)
 922 {
 923         char *buffer, *str;
 924         int rc;
 925         struct seq_file *m = (struct seq_file *)file->private_data;
 926         struct dasd_profile *prof = m->private;
 927
 928         if (user_len > 65536)
 929                 user_len = 65536;
 930         buffer = dasd_get_user_string(user_buf, user_len);
 931         if (IS_ERR(buffer))
 932                 return PTR_ERR(buffer);
 933
 934         str = skip_spaces(buffer);
 935         rc = user_len;
 936         if (strncmp(str, "reset", 5) == 0) {
 937                 dasd_profile_reset(prof);
 938         } else if (strncmp(str, "on", 2) == 0) {
 939                 rc = dasd_profile_on(prof);
 940                 if (rc)
 941                         goto out;
 942                 rc = user_len;
 943                 if (prof == &dasd_global_profile) {
 944                         dasd_profile_reset(prof);
 945                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 946                 }
 947         } else if (strncmp(str, "off", 3) == 0) {
 948                 if (prof == &dasd_global_profile)
 949                         dasd_global_profile_level = DASD_PROFILE_OFF;
 950                 dasd_profile_off(prof);
 951         } else
 952                 rc = -EINVAL;
 953 out:
 954         vfree(buffer);
 955         return rc;
 956 }
 957
 958 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 959 {
 960         int i;
 961
 962         for (i = 0; i < 32; i++)
 963                 seq_printf(m, "%u ", array[i]);
 964         seq_putc(m, '\n');
 965 }
 966
 967 static void dasd_stats_seq_print(struct seq_file *m,
 968                                  struct dasd_profile_info *data)
 969 {
 970         seq_printf(m, "start_time %lld.%09ld\n",
 971                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
 972         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 973         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 974         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 975         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 976         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
 977                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
 978         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
 979                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
 980         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
 981                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
 982         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
 983                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
 984         seq_puts(m, "histogram_sectors ");
 985         dasd_stats_array(m, data->dasd_io_secs);
 986         seq_puts(m, "histogram_io_times ");
 987         dasd_stats_array(m, data->dasd_io_times);
 988         seq_puts(m, "histogram_io_times_weighted ");
 989         dasd_stats_array(m, data->dasd_io_timps);
 990         seq_puts(m, "histogram_time_build_to_ssch ");
 991         dasd_stats_array(m, data->dasd_io_time1);
 992         seq_puts(m, "histogram_time_ssch_to_irq ");
 993         dasd_stats_array(m, data->dasd_io_time2);
 994         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
 995         dasd_stats_array(m, data->dasd_io_time2ps);
 996         seq_puts(m, "histogram_time_irq_to_end ");
 997         dasd_stats_array(m, data->dasd_io_time3);
 998         seq_puts(m, "histogram_ccw_queue_length ");
 999         dasd_stats_array(m, data->dasd_io_nr_req);
1000         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1001         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1002         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1003         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1004         seq_puts(m, "histogram_read_sectors ");
1005         dasd_stats_array(m, data->dasd_read_secs);
1006         seq_puts(m, "histogram_read_times ");
1007         dasd_stats_array(m, data->dasd_read_times);
1008         seq_puts(m, "histogram_read_time_build_to_ssch ");
1009         dasd_stats_array(m, data->dasd_read_time1);
1010         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1011         dasd_stats_array(m, data->dasd_read_time2);
1012         seq_puts(m, "histogram_read_time_irq_to_end ");
1013         dasd_stats_array(m, data->dasd_read_time3);
1014         seq_puts(m, "histogram_read_ccw_queue_length ");
1015         dasd_stats_array(m, data->dasd_read_nr_req);
1016 }
1017
1018 static int dasd_stats_show(struct seq_file *m, void *v)
1019 {
1020         struct dasd_profile *profile;
1021         struct dasd_profile_info *data;
1022
1023         profile = m->private;
1024         spin_lock_bh(&profile->lock);
1025         data = profile->data;
1026         if (!data) {
1027                 spin_unlock_bh(&profile->lock);
1028                 seq_puts(m, "disabled\n");
1029                 return 0;
1030         }
1031         dasd_stats_seq_print(m, data);
1032         spin_unlock_bh(&profile->lock);
1033         return 0;
1034 }
1035
1036 static int dasd_stats_open(struct inode *inode, struct file *file)
1037 {
1038         struct dasd_profile *profile = inode->i_private;
1039         return single_open(file, dasd_stats_show, profile);
1040 }
1041
1042 static const struct file_operations dasd_stats_raw_fops = {
1043         .owner          = THIS_MODULE,
1044         .open           = dasd_stats_open,
1045         .read           = seq_read,
1046         .llseek         = seq_lseek,
1047         .release        = single_release,
1048         .write          = dasd_stats_write,
1049 };
1050
1051 static void dasd_profile_init(struct dasd_profile *profile,
1052                               struct dentry *base_dentry)
1053 {
1054         umode_t mode;
1055         struct dentry *pde;
1056
1057         if (!base_dentry)
1058                 return;
1059         profile->dentry = NULL;
1060         profile->data = NULL;
1061         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1062         pde = debugfs_create_file("statistics", mode, base_dentry,
1063                                   profile, &dasd_stats_raw_fops);
1064         if (pde && !IS_ERR(pde))
1065                 profile->dentry = pde;
1066         return;
1067 }
1068
1069 static void dasd_profile_exit(struct dasd_profile *profile)
1070 {
1071         dasd_profile_off(profile);
1072         debugfs_remove(profile->dentry);
1073         profile->dentry = NULL;
1074 }
1075
1076 static void dasd_statistics_removeroot(void)
1077 {
1078         dasd_global_profile_level = DASD_PROFILE_OFF;
1079         dasd_profile_exit(&dasd_global_profile);
1080         debugfs_remove(dasd_debugfs_global_entry);
1081         debugfs_remove(dasd_debugfs_root_entry);
1082 }
1083
1084 static void dasd_statistics_createroot(void)
1085 {
1086         struct dentry *pde;
1087
1088         dasd_debugfs_root_entry = NULL;
1089         pde = debugfs_create_dir("dasd", NULL);
1090         if (!pde || IS_ERR(pde))
1091                 goto error;
1092         dasd_debugfs_root_entry = pde;
1093         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1094         if (!pde || IS_ERR(pde))
1095                 goto error;
1096         dasd_debugfs_global_entry = pde;
1097         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1098         return;
1099
1100 error:
1101         DBF_EVENT(DBF_ERR, "%s",
1102                   "Creation of the dasd debugfs interface failed");
1103         dasd_statistics_removeroot();
1104         return;
1105 }
1106
1107 #else
1108 #define dasd_profile_start(block, cqr, req) do {} while (0)
1109 #define dasd_profile_end(block, cqr, req) do {} while (0)
1110
1111 static void dasd_statistics_createroot(void)
1112 {
1113         return;
1114 }
1115
1116 static void dasd_statistics_removeroot(void)
1117 {
1118         return;
1119 }
1120
1121 static void dasd_profile_init(struct dasd_profile *profile,
1122                               struct dentry *base_dentry)
1123 {
1124         return;
1125 }
1126
1127 static void dasd_profile_exit(struct dasd_profile *profile)
1128 {
1129         return;
1130 }
1131
1132 int dasd_profile_on(struct dasd_profile *profile)
1133 {
1134         return 0;
1135 }
1136
1137 #endif                          /* CONFIG_DASD_PROFILE */
1138
1139 static int dasd_hosts_show(struct seq_file *m, void *v)
1140 {
1141         struct dasd_device *device;
1142         int rc = -EOPNOTSUPP;
1143
1144         device = m->private;
1145         dasd_get_device(device);
1146
1147         if (device->discipline->hosts_print)
1148                 rc = device->discipline->hosts_print(device, m);
1149
1150         dasd_put_device(device);
1151         return rc;
1152 }
1153
1154 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1155
1156 static void dasd_hosts_exit(struct dasd_device *device)
1157 {
1158         debugfs_remove(device->hosts_dentry);
1159         device->hosts_dentry = NULL;
1160 }
1161
1162 static void dasd_hosts_init(struct dentry *base_dentry,
1163                             struct dasd_device *device)
1164 {
1165         struct dentry *pde;
1166         umode_t mode;
1167
1168         if (!base_dentry)
1169                 return;
1170
1171         mode = S_IRUSR | S_IFREG;
1172         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1173                                   device, &dasd_hosts_fops);
1174         if (pde && !IS_ERR(pde))
1175                 device->hosts_dentry = pde;
1176 }
1177
1178 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1179                                           struct dasd_device *device,
1180                                           struct dasd_ccw_req *cqr)
1181 {
1182         unsigned long flags;
1183         char *data, *chunk;
1184         int size = 0;
1185
1186         if (cplength > 0)
1187                 size += cplength * sizeof(struct ccw1);
1188         if (datasize > 0)
1189                 size += datasize;
1190         if (!cqr)
1191                 size += (sizeof(*cqr) + 7L) & -8L;
1192
1193         spin_lock_irqsave(&device->mem_lock, flags);
1194         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1195         spin_unlock_irqrestore(&device->mem_lock, flags);
1196         if (!chunk)
1197                 return ERR_PTR(-ENOMEM);
1198         if (!cqr) {
1199                 cqr = (void *) data;
1200                 data += (sizeof(*cqr) + 7L) & -8L;
1201         }
1202         memset(cqr, 0, sizeof(*cqr));
1203         cqr->mem_chunk = chunk;
1204         if (cplength > 0) {
1205                 cqr->cpaddr = data;
1206                 data += cplength * sizeof(struct ccw1);
1207                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1208         }
1209         if (datasize > 0) {
1210                 cqr->data = data;
1211                 memset(cqr->data, 0, datasize);
1212         }
1213         cqr->magic = magic;
1214         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1215         dasd_get_device(device);
1216         return cqr;
1217 }
1218 EXPORT_SYMBOL(dasd_smalloc_request);
1219
1220 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1221                                           int datasize,
1222                                           struct dasd_device *device)
1223 {
1224         struct dasd_ccw_req *cqr;
1225         unsigned long flags;
1226         int size, cqr_size;
1227         char *data;
1228
1229         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1230         size = cqr_size;
1231         if (cplength > 0)
1232                 size += cplength * sizeof(struct ccw1);
1233         if (datasize > 0)
1234                 size += datasize;
1235
1236         spin_lock_irqsave(&device->mem_lock, flags);
1237         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1238         spin_unlock_irqrestore(&device->mem_lock, flags);
1239         if (!cqr)
1240                 return ERR_PTR(-ENOMEM);
1241         memset(cqr, 0, sizeof(*cqr));
1242         data = (char *)cqr + cqr_size;
1243         cqr->cpaddr = NULL;
1244         if (cplength > 0) {
1245                 cqr->cpaddr = data;
1246                 data += cplength * sizeof(struct ccw1);
1247                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1248         }
1249         cqr->data = NULL;
1250         if (datasize > 0) {
1251                 cqr->data = data;
1252                 memset(cqr->data, 0, datasize);
1253         }
1254
1255         cqr->magic = magic;
1256         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1257         dasd_get_device(device);
1258
1259         return cqr;
1260 }
1261 EXPORT_SYMBOL(dasd_fmalloc_request);
1262
1263 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1264 {
1265         unsigned long flags;
1266
1267         spin_lock_irqsave(&device->mem_lock, flags);
1268         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1269         spin_unlock_irqrestore(&device->mem_lock, flags);
1270         dasd_put_device(device);
1271 }
1272 EXPORT_SYMBOL(dasd_sfree_request);
1273
1274 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1275 {
1276         unsigned long flags;
1277
1278         spin_lock_irqsave(&device->mem_lock, flags);
1279         dasd_free_chunk(&device->ese_chunks, cqr);
1280         spin_unlock_irqrestore(&device->mem_lock, flags);
1281         dasd_put_device(device);
1282 }
1283 EXPORT_SYMBOL(dasd_ffree_request);
1284
1285 /*
1286  * Check discipline magic in cqr.
1287  */
1288 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1289 {
1290         struct dasd_device *device;
1291
1292         if (cqr == NULL)
1293                 return -EINVAL;
1294         device = cqr->startdev;
1295         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1296                 DBF_DEV_EVENT(DBF_WARNING, device,
1297                             " dasd_ccw_req 0x%08x magic doesn't match"
1298                             " discipline 0x%08x",
1299                             cqr->magic,
1300                             *(unsigned int *) device->discipline->name);
1301                 return -EINVAL;
1302         }
1303         return 0;
1304 }
1305
1306 /*
1307  * Terminate the current i/o and set the request to clear_pending.
1308  * Timer keeps device runnig.
1309  * ccw_device_clear can fail if the i/o subsystem
1310  * is in a bad mood.
