drivers/s390/block/dasd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_DIAG_MOD           "dasd_diag_mod"
  43
  44 static unsigned int queue_depth = 32;
  45 static unsigned int nr_hw_queues = 4;
  46
  47 module_param(queue_depth, uint, 0444);
  48 MODULE_PARM_DESC(queue_depth, "Default queue depth for new DASD devices");
  49
  50 module_param(nr_hw_queues, uint, 0444);
  51 MODULE_PARM_DESC(nr_hw_queues, "Default number of hardware queues for new DASD devices");
  52
  53 /*
  54  * SECTION: exported variables of dasd.c
  55  */
  56 debug_info_t *dasd_debug_area;
  57 EXPORT_SYMBOL(dasd_debug_area);
  58 static struct dentry *dasd_debugfs_root_entry;
  59 struct dasd_discipline *dasd_diag_discipline_pointer;
  60 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  61 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  62
  63 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  64 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  65                    " Copyright IBM Corp. 2000");
  66 MODULE_LICENSE("GPL");
  67
  68 /*
  69  * SECTION: prototypes for static functions of dasd.c
  70  */
  71 static int  dasd_alloc_queue(struct dasd_block *);
  72 static void dasd_free_queue(struct dasd_block *);
  73 static int dasd_flush_block_queue(struct dasd_block *);
  74 static void dasd_device_tasklet(unsigned long);
  75 static void dasd_block_tasklet(unsigned long);
  76 static void do_kick_device(struct work_struct *);
  77 static void do_reload_device(struct work_struct *);
  78 static void do_requeue_requests(struct work_struct *);
  79 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  80 static void dasd_device_timeout(struct timer_list *);
  81 static void dasd_block_timeout(struct timer_list *);
  82 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  83 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  84 static void dasd_profile_exit(struct dasd_profile *);
  85 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  86 static void dasd_hosts_exit(struct dasd_device *);
  87
  88 /*
  89  * SECTION: Operations on the device structure.
  90  */
  91 static wait_queue_head_t dasd_init_waitq;
  92 static wait_queue_head_t dasd_flush_wq;
  93 static wait_queue_head_t generic_waitq;
  94 static wait_queue_head_t shutdown_waitq;
  95
  96 /*
  97  * Allocate memory for a new device structure.
  98  */
  99 struct dasd_device *dasd_alloc_device(void)
 100 {
 101         struct dasd_device *device;
 102
 103         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
 104         if (!device)
 105                 return ERR_PTR(-ENOMEM);
 106
 107         /* Get two pages for normal block device operations. */
 108         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 109         if (!device->ccw_mem) {
 110                 kfree(device);
 111                 return ERR_PTR(-ENOMEM);
 112         }
 113         /* Get one page for error recovery. */
 114         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 115         if (!device->erp_mem) {
 116                 free_pages((unsigned long) device->ccw_mem, 1);
 117                 kfree(device);
 118                 return ERR_PTR(-ENOMEM);
 119         }
 120         /* Get two pages for ese format. */
 121         device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 122         if (!device->ese_mem) {
 123                 free_page((unsigned long) device->erp_mem);
 124                 free_pages((unsigned long) device->ccw_mem, 1);
 125                 kfree(device);
 126                 return ERR_PTR(-ENOMEM);
 127         }
 128
 129         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 130         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 131         dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
 132         spin_lock_init(&device->mem_lock);
 133         atomic_set(&device->tasklet_scheduled, 0);
 134         tasklet_init(&device->tasklet, dasd_device_tasklet,
 135                      (unsigned long) device);
 136         INIT_LIST_HEAD(&device->ccw_queue);
 137         timer_setup(&device->timer, dasd_device_timeout, 0);
 138         INIT_WORK(&device->kick_work, do_kick_device);
 139         INIT_WORK(&device->reload_device, do_reload_device);
 140         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 141         device->state = DASD_STATE_NEW;
 142         device->target = DASD_STATE_NEW;
 143         mutex_init(&device->state_mutex);
 144         spin_lock_init(&device->profile.lock);
 145         return device;
 146 }
 147
 148 /*
 149  * Free memory of a device structure.
