drivers/s390/block/dasd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_DIAG_MOD           "dasd_diag_mod"
  43
  44 /*
  45  * SECTION: exported variables of dasd.c
  46  */
  47 debug_info_t *dasd_debug_area;
  48 EXPORT_SYMBOL(dasd_debug_area);
  49 static struct dentry *dasd_debugfs_root_entry;
  50 struct dasd_discipline *dasd_diag_discipline_pointer;
  51 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  52 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  53
  54 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  55 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  56                    " Copyright IBM Corp. 2000");
  57 MODULE_LICENSE("GPL");
  58
  59 /*
  60  * SECTION: prototypes for static functions of dasd.c
  61  */
  62 static int dasd_flush_block_queue(struct dasd_block *);
  63 static void dasd_device_tasklet(unsigned long);
  64 static void dasd_block_tasklet(unsigned long);
  65 static void do_kick_device(struct work_struct *);
  66 static void do_reload_device(struct work_struct *);
  67 static void do_requeue_requests(struct work_struct *);
  68 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  69 static void dasd_device_timeout(struct timer_list *);
  70 static void dasd_block_timeout(struct timer_list *);
  71 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  72 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  73 static void dasd_profile_exit(struct dasd_profile *);
  74 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  75 static void dasd_hosts_exit(struct dasd_device *);
  76 static int dasd_handle_autoquiesce(struct dasd_device *, struct dasd_ccw_req *,
  77                                    unsigned int);
  78 /*
  79  * SECTION: Operations on the device structure.
  80  */
  81 static wait_queue_head_t dasd_init_waitq;
  82 static wait_queue_head_t dasd_flush_wq;
  83 static wait_queue_head_t generic_waitq;
  84 static wait_queue_head_t shutdown_waitq;
  85
  86 /*
  87  * Allocate memory for a new device structure.
  88  */
  89 struct dasd_device *dasd_alloc_device(void)
  90 {
  91         struct dasd_device *device;
  92
  93         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  94         if (!device)
  95                 return ERR_PTR(-ENOMEM);
  96
  97         /* Get two pages for normal block device operations. */
  98         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
  99         if (!device->ccw_mem) {
 100                 kfree(device);
 101                 return ERR_PTR(-ENOMEM);
 102         }
 103         /* Get one page for error recovery. */
 104         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 105         if (!device->erp_mem) {
 106                 free_pages((unsigned long) device->ccw_mem, 1);
 107                 kfree(device);
 108                 return ERR_PTR(-ENOMEM);
 109         }
 110         /* Get two pages for ese format. */
 111         device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 112         if (!device->ese_mem) {
 113                 free_page((unsigned long) device->erp_mem);
 114                 free_pages((unsigned long) device->ccw_mem, 1);
 115                 kfree(device);
 116                 return ERR_PTR(-ENOMEM);
 117         }
 118
 119         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 120         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 121         dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 122         spin_lock_init(&device->mem_lock);
 123         atomic_set(&device->tasklet_scheduled, 0);
 124         tasklet_init(&device->tasklet, dasd_device_tasklet,
 125                      (unsigned long) device);
 126         INIT_LIST_HEAD(&device->ccw_queue);
 127         timer_setup(&device->timer, dasd_device_timeout, 0);
 128         INIT_WORK(&device->kick_work, do_kick_device);
 129         INIT_WORK(&device->reload_device, do_reload_device);
 130         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 131         device->state = DASD_STATE_NEW;
 132         device->target = DASD_STATE_NEW;
 133         mutex_init(&device->state_mutex);
 134         spin_lock_init(&device->profile.lock);
 135         return device;
 136 }
 137
 138 /*
 139  * Free memory of a device structure.
 140  */
 141 void dasd_free_device(struct dasd_device *device)
 142 {
 143         kfree(device->private);
 144         free_pages((unsigned long) device->ese_mem, 1);
 145         free_page((unsigned long) device->erp_mem);
 146         free_pages((unsigned long) device->ccw_mem, 1);
 147         kfree(device);
 148 }
 149
 150 /*
 151  * Allocate memory for a new device structure.
 152  */
 153 struct dasd_block *dasd_alloc_block(void)
 154 {
 155         struct dasd_block *block;
 156
 157         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 158         if (!block)
 159                 return ERR_PTR(-ENOMEM);
 160         /* open_count = 0 means device online but not in use */
 161         atomic_set(&block->open_count, -1);
 162
 163         atomic_set(&block->tasklet_scheduled, 0);
 164         tasklet_init(&block->tasklet, dasd_block_tasklet,
 165                      (unsigned long) block);
 166         INIT_LIST_HEAD(&block->ccw_queue);
 167         spin_lock_init(&block->queue_lock);
 168         INIT_LIST_HEAD(&block->format_list);
 169         spin_lock_init(&block->format_lock);
 170         timer_setup(&block->timer, dasd_block_timeout, 0);
 171         spin_lock_init(&block->profile.lock);
 172
 173         return block;
 174 }
 175 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 176
 177 /*
 178  * Free memory of a device structure.
 179  */
 180 void dasd_free_block(struct dasd_block *block)
 181 {
 182         kfree(block);
 183 }
 184 EXPORT_SYMBOL_GPL(dasd_free_block);
 185
 186 /*
 187  * Make a new device known to the system.
 188  */
 189 static int dasd_state_new_to_known(struct dasd_device *device)
 190 {
 191         /*
 192          * As long as the device is not in state DASD_STATE_NEW we want to
 193          * keep the reference count > 0.
 194          */
 195         dasd_get_device(device);
 196         device->state = DASD_STATE_KNOWN;
 197         return 0;
 198 }
 199
 200 /*
 201  * Let the system forget about a device.
 202  */
 203 static int dasd_state_known_to_new(struct dasd_device *device)
 204 {
 205         /* Disable extended error reporting for this device. */
 206         dasd_eer_disable(device);
 207         device->state = DASD_STATE_NEW;
 208
 209         /* Give up reference we took in dasd_state_new_to_known. */
 210         dasd_put_device(device);
 211         return 0;
 212 }
 213
 214 static struct dentry *dasd_debugfs_setup(const char *name,
 215                                          struct dentry *base_dentry)
 216 {
 217         struct dentry *pde;
 218
 219         if (!base_dentry)
 220                 return NULL;
 221         pde = debugfs_create_dir(name, base_dentry);
 222         if (!pde || IS_ERR(pde))
 223                 return NULL;
 224         return pde;
 225 }
 226
 227 /*
 228  * Request the irq line for the device.
 229  */
 230 static int dasd_state_known_to_basic(struct dasd_device *device)
 231 {
 232         struct dasd_block *block = device->block;
 233         int rc = 0;
 234
 235         /* Allocate and register gendisk structure. */
 236         if (block) {
 237                 rc = dasd_gendisk_alloc(block);
 238                 if (rc)
 239                         return rc;
 240                 block->debugfs_dentry =
 241                         dasd_debugfs_setup(block->gdp->disk_name,
 242                                            dasd_debugfs_root_entry);
 243                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 244                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 245                         dasd_profile_on(&device->block->profile);
 246         }
 247         device->debugfs_dentry =
 248                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 249                                    dasd_debugfs_root_entry);
 250         dasd_profile_init(&device->profile, device->debugfs_dentry);
 251         dasd_hosts_init(device->debugfs_dentry, device);
 252
 253         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 254         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 255                                             8 * sizeof(long));
 256         debug_register_view(device->debug_area, &debug_sprintf_view);
 257         debug_set_level(device->debug_area, DBF_WARNING);
 258         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 259
 260         device->state = DASD_STATE_BASIC;
 261
 262         return rc;
 263 }
 264
 265 /*
 266  * Release the irq line for the device. Terminate any running i/o.
 267  */
 268 static int dasd_state_basic_to_known(struct dasd_device *device)
 269 {
 270         int rc;
 271
 272         if (device->discipline->basic_to_known) {
 273                 rc = device->discipline->basic_to_known(device);
 274                 if (rc)
 275                         return rc;
 276         }
 277
 278         if (device->block) {
 279                 dasd_profile_exit(&device->block->profile);
 280                 debugfs_remove(device->block->debugfs_dentry);
 281                 dasd_gendisk_free(device->block);
 282                 dasd_block_clear_timer(device->block);
 283         }
 284         rc = dasd_flush_device_queue(device);
 285         if (rc)
 286                 return rc;
 287         dasd_device_clear_timer(device);
 288         dasd_profile_exit(&device->profile);
 289         dasd_hosts_exit(device);
 290         debugfs_remove(device->debugfs_dentry);
 291         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 292         if (device->debug_area != NULL) {
 293                 debug_unregister(device->debug_area);
 294                 device->debug_area = NULL;
 295         }
 296         device->state = DASD_STATE_KNOWN;
 297         return 0;
 298 }
 299
 300 /*
 301  * Do the initial analysis. The do_analysis function may return
 302  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 303  * until the discipline decides to continue the startup sequence
 304  * by calling the function dasd_change_state. The eckd disciplines
 305  * uses this to start a ccw that detects the format. The completion
 306  * interrupt for this detection ccw uses the kernel event daemon to
 307  * trigger the call to dasd_change_state. All this is done in the
 308  * discipline code, see dasd_eckd.c.
 309  * After the analysis ccw is done (do_analysis returned 0) the block
 310  * device is setup.
 311  * In case the analysis returns an error, the device setup is stopped
 312  * (a fake disk was already added to allow formatting).
 313  */
 314 static int dasd_state_basic_to_ready(struct dasd_device *device)
 315 {
 316         int rc;
 317         struct dasd_block *block;
 318         struct gendisk *disk;
 319
 320         rc = 0;
 321         block = device->block;
 322         /* make disk known with correct capacity */
 323         if (block) {
 324                 if (block->base->discipline->do_analysis != NULL)
 325                         rc = block->base->discipline->do_analysis(block);
 326                 if (rc) {
 327                         if (rc != -EAGAIN) {
 328                                 device->state = DASD_STATE_UNFMT;
 329                                 disk = device->block->gdp;
 330                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 331                                                KOBJ_CHANGE);
 332                                 goto out;
 333                         }
 334                         return rc;
 335                 }
 336                 if (device->discipline->setup_blk_queue)
 337                         device->discipline->setup_blk_queue(block);
 338                 set_capacity(block->gdp,
 339                              block->blocks << block->s2b_shift);
 340                 device->state = DASD_STATE_READY;
 341                 rc = dasd_scan_partitions(block);
 342                 if (rc) {
 343                         device->state = DASD_STATE_BASIC;
 344                         return rc;
 345                 }
 346         } else {
 347                 device->state = DASD_STATE_READY;
 348         }
 349 out:
 350         if (device->discipline->basic_to_ready)
 351                 rc = device->discipline->basic_to_ready(device);
 352         return rc;
 353 }
 354
 355 static inline
 356 int _wait_for_empty_queues(struct dasd_device *device)
 357 {
 358         if (device->block)
 359                 return list_empty(&device->ccw_queue) &&
 360                         list_empty(&device->block->ccw_queue);
 361         else
 362                 return list_empty(&device->ccw_queue);
 363 }
 364
 365 /*
 366  * Remove device from block device layer. Destroy dirty buffers.
 367  * Forget format information. Check if the target level is basic
 368  * and if it is create fake disk for formatting.
 369  */
 370 static int dasd_state_ready_to_basic(struct dasd_device *device)
 371 {
 372         int rc;
 373
 374         device->state = DASD_STATE_BASIC;
 375         if (device->block) {
 376                 struct dasd_block *block = device->block;
 377                 rc = dasd_flush_block_queue(block);
 378                 if (rc) {
 379                         device->state = DASD_STATE_READY;
 380                         return rc;
 381                 }
 382                 dasd_destroy_partitions(block);
 383                 block->blocks = 0;
 384                 block->bp_block = 0;
 385                 block->s2b_shift = 0;
 386         }
 387         return 0;
 388 }
 389
 390 /*
 391  * Back to basic.
 392  */
 393 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 394 {
 395         device->state = DASD_STATE_BASIC;
 396         return 0;
 397 }
 398
 399 /*
 400  * Make the device online and schedule the bottom half to start
 401  * the requeueing of requests from the linux request queue to the
 402  * ccw queue.
 403  */
 404 static int
 405 dasd_state_ready_to_online(struct dasd_device * device)
 406 {
 407         device->state = DASD_STATE_ONLINE;
 408         if (device->block) {
 409                 dasd_schedule_block_bh(device->block);
 410                 if ((device->features & DASD_FEATURE_USERAW)) {
 411                         kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
 412                                         KOBJ_CHANGE);
 413                         return 0;
 414                 }
 415                 disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
 416         }
 417         return 0;
 418 }
 419
 420 /*
 421  * Stop the requeueing of requests again.
 422  */
 423 static int dasd_state_online_to_ready(struct dasd_device *device)
 424 {
 425         int rc;
 426
 427         if (device->discipline->online_to_ready) {
 428                 rc = device->discipline->online_to_ready(device);
 429                 if (rc)
 430                         return rc;
 431         }
 432
 433         device->state = DASD_STATE_READY;
 434         if (device->block && !(device->features & DASD_FEATURE_USERAW))
 435                 disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
 436         return 0;
 437 }
 438
 439 /*
 440  * Device startup state changes.
 441  */
 442 static int dasd_increase_state(struct dasd_device *device)
 443 {
 444         int rc;
 445
 446         rc = 0;
 447         if (device->state == DASD_STATE_NEW &&
 448             device->target >= DASD_STATE_KNOWN)
 449                 rc = dasd_state_new_to_known(device);
 450
 451         if (!rc &&
 452             device->state == DASD_STATE_KNOWN &&
 453             device->target >= DASD_STATE_BASIC)
 454                 rc = dasd_state_known_to_basic(device);
 455
 456         if (!rc &&
 457             device->state == DASD_STATE_BASIC &&
 458             device->target >= DASD_STATE_READY)
 459                 rc = dasd_state_basic_to_ready(device);
 460
 461         if (!rc &&
 462             device->state == DASD_STATE_UNFMT &&
 463             device->target > DASD_STATE_UNFMT)
 464                 rc = -EPERM;
 465
 466         if (!rc &&
 467             device->state == DASD_STATE_READY &&
 468             device->target >= DASD_STATE_ONLINE)
 469                 rc = dasd_state_ready_to_online(device);
 470
 471         return rc;
 472 }
 473
 474 /*
 475  * Device shutdown state changes.
 476  */
 477 static int dasd_decrease_state(struct dasd_device *device)
 478 {
 479         int rc;
 480
 481         rc = 0;
 482         if (device->state == DASD_STATE_ONLINE &&
 483             device->target <= DASD_STATE_READY)
 484                 rc = dasd_state_online_to_ready(device);
 485
 486         if (!rc &&
 487             device->state == DASD_STATE_READY &&
 488             device->target <= DASD_STATE_BASIC)
 489                 rc = dasd_state_ready_to_basic(device);
 490
 491         if (!rc &&
 492             device->state == DASD_STATE_UNFMT &&
 493             device->target <= DASD_STATE_BASIC)
 494                 rc = dasd_state_unfmt_to_basic(device);
 495
 496         if (!rc &&
 497             device->state == DASD_STATE_BASIC &&
 498             device->target <= DASD_STATE_KNOWN)
 499                 rc = dasd_state_basic_to_known(device);
 500
 501         if (!rc &&
 502             device->state == DASD_STATE_KNOWN &&
 503             device->target <= DASD_STATE_NEW)
 504                 rc = dasd_state_known_to_new(device);
 505
 506         return rc;
 507 }
 508
 509 /*
 510  * This is the main startup/shutdown routine.
 511  */
 512 static void dasd_change_state(struct dasd_device *device)
 513 {
 514         int rc;
 515
 516         if (device->state == device->target)
 517                 /* Already where we want to go today... */
 518                 return;
 519         if (device->state < device->target)
 520                 rc = dasd_increase_state(device);
 521         else
 522                 rc = dasd_decrease_state(device);
 523         if (rc == -EAGAIN)
 524                 return;
 525         if (rc)
 526                 device->target = device->state;
 527
 528         /* let user-space know that the device status changed */
 529         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 530
 531         if (device->state == device->target)
 532                 wake_up(&dasd_init_waitq);
 533 }
 534
 535 /*
 536  * Kick starter for devices that did not complete the startup/shutdown
 537  * procedure or were sleeping because of a pending state.
 538  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 539  * event daemon.