1311  */
1312 int dasd_term_IO(struct dasd_ccw_req *cqr)
1313 {
1314         struct dasd_device *device;
1315         int retries, rc;
1316
1317         /* Check the cqr */
1318         rc = dasd_check_cqr(cqr);
1319         if (rc)
1320                 return rc;
1321         retries = 0;
1322         device = (struct dasd_device *) cqr->startdev;
1323         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1324                 rc = ccw_device_clear(device->cdev, (long) cqr);
1325                 switch (rc) {
1326                 case 0: /* termination successful */
1327                         cqr->status = DASD_CQR_CLEAR_PENDING;
1328                         cqr->stopclk = get_tod_clock();
1329                         cqr->starttime = 0;
1330                         DBF_DEV_EVENT(DBF_DEBUG, device,
1331                                       "terminate cqr %p successful",
1332                                       cqr);
1333                         break;
1334                 case -ENODEV:
1335                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1336                                       "device gone, retry");
1337                         break;
1338                 case -EINVAL:
1339                         /*
1340                          * device not valid so no I/O could be running
1341                          * handle CQR as termination successful
1342                          */
1343                         cqr->status = DASD_CQR_CLEARED;
1344                         cqr->stopclk = get_tod_clock();
1345                         cqr->starttime = 0;
1346                         /* no retries for invalid devices */
1347                         cqr->retries = -1;
1348                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1349                                       "EINVAL, handle as terminated");
1350                         /* fake rc to success */
1351                         rc = 0;
1352                         break;
1353                 default:
1354                         dev_err(&device->cdev->dev,
1355                                 "Unexpected error during request termination %d\n", rc);
1356                         BUG();
1357                         break;
1358                 }
1359                 retries++;
1360         }
1361         dasd_schedule_device_bh(device);
1362         return rc;
1363 }
1364 EXPORT_SYMBOL(dasd_term_IO);
1365
1366 /*
1367  * Start the i/o. This start_IO can fail if the channel is really busy.
1368  * In that case set up a timer to start the request later.
1369  */
1370 int dasd_start_IO(struct dasd_ccw_req *cqr)
1371 {
1372         struct dasd_device *device;
1373         int rc;
1374
1375         /* Check the cqr */
1376         rc = dasd_check_cqr(cqr);
1377         if (rc) {
1378                 cqr->intrc = rc;
1379                 return rc;
1380         }
1381         device = (struct dasd_device *) cqr->startdev;
1382         if (((cqr->block &&
1383               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1384              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1385             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1386                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1387                               "because of stolen lock", cqr);
1388                 cqr->status = DASD_CQR_ERROR;
1389                 cqr->intrc = -EPERM;
1390                 return -EPERM;
1391         }
1392         if (cqr->retries < 0) {
1393                 dev_err(&device->cdev->dev,
1394                         "Start I/O ran out of retries\n");
1395                 cqr->status = DASD_CQR_ERROR;
1396                 return -EIO;
1397         }
1398         cqr->startclk = get_tod_clock();
1399         cqr->starttime = jiffies;
1400         cqr->retries--;
1401         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1402                 cqr->lpm &= dasd_path_get_opm(device);
1403                 if (!cqr->lpm)
1404                         cqr->lpm = dasd_path_get_opm(device);
1405         }
1406         /*
1407          * remember the amount of formatted tracks to prevent double format on
1408          * ESE devices
1409          */
1410         if (cqr->block)
1411                 cqr->trkcount = atomic_read(&cqr->block->trkcount);
1412
1413         if (cqr->cpmode == 1) {
1414                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1415                                          (long) cqr, cqr->lpm);
1416         } else {
1417                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1418                                       (long) cqr, cqr->lpm, 0);
1419         }
1420         switch (rc) {
1421         case 0:
1422                 cqr->status = DASD_CQR_IN_IO;
1423                 break;
1424         case -EBUSY:
1425                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1426                               "start_IO: device busy, retry later");
1427                 break;
1428         case -EACCES:
1429                 /* -EACCES indicates that the request used only a subset of the
1430                  * available paths and all these paths are gone. If the lpm of
1431                  * this request was only a subset of the opm (e.g. the ppm) then
1432                  * we just do a retry with all available paths.
1433                  * If we already use the full opm, something is amiss, and we
1434                  * need a full path verification.
1435                  */
1436                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1437                         DBF_DEV_EVENT(DBF_WARNING, device,
1438                                       "start_IO: selected paths gone (%x)",
1439                                       cqr->lpm);
1440                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1441                         cqr->lpm = dasd_path_get_opm(device);
1442                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1443                                       "start_IO: selected paths gone,"
1444                                       " retry on all paths");
1445                 } else {
1446                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1447                                       "start_IO: all paths in opm gone,"
1448                                       " do path verification");
1449                         dasd_generic_last_path_gone(device);
1450                         dasd_path_no_path(device);
1451                         dasd_path_set_tbvpm(device,
1452                                           ccw_device_get_path_mask(
1453                                                   device->cdev));
1454                 }
1455                 break;
1456         case -ENODEV:
1457                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1458                               "start_IO: -ENODEV device gone, retry");
1459                 /* this is equivalent to CC=3 for SSCH report this to EER */
1460                 dasd_handle_autoquiesce(device, cqr, DASD_EER_STARTIO);
1461                 break;
1462         case -EIO:
1463                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1464                               "start_IO: -EIO device gone, retry");
1465                 break;
1466         case -EINVAL:
1467                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1468                               "start_IO: -EINVAL device currently "
1469                               "not accessible");
1470                 break;
1471         default:
1472                 dev_err(&device->cdev->dev,
1473                         "Unexpected error during request start %d", rc);
1474                 BUG();
1475                 break;
1476         }
1477         cqr->intrc = rc;
1478         return rc;
1479 }
1480 EXPORT_SYMBOL(dasd_start_IO);
1481
1482 /*
1483  * Timeout function for dasd devices. This is used for different purposes
1484  *  1) missing interrupt handler for normal operation
1485  *  2) delayed start of request where start_IO failed with -EBUSY
1486  *  3) timeout for missing state change interrupts
1487  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1488  * DASD_CQR_QUEUED for 2) and 3).
1489  */
1490 static void dasd_device_timeout(struct timer_list *t)
1491 {
1492         unsigned long flags;
1493         struct dasd_device *device;
1494
1495         device = from_timer(device, t, timer);
1496         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1497         /* re-activate request queue */
1498         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1499         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1500         dasd_schedule_device_bh(device);
1501 }
1502
1503 /*
1504  * Setup timeout for a device in jiffies.
1505  */
1506 void dasd_device_set_timer(struct dasd_device *device, int expires)
1507 {
1508         if (expires == 0)
1509                 del_timer(&device->timer);
1510         else
1511                 mod_timer(&device->timer, jiffies + expires);
1512 }
1513 EXPORT_SYMBOL(dasd_device_set_timer);
1514
1515 /*
1516  * Clear timeout for a device.
1517  */
1518 void dasd_device_clear_timer(struct dasd_device *device)
1519 {
1520         del_timer(&device->timer);
1521 }
1522 EXPORT_SYMBOL(dasd_device_clear_timer);
1523
1524 static void dasd_handle_killed_request(struct ccw_device *cdev,
1525                                        unsigned long intparm)
1526 {
1527         struct dasd_ccw_req *cqr;
1528         struct dasd_device *device;
1529
1530         if (!intparm)
1531                 return;
1532         cqr = (struct dasd_ccw_req *) intparm;
1533         if (cqr->status != DASD_CQR_IN_IO) {
1534                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1535                                 "invalid status in handle_killed_request: "
1536                                 "%02x", cqr->status);
1537                 return;
1538         }
1539
1540         device = dasd_device_from_cdev_locked(cdev);
1541         if (IS_ERR(device)) {
1542                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1543                                 "unable to get device from cdev");
1544                 return;
1545         }
1546
1547         if (!cqr->startdev ||
1548             device != cqr->startdev ||
1549             strncmp(cqr->startdev->discipline->ebcname,
1550                     (char *) &cqr->magic, 4)) {
1551                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1552                                 "invalid device in request");
1553                 dasd_put_device(device);
1554                 return;
1555         }
1556
1557         /* Schedule request to be retried. */
1558         cqr->status = DASD_CQR_QUEUED;
1559
1560         dasd_device_clear_timer(device);
1561         dasd_schedule_device_bh(device);
1562         dasd_put_device(device);
1563 }
1564
1565 void dasd_generic_handle_state_change(struct dasd_device *device)
1566 {
1567         /* First of all start sense subsystem status request. */
1568         dasd_eer_snss(device);
1569
1570         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1571         dasd_schedule_device_bh(device);
1572         if (device->block) {
1573                 dasd_schedule_block_bh(device->block);
1574                 if (device->block->gdp)
1575                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
1576         }
1577 }
1578 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1579
1580 static int dasd_check_hpf_error(struct irb *irb)
1581 {
1582         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1583             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1584              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1585 }
1586
1587 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1588 {
1589         struct dasd_device *device = NULL;
1590         u8 *sense = NULL;
1591
1592         if (!block)
1593                 return 0;
1594         device = block->base;
1595         if (!device || !device->discipline->is_ese)
1596                 return 0;
1597         if (!device->discipline->is_ese(device))
1598                 return 0;
1599
1600         sense = dasd_get_sense(irb);
1601         if (!sense)
1602                 return 0;
1603
1604         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1605                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1606                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1607 }
1608
1609 static int dasd_ese_oos_cond(u8 *sense)
1610 {
1611         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1612                 sense[1] & SNS1_PERM_ERR &&
1613                 sense[1] & SNS1_WRITE_INHIBITED &&
1614                 sense[25] == 0x01;
1615 }
1616
1617 /*
1618  * Interrupt handler for "normal" ssch-io based dasd devices.
1619  */
1620 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1621                       struct irb *irb)
1622 {
1623         struct dasd_ccw_req *cqr, *next, *fcqr;
1624         struct dasd_device *device;
1625         unsigned long now;
1626         int nrf_suppressed = 0;
1627         int fp_suppressed = 0;
1628         struct request *req;
1629         u8 *sense = NULL;
1630         int expires;
1631
1632         cqr = (struct dasd_ccw_req *) intparm;
1633         if (IS_ERR(irb)) {
1634                 switch (PTR_ERR(irb)) {
1635                 case -EIO:
1636                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1637                                 device = cqr->startdev;
1638                                 cqr->status = DASD_CQR_CLEARED;
1639                                 dasd_device_clear_timer(device);
1640                                 wake_up(&dasd_flush_wq);
1641                                 dasd_schedule_device_bh(device);
1642                                 return;
1643                         }
1644                         break;
1645                 case -ETIMEDOUT:
1646                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1647                                         "request timed out\n", __func__);
1648                         break;
1649                 default:
1650                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1651                                         "unknown error %ld\n", __func__,
1652                                         PTR_ERR(irb));
1653                 }
1654                 dasd_handle_killed_request(cdev, intparm);
1655                 return;
1656         }
1657
1658         now = get_tod_clock();
1659         /* check for conditions that should be handled immediately */
1660         if (!cqr ||
1661             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1662               scsw_cstat(&irb->scsw) == 0)) {
1663                 if (cqr)
1664                         memcpy(&cqr->irb, irb, sizeof(*irb));
1665                 device = dasd_device_from_cdev_locked(cdev);
1666                 if (IS_ERR(device))
1667                         return;
1668                 /* ignore unsolicited interrupts for DIAG discipline */
1669                 if (device->discipline == dasd_diag_discipline_pointer) {
1670                         dasd_put_device(device);
1671                         return;
1672                 }
1673
1674                 /*
1675                  * In some cases 'File Protected' or 'No Record Found' errors
1676                  * might be expected and debug log messages for the
1677                  * corresponding interrupts shouldn't be written then.
1678                  * Check if either of the according suppress bits is set.
1679                  */
1680                 sense = dasd_get_sense(irb);
1681                 if (sense) {
1682                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1683                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1684                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1685                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1686
1687                         /*
1688                          * Extent pool probably out-of-space.
1689                          * Stop device and check exhaust level.
1690                          */
1691                         if (dasd_ese_oos_cond(sense)) {
1692                                 dasd_generic_space_exhaust(device, cqr);
1693                                 device->discipline->ext_pool_exhaust(device, cqr);
1694                                 dasd_put_device(device);
1695                                 return;
1696                         }
1697                 }
1698                 if (!(fp_suppressed || nrf_suppressed))
1699                         device->discipline->dump_sense_dbf(device, irb, "int");
1700
1701                 if (device->features & DASD_FEATURE_ERPLOG)
1702                         device->discipline->dump_sense(device, cqr, irb);
1703                 device->discipline->check_for_device_change(device, cqr, irb);
1704                 dasd_put_device(device);
1705         }
1706
1707         /* check for attention message */
1708         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1709                 device = dasd_device_from_cdev_locked(cdev);
1710                 if (!IS_ERR(device)) {
1711                         device->discipline->check_attention(device,
1712                                                             irb->esw.esw1.lpum);
1713                         dasd_put_device(device);
1714                 }
1715         }
1716
1717         if (!cqr)
1718                 return;
1719
1720         device = (struct dasd_device *) cqr->startdev;
1721         if (!device ||
1722             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1723                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1724                                 "invalid device in request");
1725                 return;
1726         }
1727
1728         if (dasd_ese_needs_format(cqr->block, irb)) {
1729                 req = dasd_get_callback_data(cqr);
1730                 if (!req) {
1731                         cqr->status = DASD_CQR_ERROR;
1732                         return;
1733                 }
1734                 if (rq_data_dir(req) == READ) {
1735                         device->discipline->ese_read(cqr, irb);
1736                         cqr->status = DASD_CQR_SUCCESS;
1737                         cqr->stopclk = now;
1738                         dasd_device_clear_timer(device);
1739                         dasd_schedule_device_bh(device);
1740                         return;
1741                 }
1742                 fcqr = device->discipline->ese_format(device, cqr, irb);
1743                 if (IS_ERR(fcqr)) {
1744                         if (PTR_ERR(fcqr) == -EINVAL) {
1745                                 cqr->status = DASD_CQR_ERROR;
1746                                 return;
1747                         }
1748                         /*
1749                          * If we can't format now, let the request go
1750                          * one extra round. Maybe we can format later.