 150  */
 151 void dasd_free_device(struct dasd_device *device)
 152 {
 153         kfree(device->private);
 154         free_pages((unsigned long) device->ese_mem, 1);
 155         free_page((unsigned long) device->erp_mem);
 156         free_pages((unsigned long) device->ccw_mem, 1);
 157         kfree(device);
 158 }
 159
 160 /*
 161  * Allocate memory for a new device structure.
 162  */
 163 struct dasd_block *dasd_alloc_block(void)
 164 {
 165         struct dasd_block *block;
 166
 167         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 168         if (!block)
 169                 return ERR_PTR(-ENOMEM);
 170         /* open_count = 0 means device online but not in use */
 171         atomic_set(&block->open_count, -1);
 172
 173         atomic_set(&block->tasklet_scheduled, 0);
 174         tasklet_init(&block->tasklet, dasd_block_tasklet,
 175                      (unsigned long) block);
 176         INIT_LIST_HEAD(&block->ccw_queue);
 177         spin_lock_init(&block->queue_lock);
 178         INIT_LIST_HEAD(&block->format_list);
 179         spin_lock_init(&block->format_lock);
 180         timer_setup(&block->timer, dasd_block_timeout, 0);
 181         spin_lock_init(&block->profile.lock);
 182
 183         return block;
 184 }
 185 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 186
 187 /*
 188  * Free memory of a device structure.
 189  */
 190 void dasd_free_block(struct dasd_block *block)
 191 {
 192         kfree(block);
 193 }
 194 EXPORT_SYMBOL_GPL(dasd_free_block);
 195
 196 /*
 197  * Make a new device known to the system.
 198  */
 199 static int dasd_state_new_to_known(struct dasd_device *device)
 200 {
 201         int rc;
 202
 203         /*
 204          * As long as the device is not in state DASD_STATE_NEW we want to
 205          * keep the reference count > 0.
 206          */
 207         dasd_get_device(device);
 208
 209         if (device->block) {
 210                 rc = dasd_alloc_queue(device->block);
 211                 if (rc) {
 212                         dasd_put_device(device);
 213                         return rc;
 214                 }
 215         }
 216         device->state = DASD_STATE_KNOWN;
 217         return 0;
 218 }
 219
 220 /*
 221  * Let the system forget about a device.
 222  */
 223 static int dasd_state_known_to_new(struct dasd_device *device)
 224 {
 225         /* Disable extended error reporting for this device. */
 226         dasd_eer_disable(device);
 227         device->state = DASD_STATE_NEW;
 228
 229         if (device->block)
 230                 dasd_free_queue(device->block);
 231
 232         /* Give up reference we took in dasd_state_new_to_known. */
 233         dasd_put_device(device);
 234         return 0;
 235 }
 236
 237 static struct dentry *dasd_debugfs_setup(const char *name,
 238                                          struct dentry *base_dentry)
 239 {
 240         struct dentry *pde;
 241
 242         if (!base_dentry)
 243                 return NULL;
 244         pde = debugfs_create_dir(name, base_dentry);
 245         if (!pde || IS_ERR(pde))
 246                 return NULL;
 247         return pde;
 248 }
 249
 250 /*
 251  * Request the irq line for the device.
 252  */
 253 static int dasd_state_known_to_basic(struct dasd_device *device)
 254 {
 255         struct dasd_block *block = device->block;
 256         int rc = 0;
 257
 258         /* Allocate and register gendisk structure. */
 259         if (block) {
 260                 rc = dasd_gendisk_alloc(block);
 261                 if (rc)
 262                         return rc;
 263                 block->debugfs_dentry =
 264                         dasd_debugfs_setup(block->gdp->disk_name,
 265                                            dasd_debugfs_root_entry);
 266                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 267                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 268                         dasd_profile_on(&device->block->profile);
 269         }
 270         device->debugfs_dentry =
 271                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 272                                    dasd_debugfs_root_entry);
 273         dasd_profile_init(&device->profile, device->debugfs_dentry);
 274         dasd_hosts_init(device->debugfs_dentry, device);
 275
 276         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 277         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 278                                             8 * sizeof(long));
 279         debug_register_view(device->debug_area, &debug_sprintf_view);
 280         debug_set_level(device->debug_area, DBF_WARNING);
 281         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 282
 283         device->state = DASD_STATE_BASIC;
 284
 285         return rc;
 286 }
 287
 288 /*
 289  * Release the irq line for the device. Terminate any running i/o.