 540  */
 541 static void do_kick_device(struct work_struct *work)
 542 {
 543         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 544         mutex_lock(&device->state_mutex);
 545         dasd_change_state(device);
 546         mutex_unlock(&device->state_mutex);
 547         dasd_schedule_device_bh(device);
 548         dasd_put_device(device);
 549 }
 550
 551 void dasd_kick_device(struct dasd_device *device)
 552 {
 553         dasd_get_device(device);
 554         /* queue call to dasd_kick_device to the kernel event daemon. */
 555         if (!schedule_work(&device->kick_work))
 556                 dasd_put_device(device);
 557 }
 558 EXPORT_SYMBOL(dasd_kick_device);
 559
 560 /*
 561  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 562  * event daemon.
 563  */
 564 static void do_reload_device(struct work_struct *work)
 565 {
 566         struct dasd_device *device = container_of(work, struct dasd_device,
 567                                                   reload_device);
 568         device->discipline->reload(device);
 569         dasd_put_device(device);
 570 }
 571
 572 void dasd_reload_device(struct dasd_device *device)
 573 {
 574         dasd_get_device(device);
 575         /* queue call to dasd_reload_device to the kernel event daemon. */
 576         if (!schedule_work(&device->reload_device))
 577                 dasd_put_device(device);
 578 }
 579 EXPORT_SYMBOL(dasd_reload_device);
 580
 581 /*
 582  * Set the target state for a device and starts the state change.
 583  */
 584 void dasd_set_target_state(struct dasd_device *device, int target)
 585 {
 586         dasd_get_device(device);
 587         mutex_lock(&device->state_mutex);
 588         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 589         if (dasd_probeonly && target > DASD_STATE_READY)
 590                 target = DASD_STATE_READY;
 591         if (device->target != target) {
 592                 if (device->state == target)
 593                         wake_up(&dasd_init_waitq);
 594                 device->target = target;
 595         }
 596         if (device->state != device->target)
 597                 dasd_change_state(device);
 598         mutex_unlock(&device->state_mutex);
 599         dasd_put_device(device);
 600 }
 601
 602 /*
 603  * Enable devices with device numbers in [from..to].
 604  */
 605 static inline int _wait_for_device(struct dasd_device *device)
 606 {
 607         return (device->state == device->target);
 608 }
 609
 610 void dasd_enable_device(struct dasd_device *device)
 611 {
 612         dasd_set_target_state(device, DASD_STATE_ONLINE);
 613         if (device->state <= DASD_STATE_KNOWN)
 614                 /* No discipline for device found. */
 615                 dasd_set_target_state(device, DASD_STATE_NEW);
 616         /* Now wait for the devices to come up. */
 617         wait_event(dasd_init_waitq, _wait_for_device(device));
 618
 619         dasd_reload_device(device);
 620         if (device->discipline->kick_validate)
 621                 device->discipline->kick_validate(device);
 622 }
 623 EXPORT_SYMBOL(dasd_enable_device);
 624
 625 /*
 626  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 627  */
 628
 629 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 630
 631 #ifdef CONFIG_DASD_PROFILE
 632 struct dasd_profile dasd_global_profile = {
 633         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 634 };
 635 static struct dentry *dasd_debugfs_global_entry;
 636
 637 /*
 638  * Add profiling information for cqr before execution.
 639  */
 640 static void dasd_profile_start(struct dasd_block *block,
 641                                struct dasd_ccw_req *cqr,
 642                                struct request *req)
 643 {
 644         struct list_head *l;
 645         unsigned int counter;
 646         struct dasd_device *device;
 647
 648         /* count the length of the chanq for statistics */
 649         counter = 0;
 650         if (dasd_global_profile_level || block->profile.data)
 651                 list_for_each(l, &block->ccw_queue)
 652                         if (++counter >= 31)
 653                                 break;
 654
 655         spin_lock(&dasd_global_profile.lock);
 656         if (dasd_global_profile.data) {
 657                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 658                 if (rq_data_dir(req) == READ)
 659                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 660         }
 661         spin_unlock(&dasd_global_profile.lock);
 662
 663         spin_lock(&block->profile.lock);
 664         if (block->profile.data) {
 665                 block->profile.data->dasd_io_nr_req[counter]++;
 666                 if (rq_data_dir(req) == READ)
 667                         block->profile.data->dasd_read_nr_req[counter]++;
 668         }
 669         spin_unlock(&block->profile.lock);
 670
 671         /*
 672          * We count the request for the start device, even though it may run on
 673          * some other device due to error recovery. This way we make sure that
 674          * we count each request only once.
 675          */
 676         device = cqr->startdev;
 677         if (device->profile.data) {
 678                 counter = 1; /* request is not yet queued on the start device */
 679                 list_for_each(l, &device->ccw_queue)
 680                         if (++counter >= 31)
 681                                 break;
 682         }
 683         spin_lock(&device->profile.lock);
 684         if (device->profile.data) {
 685                 device->profile.data->dasd_io_nr_req[counter]++;
 686                 if (rq_data_dir(req) == READ)
 687                         device->profile.data->dasd_read_nr_req[counter]++;
 688         }
 689         spin_unlock(&device->profile.lock);
 690 }
 691
 692 /*
 693  * Add profiling information for cqr after execution.
 694  */
 695
 696 #define dasd_profile_counter(value, index)                         \
 697 {                                                                  \
 698         for (index = 0; index < 31 && value >> (2+index); index++) \
 699                 ;                                                  \
 700 }
 701
 702 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 703                                       int is_alias,
 704                                       int is_tpm,
 705                                       int is_read,
 706                                       long sectors,
 707                                       int sectors_ind,
 708                                       int tottime_ind,
 709                                       int tottimeps_ind,
 710                                       int strtime_ind,
 711                                       int irqtime_ind,
 712                                       int irqtimeps_ind,
 713                                       int endtime_ind)
 714 {
 715         /* in case of an overflow, reset the whole profile */
 716         if (data->dasd_io_reqs == UINT_MAX) {
 717                         memset(data, 0, sizeof(*data));
 718                         ktime_get_real_ts64(&data->starttod);
 719         }
 720         data->dasd_io_reqs++;
 721         data->dasd_io_sects += sectors;
 722         if (is_alias)
 723                 data->dasd_io_alias++;
 724         if (is_tpm)
 725                 data->dasd_io_tpm++;
 726
 727         data->dasd_io_secs[sectors_ind]++;
 728         data->dasd_io_times[tottime_ind]++;
 729         data->dasd_io_timps[tottimeps_ind]++;
 730         data->dasd_io_time1[strtime_ind]++;
 731         data->dasd_io_time2[irqtime_ind]++;
 732         data->dasd_io_time2ps[irqtimeps_ind]++;
 733         data->dasd_io_time3[endtime_ind]++;
 734
 735         if (is_read) {
 736                 data->dasd_read_reqs++;
 737                 data->dasd_read_sects += sectors;
 738                 if (is_alias)
 739                         data->dasd_read_alias++;
 740                 if (is_tpm)
 741                         data->dasd_read_tpm++;
 742                 data->dasd_read_secs[sectors_ind]++;
 743                 data->dasd_read_times[tottime_ind]++;
 744                 data->dasd_read_time1[strtime_ind]++;
 745                 data->dasd_read_time2[irqtime_ind]++;
 746                 data->dasd_read_time3[endtime_ind]++;
 747         }
 748 }
 749
 750 static void dasd_profile_end(struct dasd_block *block,
 751                              struct dasd_ccw_req *cqr,
 752                              struct request *req)
 753 {
 754         unsigned long strtime, irqtime, endtime, tottime;
 755         unsigned long tottimeps, sectors;
 756         struct dasd_device *device;
 757         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 758         int irqtime_ind, irqtimeps_ind, endtime_ind;
 759         struct dasd_profile_info *data;
 760
 761         device = cqr->startdev;
 762         if (!(dasd_global_profile_level ||
 763               block->profile.data ||
 764               device->profile.data))
 765                 return;
 766
 767         sectors = blk_rq_sectors(req);
 768         if (!cqr->buildclk || !cqr->startclk ||
 769             !cqr->stopclk || !cqr->endclk ||
 770             !sectors)
 771                 return;
 772
 773         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 774         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 775         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 776         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 777         tottimeps = tottime / sectors;
 778
 779         dasd_profile_counter(sectors, sectors_ind);
 780         dasd_profile_counter(tottime, tottime_ind);
 781         dasd_profile_counter(tottimeps, tottimeps_ind);
 782         dasd_profile_counter(strtime, strtime_ind);
 783         dasd_profile_counter(irqtime, irqtime_ind);
 784         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 785         dasd_profile_counter(endtime, endtime_ind);
 786
 787         spin_lock(&dasd_global_profile.lock);
 788         if (dasd_global_profile.data) {
 789                 data = dasd_global_profile.data;
 790                 data->dasd_sum_times += tottime;
 791                 data->dasd_sum_time_str += strtime;
 792                 data->dasd_sum_time_irq += irqtime;
 793                 data->dasd_sum_time_end += endtime;
 794                 dasd_profile_end_add_data(dasd_global_profile.data,
 795                                           cqr->startdev != block->base,
 796                                           cqr->cpmode == 1,
 797                                           rq_data_dir(req) == READ,
 798                                           sectors, sectors_ind, tottime_ind,
 799                                           tottimeps_ind, strtime_ind,
 800                                           irqtime_ind, irqtimeps_ind,
 801                                           endtime_ind);
 802         }
 803         spin_unlock(&dasd_global_profile.lock);
 804
 805         spin_lock(&block->profile.lock);
 806         if (block->profile.data) {
 807                 data = block->profile.data;
 808                 data->dasd_sum_times += tottime;
 809                 data->dasd_sum_time_str += strtime;
 810                 data->dasd_sum_time_irq += irqtime;
 811                 data->dasd_sum_time_end += endtime;
 812                 dasd_profile_end_add_data(block->profile.data,
 813                                           cqr->startdev != block->base,
 814                                           cqr->cpmode == 1,
 815                                           rq_data_dir(req) == READ,
 816                                           sectors, sectors_ind, tottime_ind,
 817                                           tottimeps_ind, strtime_ind,
 818                                           irqtime_ind, irqtimeps_ind,
 819                                           endtime_ind);
 820         }
 821         spin_unlock(&block->profile.lock);
 822
 823         spin_lock(&device->profile.lock);
 824         if (device->profile.data) {
 825                 data = device->profile.data;
 826                 data->dasd_sum_times += tottime;
 827                 data->dasd_sum_time_str += strtime;
 828                 data->dasd_sum_time_irq += irqtime;
 829                 data->dasd_sum_time_end += endtime;
 830                 dasd_profile_end_add_data(device->profile.data,
 831                                           cqr->startdev != block->base,
 832                                           cqr->cpmode == 1,
 833                                           rq_data_dir(req) == READ,
 834                                           sectors, sectors_ind, tottime_ind,
 835                                           tottimeps_ind, strtime_ind,
 836                                           irqtime_ind, irqtimeps_ind,
 837                                           endtime_ind);
 838         }
 839         spin_unlock(&device->profile.lock);
 840 }
 841
 842 void dasd_profile_reset(struct dasd_profile *profile)
 843 {
 844         struct dasd_profile_info *data;
 845
 846         spin_lock_bh(&profile->lock);
 847         data = profile->data;
 848         if (!data) {
 849                 spin_unlock_bh(&profile->lock);
 850                 return;
 851         }
 852         memset(data, 0, sizeof(*data));
 853         ktime_get_real_ts64(&data->starttod);
 854         spin_unlock_bh(&profile->lock);
 855 }
 856
 857 int dasd_profile_on(struct dasd_profile *profile)
 858 {
 859         struct dasd_profile_info *data;
 860
 861         data = kzalloc(sizeof(*data), GFP_KERNEL);
 862         if (!data)
 863                 return -ENOMEM;
 864         spin_lock_bh(&profile->lock);
 865         if (profile->data) {
 866                 spin_unlock_bh(&profile->lock);
 867                 kfree(data);
 868                 return 0;
 869         }
 870         ktime_get_real_ts64(&data->starttod);
 871         profile->data = data;
 872         spin_unlock_bh(&profile->lock);
 873         return 0;
 874 }
 875
 876 void dasd_profile_off(struct dasd_profile *profile)
 877 {
 878         spin_lock_bh(&profile->lock);
 879         kfree(profile->data);
 880         profile->data = NULL;
 881         spin_unlock_bh(&profile->lock);
 882 }
 883
 884 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 885 {
 886         char *buffer;
 887
 888         buffer = vmalloc(user_len + 1);
 889         if (buffer == NULL)
 890                 return ERR_PTR(-ENOMEM);
 891         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 892                 vfree(buffer);
 893                 return ERR_PTR(-EFAULT);
 894         }
 895         /* got the string, now strip linefeed. */
 896         if (buffer[user_len - 1] == '\n')
 897                 buffer[user_len - 1] = 0;
 898         else
 899                 buffer[user_len] = 0;
 900         return buffer;
 901 }
 902
 903 static ssize_t dasd_stats_write(struct file *file,
 904                                 const char __user *user_buf,
 905                                 size_t user_len, loff_t *pos)
 906 {
 907         char *buffer, *str;
 908         int rc;
 909         struct seq_file *m = (struct seq_file *)file->private_data;
 910         struct dasd_profile *prof = m->private;
 911
 912         if (user_len > 65536)
 913                 user_len = 65536;
 914         buffer = dasd_get_user_string(user_buf, user_len);
 915         if (IS_ERR(buffer))
 916                 return PTR_ERR(buffer);
 917
 918         str = skip_spaces(buffer);
 919         rc = user_len;
 920         if (strncmp(str, "reset", 5) == 0) {
 921                 dasd_profile_reset(prof);
 922         } else if (strncmp(str, "on", 2) == 0) {
 923                 rc = dasd_profile_on(prof);
 924                 if (rc)
 925                         goto out;
 926                 rc = user_len;
 927                 if (prof == &dasd_global_profile) {
 928                         dasd_profile_reset(prof);
 929                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 930                 }
 931         } else if (strncmp(str, "off", 3) == 0) {
 932                 if (prof == &dasd_global_profile)
 933                         dasd_global_profile_level = DASD_PROFILE_OFF;
 934                 dasd_profile_off(prof);
 935         } else
 936                 rc = -EINVAL;
 937 out:
 938         vfree(buffer);
 939         return rc;
 940 }
 941
 942 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 943 {
 944         int i;
 945
 946         for (i = 0; i < 32; i++)
 947                 seq_printf(m, "%u ", array[i]);
 948         seq_putc(m, '\n');
 949 }
 950
 951 static void dasd_stats_seq_print(struct seq_file *m,
 952                                  struct dasd_profile_info *data)
 953 {
 954         seq_printf(m, "start_time %lld.%09ld\n",
 955                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
 956         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 957         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 958         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 959         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 960         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
 961                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
 962         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
 963                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
 964         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
 965                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
 966         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
 967                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
 968         seq_puts(m, "histogram_sectors ");
 969         dasd_stats_array(m, data->dasd_io_secs);
 970         seq_puts(m, "histogram_io_times ");
 971         dasd_stats_array(m, data->dasd_io_times);
 972         seq_puts(m, "histogram_io_times_weighted ");
 973         dasd_stats_array(m, data->dasd_io_timps);
 974         seq_puts(m, "histogram_time_build_to_ssch ");
 975         dasd_stats_array(m, data->dasd_io_time1);
 976         seq_puts(m, "histogram_time_ssch_to_irq ");
 977         dasd_stats_array(m, data->dasd_io_time2);
 978         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
 979         dasd_stats_array(m, data->dasd_io_time2ps);
 980         seq_puts(m, "histogram_time_irq_to_end ");
 981         dasd_stats_array(m, data->dasd_io_time3);
 982         seq_puts(m, "histogram_ccw_queue_length ");
 983         dasd_stats_array(m, data->dasd_io_nr_req);
 984         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 985         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 986         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 987         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 988         seq_puts(m, "histogram_read_sectors ");
 989         dasd_stats_array(m, data->dasd_read_secs);
 990         seq_puts(m, "histogram_read_times ");
 991         dasd_stats_array(m, data->dasd_read_times);
 992         seq_puts(m, "histogram_read_time_build_to_ssch ");
 993         dasd_stats_array(m, data->dasd_read_time1);
 994         seq_puts(m, "histogram_read_time_ssch_to_irq ");
 995         dasd_stats_array(m, data->dasd_read_time2);
 996         seq_puts(m, "histogram_read_time_irq_to_end ");
 997         dasd_stats_array(m, data->dasd_read_time3);
 998         seq_puts(m, "histogram_read_ccw_queue_length ");
 999         dasd_stats_array(m, data->dasd_read_nr_req);
1000 }
1001
1002 static int dasd_stats_show(struct seq_file *m, void *v)