1751                          */
1752                         cqr->status = DASD_CQR_QUEUED;
1753                         dasd_schedule_device_bh(device);
1754                         return;
1755                 } else {
1756                         fcqr->status = DASD_CQR_QUEUED;
1757                         cqr->status = DASD_CQR_QUEUED;
1758                         list_add(&fcqr->devlist, &device->ccw_queue);
1759                         dasd_schedule_device_bh(device);
1760                         return;
1761                 }
1762         }
1763
1764         /* Check for clear pending */
1765         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1766             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1767                 cqr->status = DASD_CQR_CLEARED;
1768                 dasd_device_clear_timer(device);
1769                 wake_up(&dasd_flush_wq);
1770                 dasd_schedule_device_bh(device);
1771                 return;
1772         }
1773
1774         /* check status - the request might have been killed by dyn detach */
1775         if (cqr->status != DASD_CQR_IN_IO) {
1776                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1777                               "status %02x", dev_name(&cdev->dev), cqr->status);
1778                 return;
1779         }
1780
1781         next = NULL;
1782         expires = 0;
1783         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1784             scsw_cstat(&irb->scsw) == 0) {
1785                 /* request was completed successfully */
1786                 cqr->status = DASD_CQR_SUCCESS;
1787                 cqr->stopclk = now;
1788                 /* Start first request on queue if possible -> fast_io. */
1789                 if (cqr->devlist.next != &device->ccw_queue) {
1790                         next = list_entry(cqr->devlist.next,
1791                                           struct dasd_ccw_req, devlist);
1792                 }
1793         } else {  /* error */
1794                 /* check for HPF error
1795                  * call discipline function to requeue all requests
1796                  * and disable HPF accordingly
1797                  */
1798                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1799                     device->discipline->handle_hpf_error)
1800                         device->discipline->handle_hpf_error(device, irb);
1801                 /*
1802                  * If we don't want complex ERP for this request, then just
1803                  * reset this and retry it in the fastpath
1804                  */
1805                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1806                     cqr->retries > 0) {
1807                         if (cqr->lpm == dasd_path_get_opm(device))
1808                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1809                                               "default ERP in fastpath "
1810                                               "(%i retries left)",
1811                                               cqr->retries);
1812                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1813                                 cqr->lpm = dasd_path_get_opm(device);
1814                         cqr->status = DASD_CQR_QUEUED;
1815                         next = cqr;
1816                 } else
1817                         cqr->status = DASD_CQR_ERROR;
1818         }
1819         if (next && (next->status == DASD_CQR_QUEUED) &&
1820             (!device->stopped)) {
1821                 if (device->discipline->start_IO(next) == 0)
1822                         expires = next->expires;
1823         }
1824         if (expires != 0)
1825                 dasd_device_set_timer(device, expires);
1826         else
1827                 dasd_device_clear_timer(device);
1828         dasd_schedule_device_bh(device);
1829 }
1830 EXPORT_SYMBOL(dasd_int_handler);
1831
1832 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1833 {
1834         struct dasd_device *device;
1835
1836         device = dasd_device_from_cdev_locked(cdev);
1837
1838         if (IS_ERR(device))
1839                 goto out;
1840         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1841            device->state != device->target ||
1842            !device->discipline->check_for_device_change){
1843                 dasd_put_device(device);
1844                 goto out;
1845         }
1846         if (device->discipline->dump_sense_dbf)
1847                 device->discipline->dump_sense_dbf(device, irb, "uc");
1848         device->discipline->check_for_device_change(device, NULL, irb);
1849         dasd_put_device(device);
1850 out:
1851         return UC_TODO_RETRY;
1852 }
1853 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1854
1855 /*
1856  * If we have an error on a dasd_block layer request then we cancel
1857  * and return all further requests from the same dasd_block as well.
1858  */
1859 static void __dasd_device_recovery(struct dasd_device *device,
1860                                    struct dasd_ccw_req *ref_cqr)
1861 {
1862         struct list_head *l, *n;
1863         struct dasd_ccw_req *cqr;
1864
1865         /*
1866          * only requeue request that came from the dasd_block layer
1867          */
1868         if (!ref_cqr->block)
1869                 return;
1870
1871         list_for_each_safe(l, n, &device->ccw_queue) {
1872                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1873                 if (cqr->status == DASD_CQR_QUEUED &&
1874                     ref_cqr->block == cqr->block) {
1875                         cqr->status = DASD_CQR_CLEARED;
1876                 }
1877         }
1878 };
1879
1880 /*
1881  * Remove those ccw requests from the queue that need to be returned
1882  * to the upper layer.
1883  */
1884 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1885                                             struct list_head *final_queue)
1886 {
1887         struct list_head *l, *n;
1888         struct dasd_ccw_req *cqr;
1889
1890         /* Process request with final status. */
1891         list_for_each_safe(l, n, &device->ccw_queue) {
1892                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1893
1894                 /* Skip any non-final request. */
1895                 if (cqr->status == DASD_CQR_QUEUED ||
1896                     cqr->status == DASD_CQR_IN_IO ||
1897                     cqr->status == DASD_CQR_CLEAR_PENDING)
1898                         continue;
1899                 if (cqr->status == DASD_CQR_ERROR) {
1900                         __dasd_device_recovery(device, cqr);
1901                 }
1902                 /* Rechain finished requests to final queue */
1903                 list_move_tail(&cqr->devlist, final_queue);
1904         }
1905 }
1906
1907 static void __dasd_process_cqr(struct dasd_device *device,
1908                                struct dasd_ccw_req *cqr)
1909 {
1910         switch (cqr->status) {
1911         case DASD_CQR_SUCCESS:
1912                 cqr->status = DASD_CQR_DONE;
1913                 break;
1914         case DASD_CQR_ERROR:
1915                 cqr->status = DASD_CQR_NEED_ERP;
1916                 break;
1917         case DASD_CQR_CLEARED:
1918                 cqr->status = DASD_CQR_TERMINATED;
1919                 break;
1920         default:
1921                 dev_err(&device->cdev->dev,
1922                         "Unexpected CQR status %02x", cqr->status);
1923                 BUG();
1924         }
1925         if (cqr->callback)
1926                 cqr->callback(cqr, cqr->callback_data);
1927 }
1928
1929 /*
1930  * the cqrs from the final queue are returned to the upper layer
1931  * by setting a dasd_block state and calling the callback function
1932  */
1933 static void __dasd_device_process_final_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         struct dasd_block *block;
1939
1940         list_for_each_safe(l, n, final_queue) {
1941                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1942                 list_del_init(&cqr->devlist);
1943                 block = cqr->block;
1944                 if (!block) {
1945                         __dasd_process_cqr(device, cqr);
1946                 } else {
1947                         spin_lock_bh(&block->queue_lock);
1948                         __dasd_process_cqr(device, cqr);
1949                         spin_unlock_bh(&block->queue_lock);
1950                 }
1951         }
1952 }
1953
1954 /*
1955  * check if device should be autoquiesced due to too many timeouts
1956  */
1957 static void __dasd_device_check_autoquiesce_timeout(struct dasd_device *device,
1958                                                     struct dasd_ccw_req *cqr)
1959 {
1960         if ((device->default_retries - cqr->retries) >= device->aq_timeouts)
1961                 dasd_handle_autoquiesce(device, cqr, DASD_EER_TIMEOUTS);
1962 }
1963
1964 /*
1965  * Take a look at the first request on the ccw queue and check
1966  * if it reached its expire time. If so, terminate the IO.
1967  */
1968 static void __dasd_device_check_expire(struct dasd_device *device)
1969 {
1970         struct dasd_ccw_req *cqr;
1971
1972         if (list_empty(&device->ccw_queue))
1973                 return;
1974         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1975         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1976             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1977                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1978                         /*
1979                          * IO in safe offline processing should not
1980                          * run out of retries
1981                          */
1982                         cqr->retries++;
1983                 }
1984                 if (device->discipline->term_IO(cqr) != 0) {
1985                         /* Hmpf, try again in 5 sec */
1986                         dev_err(&device->cdev->dev,
1987                                 "CQR timed out (%lus) but cannot be ended, retrying in 5s\n",
1988                                 (cqr->expires / HZ));
1989                         cqr->expires += 5*HZ;
1990                         dasd_device_set_timer(device, 5*HZ);
1991                 } else {
1992                         dev_err(&device->cdev->dev,
1993                                 "CQR timed out (%lus), %i retries remaining\n",
1994                                 (cqr->expires / HZ), cqr->retries);
1995                 }
1996                 __dasd_device_check_autoquiesce_timeout(device, cqr);
1997         }
1998 }
1999
2000 /*
2001  * return 1 when device is not eligible for IO
2002  */
2003 static int __dasd_device_is_unusable(struct dasd_device *device,
2004                                      struct dasd_ccw_req *cqr)
2005 {
2006         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
2007
2008         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2009             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2010                 /*
2011                  * dasd is being set offline
2012                  * but it is no safe offline where we have to allow I/O
2013                  */
2014                 return 1;
2015         }
2016         if (device->stopped) {
2017                 if (device->stopped & mask) {
2018                         /* stopped and CQR will not change that. */
2019                         return 1;
2020                 }
2021                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2022                         /* CQR is not able to change device to
2023                          * operational. */
2024                         return 1;
2025                 }
2026                 /* CQR required to get device operational. */
2027         }
2028         return 0;
2029 }
2030
2031 /*
2032  * Take a look at the first request on the ccw queue and check
2033  * if it needs to be started.
2034  */
2035 static void __dasd_device_start_head(struct dasd_device *device)
2036 {
2037         struct dasd_ccw_req *cqr;
2038         int rc;
2039
2040         if (list_empty(&device->ccw_queue))
2041                 return;
2042         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2043         if (cqr->status != DASD_CQR_QUEUED)
2044                 return;
2045         /* if device is not usable return request to upper layer */
2046         if (__dasd_device_is_unusable(device, cqr)) {
2047                 cqr->intrc = -EAGAIN;
2048                 cqr->status = DASD_CQR_CLEARED;
2049                 dasd_schedule_device_bh(device);
2050                 return;
2051         }
2052
2053         rc = device->discipline->start_IO(cqr);
2054         if (rc == 0)
2055                 dasd_device_set_timer(device, cqr->expires);
2056         else if (rc == -EACCES) {
2057                 dasd_schedule_device_bh(device);
2058         } else
2059                 /* Hmpf, try again in 1/2 sec */
2060                 dasd_device_set_timer(device, 50);
2061 }
2062
2063 static void __dasd_device_check_path_events(struct dasd_device *device)
2064 {
2065         __u8 tbvpm, fcsecpm;
2066         int rc;
2067
2068         tbvpm = dasd_path_get_tbvpm(device);
2069         fcsecpm = dasd_path_get_fcsecpm(device);
2070
2071         if (!tbvpm && !fcsecpm)
2072                 return;
2073
2074         if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2075                 return;
2076
2077         dasd_path_clear_all_verify(device);
2078         dasd_path_clear_all_fcsec(device);
2079
2080         rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
2081         if (rc) {
2082                 dasd_path_add_tbvpm(device, tbvpm);
2083                 dasd_path_add_fcsecpm(device, fcsecpm);
2084                 dasd_device_set_timer(device, 50);
2085         }
2086 };
2087
2088 /*
2089  * Go through all request on the dasd_device request queue,
2090  * terminate them on the cdev if necessary, and return them to the
2091  * submitting layer via callback.
2092  * Note:
2093  * Make sure that all 'submitting layers' still exist when
2094  * this function is called!. In other words, when 'device' is a base
2095  * device then all block layer requests must have been removed before
2096  * via dasd_flush_block_queue.