 290  */
 291 static int dasd_state_basic_to_known(struct dasd_device *device)
 292 {
 293         int rc;
 294
 295         if (device->discipline->basic_to_known) {
 296                 rc = device->discipline->basic_to_known(device);
 297                 if (rc)
 298                         return rc;
 299         }
 300
 301         if (device->block) {
 302                 dasd_profile_exit(&device->block->profile);
 303                 debugfs_remove(device->block->debugfs_dentry);
 304                 dasd_gendisk_free(device->block);
 305                 dasd_block_clear_timer(device->block);
 306         }
 307         rc = dasd_flush_device_queue(device);
 308         if (rc)
 309                 return rc;
 310         dasd_device_clear_timer(device);
 311         dasd_profile_exit(&device->profile);
 312         dasd_hosts_exit(device);
 313         debugfs_remove(device->debugfs_dentry);
 314         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 315         if (device->debug_area != NULL) {
 316                 debug_unregister(device->debug_area);
 317                 device->debug_area = NULL;
 318         }
 319         device->state = DASD_STATE_KNOWN;
 320         return 0;
 321 }
 322
 323 /*
 324  * Do the initial analysis. The do_analysis function may return
 325  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 326  * until the discipline decides to continue the startup sequence
 327  * by calling the function dasd_change_state. The eckd disciplines
 328  * uses this to start a ccw that detects the format. The completion
 329  * interrupt for this detection ccw uses the kernel event daemon to
 330  * trigger the call to dasd_change_state. All this is done in the
 331  * discipline code, see dasd_eckd.c.
 332  * After the analysis ccw is done (do_analysis returned 0) the block
 333  * device is setup.
 334  * In case the analysis returns an error, the device setup is stopped
 335  * (a fake disk was already added to allow formatting).
 336  */
 337 static int dasd_state_basic_to_ready(struct dasd_device *device)
 338 {
 339         int rc;
 340         struct dasd_block *block;
 341         struct gendisk *disk;
 342
 343         rc = 0;
 344         block = device->block;
 345         /* make disk known with correct capacity */
 346         if (block) {
 347                 if (block->base->discipline->do_analysis != NULL)
 348                         rc = block->base->discipline->do_analysis(block);
 349                 if (rc) {
 350                         if (rc != -EAGAIN) {
 351                                 device->state = DASD_STATE_UNFMT;
 352                                 disk = device->block->gdp;
 353                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 354                                                KOBJ_CHANGE);
 355                                 goto out;
 356                         }
 357                         return rc;
 358                 }
 359                 if (device->discipline->setup_blk_queue)
 360                         device->discipline->setup_blk_queue(block);
 361                 set_capacity(block->gdp,
 362                              block->blocks << block->s2b_shift);
 363                 device->state = DASD_STATE_READY;
 364                 rc = dasd_scan_partitions(block);
 365                 if (rc) {
 366                         device->state = DASD_STATE_BASIC;
 367                         return rc;
 368                 }
 369         } else {
 370                 device->state = DASD_STATE_READY;
 371         }
 372 out:
 373         if (device->discipline->basic_to_ready)
 374                 rc = device->discipline->basic_to_ready(device);
 375         return rc;
 376 }
 377
 378 static inline
 379 int _wait_for_empty_queues(struct dasd_device *device)
 380 {
 381         if (device->block)
 382                 return list_empty(&device->ccw_queue) &&
 383                         list_empty(&device->block->ccw_queue);
 384         else
 385                 return list_empty(&device->ccw_queue);
 386 }
 387
 388 /*
 389  * Remove device from block device layer. Destroy dirty buffers.