1003 {
1004         struct dasd_profile *profile;
1005         struct dasd_profile_info *data;
1006
1007         profile = m->private;
1008         spin_lock_bh(&profile->lock);
1009         data = profile->data;
1010         if (!data) {
1011                 spin_unlock_bh(&profile->lock);
1012                 seq_puts(m, "disabled\n");
1013                 return 0;
1014         }
1015         dasd_stats_seq_print(m, data);
1016         spin_unlock_bh(&profile->lock);
1017         return 0;
1018 }
1019
1020 static int dasd_stats_open(struct inode *inode, struct file *file)
1021 {
1022         struct dasd_profile *profile = inode->i_private;
1023         return single_open(file, dasd_stats_show, profile);
1024 }
1025
1026 static const struct file_operations dasd_stats_raw_fops = {
1027         .owner          = THIS_MODULE,
1028         .open           = dasd_stats_open,
1029         .read           = seq_read,
1030         .llseek         = seq_lseek,
1031         .release        = single_release,
1032         .write          = dasd_stats_write,
1033 };
1034
1035 static void dasd_profile_init(struct dasd_profile *profile,
1036                               struct dentry *base_dentry)
1037 {
1038         umode_t mode;
1039         struct dentry *pde;
1040
1041         if (!base_dentry)
1042                 return;
1043         profile->dentry = NULL;
1044         profile->data = NULL;
1045         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1046         pde = debugfs_create_file("statistics", mode, base_dentry,
1047                                   profile, &dasd_stats_raw_fops);
1048         if (pde && !IS_ERR(pde))
1049                 profile->dentry = pde;
1050         return;
1051 }
1052
1053 static void dasd_profile_exit(struct dasd_profile *profile)
1054 {
1055         dasd_profile_off(profile);
1056         debugfs_remove(profile->dentry);
1057         profile->dentry = NULL;
1058 }
1059
1060 static void dasd_statistics_removeroot(void)
1061 {
1062         dasd_global_profile_level = DASD_PROFILE_OFF;
1063         dasd_profile_exit(&dasd_global_profile);
1064         debugfs_remove(dasd_debugfs_global_entry);
1065         debugfs_remove(dasd_debugfs_root_entry);
1066 }
1067
1068 static void dasd_statistics_createroot(void)
1069 {
1070         struct dentry *pde;
1071
1072         dasd_debugfs_root_entry = NULL;
1073         pde = debugfs_create_dir("dasd", NULL);
1074         if (!pde || IS_ERR(pde))
1075                 goto error;
1076         dasd_debugfs_root_entry = pde;
1077         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1078         if (!pde || IS_ERR(pde))
1079                 goto error;
1080         dasd_debugfs_global_entry = pde;
1081         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1082         return;
1083
1084 error:
1085         DBF_EVENT(DBF_ERR, "%s",
1086                   "Creation of the dasd debugfs interface failed");
1087         dasd_statistics_removeroot();
1088         return;
1089 }
1090
1091 #else
1092 #define dasd_profile_start(block, cqr, req) do {} while (0)
1093 #define dasd_profile_end(block, cqr, req) do {} while (0)
1094
1095 static void dasd_statistics_createroot(void)
1096 {
1097         return;
1098 }
1099
1100 static void dasd_statistics_removeroot(void)
1101 {
1102         return;
1103 }
1104
1105 int dasd_stats_generic_show(struct seq_file *m, void *v)
1106 {
1107         seq_puts(m, "Statistics are not activated in this kernel\n");
1108         return 0;
1109 }
1110
1111 static void dasd_profile_init(struct dasd_profile *profile,
1112                               struct dentry *base_dentry)
1113 {
1114         return;
1115 }
1116
1117 static void dasd_profile_exit(struct dasd_profile *profile)
1118 {
1119         return;
1120 }
1121
1122 int dasd_profile_on(struct dasd_profile *profile)
1123 {
1124         return 0;
1125 }
1126
1127 #endif                          /* CONFIG_DASD_PROFILE */
1128
1129 static int dasd_hosts_show(struct seq_file *m, void *v)
1130 {
1131         struct dasd_device *device;
1132         int rc = -EOPNOTSUPP;
1133
1134         device = m->private;
1135         dasd_get_device(device);
1136
1137         if (device->discipline->hosts_print)
1138                 rc = device->discipline->hosts_print(device, m);
1139
1140         dasd_put_device(device);
1141         return rc;
1142 }
1143
1144 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1145
1146 static void dasd_hosts_exit(struct dasd_device *device)
1147 {
1148         debugfs_remove(device->hosts_dentry);
1149         device->hosts_dentry = NULL;
1150 }
1151
1152 static void dasd_hosts_init(struct dentry *base_dentry,
1153                             struct dasd_device *device)
1154 {
1155         struct dentry *pde;
1156         umode_t mode;
1157
1158         if (!base_dentry)
1159                 return;
1160
1161         mode = S_IRUSR | S_IFREG;
1162         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1163                                   device, &dasd_hosts_fops);
1164         if (pde && !IS_ERR(pde))
1165                 device->hosts_dentry = pde;
1166 }
1167
1168 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1169                                           struct dasd_device *device,
1170                                           struct dasd_ccw_req *cqr)
1171 {
1172         unsigned long flags;
1173         char *data, *chunk;
1174         int size = 0;
1175
1176         if (cplength > 0)
1177                 size += cplength * sizeof(struct ccw1);
1178         if (datasize > 0)
1179                 size += datasize;
1180         if (!cqr)
1181                 size += (sizeof(*cqr) + 7L) & -8L;
1182
1183         spin_lock_irqsave(&device->mem_lock, flags);
1184         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1185         spin_unlock_irqrestore(&device->mem_lock, flags);
1186         if (!chunk)
1187                 return ERR_PTR(-ENOMEM);
1188         if (!cqr) {
1189                 cqr = (void *) data;
1190                 data += (sizeof(*cqr) + 7L) & -8L;
1191         }
1192         memset(cqr, 0, sizeof(*cqr));
1193         cqr->mem_chunk = chunk;
1194         if (cplength > 0) {
1195                 cqr->cpaddr = data;
1196                 data += cplength * sizeof(struct ccw1);
1197                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1198         }
1199         if (datasize > 0) {
1200                 cqr->data = data;
1201                 memset(cqr->data, 0, datasize);
1202         }
1203         cqr->magic = magic;
1204         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1205         dasd_get_device(device);
1206         return cqr;
1207 }
1208 EXPORT_SYMBOL(dasd_smalloc_request);
1209
1210 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1211                                           int datasize,
1212                                           struct dasd_device *device)
1213 {
1214         struct dasd_ccw_req *cqr;
1215         unsigned long flags;
1216         int size, cqr_size;
1217         char *data;
1218
1219         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1220         size = cqr_size;
1221         if (cplength > 0)
1222                 size += cplength * sizeof(struct ccw1);
1223         if (datasize > 0)
1224                 size += datasize;
1225
1226         spin_lock_irqsave(&device->mem_lock, flags);
1227         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1228         spin_unlock_irqrestore(&device->mem_lock, flags);
1229         if (!cqr)
1230                 return ERR_PTR(-ENOMEM);
1231         memset(cqr, 0, sizeof(*cqr));
1232         data = (char *)cqr + cqr_size;
1233         cqr->cpaddr = NULL;
1234         if (cplength > 0) {
1235                 cqr->cpaddr = data;
1236                 data += cplength * sizeof(struct ccw1);
1237                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1238         }
1239         cqr->data = NULL;
1240         if (datasize > 0) {
1241                 cqr->data = data;
1242                 memset(cqr->data, 0, datasize);
1243         }
1244
1245         cqr->magic = magic;
1246         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1247         dasd_get_device(device);
1248
1249         return cqr;
1250 }
1251 EXPORT_SYMBOL(dasd_fmalloc_request);
1252
1253 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1254 {
1255         unsigned long flags;
1256
1257         spin_lock_irqsave(&device->mem_lock, flags);
1258         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1259         spin_unlock_irqrestore(&device->mem_lock, flags);
1260         dasd_put_device(device);
1261 }
1262 EXPORT_SYMBOL(dasd_sfree_request);
1263
1264 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1265 {
1266         unsigned long flags;
1267
1268         spin_lock_irqsave(&device->mem_lock, flags);
1269         dasd_free_chunk(&device->ese_chunks, cqr);
1270         spin_unlock_irqrestore(&device->mem_lock, flags);
1271         dasd_put_device(device);
1272 }
1273 EXPORT_SYMBOL(dasd_ffree_request);
1274
1275 /*
1276  * Check discipline magic in cqr.
1277  */
1278 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1279 {
1280         struct dasd_device *device;
1281
1282         if (cqr == NULL)
1283                 return -EINVAL;
1284         device = cqr->startdev;
1285         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1286                 DBF_DEV_EVENT(DBF_WARNING, device,
1287                             " dasd_ccw_req 0x%08x magic doesn't match"
1288                             " discipline 0x%08x",
1289                             cqr->magic,
1290                             *(unsigned int *) device->discipline->name);
1291                 return -EINVAL;
1292         }
1293         return 0;
1294 }
1295
1296 /*
1297  * Terminate the current i/o and set the request to clear_pending.
1298  * Timer keeps device runnig.
1299  * ccw_device_clear can fail if the i/o subsystem
1300  * is in a bad mood.
1301  */
1302 int dasd_term_IO(struct dasd_ccw_req *cqr)
1303 {
1304         struct dasd_device *device;
1305         int retries, rc;
1306         char errorstring[ERRORLENGTH];
1307
1308         /* Check the cqr */
1309         rc = dasd_check_cqr(cqr);
1310         if (rc)
1311                 return rc;
1312         retries = 0;
1313         device = (struct dasd_device *) cqr->startdev;
1314         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1315                 rc = ccw_device_clear(device->cdev, (long) cqr);
1316                 switch (rc) {
1317                 case 0: /* termination successful */
1318                         cqr->status = DASD_CQR_CLEAR_PENDING;
1319                         cqr->stopclk = get_tod_clock();
1320                         cqr->starttime = 0;
1321                         DBF_DEV_EVENT(DBF_DEBUG, device,
1322                                       "terminate cqr %p successful",
1323                                       cqr);
1324                         break;
1325                 case -ENODEV:
1326                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1327                                       "device gone, retry");
1328                         break;
1329                 case -EINVAL:
1330                         /*
1331                          * device not valid so no I/O could be running
1332                          * handle CQR as termination successful
1333                          */
1334                         cqr->status = DASD_CQR_CLEARED;
1335                         cqr->stopclk = get_tod_clock();
1336                         cqr->starttime = 0;
1337                         /* no retries for invalid devices */
1338                         cqr->retries = -1;
1339                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1340                                       "EINVAL, handle as terminated");
1341                         /* fake rc to success */
1342                         rc = 0;
1343                         break;
1344                 default:
1345                         /* internal error 10 - unknown rc*/
1346                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1347                         dev_err(&device->cdev->dev, "An error occurred in the "
1348                                 "DASD device driver, reason=%s\n", errorstring);
1349                         BUG();
1350                         break;
1351                 }
1352                 retries++;
1353         }
1354         dasd_schedule_device_bh(device);
1355         return rc;
1356 }
1357 EXPORT_SYMBOL(dasd_term_IO);
1358
1359 /*
1360  * Start the i/o. This start_IO can fail if the channel is really busy.
1361  * In that case set up a timer to start the request later.
1362  */
1363 int dasd_start_IO(struct dasd_ccw_req *cqr)
1364 {
1365         struct dasd_device *device;
1366         int rc;
1367         char errorstring[ERRORLENGTH];
1368
1369         /* Check the cqr */
1370         rc = dasd_check_cqr(cqr);
1371         if (rc) {
1372                 cqr->intrc = rc;
1373                 return rc;
1374         }
1375         device = (struct dasd_device *) cqr->startdev;
1376         if (((cqr->block &&
1377               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1378              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1379             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1380                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1381                               "because of stolen lock", cqr);
1382                 cqr->status = DASD_CQR_ERROR;
1383                 cqr->intrc = -EPERM;
1384                 return -EPERM;
1385         }
1386         if (cqr->retries < 0) {
1387                 /* internal error 14 - start_IO run out of retries */
1388                 sprintf(errorstring, "14 %p", cqr);
1389                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1390                         "device driver, reason=%s\n", errorstring);
1391                 cqr->status = DASD_CQR_ERROR;
1392                 return -EIO;
1393         }
1394         cqr->startclk = get_tod_clock();
1395         cqr->starttime = jiffies;
1396         cqr->retries--;
1397         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1398                 cqr->lpm &= dasd_path_get_opm(device);
1399                 if (!cqr->lpm)
1400                         cqr->lpm = dasd_path_get_opm(device);
1401         }
1402         /*
1403          * remember the amount of formatted tracks to prevent double format on
1404          * ESE devices
1405          */
1406         if (cqr->block)
1407                 cqr->trkcount = atomic_read(&cqr->block->trkcount);
1408
1409         if (cqr->cpmode == 1) {
1410                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1411                                          (long) cqr, cqr->lpm);
1412         } else {
1413                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1414                                       (long) cqr, cqr->lpm, 0);
1415         }
1416         switch (rc) {
1417         case 0:
1418                 cqr->status = DASD_CQR_IN_IO;
1419                 break;
1420         case -EBUSY:
1421                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1422                               "start_IO: device busy, retry later");
1423                 break;
1424         case -EACCES:
1425                 /* -EACCES indicates that the request used only a subset of the
1426                  * available paths and all these paths are gone. If the lpm of
1427                  * this request was only a subset of the opm (e.g. the ppm) then
1428                  * we just do a retry with all available paths.
1429                  * If we already use the full opm, something is amiss, and we
1430                  * need a full path verification.
1431                  */
1432                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1433                         DBF_DEV_EVENT(DBF_WARNING, device,
1434                                       "start_IO: selected paths gone (%x)",
1435                                       cqr->lpm);
1436                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1437                         cqr->lpm = dasd_path_get_opm(device);
1438                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1439                                       "start_IO: selected paths gone,"
1440                                       " retry on all paths");
1441                 } else {
1442                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1443                                       "start_IO: all paths in opm gone,"
1444                                       " do path verification");
1445                         dasd_generic_last_path_gone(device);
1446                         dasd_path_no_path(device);
1447                         dasd_path_set_tbvpm(device,
1448                                           ccw_device_get_path_mask(
1449                                                   device->cdev));
1450                 }
1451                 break;
1452         case -ENODEV:
1453                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1454                               "start_IO: -ENODEV device gone, retry");
1455                 /* this is equivalent to CC=3 for SSCH report this to EER */
1456                 dasd_handle_autoquiesce(device, cqr, DASD_EER_STARTIO);
1457                 break;
1458         case -EIO:
1459                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1460                               "start_IO: -EIO device gone, retry");
1461                 break;
1462         case -EINVAL:
1463                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1464                               "start_IO: -EINVAL device currently "
1465                               "not accessible");
1466                 break;
1467         default:
1468                 /* internal error 11 - unknown rc */
1469                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1470                 dev_err(&device->cdev->dev,
1471                         "An error occurred in the DASD device driver, "
1472                         "reason=%s\n", errorstring);
1473                 BUG();
1474                 break;
1475         }
1476         cqr->intrc = rc;
1477         return rc;
1478 }
1479 EXPORT_SYMBOL(dasd_start_IO);
1480
1481 /*
1482  * Timeout function for dasd devices. This is used for different purposes
1483  *  1) missing interrupt handler for normal operation
1484  *  2) delayed start of request where start_IO failed with -EBUSY
1485  *  3) timeout for missing state change interrupts
1486  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1487  * DASD_CQR_QUEUED for 2) and 3).
1488  */
1489 static void dasd_device_timeout(struct timer_list *t)
1490 {
1491         unsigned long flags;
1492         struct dasd_device *device;
1493
1494         device = from_timer(device, t, timer);
1495         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1496         /* re-activate request queue */
1497         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1498         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1499         dasd_schedule_device_bh(device);
1500 }
1501
1502 /*
1503  * Setup timeout for a device in jiffies.
1504  */
1505 void dasd_device_set_timer(struct dasd_device *device, int expires)
1506 {
1507         if (expires == 0)
1508                 del_timer(&device->timer);
1509         else
1510                 mod_timer(&device->timer, jiffies + expires);
1511 }
1512 EXPORT_SYMBOL(dasd_device_set_timer);
1513
1514 /*
1515  * Clear timeout for a device.