2097  */
2098 int dasd_flush_device_queue(struct dasd_device *device)
2099 {
2100         struct dasd_ccw_req *cqr, *n;
2101         int rc;
2102         struct list_head flush_queue;
2103
2104         INIT_LIST_HEAD(&flush_queue);
2105         spin_lock_irq(get_ccwdev_lock(device->cdev));
2106         rc = 0;
2107         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2108                 /* Check status and move request to flush_queue */
2109                 switch (cqr->status) {
2110                 case DASD_CQR_IN_IO:
2111                         rc = device->discipline->term_IO(cqr);
2112                         if (rc) {
2113                                 /* unable to terminate requeust */
2114                                 dev_err(&device->cdev->dev,
2115                                         "Flushing the DASD request queue failed\n");
2116                                 /* stop flush processing */
2117                                 goto finished;
2118                         }
2119                         break;
2120                 case DASD_CQR_QUEUED:
2121                         cqr->stopclk = get_tod_clock();
2122                         cqr->status = DASD_CQR_CLEARED;
2123                         break;
2124                 default: /* no need to modify the others */
2125                         break;
2126                 }
2127                 list_move_tail(&cqr->devlist, &flush_queue);
2128         }
2129 finished:
2130         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2131         /*
2132          * After this point all requests must be in state CLEAR_PENDING,
2133          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2134          * one of the others.
2135          */
2136         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2137                 wait_event(dasd_flush_wq,
2138                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2139         /*
2140          * Now set each request back to TERMINATED, DONE or NEED_ERP
2141          * and call the callback function of flushed requests
2142          */
2143         __dasd_device_process_final_queue(device, &flush_queue);
2144         return rc;
2145 }
2146 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2147
2148 /*
2149  * Acquire the device lock and process queues for the device.
2150  */
2151 static void dasd_device_tasklet(unsigned long data)
2152 {
2153         struct dasd_device *device = (struct dasd_device *) data;
2154         struct list_head final_queue;
2155
2156         atomic_set (&device->tasklet_scheduled, 0);
2157         INIT_LIST_HEAD(&final_queue);
2158         spin_lock_irq(get_ccwdev_lock(device->cdev));
2159         /* Check expire time of first request on the ccw queue. */
2160         __dasd_device_check_expire(device);
2161         /* find final requests on ccw queue */
2162         __dasd_device_process_ccw_queue(device, &final_queue);
2163         __dasd_device_check_path_events(device);
2164         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2165         /* Now call the callback function of requests with final status */
2166         __dasd_device_process_final_queue(device, &final_queue);
2167         spin_lock_irq(get_ccwdev_lock(device->cdev));
2168         /* Now check if the head of the ccw queue needs to be started. */
2169         __dasd_device_start_head(device);
2170         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2171         if (waitqueue_active(&shutdown_waitq))
2172                 wake_up(&shutdown_waitq);
2173         dasd_put_device(device);
2174 }
2175
2176 /*
2177  * Schedules a call to dasd_tasklet over the device tasklet.
2178  */
2179 void dasd_schedule_device_bh(struct dasd_device *device)
2180 {
2181         /* Protect against rescheduling. */
2182         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2183                 return;
2184         dasd_get_device(device);
2185         tasklet_hi_schedule(&device->tasklet);
2186 }
2187 EXPORT_SYMBOL(dasd_schedule_device_bh);
2188
2189 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2190 {
2191         device->stopped |= bits;
2192 }
2193 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2194
2195 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2196 {
2197         device->stopped &= ~bits;
2198         if (!device->stopped)
2199                 wake_up(&generic_waitq);
2200 }
2201 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2202
2203 /*
2204  * Queue a request to the head of the device ccw_queue.
2205  * Start the I/O if possible.
2206  */
2207 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2208 {
2209         struct dasd_device *device;
2210         unsigned long flags;
2211
2212         device = cqr->startdev;
2213         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2214         cqr->status = DASD_CQR_QUEUED;
2215         list_add(&cqr->devlist, &device->ccw_queue);
2216         /* let the bh start the request to keep them in order */
2217         dasd_schedule_device_bh(device);
2218         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2219 }
2220 EXPORT_SYMBOL(dasd_add_request_head);
2221
2222 /*
2223  * Queue a request to the tail of the device ccw_queue.
2224  * Start the I/O if possible.
2225  */
2226 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2227 {
2228         struct dasd_device *device;
2229         unsigned long flags;
2230
2231         device = cqr->startdev;
2232         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2233         cqr->status = DASD_CQR_QUEUED;
2234         list_add_tail(&cqr->devlist, &device->ccw_queue);
2235         /* let the bh start the request to keep them in order */
2236         dasd_schedule_device_bh(device);
2237         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2238 }
2239 EXPORT_SYMBOL(dasd_add_request_tail);
2240
2241 /*
2242  * Wakeup helper for the 'sleep_on' functions.
2243  */
2244 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2245 {
2246         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2247         cqr->callback_data = DASD_SLEEPON_END_TAG;
2248         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2249         wake_up(&generic_waitq);
2250 }
2251 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2252
2253 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2254 {
2255         struct dasd_device *device;
2256         int rc;
2257
2258         device = cqr->startdev;
2259         spin_lock_irq(get_ccwdev_lock(device->cdev));
2260         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2261         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2262         return rc;
2263 }
2264
2265 /*
2266  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2267  */
2268 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2269 {
2270         struct dasd_device *device;
2271         dasd_erp_fn_t erp_fn;
2272
2273         if (cqr->status == DASD_CQR_FILLED)
2274                 return 0;
2275         device = cqr->startdev;
2276         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2277                 if (cqr->status == DASD_CQR_TERMINATED) {
2278                         device->discipline->handle_terminated_request(cqr);
2279                         return 1;
2280                 }
2281                 if (cqr->status == DASD_CQR_NEED_ERP) {
2282                         erp_fn = device->discipline->erp_action(cqr);
2283                         erp_fn(cqr);
2284                         return 1;
2285                 }
2286                 if (cqr->status == DASD_CQR_FAILED)
2287                         dasd_log_sense(cqr, &cqr->irb);
2288                 if (cqr->refers) {
2289                         __dasd_process_erp(device, cqr);
2290                         return 1;
2291                 }
2292         }
2293         return 0;
2294 }
2295
2296 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2297 {
2298         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2299                 if (cqr->refers) /* erp is not done yet */
2300                         return 1;
2301                 return ((cqr->status != DASD_CQR_DONE) &&
2302                         (cqr->status != DASD_CQR_FAILED));
2303         } else
2304                 return (cqr->status == DASD_CQR_FILLED);
2305 }
2306
2307 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2308 {
2309         struct dasd_device *device;
2310         int rc;
2311         struct list_head ccw_queue;
2312         struct dasd_ccw_req *cqr;
2313
2314         INIT_LIST_HEAD(&ccw_queue);
2315         maincqr->status = DASD_CQR_FILLED;
2316         device = maincqr->startdev;
2317         list_add(&maincqr->blocklist, &ccw_queue);
2318         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2319              cqr = list_first_entry(&ccw_queue,
2320                                     struct dasd_ccw_req, blocklist)) {
2321
2322                 if (__dasd_sleep_on_erp(cqr))
2323                         continue;
2324                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2325                         continue;
2326                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2327                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2328                         cqr->status = DASD_CQR_FAILED;
2329                         cqr->intrc = -EPERM;
2330                         continue;
2331                 }
2332                 /* Non-temporary stop condition will trigger fail fast */
2333                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2334                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2335                     !dasd_eer_enabled(device) && device->aq_mask == 0) {
2336                         cqr->status = DASD_CQR_FAILED;
2337                         cqr->intrc = -ENOLINK;
2338                         continue;
2339                 }
2340                 /*
2341                  * Don't try to start requests if device is in
2342                  * offline processing, it might wait forever
2343                  */
2344                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2345                         cqr->status = DASD_CQR_FAILED;
2346                         cqr->intrc = -ENODEV;
2347                         continue;
2348                 }
2349                 /*
2350                  * Don't try to start requests if device is stopped
2351                  * except path verification requests
2352                  */
2353                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2354                         if (interruptible) {
2355                                 rc = wait_event_interruptible(
2356                                         generic_waitq, !(device->stopped));
2357                                 if (rc == -ERESTARTSYS) {
2358                                         cqr->status = DASD_CQR_FAILED;
2359                                         maincqr->intrc = rc;
2360                                         continue;
2361                                 }
2362                         } else
2363                                 wait_event(generic_waitq, !(device->stopped));
2364                 }
2365                 if (!cqr->callback)
2366                         cqr->callback = dasd_wakeup_cb;
2367
2368                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2369                 dasd_add_request_tail(cqr);
2370                 if (interruptible) {
2371                         rc = wait_event_interruptible(
2372                                 generic_waitq, _wait_for_wakeup(cqr));
2373                         if (rc == -ERESTARTSYS) {
2374                                 dasd_cancel_req(cqr);
2375                                 /* wait (non-interruptible) for final status */
2376                                 wait_event(generic_waitq,
2377                                            _wait_for_wakeup(cqr));
2378                                 cqr->status = DASD_CQR_FAILED;
2379                                 maincqr->intrc = rc;
2380                                 continue;
2381                         }
2382                 } else
2383                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2384         }
2385
2386         maincqr->endclk = get_tod_clock();
2387         if ((maincqr->status != DASD_CQR_DONE) &&
2388             (maincqr->intrc != -ERESTARTSYS))
2389                 dasd_log_sense(maincqr, &maincqr->irb);
2390         if (maincqr->status == DASD_CQR_DONE)
2391                 rc = 0;
2392         else if (maincqr->intrc)
2393                 rc = maincqr->intrc;
2394         else
2395                 rc = -EIO;
2396         return rc;
2397 }
2398
2399 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2400 {
2401         struct dasd_ccw_req *cqr;
2402
2403         list_for_each_entry(cqr, ccw_queue, blocklist) {
2404                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2405                         return 0;
2406         }
2407
2408         return 1;
2409 }
2410
2411 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2412 {
2413         struct dasd_device *device;
2414         struct dasd_ccw_req *cqr, *n;
2415         u8 *sense = NULL;
2416         int rc;
2417
2418 retry:
2419         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2420                 device = cqr->startdev;
2421                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2422                         continue;
2423
2424                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2425                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2426                         cqr->status = DASD_CQR_FAILED;
2427                         cqr->intrc = -EPERM;
2428                         continue;
2429                 }
2430                 /*Non-temporary stop condition will trigger fail fast*/
2431                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2432                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2433                     !dasd_eer_enabled(device)) {
2434                         cqr->status = DASD_CQR_FAILED;
2435                         cqr->intrc = -EAGAIN;
2436                         continue;
2437                 }
2438
2439                 /*Don't try to start requests if device is stopped*/
2440                 if (interruptible) {
2441                         rc = wait_event_interruptible(
2442                                 generic_waitq, !device->stopped);
2443                         if (rc == -ERESTARTSYS) {
2444                                 cqr->status = DASD_CQR_FAILED;
2445                                 cqr->intrc = rc;
2446                                 continue;
2447                         }
2448                 } else
2449                         wait_event(generic_waitq, !(device->stopped));
2450
2451                 if (!cqr->callback)
2452                         cqr->callback = dasd_wakeup_cb;
2453                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2454                 dasd_add_request_tail(cqr);
2455         }
2456
2457         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2458
2459         rc = 0;
2460         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2461                 /*
2462                  * In some cases the 'File Protected' or 'Incorrect Length'
2463                  * error might be expected and error recovery would be
2464                  * unnecessary in these cases.  Check if the according suppress
2465                  * bit is set.
2466                  */
2467                 sense = dasd_get_sense(&cqr->irb);
2468                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2469                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2470                         continue;
2471                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2472                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2473                         continue;
2474
2475                 /*
2476                  * for alias devices simplify error recovery and
2477                  * return to upper layer
2478                  * do not skip ERP requests
2479                  */
2480                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2481                     (cqr->status == DASD_CQR_TERMINATED ||
2482                      cqr->status == DASD_CQR_NEED_ERP))
2483                         return -EAGAIN;
2484
2485                 /* normal recovery for basedev IO */
2486                 if (__dasd_sleep_on_erp(cqr))
2487                         /* handle erp first */
2488                         goto retry;
2489         }
2490
2491         return 0;
2492 }
2493
2494 /*
2495  * Queue a request to the tail of the device ccw_queue and wait for
2496  * it's completion.
2497  */
2498 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2499 {
2500         return _dasd_sleep_on(cqr, 0);
2501 }
2502 EXPORT_SYMBOL(dasd_sleep_on);
2503
2504 /*
2505  * Start requests from a ccw_queue and wait for their completion.
2506  */
2507 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2508 {
2509         return _dasd_sleep_on_queue(ccw_queue, 0);
2510 }
2511 EXPORT_SYMBOL(dasd_sleep_on_queue);
2512
2513 /*
2514  * Start requests from a ccw_queue and wait interruptible for their completion.
2515  */
2516 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2517 {
2518         return _dasd_sleep_on_queue(ccw_queue, 1);
2519 }
2520 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2521
2522 /*
2523  * Queue a request to the tail of the device ccw_queue and wait
2524  * interruptible for it's completion.