 390  * Forget format information. Check if the target level is basic
 391  * and if it is create fake disk for formatting.
 392  */
 393 static int dasd_state_ready_to_basic(struct dasd_device *device)
 394 {
 395         int rc;
 396
 397         device->state = DASD_STATE_BASIC;
 398         if (device->block) {
 399                 struct dasd_block *block = device->block;
 400                 rc = dasd_flush_block_queue(block);
 401                 if (rc) {
 402                         device->state = DASD_STATE_READY;
 403                         return rc;
 404                 }
 405                 dasd_destroy_partitions(block);
 406                 block->blocks = 0;
 407                 block->bp_block = 0;
 408                 block->s2b_shift = 0;
 409         }
 410         return 0;
 411 }
 412
 413 /*
 414  * Back to basic.
 415  */
 416 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 417 {
 418         device->state = DASD_STATE_BASIC;
 419         return 0;
 420 }
 421
 422 /*
 423  * Make the device online and schedule the bottom half to start
 424  * the requeueing of requests from the linux request queue to the
 425  * ccw queue.
 426  */
 427 static int
 428 dasd_state_ready_to_online(struct dasd_device * device)
 429 {
 430         device->state = DASD_STATE_ONLINE;
 431         if (device->block) {
 432                 dasd_schedule_block_bh(device->block);
 433                 if ((device->features & DASD_FEATURE_USERAW)) {
 434                         kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
 435                                         KOBJ_CHANGE);
 436                         return 0;
 437                 }
 438                 disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
 439         }
 440         return 0;
 441 }
 442
 443 /*
 444  * Stop the requeueing of requests again.
 445  */
 446 static int dasd_state_online_to_ready(struct dasd_device *device)
 447 {
 448         int rc;
 449
 450         if (device->discipline->online_to_ready) {
 451                 rc = device->discipline->online_to_ready(device);
 452                 if (rc)
 453                         return rc;
 454         }
 455
 456         device->state = DASD_STATE_READY;
 457         if (device->block && !(device->features & DASD_FEATURE_USERAW))
 458                 disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
 459         return 0;
 460 }
 461
 462 /*
 463  * Device startup state changes.
 464  */
 465 static int dasd_increase_state(struct dasd_device *device)
 466 {
 467         int rc;
 468
 469         rc = 0;
 470         if (device->state == DASD_STATE_NEW &&
 471             device->target >= DASD_STATE_KNOWN)
 472                 rc = dasd_state_new_to_known(device);
 473
 474         if (!rc &&
 475             device->state == DASD_STATE_KNOWN &&
 476             device->target >= DASD_STATE_BASIC)
 477                 rc = dasd_state_known_to_basic(device);
 478
 479         if (!rc &&
 480             device->state == DASD_STATE_BASIC &&
 481             device->target >= DASD_STATE_READY)
 482                 rc = dasd_state_basic_to_ready(device);
 483
 484         if (!rc &&
 485             device->state == DASD_STATE_UNFMT &&
 486             device->target > DASD_STATE_UNFMT)
 487                 rc = -EPERM;
 488
 489         if (!rc &&
 490             device->state == DASD_STATE_READY &&
 491             device->target >= DASD_STATE_ONLINE)
 492                 rc = dasd_state_ready_to_online(device);
 493
 494         return rc;
 495 }
 496
 497 /*
 498  * Device shutdown state changes.