1516  */
1517 void dasd_device_clear_timer(struct dasd_device *device)
1518 {
1519         del_timer(&device->timer);
1520 }
1521 EXPORT_SYMBOL(dasd_device_clear_timer);
1522
1523 static void dasd_handle_killed_request(struct ccw_device *cdev,
1524                                        unsigned long intparm)
1525 {
1526         struct dasd_ccw_req *cqr;
1527         struct dasd_device *device;
1528
1529         if (!intparm)
1530                 return;
1531         cqr = (struct dasd_ccw_req *) intparm;
1532         if (cqr->status != DASD_CQR_IN_IO) {
1533                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1534                                 "invalid status in handle_killed_request: "
1535                                 "%02x", cqr->status);
1536                 return;
1537         }
1538
1539         device = dasd_device_from_cdev_locked(cdev);
1540         if (IS_ERR(device)) {
1541                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1542                                 "unable to get device from cdev");
1543                 return;
1544         }
1545
1546         if (!cqr->startdev ||
1547             device != cqr->startdev ||
1548             strncmp(cqr->startdev->discipline->ebcname,
1549                     (char *) &cqr->magic, 4)) {
1550                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1551                                 "invalid device in request");
1552                 dasd_put_device(device);
1553                 return;
1554         }
1555
1556         /* Schedule request to be retried. */
1557         cqr->status = DASD_CQR_QUEUED;
1558
1559         dasd_device_clear_timer(device);
1560         dasd_schedule_device_bh(device);
1561         dasd_put_device(device);
1562 }
1563
1564 void dasd_generic_handle_state_change(struct dasd_device *device)
1565 {
1566         /* First of all start sense subsystem status request. */
1567         dasd_eer_snss(device);
1568
1569         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1570         dasd_schedule_device_bh(device);
1571         if (device->block) {
1572                 dasd_schedule_block_bh(device->block);
1573                 if (device->block->gdp)
1574                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
1575         }
1576 }
1577 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1578
1579 static int dasd_check_hpf_error(struct irb *irb)
1580 {
1581         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1582             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1583              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1584 }
1585
1586 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1587 {
1588         struct dasd_device *device = NULL;
1589         u8 *sense = NULL;
1590
1591         if (!block)
1592                 return 0;
1593         device = block->base;
1594         if (!device || !device->discipline->is_ese)
1595                 return 0;
1596         if (!device->discipline->is_ese(device))
1597                 return 0;
1598
1599         sense = dasd_get_sense(irb);
1600         if (!sense)
1601                 return 0;
1602
1603         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1604                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1605                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1606 }
1607
1608 static int dasd_ese_oos_cond(u8 *sense)
1609 {
1610         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1611                 sense[1] & SNS1_PERM_ERR &&
1612                 sense[1] & SNS1_WRITE_INHIBITED &&
1613                 sense[25] == 0x01;
1614 }
1615
1616 /*
1617  * Interrupt handler for "normal" ssch-io based dasd devices.
1618  */
1619 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1620                       struct irb *irb)
1621 {
1622         struct dasd_ccw_req *cqr, *next, *fcqr;
1623         struct dasd_device *device;
1624         unsigned long now;
1625         int nrf_suppressed = 0;
1626         int fp_suppressed = 0;
1627         struct request *req;
1628         u8 *sense = NULL;
1629         int expires;
1630
1631         cqr = (struct dasd_ccw_req *) intparm;
1632         if (IS_ERR(irb)) {
1633                 switch (PTR_ERR(irb)) {
1634                 case -EIO:
1635                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1636                                 device = cqr->startdev;
1637                                 cqr->status = DASD_CQR_CLEARED;
1638                                 dasd_device_clear_timer(device);
1639                                 wake_up(&dasd_flush_wq);
1640                                 dasd_schedule_device_bh(device);
1641                                 return;
1642                         }
1643                         break;
1644                 case -ETIMEDOUT:
1645                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1646                                         "request timed out\n", __func__);
1647                         break;
1648                 default:
1649                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1650                                         "unknown error %ld\n", __func__,
1651                                         PTR_ERR(irb));
1652                 }
1653                 dasd_handle_killed_request(cdev, intparm);
1654                 return;
1655         }
1656
1657         now = get_tod_clock();
1658         /* check for conditions that should be handled immediately */
1659         if (!cqr ||
1660             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1661               scsw_cstat(&irb->scsw) == 0)) {
1662                 if (cqr)
1663                         memcpy(&cqr->irb, irb, sizeof(*irb));
1664                 device = dasd_device_from_cdev_locked(cdev);
1665                 if (IS_ERR(device))
1666                         return;
1667                 /* ignore unsolicited interrupts for DIAG discipline */
1668                 if (device->discipline == dasd_diag_discipline_pointer) {
1669                         dasd_put_device(device);
1670                         return;
1671                 }
1672
1673                 /*
1674                  * In some cases 'File Protected' or 'No Record Found' errors
1675                  * might be expected and debug log messages for the
1676                  * corresponding interrupts shouldn't be written then.
1677                  * Check if either of the according suppress bits is set.
1678                  */
1679                 sense = dasd_get_sense(irb);
1680                 if (sense) {
1681                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1682                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1683                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1684                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1685
1686                         /*
1687                          * Extent pool probably out-of-space.
1688                          * Stop device and check exhaust level.
1689                          */
1690                         if (dasd_ese_oos_cond(sense)) {
1691                                 dasd_generic_space_exhaust(device, cqr);
1692                                 device->discipline->ext_pool_exhaust(device, cqr);
1693                                 dasd_put_device(device);
1694                                 return;
1695                         }
1696                 }
1697                 if (!(fp_suppressed || nrf_suppressed))
1698                         device->discipline->dump_sense_dbf(device, irb, "int");
1699
1700                 if (device->features & DASD_FEATURE_ERPLOG)
1701                         device->discipline->dump_sense(device, cqr, irb);
1702                 device->discipline->check_for_device_change(device, cqr, irb);
1703                 dasd_put_device(device);
1704         }
1705
1706         /* check for attention message */
1707         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1708                 device = dasd_device_from_cdev_locked(cdev);
1709                 if (!IS_ERR(device)) {
1710                         device->discipline->check_attention(device,
1711                                                             irb->esw.esw1.lpum);
1712                         dasd_put_device(device);
1713                 }
1714         }
1715
1716         if (!cqr)
1717                 return;
1718
1719         device = (struct dasd_device *) cqr->startdev;
1720         if (!device ||
1721             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1722                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1723                                 "invalid device in request");
1724                 return;
1725         }
1726
1727         if (dasd_ese_needs_format(cqr->block, irb)) {
1728                 req = dasd_get_callback_data(cqr);
1729                 if (!req) {
1730                         cqr->status = DASD_CQR_ERROR;
1731                         return;
1732                 }
1733                 if (rq_data_dir(req) == READ) {
1734                         device->discipline->ese_read(cqr, irb);
1735                         cqr->status = DASD_CQR_SUCCESS;
1736                         cqr->stopclk = now;
1737                         dasd_device_clear_timer(device);
1738                         dasd_schedule_device_bh(device);
1739                         return;
1740                 }
1741                 fcqr = device->discipline->ese_format(device, cqr, irb);
1742                 if (IS_ERR(fcqr)) {
1743                         if (PTR_ERR(fcqr) == -EINVAL) {
1744                                 cqr->status = DASD_CQR_ERROR;
1745                                 return;
1746                         }
1747                         /*
1748                          * If we can't format now, let the request go
1749                          * one extra round. Maybe we can format later.
1750                          */
1751                         cqr->status = DASD_CQR_QUEUED;
1752                         dasd_schedule_device_bh(device);
1753                         return;
1754                 } else {
1755                         fcqr->status = DASD_CQR_QUEUED;
1756                         cqr->status = DASD_CQR_QUEUED;
1757                         list_add(&fcqr->devlist, &device->ccw_queue);
1758                         dasd_schedule_device_bh(device);
1759                         return;
1760                 }
1761         }
1762
1763         /* Check for clear pending */
1764         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1765             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1766                 cqr->status = DASD_CQR_CLEARED;
1767                 dasd_device_clear_timer(device);
1768                 wake_up(&dasd_flush_wq);
1769                 dasd_schedule_device_bh(device);
1770                 return;
1771         }
1772
1773         /* check status - the request might have been killed by dyn detach */
1774         if (cqr->status != DASD_CQR_IN_IO) {
1775                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1776                               "status %02x", dev_name(&cdev->dev), cqr->status);
1777                 return;
1778         }
1779
1780         next = NULL;
1781         expires = 0;
1782         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1783             scsw_cstat(&irb->scsw) == 0) {
1784                 /* request was completed successfully */
1785                 cqr->status = DASD_CQR_SUCCESS;
1786                 cqr->stopclk = now;
1787                 /* Start first request on queue if possible -> fast_io. */
1788                 if (cqr->devlist.next != &device->ccw_queue) {
1789                         next = list_entry(cqr->devlist.next,
1790                                           struct dasd_ccw_req, devlist);
1791                 }
1792         } else {  /* error */
1793                 /* check for HPF error
1794                  * call discipline function to requeue all requests
1795                  * and disable HPF accordingly
1796                  */
1797                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1798                     device->discipline->handle_hpf_error)
1799                         device->discipline->handle_hpf_error(device, irb);
1800                 /*
1801                  * If we don't want complex ERP for this request, then just
1802                  * reset this and retry it in the fastpath
1803                  */
1804                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1805                     cqr->retries > 0) {
1806                         if (cqr->lpm == dasd_path_get_opm(device))
1807                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1808                                               "default ERP in fastpath "
1809                                               "(%i retries left)",
1810                                               cqr->retries);
1811                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1812                                 cqr->lpm = dasd_path_get_opm(device);
1813                         cqr->status = DASD_CQR_QUEUED;
1814                         next = cqr;
1815                 } else
1816                         cqr->status = DASD_CQR_ERROR;
1817         }
1818         if (next && (next->status == DASD_CQR_QUEUED) &&
1819             (!device->stopped)) {
1820                 if (device->discipline->start_IO(next) == 0)
1821                         expires = next->expires;
1822         }
1823         if (expires != 0)
1824                 dasd_device_set_timer(device, expires);
1825         else
1826                 dasd_device_clear_timer(device);
1827         dasd_schedule_device_bh(device);
1828 }
1829 EXPORT_SYMBOL(dasd_int_handler);
1830
1831 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1832 {
1833         struct dasd_device *device;
1834
1835         device = dasd_device_from_cdev_locked(cdev);
1836
1837         if (IS_ERR(device))
1838                 goto out;
1839         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1840            device->state != device->target ||
1841            !device->discipline->check_for_device_change){
1842                 dasd_put_device(device);
1843                 goto out;
1844         }
1845         if (device->discipline->dump_sense_dbf)
1846                 device->discipline->dump_sense_dbf(device, irb, "uc");
1847         device->discipline->check_for_device_change(device, NULL, irb);
1848         dasd_put_device(device);
1849 out:
1850         return UC_TODO_RETRY;
1851 }
1852 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1853
1854 /*
1855  * If we have an error on a dasd_block layer request then we cancel
1856  * and return all further requests from the same dasd_block as well.
1857  */
1858 static void __dasd_device_recovery(struct dasd_device *device,
1859                                    struct dasd_ccw_req *ref_cqr)
1860 {
1861         struct list_head *l, *n;
1862         struct dasd_ccw_req *cqr;
1863
1864         /*
1865          * only requeue request that came from the dasd_block layer
1866          */
1867         if (!ref_cqr->block)
1868                 return;
1869
1870         list_for_each_safe(l, n, &device->ccw_queue) {
1871                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1872                 if (cqr->status == DASD_CQR_QUEUED &&
1873                     ref_cqr->block == cqr->block) {
1874                         cqr->status = DASD_CQR_CLEARED;
1875                 }
1876         }
1877 };
1878
1879 /*
1880  * Remove those ccw requests from the queue that need to be returned
1881  * to the upper layer.
1882  */
1883 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1884                                             struct list_head *final_queue)
1885 {
1886         struct list_head *l, *n;
1887         struct dasd_ccw_req *cqr;
1888
1889         /* Process request with final status. */
1890         list_for_each_safe(l, n, &device->ccw_queue) {
1891                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1892
1893                 /* Skip any non-final request. */
1894                 if (cqr->status == DASD_CQR_QUEUED ||
1895                     cqr->status == DASD_CQR_IN_IO ||
1896                     cqr->status == DASD_CQR_CLEAR_PENDING)
1897                         continue;
1898                 if (cqr->status == DASD_CQR_ERROR) {
1899                         __dasd_device_recovery(device, cqr);
1900                 }
1901                 /* Rechain finished requests to final queue */
1902                 list_move_tail(&cqr->devlist, final_queue);
1903         }
1904 }
1905
1906 static void __dasd_process_cqr(struct dasd_device *device,
1907                                struct dasd_ccw_req *cqr)
1908 {
1909         char errorstring[ERRORLENGTH];
1910
1911         switch (cqr->status) {
1912         case DASD_CQR_SUCCESS:
1913                 cqr->status = DASD_CQR_DONE;
1914                 break;
1915         case DASD_CQR_ERROR:
1916                 cqr->status = DASD_CQR_NEED_ERP;
1917                 break;
1918         case DASD_CQR_CLEARED:
1919                 cqr->status = DASD_CQR_TERMINATED;
1920                 break;
1921         default:
1922                 /* internal error 12 - wrong cqr status*/
1923                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1924                 dev_err(&device->cdev->dev,
1925                         "An error occurred in the DASD device driver, "
1926                         "reason=%s\n", errorstring);
1927                 BUG();
1928         }
1929         if (cqr->callback)
1930                 cqr->callback(cqr, cqr->callback_data);
1931 }
1932
1933 /*
1934  * the cqrs from the final queue are returned to the upper layer
1935  * by setting a dasd_block state and calling the callback function
1936  */
1937 static void __dasd_device_process_final_queue(struct dasd_device *device,
1938                                               struct list_head *final_queue)
1939 {
1940         struct list_head *l, *n;
1941         struct dasd_ccw_req *cqr;
1942         struct dasd_block *block;
1943
1944         list_for_each_safe(l, n, final_queue) {
1945                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1946                 list_del_init(&cqr->devlist);
1947                 block = cqr->block;
1948                 if (!block) {
1949                         __dasd_process_cqr(device, cqr);
1950                 } else {
1951                         spin_lock_bh(&block->queue_lock);
1952                         __dasd_process_cqr(device, cqr);
1953                         spin_unlock_bh(&block->queue_lock);
1954                 }
1955         }
1956 }
1957
1958 /*
1959  * check if device should be autoquiesced due to too many timeouts
1960  */
1961 static void __dasd_device_check_autoquiesce_timeout(struct dasd_device *device,
1962                                                     struct dasd_ccw_req *cqr)
1963 {
1964         if ((device->default_retries - cqr->retries) >= device->aq_timeouts)
1965                 dasd_handle_autoquiesce(device, cqr, DASD_EER_TIMEOUTS);
1966 }
1967
1968 /*
1969  * Take a look at the first request on the ccw queue and check
1970  * if it reached its expire time. If so, terminate the IO.
1971  */
1972 static void __dasd_device_check_expire(struct dasd_device *device)
1973 {
1974         struct dasd_ccw_req *cqr;
1975
1976         if (list_empty(&device->ccw_queue))
1977                 return;
1978         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1979         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1980             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1981                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1982                         /*
1983                          * IO in safe offline processing should not
1984                          * run out of retries
1985                          */
1986                         cqr->retries++;
1987                 }
1988                 if (device->discipline->term_IO(cqr) != 0) {
1989                         /* Hmpf, try again in 5 sec */
1990                         dev_err(&device->cdev->dev,
1991                                 "cqr %p timed out (%lus) but cannot be "
1992                                 "ended, retrying in 5 s\n",
1993                                 cqr, (cqr->expires/HZ));
1994                         cqr->expires += 5*HZ;
1995                         dasd_device_set_timer(device, 5*HZ);
1996                 } else {
1997                         dev_err(&device->cdev->dev,
1998                                 "cqr %p timed out (%lus), %i retries "
1999                                 "remaining\n", cqr, (cqr->expires/HZ),
2000                                 cqr->retries);
2001                 }
2002                 __dasd_device_check_autoquiesce_timeout(device, cqr);
2003         }
2004 }
2005
2006 /*
2007  * return 1 when device is not eligible for IO
2008  */
2009 static int __dasd_device_is_unusable(struct dasd_device *device,
2010                                      struct dasd_ccw_req *cqr)
2011 {
2012         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
2013
2014         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2015             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2016                 /*
2017                  * dasd is being set offline
2018                  * but it is no safe offline where we have to allow I/O
2019                  */
2020                 return 1;
2021         }
2022         if (device->stopped) {
2023                 if (device->stopped & mask) {
2024                         /* stopped and CQR will not change that. */
2025                         return 1;
2026                 }
2027                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2028                         /* CQR is not able to change device to
2029                          * operational. */
2030                         return 1;
2031                 }
2032                 /* CQR required to get device operational. */
2033         }
2034         return 0;
2035 }
2036
2037 /*
2038  * Take a look at the first request on the ccw queue and check
2039  * if it needs to be started.