2525  */
2526 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2527 {
2528         return _dasd_sleep_on(cqr, 1);
2529 }
2530 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2531
2532 /*
2533  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2534  * for eckd devices) the currently running request has to be terminated
2535  * and be put back to status queued, before the special request is added
2536  * to the head of the queue. Then the special request is waited on normally.
2537  */
2538 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2539 {
2540         struct dasd_ccw_req *cqr;
2541         int rc;
2542
2543         if (list_empty(&device->ccw_queue))
2544                 return 0;
2545         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2546         rc = device->discipline->term_IO(cqr);
2547         if (!rc)
2548                 /*
2549                  * CQR terminated because a more important request is pending.
2550                  * Undo decreasing of retry counter because this is
2551                  * not an error case.
2552                  */
2553                 cqr->retries++;
2554         return rc;
2555 }
2556
2557 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2558 {
2559         struct dasd_device *device;
2560         int rc;
2561
2562         device = cqr->startdev;
2563         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2564             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2565                 cqr->status = DASD_CQR_FAILED;
2566                 cqr->intrc = -EPERM;
2567                 return -EIO;
2568         }
2569         spin_lock_irq(get_ccwdev_lock(device->cdev));
2570         rc = _dasd_term_running_cqr(device);
2571         if (rc) {
2572                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2573                 return rc;
2574         }
2575         cqr->callback = dasd_wakeup_cb;
2576         cqr->callback_data = DASD_SLEEPON_START_TAG;
2577         cqr->status = DASD_CQR_QUEUED;
2578         /*
2579          * add new request as second
2580          * first the terminated cqr needs to be finished
2581          */
2582         list_add(&cqr->devlist, device->ccw_queue.next);
2583
2584         /* let the bh start the request to keep them in order */
2585         dasd_schedule_device_bh(device);
2586
2587         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2588
2589         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2590
2591         if (cqr->status == DASD_CQR_DONE)
2592                 rc = 0;
2593         else if (cqr->intrc)
2594                 rc = cqr->intrc;
2595         else
2596                 rc = -EIO;
2597
2598         /* kick tasklets */
2599         dasd_schedule_device_bh(device);
2600         if (device->block)
2601                 dasd_schedule_block_bh(device->block);
2602
2603         return rc;
2604 }
2605 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2606
2607 /*
2608  * Cancels a request that was started with dasd_sleep_on_req.
2609  * This is useful to timeout requests. The request will be
2610  * terminated if it is currently in i/o.
2611  * Returns 0 if request termination was successful
2612  *         negative error code if termination failed
2613  * Cancellation of a request is an asynchronous operation! The calling
2614  * function has to wait until the request is properly returned via callback.
2615  */
2616 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2617 {
2618         struct dasd_device *device = cqr->startdev;
2619         int rc = 0;
2620
2621         switch (cqr->status) {
2622         case DASD_CQR_QUEUED:
2623                 /* request was not started - just set to cleared */
2624                 cqr->status = DASD_CQR_CLEARED;
2625                 break;
2626         case DASD_CQR_IN_IO:
2627                 /* request in IO - terminate IO and release again */
2628                 rc = device->discipline->term_IO(cqr);
2629                 if (rc) {
2630                         dev_err(&device->cdev->dev,
2631                                 "Cancelling request failed with rc=%d\n", rc);
2632                 } else {
2633                         cqr->stopclk = get_tod_clock();
2634                 }
2635                 break;
2636         default: /* already finished or clear pending - do nothing */
2637                 break;
2638         }
2639         dasd_schedule_device_bh(device);
2640         return rc;
2641 }
2642
2643 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2644 {
2645         struct dasd_device *device = cqr->startdev;
2646         unsigned long flags;
2647         int rc;
2648
2649         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2650         rc = __dasd_cancel_req(cqr);
2651         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2652         return rc;
2653 }
2654
2655 /*
2656  * SECTION: Operations of the dasd_block layer.
2657  */
2658
2659 /*
2660  * Timeout function for dasd_block. This is used when the block layer
2661  * is waiting for something that may not come reliably, (e.g. a state
2662  * change interrupt)
2663  */
2664 static void dasd_block_timeout(struct timer_list *t)
2665 {
2666         unsigned long flags;
2667         struct dasd_block *block;
2668
2669         block = from_timer(block, t, timer);
2670         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2671         /* re-activate request queue */
2672         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2673         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2674         dasd_schedule_block_bh(block);
2675         blk_mq_run_hw_queues(block->gdp->queue, true);
2676 }
2677
2678 /*
2679  * Setup timeout for a dasd_block in jiffies.
2680  */
2681 void dasd_block_set_timer(struct dasd_block *block, int expires)
2682 {
2683         if (expires == 0)
2684                 del_timer(&block->timer);
2685         else
2686                 mod_timer(&block->timer, jiffies + expires);
2687 }
2688 EXPORT_SYMBOL(dasd_block_set_timer);
2689
2690 /*
2691  * Clear timeout for a dasd_block.
2692  */
2693 void dasd_block_clear_timer(struct dasd_block *block)
2694 {
2695         del_timer(&block->timer);
2696 }
2697 EXPORT_SYMBOL(dasd_block_clear_timer);
2698
2699 /*
2700  * Process finished error recovery ccw.
2701  */
2702 static void __dasd_process_erp(struct dasd_device *device,
2703                                struct dasd_ccw_req *cqr)
2704 {
2705         dasd_erp_fn_t erp_fn;
2706
2707         if (cqr->status == DASD_CQR_DONE)
2708                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2709         else
2710                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2711         erp_fn = device->discipline->erp_postaction(cqr);
2712         erp_fn(cqr);
2713 }
2714
2715 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2716 {
2717         struct request *req;
2718         blk_status_t error = BLK_STS_OK;
2719         unsigned int proc_bytes;
2720         int status;
2721
2722         req = (struct request *) cqr->callback_data;
2723         dasd_profile_end(cqr->block, cqr, req);
2724
2725         proc_bytes = cqr->proc_bytes;
2726         status = cqr->block->base->discipline->free_cp(cqr, req);
2727         if (status < 0)
2728                 error = errno_to_blk_status(status);
2729         else if (status == 0) {
2730                 switch (cqr->intrc) {
2731                 case -EPERM:
2732                         /*
2733                          * DASD doesn't implement SCSI/NVMe reservations, but it
2734                          * implements a locking scheme similar to them. We
2735                          * return this error when we no longer have the lock.
2736                          */
2737                         error = BLK_STS_RESV_CONFLICT;
2738                         break;
2739                 case -ENOLINK:
2740                         error = BLK_STS_TRANSPORT;
2741                         break;
2742                 case -ETIMEDOUT:
2743                         error = BLK_STS_TIMEOUT;
2744                         break;
2745                 default:
2746                         error = BLK_STS_IOERR;
2747                         break;
2748                 }
2749         }
2750
2751         /*
2752          * We need to take care for ETIMEDOUT errors here since the
2753          * complete callback does not get called in this case.
2754          * Take care of all errors here and avoid additional code to
2755          * transfer the error value to the complete callback.
2756          */
2757         if (error) {
2758                 blk_mq_end_request(req, error);
2759                 blk_mq_run_hw_queues(req->q, true);
2760         } else {
2761                 /*
2762                  * Partial completed requests can happen with ESE devices.
2763                  * During read we might have gotten a NRF error and have to
2764                  * complete a request partially.
2765                  */
2766                 if (proc_bytes) {
2767                         blk_update_request(req, BLK_STS_OK, proc_bytes);
2768                         blk_mq_requeue_request(req, true);
2769                 } else if (likely(!blk_should_fake_timeout(req->q))) {
2770                         blk_mq_complete_request(req);
2771                 }
2772         }
2773 }
2774
2775 /*
2776  * Process ccw request queue.
2777  */
2778 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2779                                            struct list_head *final_queue)
2780 {
2781         struct list_head *l, *n;
2782         struct dasd_ccw_req *cqr;
2783         dasd_erp_fn_t erp_fn;
2784         unsigned long flags;
2785         struct dasd_device *base = block->base;
2786
2787 restart:
2788         /* Process request with final status. */
2789         list_for_each_safe(l, n, &block->ccw_queue) {
2790                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2791                 if (cqr->status != DASD_CQR_DONE &&
2792                     cqr->status != DASD_CQR_FAILED &&
2793                     cqr->status != DASD_CQR_NEED_ERP &&
2794                     cqr->status != DASD_CQR_TERMINATED)
2795                         continue;
2796
2797                 if (cqr->status == DASD_CQR_TERMINATED) {
2798                         base->discipline->handle_terminated_request(cqr);
2799                         goto restart;
2800                 }
2801
2802                 /*  Process requests that may be recovered */
2803                 if (cqr->status == DASD_CQR_NEED_ERP) {
2804                         erp_fn = base->discipline->erp_action(cqr);
2805                         if (IS_ERR(erp_fn(cqr)))
2806                                 continue;
2807                         goto restart;
2808                 }
2809
2810                 /* log sense for fatal error */
2811                 if (cqr->status == DASD_CQR_FAILED) {
2812                         dasd_log_sense(cqr, &cqr->irb);
2813                 }
2814
2815                 /*
2816                  * First call extended error reporting and check for autoquiesce
2817                  */
2818                 spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2819                 if (cqr->status == DASD_CQR_FAILED &&
2820                     dasd_handle_autoquiesce(base, cqr, DASD_EER_FATALERROR)) {
2821                         cqr->status = DASD_CQR_FILLED;
2822                         cqr->retries = 255;
2823                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2824                         goto restart;
2825                 }
2826                 spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2827
2828                 /* Process finished ERP request. */
2829                 if (cqr->refers) {
2830                         __dasd_process_erp(base, cqr);
2831                         goto restart;
2832                 }
2833
2834                 /* Rechain finished requests to final queue */
2835                 cqr->endclk = get_tod_clock();
2836                 list_move_tail(&cqr->blocklist, final_queue);
2837         }
2838 }
2839
2840 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2841 {
2842         dasd_schedule_block_bh(cqr->block);
2843 }
2844
2845 static void __dasd_block_start_head(struct dasd_block *block)
2846 {
2847         struct dasd_ccw_req *cqr;
2848
2849         if (list_empty(&block->ccw_queue))
2850                 return;
2851         /* We allways begin with the first requests on the queue, as some
2852          * of previously started requests have to be enqueued on a
2853          * dasd_device again for error recovery.
2854          */
2855         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2856                 if (cqr->status != DASD_CQR_FILLED)
2857                         continue;
2858                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2859                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2860                         cqr->status = DASD_CQR_FAILED;
2861                         cqr->intrc = -EPERM;
2862                         dasd_schedule_block_bh(block);
2863                         continue;
2864                 }
2865                 /* Non-temporary stop condition will trigger fail fast */
2866                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2867                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2868                     !dasd_eer_enabled(block->base) && block->base->aq_mask == 0) {
2869                         cqr->status = DASD_CQR_FAILED;
2870                         cqr->intrc = -ENOLINK;
2871                         dasd_schedule_block_bh(block);
2872                         continue;
2873                 }
2874                 /* Don't try to start requests if device is stopped */
2875                 if (block->base->stopped)
2876                         return;
2877
2878                 /* just a fail safe check, should not happen */
2879                 if (!cqr->startdev)
2880                         cqr->startdev = block->base;
2881
2882                 /* make sure that the requests we submit find their way back */
2883                 cqr->callback = dasd_return_cqr_cb;
2884
2885                 dasd_add_request_tail(cqr);
2886         }
2887 }
2888
2889 /*
2890  * Central dasd_block layer routine. Takes requests from the generic
2891  * block layer request queue, creates ccw requests, enqueues them on
2892  * a dasd_device and processes ccw requests that have been returned.
2893  */
2894 static void dasd_block_tasklet(unsigned long data)
2895 {
2896         struct dasd_block *block = (struct dasd_block *) data;
2897         struct list_head final_queue;
2898         struct list_head *l, *n;
2899         struct dasd_ccw_req *cqr;
2900         struct dasd_queue *dq;
2901
2902         atomic_set(&block->tasklet_scheduled, 0);
2903         INIT_LIST_HEAD(&final_queue);
2904         spin_lock_irq(&block->queue_lock);
2905         /* Finish off requests on ccw queue */
2906         __dasd_process_block_ccw_queue(block, &final_queue);
2907         spin_unlock_irq(&block->queue_lock);
2908
2909         /* Now call the callback function of requests with final status */
2910         list_for_each_safe(l, n, &final_queue) {
2911                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2912                 dq = cqr->dq;
2913                 spin_lock_irq(&dq->lock);
2914                 list_del_init(&cqr->blocklist);
2915                 __dasd_cleanup_cqr(cqr);
2916                 spin_unlock_irq(&dq->lock);
2917         }
2918
2919         spin_lock_irq(&block->queue_lock);
2920         /* Now check if the head of the ccw queue needs to be started. */
2921         __dasd_block_start_head(block);
2922         spin_unlock_irq(&block->queue_lock);
2923
2924         if (waitqueue_active(&shutdown_waitq))
2925                 wake_up(&shutdown_waitq);
2926         dasd_put_device(block->base);
2927 }
2928
2929 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2930 {
2931         wake_up(&dasd_flush_wq);
2932 }
2933
2934 /*
2935  * Requeue a request back to the block request queue
2936  * only works for block requests
2937  */
2938 static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
2939 {
2940         struct request *req;
2941
2942         /*
2943          * If the request is an ERP request there is nothing to requeue.