 499  */
 500 static int dasd_decrease_state(struct dasd_device *device)
 501 {
 502         int rc;
 503
 504         rc = 0;
 505         if (device->state == DASD_STATE_ONLINE &&
 506             device->target <= DASD_STATE_READY)
 507                 rc = dasd_state_online_to_ready(device);
 508
 509         if (!rc &&
 510             device->state == DASD_STATE_READY &&
 511             device->target <= DASD_STATE_BASIC)
 512                 rc = dasd_state_ready_to_basic(device);
 513
 514         if (!rc &&
 515             device->state == DASD_STATE_UNFMT &&
 516             device->target <= DASD_STATE_BASIC)
 517                 rc = dasd_state_unfmt_to_basic(device);
 518
 519         if (!rc &&
 520             device->state == DASD_STATE_BASIC &&
 521             device->target <= DASD_STATE_KNOWN)
 522                 rc = dasd_state_basic_to_known(device);
 523
 524         if (!rc &&
 525             device->state == DASD_STATE_KNOWN &&
 526             device->target <= DASD_STATE_NEW)
 527                 rc = dasd_state_known_to_new(device);
 528
 529         return rc;
 530 }
 531
 532 /*
 533  * This is the main startup/shutdown routine.
 534  */
 535 static void dasd_change_state(struct dasd_device *device)
 536 {
 537         int rc;
 538
 539         if (device->state == device->target)
 540                 /* Already where we want to go today... */
 541                 return;
 542         if (device->state < device->target)
 543                 rc = dasd_increase_state(device);
 544         else
 545                 rc = dasd_decrease_state(device);
 546         if (rc == -EAGAIN)
 547                 return;
 548         if (rc)
 549                 device->target = device->state;
 550
 551         /* let user-space know that the device status changed */
 552         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 553
 554         if (device->state == device->target)
 555                 wake_up(&dasd_init_waitq);
 556 }
 557
 558 /*
 559  * Kick starter for devices that did not complete the startup/shutdown
 560  * procedure or were sleeping because of a pending state.
 561  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 562  * event daemon.
 563  */
 564 static void do_kick_device(struct work_struct *work)
 565 {
 566         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 567         mutex_lock(&device->state_mutex);
 568         dasd_change_state(device);
 569         mutex_unlock(&device->state_mutex);
 570         dasd_schedule_device_bh(device);
 571         dasd_put_device(device);
 572 }
 573
 574 void dasd_kick_device(struct dasd_device *device)
 575 {
 576         dasd_get_device(device);
 577         /* queue call to dasd_kick_device to the kernel event daemon. */
 578         if (!schedule_work(&device->kick_work))
 579                 dasd_put_device(device);
 580 }
 581 EXPORT_SYMBOL(dasd_kick_device);
 582
 583 /*
 584  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 585  * event daemon.
 586  */
 587 static void do_reload_device(struct work_struct *work)
 588 {
 589         struct dasd_device *device = container_of(work, struct dasd_device,
 590                                                   reload_device);
 591         device->discipline->reload(device);
 592         dasd_put_device(device);
 593 }
 594
 595 void dasd_reload_device(struct dasd_device *device)
 596 {
 597         dasd_get_device(device);
 598         /* queue call to dasd_reload_device to the kernel event daemon. */
 599         if (!schedule_work(&device->reload_device))
 600                 dasd_put_device(device);
 601 }
 602 EXPORT_SYMBOL(dasd_reload_device);
 603
 604 /*
 605  * Set the target state for a device and starts the state change.
 606  */
 607 void dasd_set_target_state(struct dasd_device *device, int target)
 608 {
 609         dasd_get_device(device);
 610         mutex_lock(&device->state_mutex);
 611         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 612         if (dasd_probeonly && target > DASD_STATE_READY)
 613                 target = DASD_STATE_READY;
 614         if (device->target != target) {
 615                 if (device->state == target)
 616                         wake_up(&dasd_init_waitq);
 617                 device->target = target;
 618         }
 619         if (device->state != device->target)
 620                 dasd_change_state(device);
 621         mutex_unlock(&device->state_mutex);
 622         dasd_put_device(device);
 623 }
 624
 625 /*
 626  * Enable devices with device numbers in [from..to].