2040  */
2041 static void __dasd_device_start_head(struct dasd_device *device)
2042 {
2043         struct dasd_ccw_req *cqr;
2044         int rc;
2045
2046         if (list_empty(&device->ccw_queue))
2047                 return;
2048         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2049         if (cqr->status != DASD_CQR_QUEUED)
2050                 return;
2051         /* if device is not usable return request to upper layer */
2052         if (__dasd_device_is_unusable(device, cqr)) {
2053                 cqr->intrc = -EAGAIN;
2054                 cqr->status = DASD_CQR_CLEARED;
2055                 dasd_schedule_device_bh(device);
2056                 return;
2057         }
2058
2059         rc = device->discipline->start_IO(cqr);
2060         if (rc == 0)
2061                 dasd_device_set_timer(device, cqr->expires);
2062         else if (rc == -EACCES) {
2063                 dasd_schedule_device_bh(device);
2064         } else
2065                 /* Hmpf, try again in 1/2 sec */
2066                 dasd_device_set_timer(device, 50);
2067 }
2068
2069 static void __dasd_device_check_path_events(struct dasd_device *device)
2070 {
2071         __u8 tbvpm, fcsecpm;
2072         int rc;
2073
2074         tbvpm = dasd_path_get_tbvpm(device);
2075         fcsecpm = dasd_path_get_fcsecpm(device);
2076
2077         if (!tbvpm && !fcsecpm)
2078                 return;
2079
2080         if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2081                 return;
2082
2083         dasd_path_clear_all_verify(device);
2084         dasd_path_clear_all_fcsec(device);
2085
2086         rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
2087         if (rc) {
2088                 dasd_path_add_tbvpm(device, tbvpm);
2089                 dasd_path_add_fcsecpm(device, fcsecpm);
2090                 dasd_device_set_timer(device, 50);
2091         }
2092 };
2093
2094 /*
2095  * Go through all request on the dasd_device request queue,
2096  * terminate them on the cdev if necessary, and return them to the
2097  * submitting layer via callback.
2098  * Note:
2099  * Make sure that all 'submitting layers' still exist when
2100  * this function is called!. In other words, when 'device' is a base
2101  * device then all block layer requests must have been removed before
2102  * via dasd_flush_block_queue.
2103  */
2104 int dasd_flush_device_queue(struct dasd_device *device)
2105 {
2106         struct dasd_ccw_req *cqr, *n;
2107         int rc;
2108         struct list_head flush_queue;
2109
2110         INIT_LIST_HEAD(&flush_queue);
2111         spin_lock_irq(get_ccwdev_lock(device->cdev));
2112         rc = 0;
2113         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2114                 /* Check status and move request to flush_queue */
2115                 switch (cqr->status) {
2116                 case DASD_CQR_IN_IO:
2117                         rc = device->discipline->term_IO(cqr);
2118                         if (rc) {
2119                                 /* unable to terminate requeust */
2120                                 dev_err(&device->cdev->dev,
2121                                         "Flushing the DASD request queue "
2122                                         "failed for request %p\n", cqr);
2123                                 /* stop flush processing */
2124                                 goto finished;
2125                         }
2126                         break;
2127                 case DASD_CQR_QUEUED:
2128                         cqr->stopclk = get_tod_clock();
2129                         cqr->status = DASD_CQR_CLEARED;
2130                         break;
2131                 default: /* no need to modify the others */
2132                         break;
2133                 }
2134                 list_move_tail(&cqr->devlist, &flush_queue);
2135         }
2136 finished:
2137         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2138         /*
2139          * After this point all requests must be in state CLEAR_PENDING,
2140          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2141          * one of the others.
2142          */
2143         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2144                 wait_event(dasd_flush_wq,
2145                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2146         /*
2147          * Now set each request back to TERMINATED, DONE or NEED_ERP
2148          * and call the callback function of flushed requests
2149          */
2150         __dasd_device_process_final_queue(device, &flush_queue);
2151         return rc;
2152 }
2153 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2154
2155 /*
2156  * Acquire the device lock and process queues for the device.
2157  */
2158 static void dasd_device_tasklet(unsigned long data)
2159 {
2160         struct dasd_device *device = (struct dasd_device *) data;
2161         struct list_head final_queue;
2162
2163         atomic_set (&device->tasklet_scheduled, 0);
2164         INIT_LIST_HEAD(&final_queue);
2165         spin_lock_irq(get_ccwdev_lock(device->cdev));
2166         /* Check expire time of first request on the ccw queue. */
2167         __dasd_device_check_expire(device);
2168         /* find final requests on ccw queue */
2169         __dasd_device_process_ccw_queue(device, &final_queue);
2170         __dasd_device_check_path_events(device);
2171         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2172         /* Now call the callback function of requests with final status */
2173         __dasd_device_process_final_queue(device, &final_queue);
2174         spin_lock_irq(get_ccwdev_lock(device->cdev));
2175         /* Now check if the head of the ccw queue needs to be started. */
2176         __dasd_device_start_head(device);
2177         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2178         if (waitqueue_active(&shutdown_waitq))
2179                 wake_up(&shutdown_waitq);
2180         dasd_put_device(device);
2181 }
2182
2183 /*
2184  * Schedules a call to dasd_tasklet over the device tasklet.
2185  */
2186 void dasd_schedule_device_bh(struct dasd_device *device)
2187 {
2188         /* Protect against rescheduling. */
2189         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2190                 return;
2191         dasd_get_device(device);
2192         tasklet_hi_schedule(&device->tasklet);
2193 }
2194 EXPORT_SYMBOL(dasd_schedule_device_bh);
2195
2196 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2197 {
2198         device->stopped |= bits;
2199 }
2200 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2201
2202 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2203 {
2204         device->stopped &= ~bits;
2205         if (!device->stopped)
2206                 wake_up(&generic_waitq);
2207 }
2208 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2209
2210 /*
2211  * Queue a request to the head of the device ccw_queue.
2212  * Start the I/O if possible.
2213  */
2214 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2215 {
2216         struct dasd_device *device;
2217         unsigned long flags;
2218
2219         device = cqr->startdev;
2220         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2221         cqr->status = DASD_CQR_QUEUED;
2222         list_add(&cqr->devlist, &device->ccw_queue);
2223         /* let the bh start the request to keep them in order */
2224         dasd_schedule_device_bh(device);
2225         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2226 }
2227 EXPORT_SYMBOL(dasd_add_request_head);
2228
2229 /*
2230  * Queue a request to the tail of the device ccw_queue.
2231  * Start the I/O if possible.
2232  */
2233 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2234 {
2235         struct dasd_device *device;
2236         unsigned long flags;
2237
2238         device = cqr->startdev;
2239         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2240         cqr->status = DASD_CQR_QUEUED;
2241         list_add_tail(&cqr->devlist, &device->ccw_queue);
2242         /* let the bh start the request to keep them in order */
2243         dasd_schedule_device_bh(device);
2244         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2245 }
2246 EXPORT_SYMBOL(dasd_add_request_tail);
2247
2248 /*
2249  * Wakeup helper for the 'sleep_on' functions.
2250  */
2251 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2252 {
2253         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2254         cqr->callback_data = DASD_SLEEPON_END_TAG;
2255         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2256         wake_up(&generic_waitq);
2257 }
2258 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2259
2260 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2261 {
2262         struct dasd_device *device;
2263         int rc;
2264
2265         device = cqr->startdev;
2266         spin_lock_irq(get_ccwdev_lock(device->cdev));
2267         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2268         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2269         return rc;
2270 }
2271
2272 /*
2273  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2274  */
2275 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2276 {
2277         struct dasd_device *device;
2278         dasd_erp_fn_t erp_fn;
2279
2280         if (cqr->status == DASD_CQR_FILLED)
2281                 return 0;
2282         device = cqr->startdev;
2283         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2284                 if (cqr->status == DASD_CQR_TERMINATED) {
2285                         device->discipline->handle_terminated_request(cqr);
2286                         return 1;
2287                 }
2288                 if (cqr->status == DASD_CQR_NEED_ERP) {
2289                         erp_fn = device->discipline->erp_action(cqr);
2290                         erp_fn(cqr);
2291                         return 1;
2292                 }
2293                 if (cqr->status == DASD_CQR_FAILED)
2294                         dasd_log_sense(cqr, &cqr->irb);
2295                 if (cqr->refers) {
2296                         __dasd_process_erp(device, cqr);
2297                         return 1;
2298                 }
2299         }
2300         return 0;
2301 }
2302
2303 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2304 {
2305         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2306                 if (cqr->refers) /* erp is not done yet */
2307                         return 1;
2308                 return ((cqr->status != DASD_CQR_DONE) &&
2309                         (cqr->status != DASD_CQR_FAILED));
2310         } else
2311                 return (cqr->status == DASD_CQR_FILLED);
2312 }
2313
2314 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2315 {
2316         struct dasd_device *device;
2317         int rc;
2318         struct list_head ccw_queue;
2319         struct dasd_ccw_req *cqr;
2320
2321         INIT_LIST_HEAD(&ccw_queue);
2322         maincqr->status = DASD_CQR_FILLED;
2323         device = maincqr->startdev;
2324         list_add(&maincqr->blocklist, &ccw_queue);
2325         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2326              cqr = list_first_entry(&ccw_queue,
2327                                     struct dasd_ccw_req, blocklist)) {
2328
2329                 if (__dasd_sleep_on_erp(cqr))
2330                         continue;
2331                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2332                         continue;
2333                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2334                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2335                         cqr->status = DASD_CQR_FAILED;
2336                         cqr->intrc = -EPERM;
2337                         continue;
2338                 }
2339                 /* Non-temporary stop condition will trigger fail fast */
2340                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2341                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2342                     !dasd_eer_enabled(device) && device->aq_mask == 0) {
2343                         cqr->status = DASD_CQR_FAILED;
2344                         cqr->intrc = -ENOLINK;
2345                         continue;
2346                 }
2347                 /*
2348                  * Don't try to start requests if device is in
2349                  * offline processing, it might wait forever
2350                  */
2351                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2352                         cqr->status = DASD_CQR_FAILED;
2353                         cqr->intrc = -ENODEV;
2354                         continue;
2355                 }
2356                 /*
2357                  * Don't try to start requests if device is stopped
2358                  * except path verification requests
2359                  */
2360                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2361                         if (interruptible) {
2362                                 rc = wait_event_interruptible(
2363                                         generic_waitq, !(device->stopped));
2364                                 if (rc == -ERESTARTSYS) {
2365                                         cqr->status = DASD_CQR_FAILED;
2366                                         maincqr->intrc = rc;
2367                                         continue;
2368                                 }
2369                         } else
2370                                 wait_event(generic_waitq, !(device->stopped));
2371                 }
2372                 if (!cqr->callback)
2373                         cqr->callback = dasd_wakeup_cb;
2374
2375                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2376                 dasd_add_request_tail(cqr);
2377                 if (interruptible) {
2378                         rc = wait_event_interruptible(
2379                                 generic_waitq, _wait_for_wakeup(cqr));
2380                         if (rc == -ERESTARTSYS) {
2381                                 dasd_cancel_req(cqr);
2382                                 /* wait (non-interruptible) for final status */
2383                                 wait_event(generic_waitq,
2384                                            _wait_for_wakeup(cqr));
2385                                 cqr->status = DASD_CQR_FAILED;
2386                                 maincqr->intrc = rc;
2387                                 continue;
2388                         }
2389                 } else
2390                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2391         }
2392
2393         maincqr->endclk = get_tod_clock();
2394         if ((maincqr->status != DASD_CQR_DONE) &&
2395             (maincqr->intrc != -ERESTARTSYS))
2396                 dasd_log_sense(maincqr, &maincqr->irb);
2397         if (maincqr->status == DASD_CQR_DONE)
2398                 rc = 0;
2399         else if (maincqr->intrc)
2400                 rc = maincqr->intrc;
2401         else
2402                 rc = -EIO;
2403         return rc;
2404 }
2405
2406 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2407 {
2408         struct dasd_ccw_req *cqr;
2409
2410         list_for_each_entry(cqr, ccw_queue, blocklist) {
2411                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2412                         return 0;
2413         }
2414
2415         return 1;
2416 }
2417
2418 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2419 {
2420         struct dasd_device *device;
2421         struct dasd_ccw_req *cqr, *n;
2422         u8 *sense = NULL;
2423         int rc;
2424
2425 retry:
2426         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2427                 device = cqr->startdev;
2428                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2429                         continue;
2430
2431                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2432                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2433                         cqr->status = DASD_CQR_FAILED;
2434                         cqr->intrc = -EPERM;
2435                         continue;
2436                 }
2437                 /*Non-temporary stop condition will trigger fail fast*/
2438                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2439                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2440                     !dasd_eer_enabled(device)) {
2441                         cqr->status = DASD_CQR_FAILED;
2442                         cqr->intrc = -EAGAIN;
2443                         continue;
2444                 }
2445
2446                 /*Don't try to start requests if device is stopped*/
2447                 if (interruptible) {
2448                         rc = wait_event_interruptible(
2449                                 generic_waitq, !device->stopped);
2450                         if (rc == -ERESTARTSYS) {
2451                                 cqr->status = DASD_CQR_FAILED;
2452                                 cqr->intrc = rc;
2453                                 continue;
2454                         }
2455                 } else
2456                         wait_event(generic_waitq, !(device->stopped));
2457
2458                 if (!cqr->callback)
2459                         cqr->callback = dasd_wakeup_cb;
2460                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2461                 dasd_add_request_tail(cqr);
2462         }
2463
2464         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2465
2466         rc = 0;
2467         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2468                 /*
2469                  * In some cases the 'File Protected' or 'Incorrect Length'
2470                  * error might be expected and error recovery would be
2471                  * unnecessary in these cases.  Check if the according suppress
2472                  * bit is set.
2473                  */
2474                 sense = dasd_get_sense(&cqr->irb);
2475                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2476                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2477                         continue;
2478                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2479                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2480                         continue;
2481
2482                 /*
2483                  * for alias devices simplify error recovery and
2484                  * return to upper layer
2485                  * do not skip ERP requests
2486                  */
2487                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2488                     (cqr->status == DASD_CQR_TERMINATED ||
2489                      cqr->status == DASD_CQR_NEED_ERP))
2490                         return -EAGAIN;
2491
2492                 /* normal recovery for basedev IO */
2493                 if (__dasd_sleep_on_erp(cqr))
2494                         /* handle erp first */
2495                         goto retry;
2496         }
2497
2498         return 0;
2499 }
2500
2501 /*
2502  * Queue a request to the tail of the device ccw_queue and wait for
2503  * it's completion.
2504  */
2505 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2506 {
2507         return _dasd_sleep_on(cqr, 0);
2508 }
2509 EXPORT_SYMBOL(dasd_sleep_on);
2510
2511 /*
2512  * Start requests from a ccw_queue and wait for their completion.
2513  */
2514 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2515 {
2516         return _dasd_sleep_on_queue(ccw_queue, 0);
2517 }
2518 EXPORT_SYMBOL(dasd_sleep_on_queue);
2519
2520 /*
2521  * Start requests from a ccw_queue and wait interruptible for their completion.
2522  */
2523 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2524 {
2525         return _dasd_sleep_on_queue(ccw_queue, 1);
2526 }
2527 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2528
2529 /*
2530  * Queue a request to the tail of the device ccw_queue and wait
2531  * interruptible for it's completion.
2532  */
2533 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2534 {
2535         return _dasd_sleep_on(cqr, 1);
2536 }
2537 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2538
2539 /*
2540  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2541  * for eckd devices) the currently running request has to be terminated
2542  * and be put back to status queued, before the special request is added
2543  * to the head of the queue. Then the special request is waited on normally.
2544  */
2545 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2546 {
2547         struct dasd_ccw_req *cqr;
2548         int rc;
2549
2550         if (list_empty(&device->ccw_queue))
2551                 return 0;
2552         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2553         rc = device->discipline->term_IO(cqr);
2554         if (!rc)
2555                 /*
2556                  * CQR terminated because a more important request is pending.
2557                  * Undo decreasing of retry counter because this is
2558                  * not an error case.