2944          * This will be done with the remaining original request.
2945          */
2946         if (cqr->refers)
2947                 return;
2948         spin_lock_irq(&cqr->dq->lock);
2949         req = (struct request *) cqr->callback_data;
2950         blk_mq_requeue_request(req, true);
2951         spin_unlock_irq(&cqr->dq->lock);
2952
2953         return;
2954 }
2955
2956 static int _dasd_requests_to_flushqueue(struct dasd_block *block,
2957                                         struct list_head *flush_queue)
2958 {
2959         struct dasd_ccw_req *cqr, *n;
2960         unsigned long flags;
2961         int rc, i;
2962
2963         spin_lock_irqsave(&block->queue_lock, flags);
2964         rc = 0;
2965 restart:
2966         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2967                 /* if this request currently owned by a dasd_device cancel it */
2968                 if (cqr->status >= DASD_CQR_QUEUED)
2969                         rc = dasd_cancel_req(cqr);
2970                 if (rc < 0)
2971                         break;
2972                 /* Rechain request (including erp chain) so it won't be
2973                  * touched by the dasd_block_tasklet anymore.
2974                  * Replace the callback so we notice when the request
2975                  * is returned from the dasd_device layer.
2976                  */
2977                 cqr->callback = _dasd_wake_block_flush_cb;
2978                 for (i = 0; cqr; cqr = cqr->refers, i++)
2979                         list_move_tail(&cqr->blocklist, flush_queue);
2980                 if (i > 1)
2981                         /* moved more than one request - need to restart */
2982                         goto restart;
2983         }
2984         spin_unlock_irqrestore(&block->queue_lock, flags);
2985
2986         return rc;
2987 }
2988
2989 /*
2990  * Go through all request on the dasd_block request queue, cancel them
2991  * on the respective dasd_device, and return them to the generic
2992  * block layer.
2993  */
2994 static int dasd_flush_block_queue(struct dasd_block *block)
2995 {
2996         struct dasd_ccw_req *cqr, *n;
2997         struct list_head flush_queue;
2998         unsigned long flags;
2999         int rc;
3000
3001         INIT_LIST_HEAD(&flush_queue);
3002         rc = _dasd_requests_to_flushqueue(block, &flush_queue);
3003
3004         /* Now call the callback function of flushed requests */
3005 restart_cb:
3006         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3007                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3008                 /* Process finished ERP request. */
3009                 if (cqr->refers) {
3010                         spin_lock_bh(&block->queue_lock);
3011                         __dasd_process_erp(block->base, cqr);
3012                         spin_unlock_bh(&block->queue_lock);
3013                         /* restart list_for_xx loop since dasd_process_erp
3014                          * might remove multiple elements */
3015                         goto restart_cb;
3016                 }
3017                 /* call the callback function */
3018                 spin_lock_irqsave(&cqr->dq->lock, flags);
3019                 cqr->endclk = get_tod_clock();
3020                 list_del_init(&cqr->blocklist);
3021                 __dasd_cleanup_cqr(cqr);
3022                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3023         }
3024         return rc;
3025 }
3026
3027 /*
3028  * Schedules a call to dasd_tasklet over the device tasklet.
3029  */
3030 void dasd_schedule_block_bh(struct dasd_block *block)
3031 {
3032         /* Protect against rescheduling. */
3033         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3034                 return;
3035         /* life cycle of block is bound to it's base device */
3036         dasd_get_device(block->base);
3037         tasklet_hi_schedule(&block->tasklet);
3038 }
3039 EXPORT_SYMBOL(dasd_schedule_block_bh);
3040
3041
3042 /*
3043  * SECTION: external block device operations
3044  * (request queue handling, open, release, etc.)
3045  */
3046
3047 /*
3048  * Dasd request queue function. Called from ll_rw_blk.c
3049  */
3050 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3051                                     const struct blk_mq_queue_data *qd)
3052 {
3053         struct dasd_block *block = hctx->queue->queuedata;
3054         struct dasd_queue *dq = hctx->driver_data;
3055         struct request *req = qd->rq;
3056         struct dasd_device *basedev;
3057         struct dasd_ccw_req *cqr;
3058         blk_status_t rc = BLK_STS_OK;
3059
3060         basedev = block->base;
3061         spin_lock_irq(&dq->lock);
3062         if (basedev->state < DASD_STATE_READY ||
3063             test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3064                 DBF_DEV_EVENT(DBF_ERR, basedev,
3065                               "device not ready for request %p", req);
3066                 rc = BLK_STS_IOERR;
3067                 goto out;
3068         }
3069
3070         /*
3071          * if device is stopped do not fetch new requests
3072          * except failfast is active which will let requests fail
3073          * immediately in __dasd_block_start_head()
3074          */
3075         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3076                 DBF_DEV_EVENT(DBF_ERR, basedev,
3077                               "device stopped request %p", req);
3078                 rc = BLK_STS_RESOURCE;
3079                 goto out;
3080         }
3081
3082         if (basedev->features & DASD_FEATURE_READONLY &&
3083             rq_data_dir(req) == WRITE) {
3084                 DBF_DEV_EVENT(DBF_ERR, basedev,
3085                               "Rejecting write request %p", req);
3086                 rc = BLK_STS_IOERR;
3087                 goto out;
3088         }
3089
3090         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3091             (basedev->features & DASD_FEATURE_FAILFAST ||
3092              blk_noretry_request(req))) {
3093                 DBF_DEV_EVENT(DBF_ERR, basedev,
3094                               "Rejecting failfast request %p", req);
3095                 rc = BLK_STS_IOERR;
3096                 goto out;
3097         }
3098
3099         cqr = basedev->discipline->build_cp(basedev, block, req);
3100         if (IS_ERR(cqr)) {
3101                 if (PTR_ERR(cqr) == -EBUSY ||
3102                     PTR_ERR(cqr) == -ENOMEM ||
3103                     PTR_ERR(cqr) == -EAGAIN) {
3104                         rc = BLK_STS_RESOURCE;
3105                         goto out;
3106                 }
3107                 DBF_DEV_EVENT(DBF_ERR, basedev,
3108                               "CCW creation failed (rc=%ld) on request %p",
3109                               PTR_ERR(cqr), req);
3110                 rc = BLK_STS_IOERR;
3111                 goto out;
3112         }
3113         /*
3114          *  Note: callback is set to dasd_return_cqr_cb in
3115          * __dasd_block_start_head to cover erp requests as well
3116          */
3117         cqr->callback_data = req;
3118         cqr->status = DASD_CQR_FILLED;
3119         cqr->dq = dq;
3120
3121         blk_mq_start_request(req);
3122         spin_lock(&block->queue_lock);
3123         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3124         INIT_LIST_HEAD(&cqr->devlist);
3125         dasd_profile_start(block, cqr, req);
3126         dasd_schedule_block_bh(block);
3127         spin_unlock(&block->queue_lock);
3128
3129 out:
3130         spin_unlock_irq(&dq->lock);
3131         return rc;
3132 }
3133
3134 /*
3135  * Block timeout callback, called from the block layer
3136  *
3137  * Return values:
3138  * BLK_EH_RESET_TIMER if the request should be left running
3139  * BLK_EH_DONE if the request is handled or terminated
3140  *                    by the driver.
3141  */
3142 enum blk_eh_timer_return dasd_times_out(struct request *req)
3143 {
3144         struct dasd_block *block = req->q->queuedata;
3145         struct dasd_device *device;
3146         struct dasd_ccw_req *cqr;
3147         unsigned long flags;
3148         int rc = 0;
3149
3150         cqr = blk_mq_rq_to_pdu(req);
3151         if (!cqr)
3152                 return BLK_EH_DONE;
3153
3154         spin_lock_irqsave(&cqr->dq->lock, flags);
3155         device = cqr->startdev ? cqr->startdev : block->base;
3156         if (!device->blk_timeout) {
3157                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3158                 return BLK_EH_RESET_TIMER;
3159         }
3160         DBF_DEV_EVENT(DBF_WARNING, device,
3161                       " dasd_times_out cqr %p status %x",
3162                       cqr, cqr->status);
3163
3164         spin_lock(&block->queue_lock);
3165         spin_lock(get_ccwdev_lock(device->cdev));
3166         cqr->retries = -1;
3167         cqr->intrc = -ETIMEDOUT;
3168         if (cqr->status >= DASD_CQR_QUEUED) {
3169                 rc = __dasd_cancel_req(cqr);
3170         } else if (cqr->status == DASD_CQR_FILLED ||
3171                    cqr->status == DASD_CQR_NEED_ERP) {
3172                 cqr->status = DASD_CQR_TERMINATED;
3173         } else if (cqr->status == DASD_CQR_IN_ERP) {
3174                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3175
3176                 list_for_each_entry_safe(searchcqr, nextcqr,
3177                                          &block->ccw_queue, blocklist) {
3178                         tmpcqr = searchcqr;
3179                         while (tmpcqr->refers)
3180                                 tmpcqr = tmpcqr->refers;
3181                         if (tmpcqr != cqr)
3182                                 continue;
3183                         /* searchcqr is an ERP request for cqr */
3184                         searchcqr->retries = -1;
3185                         searchcqr->intrc = -ETIMEDOUT;
3186                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3187                                 rc = __dasd_cancel_req(searchcqr);
3188                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3189                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3190                                 searchcqr->status = DASD_CQR_TERMINATED;
3191                                 rc = 0;
3192                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3193                                 /*
3194                                  * Shouldn't happen; most recent ERP
3195                                  * request is at the front of queue
3196                                  */
3197                                 continue;
3198                         }
3199                         break;
3200                 }
3201         }
3202         spin_unlock(get_ccwdev_lock(device->cdev));
3203         dasd_schedule_block_bh(block);
3204         spin_unlock(&block->queue_lock);
3205         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3206
3207         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3208 }
3209
3210 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3211                           unsigned int idx)
3212 {
3213         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3214
3215         if (!dq)
3216                 return -ENOMEM;
3217
3218         spin_lock_init(&dq->lock);
3219         hctx->driver_data = dq;
3220
3221         return 0;
3222 }
3223
3224 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3225 {
3226         kfree(hctx->driver_data);
3227         hctx->driver_data = NULL;
3228 }
3229
3230 static void dasd_request_done(struct request *req)
3231 {
3232         blk_mq_end_request(req, 0);
3233         blk_mq_run_hw_queues(req->q, true);
3234 }
3235
3236 struct blk_mq_ops dasd_mq_ops = {
3237         .queue_rq = do_dasd_request,
3238         .complete = dasd_request_done,
3239         .timeout = dasd_times_out,
3240         .init_hctx = dasd_init_hctx,
3241         .exit_hctx = dasd_exit_hctx,
3242 };
3243
3244 static int dasd_open(struct gendisk *disk, blk_mode_t mode)
3245 {
3246         struct dasd_device *base;
3247         int rc;
3248
3249         base = dasd_device_from_gendisk(disk);
3250         if (!base)
3251                 return -ENODEV;
3252
3253         atomic_inc(&base->block->open_count);
3254         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3255                 rc = -ENODEV;
3256                 goto unlock;
3257         }
3258
3259         if (!try_module_get(base->discipline->owner)) {
3260                 rc = -EINVAL;
3261                 goto unlock;
3262         }
3263
3264         if (dasd_probeonly) {
3265                 dev_info(&base->cdev->dev,
3266                          "Accessing the DASD failed because it is in "
3267                          "probeonly mode\n");
3268                 rc = -EPERM;
3269                 goto out;
3270         }
3271
3272         if (base->state <= DASD_STATE_BASIC) {
3273                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3274                               " Cannot open unrecognized device");
3275                 rc = -ENODEV;
3276                 goto out;
3277         }
3278         if ((mode & BLK_OPEN_WRITE) &&
3279             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3280              (base->features & DASD_FEATURE_READONLY))) {
3281                 rc = -EROFS;
3282                 goto out;
3283         }
3284         dasd_put_device(base);
3285         return 0;
3286
3287 out:
3288         module_put(base->discipline->owner);
3289 unlock:
3290         atomic_dec(&base->block->open_count);
3291         dasd_put_device(base);
3292         return rc;
3293 }
3294
3295 static void dasd_release(struct gendisk *disk)
3296 {
3297         struct dasd_device *base = dasd_device_from_gendisk(disk);
3298         if (base) {
3299                 atomic_dec(&base->block->open_count);
3300                 module_put(base->discipline->owner);
3301                 dasd_put_device(base);
3302         }
3303 }
3304
3305 /*
3306  * Return disk geometry.