 627  */
 628 static inline int _wait_for_device(struct dasd_device *device)
 629 {
 630         return (device->state == device->target);
 631 }
 632
 633 void dasd_enable_device(struct dasd_device *device)
 634 {
 635         dasd_set_target_state(device, DASD_STATE_ONLINE);
 636         if (device->state <= DASD_STATE_KNOWN)
 637                 /* No discipline for device found. */
 638                 dasd_set_target_state(device, DASD_STATE_NEW);
 639         /* Now wait for the devices to come up. */
 640         wait_event(dasd_init_waitq, _wait_for_device(device));
 641
 642         dasd_reload_device(device);
 643         if (device->discipline->kick_validate)
 644                 device->discipline->kick_validate(device);
 645 }
 646 EXPORT_SYMBOL(dasd_enable_device);
 647
 648 /*
 649  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 650  */
 651
 652 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 653
 654 #ifdef CONFIG_DASD_PROFILE
 655 struct dasd_profile dasd_global_profile = {
 656         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 657 };
 658 static struct dentry *dasd_debugfs_global_entry;
 659
 660 /*
 661  * Add profiling information for cqr before execution.
 662  */
 663 static void dasd_profile_start(struct dasd_block *block,
 664                                struct dasd_ccw_req *cqr,
 665                                struct request *req)
 666 {
 667         struct list_head *l;
 668         unsigned int counter;
 669         struct dasd_device *device;
 670
 671         /* count the length of the chanq for statistics */
 672         counter = 0;
 673         if (dasd_global_profile_level || block->profile.data)
 674                 list_for_each(l, &block->ccw_queue)
 675                         if (++counter >= 31)
 676                                 break;
 677
 678         spin_lock(&dasd_global_profile.lock);
 679         if (dasd_global_profile.data) {
 680                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 681                 if (rq_data_dir(req) == READ)
 682                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 683         }
 684         spin_unlock(&dasd_global_profile.lock);
 685
 686         spin_lock(&block->profile.lock);
 687         if (block->profile.data) {
 688                 block->profile.data->dasd_io_nr_req[counter]++;
 689                 if (rq_data_dir(req) == READ)
 690                         block->profile.data->dasd_read_nr_req[counter]++;
 691         }
 692         spin_unlock(&block->profile.lock);
 693
 694         /*
 695          * We count the request for the start device, even though it may run on
 696          * some other device due to error recovery. This way we make sure that
 697          * we count each request only once.
 698          */
 699         device = cqr->startdev;
 700         if (device->profile.data) {
 701                 counter = 1; /* request is not yet queued on the start device */
 702                 list_for_each(l, &device->ccw_queue)
 703                         if (++counter >= 31)
 704                                 break;
 705         }
 706         spin_lock(&device->profile.lock);
 707         if (device->profile.data) {
 708                 device->profile.data->dasd_io_nr_req[counter]++;
 709                 if (rq_data_dir(req) == READ)
 710                         device->profile.data->dasd_read_nr_req[counter]++;
 711         }
 712         spin_unlock(&device->profile.lock);
 713 }
 714
 715 /*
 716  * Add profiling information for cqr after execution.
 717  */
 718
 719 #define dasd_profile_counter(value, index)                         \
 720 {                                                                  \
 721         for (index = 0; index < 31 && value >> (2+index); index++) \
 722                 ;                                                  \
 723 }
 724
 725 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 726                                       int is_alias,
 727                                       int is_tpm,
 728                                       int is_read,
 729                                       long sectors,
 730                                       int sectors_ind,
 731                                       int tottime_ind,
 732                                       int tottimeps_ind,
 733                                       int strtime_ind,
 734                                       int irqtime_ind,
 735                                       int irqtimeps_ind,
 736                                       int endtime_ind)
 737 {
 738         /* in case of an overflow, reset the whole profile */
 739         if (data->dasd_io_reqs == UINT_MAX) {
 740                         memset(data, 0, sizeof(*data));
 741                         ktime_get_real_ts64(&data->starttod);
 742         }
 743         data->dasd_io_reqs++;
 744         data->dasd_io_sects += sectors;