2559                  */
2560                 cqr->retries++;
2561         return rc;
2562 }
2563
2564 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2565 {
2566         struct dasd_device *device;
2567         int rc;
2568
2569         device = cqr->startdev;
2570         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2571             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2572                 cqr->status = DASD_CQR_FAILED;
2573                 cqr->intrc = -EPERM;
2574                 return -EIO;
2575         }
2576         spin_lock_irq(get_ccwdev_lock(device->cdev));
2577         rc = _dasd_term_running_cqr(device);
2578         if (rc) {
2579                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2580                 return rc;
2581         }
2582         cqr->callback = dasd_wakeup_cb;
2583         cqr->callback_data = DASD_SLEEPON_START_TAG;
2584         cqr->status = DASD_CQR_QUEUED;
2585         /*
2586          * add new request as second
2587          * first the terminated cqr needs to be finished
2588          */
2589         list_add(&cqr->devlist, device->ccw_queue.next);
2590
2591         /* let the bh start the request to keep them in order */
2592         dasd_schedule_device_bh(device);
2593
2594         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2595
2596         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2597
2598         if (cqr->status == DASD_CQR_DONE)
2599                 rc = 0;
2600         else if (cqr->intrc)
2601                 rc = cqr->intrc;
2602         else
2603                 rc = -EIO;
2604
2605         /* kick tasklets */
2606         dasd_schedule_device_bh(device);
2607         if (device->block)
2608                 dasd_schedule_block_bh(device->block);
2609
2610         return rc;
2611 }
2612 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2613
2614 /*
2615  * Cancels a request that was started with dasd_sleep_on_req.
2616  * This is useful to timeout requests. The request will be
2617  * terminated if it is currently in i/o.
2618  * Returns 0 if request termination was successful
2619  *         negative error code if termination failed
2620  * Cancellation of a request is an asynchronous operation! The calling
2621  * function has to wait until the request is properly returned via callback.
2622  */
2623 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2624 {
2625         struct dasd_device *device = cqr->startdev;
2626         int rc = 0;
2627
2628         switch (cqr->status) {
2629         case DASD_CQR_QUEUED:
2630                 /* request was not started - just set to cleared */
2631                 cqr->status = DASD_CQR_CLEARED;
2632                 break;
2633         case DASD_CQR_IN_IO:
2634                 /* request in IO - terminate IO and release again */
2635                 rc = device->discipline->term_IO(cqr);
2636                 if (rc) {
2637                         dev_err(&device->cdev->dev,
2638                                 "Cancelling request %p failed with rc=%d\n",
2639                                 cqr, rc);
2640                 } else {
2641                         cqr->stopclk = get_tod_clock();
2642                 }
2643                 break;
2644         default: /* already finished or clear pending - do nothing */
2645                 break;
2646         }
2647         dasd_schedule_device_bh(device);
2648         return rc;
2649 }
2650
2651 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2652 {
2653         struct dasd_device *device = cqr->startdev;
2654         unsigned long flags;
2655         int rc;
2656
2657         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2658         rc = __dasd_cancel_req(cqr);
2659         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2660         return rc;
2661 }
2662
2663 /*
2664  * SECTION: Operations of the dasd_block layer.
2665  */
2666
2667 /*
2668  * Timeout function for dasd_block. This is used when the block layer
2669  * is waiting for something that may not come reliably, (e.g. a state
2670  * change interrupt)
2671  */
2672 static void dasd_block_timeout(struct timer_list *t)
2673 {
2674         unsigned long flags;
2675         struct dasd_block *block;
2676
2677         block = from_timer(block, t, timer);
2678         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2679         /* re-activate request queue */
2680         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2681         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2682         dasd_schedule_block_bh(block);
2683         blk_mq_run_hw_queues(block->gdp->queue, true);
2684 }
2685
2686 /*
2687  * Setup timeout for a dasd_block in jiffies.
2688  */
2689 void dasd_block_set_timer(struct dasd_block *block, int expires)
2690 {
2691         if (expires == 0)
2692                 del_timer(&block->timer);
2693         else
2694                 mod_timer(&block->timer, jiffies + expires);
2695 }
2696 EXPORT_SYMBOL(dasd_block_set_timer);
2697
2698 /*
2699  * Clear timeout for a dasd_block.
2700  */
2701 void dasd_block_clear_timer(struct dasd_block *block)
2702 {
2703         del_timer(&block->timer);
2704 }
2705 EXPORT_SYMBOL(dasd_block_clear_timer);
2706
2707 /*
2708  * Process finished error recovery ccw.
2709  */
2710 static void __dasd_process_erp(struct dasd_device *device,
2711                                struct dasd_ccw_req *cqr)
2712 {
2713         dasd_erp_fn_t erp_fn;
2714
2715         if (cqr->status == DASD_CQR_DONE)
2716                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2717         else
2718                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2719         erp_fn = device->discipline->erp_postaction(cqr);
2720         erp_fn(cqr);
2721 }
2722
2723 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2724 {
2725         struct request *req;
2726         blk_status_t error = BLK_STS_OK;
2727         unsigned int proc_bytes;
2728         int status;
2729
2730         req = (struct request *) cqr->callback_data;
2731         dasd_profile_end(cqr->block, cqr, req);
2732
2733         proc_bytes = cqr->proc_bytes;
2734         status = cqr->block->base->discipline->free_cp(cqr, req);
2735         if (status < 0)
2736                 error = errno_to_blk_status(status);
2737         else if (status == 0) {
2738                 switch (cqr->intrc) {
2739                 case -EPERM:
2740                         /*
2741                          * DASD doesn't implement SCSI/NVMe reservations, but it
2742                          * implements a locking scheme similar to them. We
2743                          * return this error when we no longer have the lock.
2744                          */
2745                         error = BLK_STS_RESV_CONFLICT;
2746                         break;
2747                 case -ENOLINK:
2748                         error = BLK_STS_TRANSPORT;
2749                         break;
2750                 case -ETIMEDOUT:
2751                         error = BLK_STS_TIMEOUT;
2752                         break;
2753                 default:
2754                         error = BLK_STS_IOERR;
2755                         break;
2756                 }
2757         }
2758
2759         /*
2760          * We need to take care for ETIMEDOUT errors here since the
2761          * complete callback does not get called in this case.
2762          * Take care of all errors here and avoid additional code to
2763          * transfer the error value to the complete callback.
2764          */
2765         if (error) {
2766                 blk_mq_end_request(req, error);
2767                 blk_mq_run_hw_queues(req->q, true);
2768         } else {
2769                 /*
2770                  * Partial completed requests can happen with ESE devices.
2771                  * During read we might have gotten a NRF error and have to
2772                  * complete a request partially.
2773                  */
2774                 if (proc_bytes) {
2775                         blk_update_request(req, BLK_STS_OK, proc_bytes);
2776                         blk_mq_requeue_request(req, true);
2777                 } else if (likely(!blk_should_fake_timeout(req->q))) {
2778                         blk_mq_complete_request(req);
2779                 }
2780         }
2781 }
2782
2783 /*
2784  * Process ccw request queue.
2785  */
2786 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2787                                            struct list_head *final_queue)
2788 {
2789         struct list_head *l, *n;
2790         struct dasd_ccw_req *cqr;
2791         dasd_erp_fn_t erp_fn;
2792         unsigned long flags;
2793         struct dasd_device *base = block->base;
2794
2795 restart:
2796         /* Process request with final status. */
2797         list_for_each_safe(l, n, &block->ccw_queue) {
2798                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2799                 if (cqr->status != DASD_CQR_DONE &&
2800                     cqr->status != DASD_CQR_FAILED &&
2801                     cqr->status != DASD_CQR_NEED_ERP &&
2802                     cqr->status != DASD_CQR_TERMINATED)
2803                         continue;
2804
2805                 if (cqr->status == DASD_CQR_TERMINATED) {
2806                         base->discipline->handle_terminated_request(cqr);
2807                         goto restart;
2808                 }
2809
2810                 /*  Process requests that may be recovered */
2811                 if (cqr->status == DASD_CQR_NEED_ERP) {
2812                         erp_fn = base->discipline->erp_action(cqr);
2813                         if (IS_ERR(erp_fn(cqr)))
2814                                 continue;
2815                         goto restart;
2816                 }
2817
2818                 /* log sense for fatal error */
2819                 if (cqr->status == DASD_CQR_FAILED) {
2820                         dasd_log_sense(cqr, &cqr->irb);
2821                 }
2822
2823                 /*
2824                  * First call extended error reporting and check for autoquiesce
2825                  */
2826                 spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2827                 if (cqr->status == DASD_CQR_FAILED &&
2828                     dasd_handle_autoquiesce(base, cqr, DASD_EER_FATALERROR)) {
2829                         cqr->status = DASD_CQR_FILLED;
2830                         cqr->retries = 255;
2831                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2832                         goto restart;
2833                 }
2834                 spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2835
2836                 /* Process finished ERP request. */
2837                 if (cqr->refers) {
2838                         __dasd_process_erp(base, cqr);
2839                         goto restart;
2840                 }
2841
2842                 /* Rechain finished requests to final queue */
2843                 cqr->endclk = get_tod_clock();
2844                 list_move_tail(&cqr->blocklist, final_queue);
2845         }
2846 }
2847
2848 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2849 {
2850         dasd_schedule_block_bh(cqr->block);
2851 }
2852
2853 static void __dasd_block_start_head(struct dasd_block *block)
2854 {
2855         struct dasd_ccw_req *cqr;
2856
2857         if (list_empty(&block->ccw_queue))
2858                 return;
2859         /* We allways begin with the first requests on the queue, as some
2860          * of previously started requests have to be enqueued on a
2861          * dasd_device again for error recovery.
2862          */
2863         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2864                 if (cqr->status != DASD_CQR_FILLED)
2865                         continue;
2866                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2867                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2868                         cqr->status = DASD_CQR_FAILED;
2869                         cqr->intrc = -EPERM;
2870                         dasd_schedule_block_bh(block);
2871                         continue;
2872                 }
2873                 /* Non-temporary stop condition will trigger fail fast */
2874                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2875                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2876                     !dasd_eer_enabled(block->base) && block->base->aq_mask == 0) {
2877                         cqr->status = DASD_CQR_FAILED;
2878                         cqr->intrc = -ENOLINK;
2879                         dasd_schedule_block_bh(block);
2880                         continue;
2881                 }
2882                 /* Don't try to start requests if device is stopped */
2883                 if (block->base->stopped)
2884                         return;
2885
2886                 /* just a fail safe check, should not happen */
2887                 if (!cqr->startdev)
2888                         cqr->startdev = block->base;
2889
2890                 /* make sure that the requests we submit find their way back */
2891                 cqr->callback = dasd_return_cqr_cb;
2892
2893                 dasd_add_request_tail(cqr);
2894         }
2895 }
2896
2897 /*
2898  * Central dasd_block layer routine. Takes requests from the generic
2899  * block layer request queue, creates ccw requests, enqueues them on
2900  * a dasd_device and processes ccw requests that have been returned.
2901  */
2902 static void dasd_block_tasklet(unsigned long data)
2903 {
2904         struct dasd_block *block = (struct dasd_block *) data;
2905         struct list_head final_queue;
2906         struct list_head *l, *n;
2907         struct dasd_ccw_req *cqr;
2908         struct dasd_queue *dq;
2909
2910         atomic_set(&block->tasklet_scheduled, 0);
2911         INIT_LIST_HEAD(&final_queue);
2912         spin_lock_irq(&block->queue_lock);
2913         /* Finish off requests on ccw queue */
2914         __dasd_process_block_ccw_queue(block, &final_queue);
2915         spin_unlock_irq(&block->queue_lock);
2916
2917         /* Now call the callback function of requests with final status */
2918         list_for_each_safe(l, n, &final_queue) {
2919                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2920                 dq = cqr->dq;
2921                 spin_lock_irq(&dq->lock);
2922                 list_del_init(&cqr->blocklist);
2923                 __dasd_cleanup_cqr(cqr);
2924                 spin_unlock_irq(&dq->lock);
2925         }
2926
2927         spin_lock_irq(&block->queue_lock);
2928         /* Now check if the head of the ccw queue needs to be started. */
2929         __dasd_block_start_head(block);
2930         spin_unlock_irq(&block->queue_lock);
2931
2932         if (waitqueue_active(&shutdown_waitq))
2933                 wake_up(&shutdown_waitq);
2934         dasd_put_device(block->base);
2935 }
2936
2937 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2938 {
2939         wake_up(&dasd_flush_wq);
2940 }
2941
2942 /*
2943  * Requeue a request back to the block request queue
2944  * only works for block requests
2945  */
2946 static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
2947 {
2948         struct request *req;
2949
2950         /*
2951          * If the request is an ERP request there is nothing to requeue.
2952          * This will be done with the remaining original request.
2953          */
2954         if (cqr->refers)
2955                 return;
2956         spin_lock_irq(&cqr->dq->lock);
2957         req = (struct request *) cqr->callback_data;
2958         blk_mq_requeue_request(req, true);
2959         spin_unlock_irq(&cqr->dq->lock);
2960
2961         return;
2962 }
2963
2964 static int _dasd_requests_to_flushqueue(struct dasd_block *block,
2965                                         struct list_head *flush_queue)
2966 {
2967         struct dasd_ccw_req *cqr, *n;
2968         unsigned long flags;
2969         int rc, i;
2970
2971         spin_lock_irqsave(&block->queue_lock, flags);
2972         rc = 0;
2973 restart:
2974         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2975                 /* if this request currently owned by a dasd_device cancel it */
2976                 if (cqr->status >= DASD_CQR_QUEUED)
2977                         rc = dasd_cancel_req(cqr);
2978                 if (rc < 0)
2979                         break;
2980                 /* Rechain request (including erp chain) so it won't be
2981                  * touched by the dasd_block_tasklet anymore.
2982                  * Replace the callback so we notice when the request
2983                  * is returned from the dasd_device layer.
2984                  */
2985                 cqr->callback = _dasd_wake_block_flush_cb;
2986                 for (i = 0; cqr; cqr = cqr->refers, i++)
2987                         list_move_tail(&cqr->blocklist, flush_queue);
2988                 if (i > 1)
2989                         /* moved more than one request - need to restart */
2990                         goto restart;
2991         }
2992         spin_unlock_irqrestore(&block->queue_lock, flags);
2993
2994         return rc;
2995 }
2996
2997 /*
2998  * Go through all request on the dasd_block request queue, cancel them
2999  * on the respective dasd_device, and return them to the generic
3000  * block layer.
3001  */
3002 static int dasd_flush_block_queue(struct dasd_block *block)
3003 {
3004         struct dasd_ccw_req *cqr, *n;
3005         struct list_head flush_queue;
3006         unsigned long flags;
3007         int rc;
3008
3009         INIT_LIST_HEAD(&flush_queue);
3010         rc = _dasd_requests_to_flushqueue(block, &flush_queue);
3011
3012         /* Now call the callback function of flushed requests */
3013 restart_cb:
3014         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3015                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3016                 /* Process finished ERP request. */
3017                 if (cqr->refers) {
3018                         spin_lock_bh(&block->queue_lock);
3019                         __dasd_process_erp(block->base, cqr);
3020                         spin_unlock_bh(&block->queue_lock);
3021                         /* restart list_for_xx loop since dasd_process_erp
3022                          * might remove multiple elements */
3023                         goto restart_cb;
3024                 }
3025                 /* call the callback function */
3026                 spin_lock_irqsave(&cqr->dq->lock, flags);
3027                 cqr->endclk = get_tod_clock();
3028                 list_del_init(&cqr->blocklist);
3029                 __dasd_cleanup_cqr(cqr);
3030                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3031         }
3032         return rc;
3033 }
3034
3035 /*
3036  * Schedules a call to dasd_tasklet over the device tasklet.
3037  */
3038 void dasd_schedule_block_bh(struct dasd_block *block)
3039 {
3040         /* Protect against rescheduling. */
3041         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3042                 return;
3043         /* life cycle of block is bound to it's base device */
3044         dasd_get_device(block->base);
3045         tasklet_hi_schedule(&block->tasklet);
3046 }
3047 EXPORT_SYMBOL(dasd_schedule_block_bh);
3048
3049
3050 /*
3051  * SECTION: external block device operations
3052  * (request queue handling, open, release, etc.)