3307  */
3308 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3309 {
3310         struct dasd_device *base;
3311
3312         base = dasd_device_from_gendisk(bdev->bd_disk);
3313         if (!base)
3314                 return -ENODEV;
3315
3316         if (!base->discipline ||
3317             !base->discipline->fill_geometry) {
3318                 dasd_put_device(base);
3319                 return -EINVAL;
3320         }
3321         base->discipline->fill_geometry(base->block, geo);
3322         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3323         dasd_put_device(base);
3324         return 0;
3325 }
3326
3327 const struct block_device_operations
3328 dasd_device_operations = {
3329         .owner          = THIS_MODULE,
3330         .open           = dasd_open,
3331         .release        = dasd_release,
3332         .ioctl          = dasd_ioctl,
3333         .compat_ioctl   = dasd_ioctl,
3334         .getgeo         = dasd_getgeo,
3335         .set_read_only  = dasd_set_read_only,
3336 };
3337
3338 /*******************************************************************************
3339  * end of block device operations
3340  */
3341
3342 static void
3343 dasd_exit(void)
3344 {
3345 #ifdef CONFIG_PROC_FS
3346         dasd_proc_exit();
3347 #endif
3348         dasd_eer_exit();
3349         kmem_cache_destroy(dasd_page_cache);
3350         dasd_page_cache = NULL;
3351         dasd_gendisk_exit();
3352         dasd_devmap_exit();
3353         if (dasd_debug_area != NULL) {
3354                 debug_unregister(dasd_debug_area);
3355                 dasd_debug_area = NULL;
3356         }
3357         dasd_statistics_removeroot();
3358 }
3359
3360 /*
3361  * SECTION: common functions for ccw_driver use
3362  */
3363
3364 /*
3365  * Is the device read-only?
3366  * Note that this function does not report the setting of the
3367  * readonly device attribute, but how it is configured in z/VM.
3368  */
3369 int dasd_device_is_ro(struct dasd_device *device)
3370 {
3371         struct ccw_dev_id dev_id;
3372         struct diag210 diag_data;
3373         int rc;
3374
3375         if (!MACHINE_IS_VM)
3376                 return 0;
3377         ccw_device_get_id(device->cdev, &dev_id);
3378         memset(&diag_data, 0, sizeof(diag_data));
3379         diag_data.vrdcdvno = dev_id.devno;
3380         diag_data.vrdclen = sizeof(diag_data);
3381         rc = diag210(&diag_data);
3382         if (rc == 0 || rc == 2) {
3383                 return diag_data.vrdcvfla & 0x80;
3384         } else {
3385                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3386                           dev_id.devno, rc);
3387                 return 0;
3388         }
3389 }
3390 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3391
3392 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3393 {
3394         struct ccw_device *cdev = data;
3395         int ret;
3396
3397         ret = ccw_device_set_online(cdev);
3398         if (ret)
3399                 dev_warn(&cdev->dev, "Setting the DASD online failed with rc=%d\n", ret);
3400 }
3401
3402 /*
3403  * Initial attempt at a probe function. this can be simplified once
3404  * the other detection code is gone.
3405  */
3406 int dasd_generic_probe(struct ccw_device *cdev)
3407 {
3408         cdev->handler = &dasd_int_handler;
3409
3410         /*
3411          * Automatically online either all dasd devices (dasd_autodetect)
3412          * or all devices specified with dasd= parameters during
3413          * initial probe.
3414          */
3415         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3416             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3417                 async_schedule(dasd_generic_auto_online, cdev);
3418         return 0;
3419 }
3420 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3421
3422 void dasd_generic_free_discipline(struct dasd_device *device)
3423 {
3424         /* Forget the discipline information. */
3425         if (device->discipline) {
3426                 if (device->discipline->uncheck_device)
3427                         device->discipline->uncheck_device(device);
3428                 module_put(device->discipline->owner);
3429                 device->discipline = NULL;
3430         }
3431         if (device->base_discipline) {
3432                 module_put(device->base_discipline->owner);
3433                 device->base_discipline = NULL;
3434         }
3435 }
3436 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3437
3438 /*
3439  * This will one day be called from a global not_oper handler.
3440  * It is also used by driver_unregister during module unload.
3441  */
3442 void dasd_generic_remove(struct ccw_device *cdev)
3443 {
3444         struct dasd_device *device;
3445         struct dasd_block *block;
3446
3447         device = dasd_device_from_cdev(cdev);
3448         if (IS_ERR(device))
3449                 return;
3450
3451         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3452             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3453                 /* Already doing offline processing */
3454                 dasd_put_device(device);
3455                 return;
3456         }
3457         /*
3458          * This device is removed unconditionally. Set offline
3459          * flag to prevent dasd_open from opening it while it is
3460          * no quite down yet.
3461          */
3462         dasd_set_target_state(device, DASD_STATE_NEW);
3463         cdev->handler = NULL;
3464         /* dasd_delete_device destroys the device reference. */
3465         block = device->block;
3466         dasd_delete_device(device);
3467         /*
3468          * life cycle of block is bound to device, so delete it after
3469          * device was safely removed
3470          */
3471         if (block)
3472                 dasd_free_block(block);
3473 }
3474 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3475
3476 /*
3477  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3478  * the device is detected for the first time and is supposed to be used
3479  * or the user has started activation through sysfs.
3480  */
3481 int dasd_generic_set_online(struct ccw_device *cdev,
3482                             struct dasd_discipline *base_discipline)
3483 {
3484         struct dasd_discipline *discipline;
3485         struct dasd_device *device;
3486         struct device *dev;
3487         int rc;
3488
3489         dev = &cdev->dev;
3490
3491         /* first online clears initial online feature flag */
3492         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3493         device = dasd_create_device(cdev);
3494         if (IS_ERR(device))
3495                 return PTR_ERR(device);
3496
3497         discipline = base_discipline;
3498         if (device->features & DASD_FEATURE_USEDIAG) {
3499                 if (!dasd_diag_discipline_pointer) {
3500                         /* Try to load the required module. */
3501                         rc = request_module(DASD_DIAG_MOD);
3502                         if (rc) {
3503                                 dev_warn(dev, "Setting the DASD online failed "
3504                                          "because the required module %s "
3505                                          "could not be loaded (rc=%d)\n",
3506                                          DASD_DIAG_MOD, rc);
3507                                 dasd_delete_device(device);
3508                                 return -ENODEV;
3509                         }
3510                 }
3511                 /* Module init could have failed, so check again here after
3512                  * request_module(). */
3513                 if (!dasd_diag_discipline_pointer) {
3514                         dev_warn(dev, "Setting the DASD online failed because of missing DIAG discipline\n");
3515                         dasd_delete_device(device);
3516                         return -ENODEV;
3517                 }
3518                 discipline = dasd_diag_discipline_pointer;
3519         }
3520         if (!try_module_get(base_discipline->owner)) {
3521                 dasd_delete_device(device);
3522                 return -EINVAL;
3523         }
3524         device->base_discipline = base_discipline;
3525         if (!try_module_get(discipline->owner)) {
3526                 dasd_delete_device(device);
3527                 return -EINVAL;
3528         }
3529         device->discipline = discipline;
3530
3531         /* check_device will allocate block device if necessary */
3532         rc = discipline->check_device(device);
3533         if (rc) {
3534                 dev_warn(dev, "Setting the DASD online with discipline %s failed with rc=%i\n",
3535                          discipline->name, rc);
3536                 dasd_delete_device(device);
3537                 return rc;
3538         }
3539
3540         dasd_set_target_state(device, DASD_STATE_ONLINE);
3541         if (device->state <= DASD_STATE_KNOWN) {
3542                 dev_warn(dev, "Setting the DASD online failed because of a missing discipline\n");
3543                 rc = -ENODEV;
3544                 dasd_set_target_state(device, DASD_STATE_NEW);
3545                 if (device->block)
3546                         dasd_free_block(device->block);
3547                 dasd_delete_device(device);
3548         } else {
3549                 dev_dbg(dev, "dasd_generic device found\n");
3550         }
3551
3552         wait_event(dasd_init_waitq, _wait_for_device(device));
3553
3554         dasd_put_device(device);
3555         return rc;
3556 }
3557 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3558
3559 int dasd_generic_set_offline(struct ccw_device *cdev)
3560 {
3561         int max_count, open_count, rc;
3562         struct dasd_device *device;
3563         struct dasd_block *block;
3564         unsigned long flags;
3565         struct device *dev;
3566
3567         dev = &cdev->dev;
3568
3569         rc = 0;
3570         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3571         device = dasd_device_from_cdev_locked(cdev);
3572         if (IS_ERR(device)) {
3573                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3574                 return PTR_ERR(device);
3575         }
3576
3577         /*
3578          * We must make sure that this device is currently not in use.
3579          * The open_count is increased for every opener, that includes
3580          * the blkdev_get in dasd_scan_partitions. We are only interested
3581          * in the other openers.
3582          */
3583         if (device->block) {
3584                 max_count = device->block->bdev_file ? 0 : -1;
3585                 open_count = atomic_read(&device->block->open_count);
3586                 if (open_count > max_count) {
3587                         if (open_count > 0)
3588                                 dev_warn(dev, "The DASD cannot be set offline with open count %i\n",
3589                                          open_count);
3590                         else
3591                                 dev_warn(dev, "The DASD cannot be set offline while it is in use\n");
3592                         rc = -EBUSY;
3593                         goto out_err;
3594                 }
3595         }
3596
3597         /*
3598          * Test if the offline processing is already running and exit if so.
3599          * If a safe offline is being processed this could only be a normal
3600          * offline that should be able to overtake the safe offline and
3601          * cancel any I/O we do not want to wait for any longer
3602          */
3603         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3604                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3605                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3606                                   &device->flags);
3607                 } else {
3608                         rc = -EBUSY;
3609                         goto out_err;
3610                 }
3611         }
3612         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3613
3614         /*
3615          * if safe_offline is called set safe_offline_running flag and
3616          * clear safe_offline so that a call to normal offline
3617          * can overrun safe_offline processing
3618          */
3619         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3620             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3621                 /* need to unlock here to wait for outstanding I/O */
3622                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3623                 /*
3624                  * If we want to set the device safe offline all IO operations
3625                  * should be finished before continuing the offline process
3626                  * so sync bdev first and then wait for our queues to become
3627                  * empty
3628                  */
3629                 if (device->block && device->block->bdev_file)
3630                         bdev_mark_dead(file_bdev(device->block->bdev_file), false);
3631                 dasd_schedule_device_bh(device);
3632                 rc = wait_event_interruptible(shutdown_waitq,
3633                                               _wait_for_empty_queues(device));
3634                 if (rc != 0)
3635                         goto interrupted;
3636
3637                 /*
3638                  * check if a normal offline process overtook the offline
3639                  * processing in this case simply do nothing beside returning
3640                  * that we got interrupted
3641                  * otherwise mark safe offline as not running any longer and
3642                  * continue with normal offline
3643                  */
3644                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3645                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3646                         rc = -ERESTARTSYS;
3647                         goto out_err;
3648                 }
3649                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3650         }
3651         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3652
3653         dasd_set_target_state(device, DASD_STATE_NEW);
3654         /* dasd_delete_device destroys the device reference. */
3655         block = device->block;
3656         dasd_delete_device(device);
3657         /*
3658          * life cycle of block is bound to device, so delete it after
3659          * device was safely removed
3660          */
3661         if (block)
3662                 dasd_free_block(block);
3663
3664         return 0;
3665
3666 interrupted:
3667         /* interrupted by signal */
3668         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3669         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3670         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3671 out_err:
3672         dasd_put_device(device);
3673         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3674         return rc;
3675 }
3676 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3677
3678 int dasd_generic_last_path_gone(struct dasd_device *device)
3679 {
3680         struct dasd_ccw_req *cqr;
3681
3682         dev_warn(&device->cdev->dev, "No operational channel path is left "
3683                  "for the device\n");
3684         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3685         /* First call extended error reporting and check for autoquiesce. */
3686         dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3687
3688         if (device->state < DASD_STATE_BASIC)
3689                 return 0;
3690         /* Device is active. We want to keep it. */
3691         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3692                 if ((cqr->status == DASD_CQR_IN_IO) ||
3693                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3694                         cqr->status = DASD_CQR_QUEUED;
3695                         cqr->retries++;
3696                 }
3697         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3698         dasd_device_clear_timer(device);
3699         dasd_schedule_device_bh(device);
3700         return 1;
3701 }
3702 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3703
3704 int dasd_generic_path_operational(struct dasd_device *device)
3705 {
3706         dev_info(&device->cdev->dev, "A channel path to the device has become "
3707                  "operational\n");
3708         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3709         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3710         dasd_schedule_device_bh(device);
3711         if (device->block) {
3712                 dasd_schedule_block_bh(device->block);
3713                 if (device->block->gdp)
3714                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
3715         }
3716
3717         if (!device->stopped)
3718                 wake_up(&generic_waitq);
3719
3720         return 1;
3721 }
3722 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3723
3724 int dasd_generic_notify(struct ccw_device *cdev, int event)
3725 {
3726         struct dasd_device *device;
3727         int ret;
3728
3729         device = dasd_device_from_cdev_locked(cdev);
3730         if (IS_ERR(device))
3731                 return 0;
3732         ret = 0;
3733         switch (event) {
3734         case CIO_GONE:
3735         case CIO_BOXED:
3736         case CIO_NO_PATH:
3737                 dasd_path_no_path(device);
3738                 ret = dasd_generic_last_path_gone(device);
3739                 break;
3740         case CIO_OPER:
3741                 ret = 1;
3742                 if (dasd_path_get_opm(device))
3743                         ret = dasd_generic_path_operational(device);
3744                 break;
3745         }
3746         dasd_put_device(device);
3747         return ret;
3748 }
3749 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3750
3751 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3752 {
3753         struct dasd_device *device;
3754         int chp, oldopm, hpfpm, ifccpm;
3755
3756         device = dasd_device_from_cdev_locked(cdev);
3757         if (IS_ERR(device))
3758                 return;
3759
3760         oldopm = dasd_path_get_opm(device);
3761         for (chp = 0; chp < 8; chp++) {
3762                 if (path_event[chp] & PE_PATH_GONE) {
3763                         dasd_path_notoper(device, chp);
3764                 }
3765                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3766                         dasd_path_available(device, chp);
3767                         dasd_schedule_device_bh(device);
3768                 }
3769                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3770                         if (!dasd_path_is_operational(device, chp) &&
3771                             !dasd_path_need_verify(device, chp)) {
3772                                 /*
3773                                  * we can not establish a pathgroup on an
3774                                  * unavailable path, so trigger a path
3775                                  * verification first
3776                                  */
3777                         dasd_path_available(device, chp);
3778                         dasd_schedule_device_bh(device);
3779                         }
3780                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3781                                       "Pathgroup re-established\n");
3782                         if (device->discipline->kick_validate)
3783                                 device->discipline->kick_validate(device);
3784                 }
3785                 if (path_event[chp] & PE_PATH_FCES_EVENT) {
3786                         dasd_path_fcsec_update(device, chp);
3787                         dasd_schedule_device_bh(device);
3788                 }
3789         }
3790         hpfpm = dasd_path_get_hpfpm(device);
3791         ifccpm = dasd_path_get_ifccpm(device);
3792         if (!dasd_path_get_opm(device) && hpfpm) {
3793                 /*
3794                  * device has no operational paths but at least one path is
3795                  * disabled due to HPF errors
3796                  * disable HPF at all and use the path(s) again
3797                  */
3798                 if (device->discipline->disable_hpf)
3799                         device->discipline->disable_hpf(device);
3800                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3801                 dasd_path_set_tbvpm(device, hpfpm);
3802                 dasd_schedule_device_bh(device);
3803                 dasd_schedule_requeue(device);
3804         } else if (!dasd_path_get_opm(device) && ifccpm) {
3805                 /*
3806                  * device has no operational paths but at least one path is
3807                  * disabled due to IFCC errors
3808                  * trigger path verification on paths with IFCC errors
3809                  */
3810                 dasd_path_set_tbvpm(device, ifccpm);
3811                 dasd_schedule_device_bh(device);
3812         }
3813         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3814                 dev_warn(&device->cdev->dev,
3815                          "No verified channel paths remain for the device\n");
3816                 DBF_DEV_EVENT(DBF_WARNING, device,
3817                               "%s", "last verified path gone");
3818                 /* First call extended error reporting and check for autoquiesce. */
3819                 dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3820                 dasd_device_set_stop_bits(device,
3821                                           DASD_STOPPED_DC_WAIT);
3822         }
3823         dasd_put_device(device);
3824 }
3825 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3826
3827 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3828 {
3829         if (!dasd_path_get_opm(device) && lpm) {
3830                 dasd_path_set_opm(device, lpm);
3831                 dasd_generic_path_operational(device);
3832         } else
3833                 dasd_path_add_opm(device, lpm);
3834         return 0;
3835 }
3836 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3837
3838 void dasd_generic_space_exhaust(struct dasd_device *device,
3839                                 struct dasd_ccw_req *cqr)
3840 {
3841         /* First call extended error reporting and check for autoquiesce. */
3842         dasd_handle_autoquiesce(device, NULL, DASD_EER_NOSPC);
3843
3844         if (device->state < DASD_STATE_BASIC)
3845                 return;
3846
3847         if (cqr->status == DASD_CQR_IN_IO ||
3848             cqr->status == DASD_CQR_CLEAR_PENDING) {
3849                 cqr->status = DASD_CQR_QUEUED;
3850                 cqr->retries++;
3851         }
3852         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3853         dasd_device_clear_timer(device);
3854         dasd_schedule_device_bh(device);
3855 }
3856 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3857
3858 void dasd_generic_space_avail(struct dasd_device *device)
3859 {
3860         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3861         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3862
3863         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3864         dasd_schedule_device_bh(device);
3865
3866         if (device->block) {
3867                 dasd_schedule_block_bh(device->block);
3868                 if (device->block->gdp)
3869                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
3870         }
3871         if (!device->stopped)
3872                 wake_up(&generic_waitq);
3873 }
3874 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3875
3876 /*
3877  * clear active requests and requeue them to block layer if possible
3878  */
3879 int dasd_generic_requeue_all_requests(struct dasd_device *device)
3880 {
3881         struct dasd_block *block = device->block;
3882         struct list_head requeue_queue;
3883         struct dasd_ccw_req *cqr, *n;
3884         int rc;
3885
3886         if (!block)
3887                 return 0;
3888
3889         INIT_LIST_HEAD(&requeue_queue);
3890         rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
3891
3892         /* Now call the callback function of flushed requests */
3893 restart_cb:
3894         list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
3895                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3896                 /* Process finished ERP request. */
3897                 if (cqr->refers) {
3898                         spin_lock_bh(&block->queue_lock);
3899                         __dasd_process_erp(block->base, cqr);
3900                         spin_unlock_bh(&block->queue_lock);
3901                         /* restart list_for_xx loop since dasd_process_erp
3902                          * might remove multiple elements
3903                          */
3904                         goto restart_cb;
3905                 }
3906                 _dasd_requeue_request(cqr);
3907                 list_del_init(&cqr->blocklist);
3908                 cqr->block->base->discipline->free_cp(
3909                         cqr, (struct request *) cqr->callback_data);
3910         }
3911         dasd_schedule_device_bh(device);
3912         return rc;
3913 }
3914 EXPORT_SYMBOL_GPL(dasd_generic_requeue_all_requests);
3915
3916 static void do_requeue_requests(struct work_struct *work)
3917 {
3918         struct dasd_device *device = container_of(work, struct dasd_device,
3919                                                   requeue_requests);
3920         dasd_generic_requeue_all_requests(device);
3921         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3922         if (device->block)
3923                 dasd_schedule_block_bh(device->block);
3924         dasd_put_device(device);
3925 }
3926
3927 void dasd_schedule_requeue(struct dasd_device *device)
3928 {
3929         dasd_get_device(device);
3930         /* queue call to dasd_reload_device to the kernel event daemon. */
3931         if (!schedule_work(&device->requeue_requests))
3932                 dasd_put_device(device);
3933 }
3934 EXPORT_SYMBOL(dasd_schedule_requeue);
3935
3936 static int dasd_handle_autoquiesce(struct dasd_device *device,
3937                                    struct dasd_ccw_req *cqr,
3938                                    unsigned int reason)
3939 {
3940         /* in any case write eer message with reason */
3941         if (dasd_eer_enabled(device))
3942                 dasd_eer_write(device, cqr, reason);
3943
3944         if (!test_bit(reason, &device->aq_mask))
3945                 return 0;
3946
3947         /* notify eer about autoquiesce */
3948         if (dasd_eer_enabled(device))
3949                 dasd_eer_write(device, NULL, DASD_EER_AUTOQUIESCE);
3950
3951         dev_info(&device->cdev->dev,
3952                  "The DASD has been put in the quiesce state\n");
3953         dasd_device_set_stop_bits(device, DASD_STOPPED_QUIESCE);
3954
3955         if (device->features & DASD_FEATURE_REQUEUEQUIESCE)
3956                 dasd_schedule_requeue(device);
3957
3958         return 1;
3959 }
3960
3961 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3962                                                    int rdc_buffer_size,
3963                                                    int magic)
3964 {
3965         struct dasd_ccw_req *cqr;
3966         struct ccw1 *ccw;
3967
3968         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
3969                                    NULL);
3970
3971         if (IS_ERR(cqr)) {
3972                 DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
3973                                 "Could not allocate RDC request");
3974                 return cqr;
3975         }
3976
3977         ccw = cqr->cpaddr;
3978         ccw->cmd_code = CCW_CMD_RDC;
3979         ccw->cda = virt_to_dma32(cqr->data);
3980         ccw->flags = 0;
3981         ccw->count = rdc_buffer_size;
3982         cqr->startdev = device;
3983         cqr->memdev = device;
3984         cqr->expires = 10*HZ;
3985         cqr->retries = 256;
3986         cqr->buildclk = get_tod_clock();
3987         cqr->status = DASD_CQR_FILLED;
3988         return cqr;
3989 }
3990
3991
3992 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3993                                 void *rdc_buffer, int rdc_buffer_size)
3994 {
3995         int ret;
3996         struct dasd_ccw_req *cqr;
3997
3998         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
3999         if (IS_ERR(cqr))
4000                 return PTR_ERR(cqr);
4001
4002         ret = dasd_sleep_on(cqr);
4003         if (ret == 0)
4004                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4005         dasd_sfree_request(cqr, cqr->memdev);
4006         return ret;
4007 }
4008 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4009
4010 /*
4011  *   In command mode and transport mode we need to look for sense
4012  *   data in different places. The sense data itself is allways
4013  *   an array of 32 bytes, so we can unify the sense data access
4014  *   for both modes.
4015  */
4016 char *dasd_get_sense(struct irb *irb)
4017 {
4018         struct tsb *tsb = NULL;
4019         char *sense = NULL;
4020
4021         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4022                 if (irb->scsw.tm.tcw)
4023                         tsb = tcw_get_tsb(dma32_to_virt(irb->scsw.tm.tcw));
4024                 if (tsb && tsb->length == 64 && tsb->flags)
4025                         switch (tsb->flags & 0x07) {
4026                         case 1: /* tsa_iostat */
4027                                 sense = tsb->tsa.iostat.sense;
4028                                 break;
4029                         case 2: /* tsa_ddpc */
4030                                 sense = tsb->tsa.ddpc.sense;
4031                                 break;
4032                         default:
4033                                 /* currently we don't use interrogate data */
4034                                 break;
4035                         }
4036         } else if (irb->esw.esw0.erw.cons) {
4037                 sense = irb->ecw;
4038         }
4039         return sense;
4040 }
4041 EXPORT_SYMBOL_GPL(dasd_get_sense);
4042
4043 void dasd_generic_shutdown(struct ccw_device *cdev)
4044 {
4045         struct dasd_device *device;
4046
4047         device = dasd_device_from_cdev(cdev);
4048         if (IS_ERR(device))
4049                 return;
4050
4051         if (device->block)
4052                 dasd_schedule_block_bh(device->block);
4053
4054         dasd_schedule_device_bh(device);
4055
4056         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4057 }
4058 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4059
4060 static int __init dasd_init(void)
4061 {
4062         int rc;
4063
4064         init_waitqueue_head(&dasd_init_waitq);
4065         init_waitqueue_head(&dasd_flush_wq);
4066         init_waitqueue_head(&generic_waitq);
4067         init_waitqueue_head(&shutdown_waitq);
4068
4069         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4070         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4071         if (dasd_debug_area == NULL) {
4072                 rc = -ENOMEM;
4073                 goto failed;
4074         }
4075         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4076         debug_set_level(dasd_debug_area, DBF_WARNING);
4077
4078         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4079
4080         dasd_diag_discipline_pointer = NULL;
4081
4082         dasd_statistics_createroot();
4083
4084         rc = dasd_devmap_init();
4085         if (rc)
4086                 goto failed;
4087         rc = dasd_gendisk_init();
4088         if (rc)
4089                 goto failed;
4090         rc = dasd_parse();
4091         if (rc)
4092                 goto failed;
4093         rc = dasd_eer_init();
4094         if (rc)
4095                 goto failed;
4096 #ifdef CONFIG_PROC_FS
4097         rc = dasd_proc_init();
4098         if (rc)
4099                 goto failed;
4100 #endif
4101
4102         return 0;
4103 failed:
4104         pr_info("The DASD device driver could not be initialized\n");
4105         dasd_exit();
4106         return rc;
4107 }
4108
4109 module_init(dasd_init);
4110 module_exit(dasd_exit);