3053  */
3054
3055 /*
3056  * Dasd request queue function. Called from ll_rw_blk.c
3057  */
3058 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3059                                     const struct blk_mq_queue_data *qd)
3060 {
3061         struct dasd_block *block = hctx->queue->queuedata;
3062         struct dasd_queue *dq = hctx->driver_data;
3063         struct request *req = qd->rq;
3064         struct dasd_device *basedev;
3065         struct dasd_ccw_req *cqr;
3066         blk_status_t rc = BLK_STS_OK;
3067
3068         basedev = block->base;
3069         spin_lock_irq(&dq->lock);
3070         if (basedev->state < DASD_STATE_READY ||
3071             test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3072                 DBF_DEV_EVENT(DBF_ERR, basedev,
3073                               "device not ready for request %p", req);
3074                 rc = BLK_STS_IOERR;
3075                 goto out;
3076         }
3077
3078         /*
3079          * if device is stopped do not fetch new requests
3080          * except failfast is active which will let requests fail
3081          * immediately in __dasd_block_start_head()
3082          */
3083         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3084                 DBF_DEV_EVENT(DBF_ERR, basedev,
3085                               "device stopped request %p", req);
3086                 rc = BLK_STS_RESOURCE;
3087                 goto out;
3088         }
3089
3090         if (basedev->features & DASD_FEATURE_READONLY &&
3091             rq_data_dir(req) == WRITE) {
3092                 DBF_DEV_EVENT(DBF_ERR, basedev,
3093                               "Rejecting write request %p", req);
3094                 rc = BLK_STS_IOERR;
3095                 goto out;
3096         }
3097
3098         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3099             (basedev->features & DASD_FEATURE_FAILFAST ||
3100              blk_noretry_request(req))) {
3101                 DBF_DEV_EVENT(DBF_ERR, basedev,
3102                               "Rejecting failfast request %p", req);
3103                 rc = BLK_STS_IOERR;
3104                 goto out;
3105         }
3106
3107         cqr = basedev->discipline->build_cp(basedev, block, req);
3108         if (IS_ERR(cqr)) {
3109                 if (PTR_ERR(cqr) == -EBUSY ||
3110                     PTR_ERR(cqr) == -ENOMEM ||
3111                     PTR_ERR(cqr) == -EAGAIN) {
3112                         rc = BLK_STS_RESOURCE;
3113                         goto out;
3114                 }
3115                 DBF_DEV_EVENT(DBF_ERR, basedev,
3116                               "CCW creation failed (rc=%ld) on request %p",
3117                               PTR_ERR(cqr), req);
3118                 rc = BLK_STS_IOERR;
3119                 goto out;
3120         }
3121         /*
3122          *  Note: callback is set to dasd_return_cqr_cb in
3123          * __dasd_block_start_head to cover erp requests as well
3124          */
3125         cqr->callback_data = req;
3126         cqr->status = DASD_CQR_FILLED;
3127         cqr->dq = dq;
3128
3129         blk_mq_start_request(req);
3130         spin_lock(&block->queue_lock);
3131         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3132         INIT_LIST_HEAD(&cqr->devlist);
3133         dasd_profile_start(block, cqr, req);
3134         dasd_schedule_block_bh(block);
3135         spin_unlock(&block->queue_lock);
3136
3137 out:
3138         spin_unlock_irq(&dq->lock);
3139         return rc;
3140 }
3141
3142 /*
3143  * Block timeout callback, called from the block layer
3144  *
3145  * Return values:
3146  * BLK_EH_RESET_TIMER if the request should be left running
3147  * BLK_EH_DONE if the request is handled or terminated
3148  *                    by the driver.
3149  */
3150 enum blk_eh_timer_return dasd_times_out(struct request *req)
3151 {
3152         struct dasd_block *block = req->q->queuedata;
3153         struct dasd_device *device;
3154         struct dasd_ccw_req *cqr;
3155         unsigned long flags;
3156         int rc = 0;
3157
3158         cqr = blk_mq_rq_to_pdu(req);
3159         if (!cqr)
3160                 return BLK_EH_DONE;
3161
3162         spin_lock_irqsave(&cqr->dq->lock, flags);
3163         device = cqr->startdev ? cqr->startdev : block->base;
3164         if (!device->blk_timeout) {
3165                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3166                 return BLK_EH_RESET_TIMER;
3167         }
3168         DBF_DEV_EVENT(DBF_WARNING, device,
3169                       " dasd_times_out cqr %p status %x",
3170                       cqr, cqr->status);
3171
3172         spin_lock(&block->queue_lock);
3173         spin_lock(get_ccwdev_lock(device->cdev));
3174         cqr->retries = -1;
3175         cqr->intrc = -ETIMEDOUT;
3176         if (cqr->status >= DASD_CQR_QUEUED) {
3177                 rc = __dasd_cancel_req(cqr);
3178         } else if (cqr->status == DASD_CQR_FILLED ||
3179                    cqr->status == DASD_CQR_NEED_ERP) {
3180                 cqr->status = DASD_CQR_TERMINATED;
3181         } else if (cqr->status == DASD_CQR_IN_ERP) {
3182                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3183
3184                 list_for_each_entry_safe(searchcqr, nextcqr,
3185                                          &block->ccw_queue, blocklist) {
3186                         tmpcqr = searchcqr;
3187                         while (tmpcqr->refers)
3188                                 tmpcqr = tmpcqr->refers;
3189                         if (tmpcqr != cqr)
3190                                 continue;
3191                         /* searchcqr is an ERP request for cqr */
3192                         searchcqr->retries = -1;
3193                         searchcqr->intrc = -ETIMEDOUT;
3194                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3195                                 rc = __dasd_cancel_req(searchcqr);
3196                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3197                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3198                                 searchcqr->status = DASD_CQR_TERMINATED;
3199                                 rc = 0;
3200                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3201                                 /*
3202                                  * Shouldn't happen; most recent ERP
3203                                  * request is at the front of queue
3204                                  */
3205                                 continue;
3206                         }
3207                         break;
3208                 }
3209         }
3210         spin_unlock(get_ccwdev_lock(device->cdev));
3211         dasd_schedule_block_bh(block);
3212         spin_unlock(&block->queue_lock);
3213         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3214
3215         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3216 }
3217
3218 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3219                           unsigned int idx)
3220 {
3221         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3222
3223         if (!dq)
3224                 return -ENOMEM;
3225
3226         spin_lock_init(&dq->lock);
3227         hctx->driver_data = dq;
3228
3229         return 0;
3230 }
3231
3232 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3233 {
3234         kfree(hctx->driver_data);
3235         hctx->driver_data = NULL;
3236 }
3237
3238 static void dasd_request_done(struct request *req)
3239 {
3240         blk_mq_end_request(req, 0);
3241         blk_mq_run_hw_queues(req->q, true);
3242 }
3243
3244 struct blk_mq_ops dasd_mq_ops = {
3245         .queue_rq = do_dasd_request,
3246         .complete = dasd_request_done,
3247         .timeout = dasd_times_out,
3248         .init_hctx = dasd_init_hctx,
3249         .exit_hctx = dasd_exit_hctx,
3250 };
3251
3252 static int dasd_open(struct gendisk *disk, blk_mode_t mode)
3253 {
3254         struct dasd_device *base;
3255         int rc;
3256
3257         base = dasd_device_from_gendisk(disk);
3258         if (!base)
3259                 return -ENODEV;
3260
3261         atomic_inc(&base->block->open_count);
3262         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3263                 rc = -ENODEV;
3264                 goto unlock;
3265         }
3266
3267         if (!try_module_get(base->discipline->owner)) {
3268                 rc = -EINVAL;
3269                 goto unlock;
3270         }
3271
3272         if (dasd_probeonly) {
3273                 dev_info(&base->cdev->dev,
3274                          "Accessing the DASD failed because it is in "
3275                          "probeonly mode\n");
3276                 rc = -EPERM;
3277                 goto out;
3278         }
3279
3280         if (base->state <= DASD_STATE_BASIC) {
3281                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3282                               " Cannot open unrecognized device");
3283                 rc = -ENODEV;
3284                 goto out;
3285         }
3286         if ((mode & BLK_OPEN_WRITE) &&
3287             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3288              (base->features & DASD_FEATURE_READONLY))) {
3289                 rc = -EROFS;
3290                 goto out;
3291         }
3292         dasd_put_device(base);
3293         return 0;
3294
3295 out:
3296         module_put(base->discipline->owner);
3297 unlock:
3298         atomic_dec(&base->block->open_count);
3299         dasd_put_device(base);
3300         return rc;
3301 }
3302
3303 static void dasd_release(struct gendisk *disk)
3304 {
3305         struct dasd_device *base = dasd_device_from_gendisk(disk);
3306         if (base) {
3307                 atomic_dec(&base->block->open_count);
3308                 module_put(base->discipline->owner);
3309                 dasd_put_device(base);
3310         }
3311 }
3312
3313 /*
3314  * Return disk geometry.
3315  */
3316 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3317 {
3318         struct dasd_device *base;
3319
3320         base = dasd_device_from_gendisk(bdev->bd_disk);
3321         if (!base)
3322                 return -ENODEV;
3323
3324         if (!base->discipline ||
3325             !base->discipline->fill_geometry) {
3326                 dasd_put_device(base);
3327                 return -EINVAL;
3328         }
3329         base->discipline->fill_geometry(base->block, geo);
3330         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3331         dasd_put_device(base);
3332         return 0;
3333 }
3334
3335 const struct block_device_operations
3336 dasd_device_operations = {
3337         .owner          = THIS_MODULE,
3338         .open           = dasd_open,
3339         .release        = dasd_release,
3340         .ioctl          = dasd_ioctl,
3341         .compat_ioctl   = dasd_ioctl,
3342         .getgeo         = dasd_getgeo,
3343         .set_read_only  = dasd_set_read_only,
3344 };
3345
3346 /*******************************************************************************
3347  * end of block device operations
3348  */
3349
3350 static void
3351 dasd_exit(void)
3352 {
3353 #ifdef CONFIG_PROC_FS
3354         dasd_proc_exit();
3355 #endif
3356         dasd_eer_exit();
3357         kmem_cache_destroy(dasd_page_cache);
3358         dasd_page_cache = NULL;
3359         dasd_gendisk_exit();
3360         dasd_devmap_exit();
3361         if (dasd_debug_area != NULL) {
3362                 debug_unregister(dasd_debug_area);
3363                 dasd_debug_area = NULL;
3364         }
3365         dasd_statistics_removeroot();
3366 }
3367
3368 /*
3369  * SECTION: common functions for ccw_driver use
3370  */
3371
3372 /*
3373  * Is the device read-only?
3374  * Note that this function does not report the setting of the
3375  * readonly device attribute, but how it is configured in z/VM.
3376  */
3377 int dasd_device_is_ro(struct dasd_device *device)
3378 {
3379         struct ccw_dev_id dev_id;
3380         struct diag210 diag_data;
3381         int rc;
3382
3383         if (!MACHINE_IS_VM)
3384                 return 0;
3385         ccw_device_get_id(device->cdev, &dev_id);
3386         memset(&diag_data, 0, sizeof(diag_data));
3387         diag_data.vrdcdvno = dev_id.devno;
3388         diag_data.vrdclen = sizeof(diag_data);
3389         rc = diag210(&diag_data);
3390         if (rc == 0 || rc == 2) {
3391                 return diag_data.vrdcvfla & 0x80;
3392         } else {
3393                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3394                           dev_id.devno, rc);
3395                 return 0;
3396         }
3397 }
3398 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3399
3400 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3401 {
3402         struct ccw_device *cdev = data;
3403         int ret;
3404
3405         ret = ccw_device_set_online(cdev);
3406         if (ret)
3407                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3408                         dev_name(&cdev->dev), ret);
3409 }
3410
3411 /*
3412  * Initial attempt at a probe function. this can be simplified once
3413  * the other detection code is gone.
3414  */
3415 int dasd_generic_probe(struct ccw_device *cdev)
3416 {
3417         cdev->handler = &dasd_int_handler;
3418
3419         /*
3420          * Automatically online either all dasd devices (dasd_autodetect)
3421          * or all devices specified with dasd= parameters during
3422          * initial probe.
3423          */
3424         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3425             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3426                 async_schedule(dasd_generic_auto_online, cdev);
3427         return 0;
3428 }
3429 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3430
3431 void dasd_generic_free_discipline(struct dasd_device *device)
3432 {
3433         /* Forget the discipline information. */
3434         if (device->discipline) {
3435                 if (device->discipline->uncheck_device)
3436                         device->discipline->uncheck_device(device);
3437                 module_put(device->discipline->owner);
3438                 device->discipline = NULL;
3439         }
3440         if (device->base_discipline) {
3441                 module_put(device->base_discipline->owner);
3442                 device->base_discipline = NULL;
3443         }
3444 }
3445 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3446
3447 /*
3448  * This will one day be called from a global not_oper handler.
3449  * It is also used by driver_unregister during module unload.
3450  */
3451 void dasd_generic_remove(struct ccw_device *cdev)
3452 {
3453         struct dasd_device *device;
3454         struct dasd_block *block;
3455
3456         device = dasd_device_from_cdev(cdev);
3457         if (IS_ERR(device))
3458                 return;
3459
3460         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3461             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3462                 /* Already doing offline processing */
3463                 dasd_put_device(device);
3464                 return;
3465         }
3466         /*
3467          * This device is removed unconditionally. Set offline
3468          * flag to prevent dasd_open from opening it while it is
3469          * no quite down yet.
3470          */
3471         dasd_set_target_state(device, DASD_STATE_NEW);
3472         cdev->handler = NULL;
3473         /* dasd_delete_device destroys the device reference. */
3474         block = device->block;
3475         dasd_delete_device(device);
3476         /*
3477          * life cycle of block is bound to device, so delete it after
3478          * device was safely removed
3479          */
3480         if (block)
3481                 dasd_free_block(block);
3482 }
3483 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3484
3485 /*
3486  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3487  * the device is detected for the first time and is supposed to be used
3488  * or the user has started activation through sysfs.
3489  */
3490 int dasd_generic_set_online(struct ccw_device *cdev,
3491                             struct dasd_discipline *base_discipline)
3492 {
3493         struct dasd_discipline *discipline;
3494         struct dasd_device *device;
3495         int rc;
3496
3497         /* first online clears initial online feature flag */
3498         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3499         device = dasd_create_device(cdev);
3500         if (IS_ERR(device))
3501                 return PTR_ERR(device);
3502
3503         discipline = base_discipline;
3504         if (device->features & DASD_FEATURE_USEDIAG) {
3505                 if (!dasd_diag_discipline_pointer) {
3506                         /* Try to load the required module. */
3507                         rc = request_module(DASD_DIAG_MOD);
3508                         if (rc) {
3509                                 pr_warn("%s Setting the DASD online failed "
3510                                         "because the required module %s "
3511                                         "could not be loaded (rc=%d)\n",
3512                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3513                                         rc);
3514                                 dasd_delete_device(device);
3515                                 return -ENODEV;
3516                         }
3517                 }
3518                 /* Module init could have failed, so check again here after
3519                  * request_module(). */
3520                 if (!dasd_diag_discipline_pointer) {
3521                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3522                                 dev_name(&cdev->dev));
3523                         dasd_delete_device(device);
3524                         return -ENODEV;
3525                 }
3526                 discipline = dasd_diag_discipline_pointer;
3527         }
3528         if (!try_module_get(base_discipline->owner)) {
3529                 dasd_delete_device(device);
3530                 return -EINVAL;
3531         }
3532         if (!try_module_get(discipline->owner)) {
3533                 module_put(base_discipline->owner);
3534                 dasd_delete_device(device);
3535                 return -EINVAL;
3536         }
3537         device->base_discipline = base_discipline;
3538         device->discipline = discipline;
3539
3540         /* check_device will allocate block device if necessary */
3541         rc = discipline->check_device(device);
3542         if (rc) {
3543                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3544                         dev_name(&cdev->dev), discipline->name, rc);
3545                 module_put(discipline->owner);
3546                 module_put(base_discipline->owner);
3547                 dasd_delete_device(device);
3548                 return rc;
3549         }
3550
3551         dasd_set_target_state(device, DASD_STATE_ONLINE);
3552         if (device->state <= DASD_STATE_KNOWN) {
3553                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3554                         dev_name(&cdev->dev));
3555                 rc = -ENODEV;
3556                 dasd_set_target_state(device, DASD_STATE_NEW);
3557                 if (device->block)
3558                         dasd_free_block(device->block);
3559                 dasd_delete_device(device);
3560         } else
3561                 pr_debug("dasd_generic device %s found\n",
3562                                 dev_name(&cdev->dev));
3563
3564         wait_event(dasd_init_waitq, _wait_for_device(device));
3565
3566         dasd_put_device(device);
3567         return rc;
3568 }
3569 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3570
3571 int dasd_generic_set_offline(struct ccw_device *cdev)
3572 {
3573         struct dasd_device *device;
3574         struct dasd_block *block;
3575         int max_count, open_count, rc;
3576         unsigned long flags;
3577
3578         rc = 0;
3579         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3580         device = dasd_device_from_cdev_locked(cdev);
3581         if (IS_ERR(device)) {
3582                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3583                 return PTR_ERR(device);
3584         }
3585
3586         /*
3587          * We must make sure that this device is currently not in use.
3588          * The open_count is increased for every opener, that includes
3589          * the blkdev_get in dasd_scan_partitions. We are only interested
3590          * in the other openers.
3591          */
3592         if (device->block) {
3593                 max_count = device->block->bdev ? 0 : -1;
3594                 open_count = atomic_read(&device->block->open_count);
3595                 if (open_count > max_count) {
3596                         if (open_count > 0)
3597                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3598                                         dev_name(&cdev->dev), open_count);
3599                         else
3600                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3601                                         dev_name(&cdev->dev));
3602                         rc = -EBUSY;
3603                         goto out_err;
3604                 }
3605         }
3606
3607         /*
3608          * Test if the offline processing is already running and exit if so.
3609          * If a safe offline is being processed this could only be a normal
3610          * offline that should be able to overtake the safe offline and
3611          * cancel any I/O we do not want to wait for any longer
3612          */
3613         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3614                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3615                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3616                                   &device->flags);
3617                 } else {
3618                         rc = -EBUSY;
3619                         goto out_err;
3620                 }
3621         }
3622         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3623
3624         /*
3625          * if safe_offline is called set safe_offline_running flag and
3626          * clear safe_offline so that a call to normal offline
3627          * can overrun safe_offline processing
3628          */
3629         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3630             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3631                 /* need to unlock here to wait for outstanding I/O */
3632                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3633                 /*
3634                  * If we want to set the device safe offline all IO operations
3635                  * should be finished before continuing the offline process
3636                  * so sync bdev first and then wait for our queues to become
3637                  * empty
3638                  */
3639                 if (device->block)
3640                         bdev_mark_dead(device->block->bdev, false);
3641                 dasd_schedule_device_bh(device);
3642                 rc = wait_event_interruptible(shutdown_waitq,
3643                                               _wait_for_empty_queues(device));
3644                 if (rc != 0)
3645                         goto interrupted;
3646
3647                 /*
3648                  * check if a normal offline process overtook the offline
3649                  * processing in this case simply do nothing beside returning
3650                  * that we got interrupted
3651                  * otherwise mark safe offline as not running any longer and
3652                  * continue with normal offline
3653                  */
3654                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3655                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3656                         rc = -ERESTARTSYS;
3657                         goto out_err;
3658                 }
3659                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3660         }
3661         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3662
3663         dasd_set_target_state(device, DASD_STATE_NEW);
3664         /* dasd_delete_device destroys the device reference. */
3665         block = device->block;
3666         dasd_delete_device(device);
3667         /*
3668          * life cycle of block is bound to device, so delete it after
3669          * device was safely removed
3670          */
3671         if (block)
3672                 dasd_free_block(block);
3673
3674         return 0;
3675
3676 interrupted:
3677         /* interrupted by signal */
3678         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3679         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3680         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3681 out_err:
3682         dasd_put_device(device);
3683         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3684         return rc;
3685 }
3686 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3687
3688 int dasd_generic_last_path_gone(struct dasd_device *device)
3689 {
3690         struct dasd_ccw_req *cqr;
3691
3692         dev_warn(&device->cdev->dev, "No operational channel path is left "
3693                  "for the device\n");
3694         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3695         /* First call extended error reporting and check for autoquiesce. */
3696         dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3697
3698         if (device->state < DASD_STATE_BASIC)
3699                 return 0;
3700         /* Device is active. We want to keep it. */
3701         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3702                 if ((cqr->status == DASD_CQR_IN_IO) ||
3703                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3704                         cqr->status = DASD_CQR_QUEUED;
3705                         cqr->retries++;
3706                 }
3707         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3708         dasd_device_clear_timer(device);
3709         dasd_schedule_device_bh(device);
3710         return 1;
3711 }
3712 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3713
3714 int dasd_generic_path_operational(struct dasd_device *device)
3715 {
3716         dev_info(&device->cdev->dev, "A channel path to the device has become "
3717                  "operational\n");
3718         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3719         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3720         dasd_schedule_device_bh(device);
3721         if (device->block) {
3722                 dasd_schedule_block_bh(device->block);
3723                 if (device->block->gdp)
3724                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
3725         }
3726
3727         if (!device->stopped)
3728                 wake_up(&generic_waitq);
3729
3730         return 1;
3731 }
3732 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3733
3734 int dasd_generic_notify(struct ccw_device *cdev, int event)
3735 {
3736         struct dasd_device *device;
3737         int ret;
3738
3739         device = dasd_device_from_cdev_locked(cdev);
3740         if (IS_ERR(device))
3741                 return 0;
3742         ret = 0;
3743         switch (event) {
3744         case CIO_GONE:
3745         case CIO_BOXED:
3746         case CIO_NO_PATH:
3747                 dasd_path_no_path(device);
3748                 ret = dasd_generic_last_path_gone(device);
3749                 break;
3750         case CIO_OPER:
3751                 ret = 1;
3752                 if (dasd_path_get_opm(device))
3753                         ret = dasd_generic_path_operational(device);
3754                 break;
3755         }
3756         dasd_put_device(device);
3757         return ret;
3758 }
3759 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3760
3761 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3762 {
3763         struct dasd_device *device;
3764         int chp, oldopm, hpfpm, ifccpm;
3765
3766         device = dasd_device_from_cdev_locked(cdev);
3767         if (IS_ERR(device))
3768                 return;
3769
3770         oldopm = dasd_path_get_opm(device);
3771         for (chp = 0; chp < 8; chp++) {
3772                 if (path_event[chp] & PE_PATH_GONE) {
3773                         dasd_path_notoper(device, chp);
3774                 }
3775                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3776                         dasd_path_available(device, chp);
3777                         dasd_schedule_device_bh(device);
3778                 }
3779                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3780                         if (!dasd_path_is_operational(device, chp) &&
3781                             !dasd_path_need_verify(device, chp)) {
3782                                 /*
3783                                  * we can not establish a pathgroup on an
3784                                  * unavailable path, so trigger a path
3785                                  * verification first
3786                                  */
3787                         dasd_path_available(device, chp);
3788                         dasd_schedule_device_bh(device);
3789                         }
3790                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3791                                       "Pathgroup re-established\n");
3792                         if (device->discipline->kick_validate)
3793                                 device->discipline->kick_validate(device);
3794                 }
3795                 if (path_event[chp] & PE_PATH_FCES_EVENT) {
3796                         dasd_path_fcsec_update(device, chp);
3797                         dasd_schedule_device_bh(device);
3798                 }
3799         }
3800         hpfpm = dasd_path_get_hpfpm(device);
3801         ifccpm = dasd_path_get_ifccpm(device);
3802         if (!dasd_path_get_opm(device) && hpfpm) {
3803                 /*
3804                  * device has no operational paths but at least one path is
3805                  * disabled due to HPF errors
3806                  * disable HPF at all and use the path(s) again
3807                  */
3808                 if (device->discipline->disable_hpf)
3809                         device->discipline->disable_hpf(device);
3810                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3811                 dasd_path_set_tbvpm(device, hpfpm);
3812                 dasd_schedule_device_bh(device);
3813                 dasd_schedule_requeue(device);
3814         } else if (!dasd_path_get_opm(device) && ifccpm) {
3815                 /*
3816                  * device has no operational paths but at least one path is
3817                  * disabled due to IFCC errors
3818                  * trigger path verification on paths with IFCC errors
3819                  */
3820                 dasd_path_set_tbvpm(device, ifccpm);
3821                 dasd_schedule_device_bh(device);
3822         }
3823         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3824                 dev_warn(&device->cdev->dev,
3825                          "No verified channel paths remain for the device\n");
3826                 DBF_DEV_EVENT(DBF_WARNING, device,
3827                               "%s", "last verified path gone");
3828                 /* First call extended error reporting and check for autoquiesce. */
3829                 dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3830                 dasd_device_set_stop_bits(device,
3831                                           DASD_STOPPED_DC_WAIT);
3832         }
3833         dasd_put_device(device);
3834 }
3835 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3836
3837 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3838 {
3839         if (!dasd_path_get_opm(device) && lpm) {
3840                 dasd_path_set_opm(device, lpm);
3841                 dasd_generic_path_operational(device);
3842         } else
3843                 dasd_path_add_opm(device, lpm);
3844         return 0;
3845 }
3846 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3847
3848 void dasd_generic_space_exhaust(struct dasd_device *device,
3849                                 struct dasd_ccw_req *cqr)
3850 {
3851         /* First call extended error reporting and check for autoquiesce. */
3852         dasd_handle_autoquiesce(device, NULL, DASD_EER_NOSPC);
3853
3854         if (device->state < DASD_STATE_BASIC)
3855                 return;
3856
3857         if (cqr->status == DASD_CQR_IN_IO ||
3858             cqr->status == DASD_CQR_CLEAR_PENDING) {
3859                 cqr->status = DASD_CQR_QUEUED;
3860                 cqr->retries++;
3861         }
3862         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3863         dasd_device_clear_timer(device);
3864         dasd_schedule_device_bh(device);
3865 }
3866 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3867
3868 void dasd_generic_space_avail(struct dasd_device *device)
3869 {
3870         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3871         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3872
3873         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3874         dasd_schedule_device_bh(device);
3875
3876         if (device->block) {
3877                 dasd_schedule_block_bh(device->block);
3878                 if (device->block->gdp)
3879                         blk_mq_run_hw_queues(device->block->gdp->queue, true);
3880         }
3881         if (!device->stopped)
3882                 wake_up(&generic_waitq);
3883 }
3884 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3885
3886 /*
3887  * clear active requests and requeue them to block layer if possible
3888  */
3889 int dasd_generic_requeue_all_requests(struct dasd_device *device)
3890 {
3891         struct dasd_block *block = device->block;
3892         struct list_head requeue_queue;
3893         struct dasd_ccw_req *cqr, *n;
3894         int rc;
3895
3896         if (!block)
3897                 return 0;
3898
3899         INIT_LIST_HEAD(&requeue_queue);
3900         rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
3901
3902         /* Now call the callback function of flushed requests */
3903 restart_cb:
3904         list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
3905                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3906                 /* Process finished ERP request. */
3907                 if (cqr->refers) {
3908                         spin_lock_bh(&block->queue_lock);
3909                         __dasd_process_erp(block->base, cqr);
3910                         spin_unlock_bh(&block->queue_lock);
3911                         /* restart list_for_xx loop since dasd_process_erp
3912                          * might remove multiple elements
3913                          */
3914                         goto restart_cb;
3915                 }
3916                 _dasd_requeue_request(cqr);
3917                 list_del_init(&cqr->blocklist);
3918                 cqr->block->base->discipline->free_cp(
3919                         cqr, (struct request *) cqr->callback_data);
3920         }
3921         dasd_schedule_device_bh(device);
3922         return rc;
3923 }
3924 EXPORT_SYMBOL_GPL(dasd_generic_requeue_all_requests);
3925
3926 static void do_requeue_requests(struct work_struct *work)
3927 {
3928         struct dasd_device *device = container_of(work, struct dasd_device,
3929                                                   requeue_requests);
3930         dasd_generic_requeue_all_requests(device);
3931         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3932         if (device->block)
3933                 dasd_schedule_block_bh(device->block);
3934         dasd_put_device(device);
3935 }
3936
3937 void dasd_schedule_requeue(struct dasd_device *device)
3938 {
3939         dasd_get_device(device);
3940         /* queue call to dasd_reload_device to the kernel event daemon. */
3941         if (!schedule_work(&device->requeue_requests))
3942                 dasd_put_device(device);
3943 }
3944 EXPORT_SYMBOL(dasd_schedule_requeue);
3945
3946 static int dasd_handle_autoquiesce(struct dasd_device *device,
3947                                    struct dasd_ccw_req *cqr,
3948                                    unsigned int reason)
3949 {
3950         /* in any case write eer message with reason */
3951         if (dasd_eer_enabled(device))
3952                 dasd_eer_write(device, cqr, reason);
3953
3954         if (!test_bit(reason, &device->aq_mask))
3955                 return 0;
3956
3957         /* notify eer about autoquiesce */
3958         if (dasd_eer_enabled(device))
3959                 dasd_eer_write(device, NULL, DASD_EER_AUTOQUIESCE);
3960
3961         pr_info("%s: The DASD has been put in the quiesce state\n",
3962                 dev_name(&device->cdev->dev));
3963         dasd_device_set_stop_bits(device, DASD_STOPPED_QUIESCE);
3964
3965         if (device->features & DASD_FEATURE_REQUEUEQUIESCE)
3966                 dasd_schedule_requeue(device);
3967
3968         return 1;
3969 }
3970
3971 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3972                                                    int rdc_buffer_size,
3973                                                    int magic)
3974 {
3975         struct dasd_ccw_req *cqr;
3976         struct ccw1 *ccw;
3977
3978         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
3979                                    NULL);
3980
3981         if (IS_ERR(cqr)) {
3982                 /* internal error 13 - Allocating the RDC request failed*/
3983                 dev_err(&device->cdev->dev,
3984                          "An error occurred in the DASD device driver, "
3985                          "reason=%s\n", "13");
3986                 return cqr;
3987         }
3988
3989         ccw = cqr->cpaddr;
3990         ccw->cmd_code = CCW_CMD_RDC;
3991         ccw->cda = (__u32)virt_to_phys(cqr->data);
3992         ccw->flags = 0;
3993         ccw->count = rdc_buffer_size;
3994         cqr->startdev = device;
3995         cqr->memdev = device;
3996         cqr->expires = 10*HZ;
3997         cqr->retries = 256;
3998         cqr->buildclk = get_tod_clock();
3999         cqr->status = DASD_CQR_FILLED;
4000         return cqr;
4001 }
4002
4003
4004 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4005                                 void *rdc_buffer, int rdc_buffer_size)
4006 {
4007         int ret;
4008         struct dasd_ccw_req *cqr;
4009
4010         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4011         if (IS_ERR(cqr))
4012                 return PTR_ERR(cqr);
4013
4014         ret = dasd_sleep_on(cqr);
4015         if (ret == 0)
4016                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4017         dasd_sfree_request(cqr, cqr->memdev);
4018         return ret;
4019 }
4020 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4021
4022 /*
4023  *   In command mode and transport mode we need to look for sense
4024  *   data in different places. The sense data itself is allways
4025  *   an array of 32 bytes, so we can unify the sense data access
4026  *   for both modes.
4027  */
4028 char *dasd_get_sense(struct irb *irb)
4029 {
4030         struct tsb *tsb = NULL;
4031         char *sense = NULL;
4032
4033         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4034                 if (irb->scsw.tm.tcw)
4035                         tsb = tcw_get_tsb(phys_to_virt(irb->scsw.tm.tcw));
4036                 if (tsb && tsb->length == 64 && tsb->flags)
4037                         switch (tsb->flags & 0x07) {
4038                         case 1: /* tsa_iostat */
4039                                 sense = tsb->tsa.iostat.sense;
4040                                 break;
4041                         case 2: /* tsa_ddpc */
4042                                 sense = tsb->tsa.ddpc.sense;
4043                                 break;
4044                         default:
4045                                 /* currently we don't use interrogate data */
4046                                 break;
4047                         }
4048         } else if (irb->esw.esw0.erw.cons) {
4049                 sense = irb->ecw;
4050         }
4051         return sense;
4052 }
4053 EXPORT_SYMBOL_GPL(dasd_get_sense);
4054
4055 void dasd_generic_shutdown(struct ccw_device *cdev)
4056 {
4057         struct dasd_device *device;
4058
4059         device = dasd_device_from_cdev(cdev);
4060         if (IS_ERR(device))
4061                 return;
4062
4063         if (device->block)
4064                 dasd_schedule_block_bh(device->block);
4065
4066         dasd_schedule_device_bh(device);
4067
4068         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4069 }
4070 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4071
4072 static int __init dasd_init(void)
4073 {
4074         int rc;
4075
4076         init_waitqueue_head(&dasd_init_waitq);
4077         init_waitqueue_head(&dasd_flush_wq);
4078         init_waitqueue_head(&generic_waitq);
4079         init_waitqueue_head(&shutdown_waitq);
4080
4081         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4082         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4083         if (dasd_debug_area == NULL) {
4084                 rc = -ENOMEM;
4085                 goto failed;
4086         }
4087         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4088         debug_set_level(dasd_debug_area, DBF_WARNING);
4089
4090         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4091
4092         dasd_diag_discipline_pointer = NULL;
4093
4094         dasd_statistics_createroot();
4095
4096         rc = dasd_devmap_init();
4097         if (rc)
4098                 goto failed;
4099         rc = dasd_gendisk_init();
4100         if (rc)
4101                 goto failed;
4102         rc = dasd_parse();
4103         if (rc)
4104                 goto failed;
4105         rc = dasd_eer_init();
4106         if (rc)
4107                 goto failed;
4108 #ifdef CONFIG_PROC_FS
4109         rc = dasd_proc_init();
4110         if (rc)
4111                 goto failed;
4112 #endif
4113
4114         return 0;
4115 failed:
4116         pr_info("The DASD device driver could not be initialized\n");
4117         dasd_exit();
4118         return rc;
4119 }
4120
4121 module_init(dasd_init);
4122 module_exit(dasd_exit);