 745         if (is_alias)
 746                 data->dasd_io_alias++;
 747         if (is_tpm)
 748                 data->dasd_io_tpm++;
 749
 750         data->dasd_io_secs[sectors_ind]++;
 751         data->dasd_io_times[tottime_ind]++;
 752         data->dasd_io_timps[tottimeps_ind]++;
 753         data->dasd_io_time1[strtime_ind]++;
 754         data->dasd_io_time2[irqtime_ind]++;
 755         data->dasd_io_time2ps[irqtimeps_ind]++;
 756         data->dasd_io_time3[endtime_ind]++;
 757
 758         if (is_read) {
 759                 data->dasd_read_reqs++;
 760                 data->dasd_read_sects += sectors;
 761                 if (is_alias)
 762                         data->dasd_read_alias++;
 763                 if (is_tpm)
 764                         data->dasd_read_tpm++;
 765                 data->dasd_read_secs[sectors_ind]++;
 766                 data->dasd_read_times[tottime_ind]++;
 767                 data->dasd_read_time1[strtime_ind]++;
 768                 data->dasd_read_time2[irqtime_ind]++;
 769                 data->dasd_read_time3[endtime_ind]++;
 770         }
 771 }
 772
 773 static void dasd_profile_end(struct dasd_block *block,
 774                              struct dasd_ccw_req *cqr,
 775                              struct request *req)
 776 {
 777         unsigned long strtime, irqtime, endtime, tottime;
 778         unsigned long tottimeps, sectors;
 779         struct dasd_device *device;
 780         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 781         int irqtime_ind, irqtimeps_ind, endtime_ind;
 782         struct dasd_profile_info *data;
 783
 784         device = cqr->startdev;
 785         if (!(dasd_global_profile_level ||
 786               block->profile.data ||
 787               device->profile.data))
 788                 return;
 789
 790         sectors = blk_rq_sectors(req);
 791         if (!cqr->buildclk || !cqr->startclk ||
 792             !cqr->stopclk || !cqr->endclk ||
 793             !sectors)
 794                 return;
 795
 796         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 797         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 798         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 799         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 800         tottimeps = tottime / sectors;
 801
 802         dasd_profile_counter(sectors, sectors_ind);
 803         dasd_profile_counter(tottime, tottime_ind);
 804         dasd_profile_counter(tottimeps, tottimeps_ind);
 805         dasd_profile_counter(strtime, strtime_ind);
 806         dasd_profile_counter(irqtime, irqtime_ind);
 807         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 808         dasd_profile_counter(endtime, endtime_ind);
 809
 810         spin_lock(&dasd_global_profile.lock);
 811         if (dasd_global_profile.data) {
 812                 data = dasd_global_profile.data;
 813                 data->dasd_sum_times += tottime;
 814                 data->dasd_sum_time_str += strtime;
 815                 data->dasd_sum_time_irq += irqtime;
 816                 data->dasd_sum_time_end += endtime;
 817                 dasd_profile_end_add_data(dasd_global_profile.data,
 818                                           cqr->startdev != block->base,
 819                                           cqr->cpmode == 1,
 820                                           rq_data_dir(req) == READ,
 821                                           sectors, sectors_ind, tottime_ind,
 822                                           tottimeps_ind, strtime_ind,
 823                                           irqtime_ind, irqtimeps_ind,
 824                                           endtime_ind);
 825         }
 826         spin_unlock(&dasd_global_profile.lock);
 827
 828         spin_lock(&block->profile.lock);
 829         if (block->profile.data) {
 830                 data = block->profile.data;
 831                 data->dasd_sum_times += tottime;
 832                 data->dasd_sum_time_str += strtime;
 833                 data->dasd_sum_time_irq += irqtime;
 834                 data->dasd_sum_time_end += endtime;
 835                 dasd_profile_end_add_data(block->profile.data,
 836                                           cqr->startdev != block->base,
 837                                           cqr->cpmode == 1,
 838                                           rq_data_dir(req) == READ,
 839                                           sectors, sectors_ind, tottime_ind,
 840                                           tottimeps_ind, strtime_ind,
 841                                           irqtime_ind, irqtimeps_ind,
 842                                           endtime_ind);
 843         }
 844         spin_unlock(&block->profile.lock);
 845
 846         spin_lock(&device->profile.lock);
 847         if (device->profile.data) {
 848                 data = device->profile.data;
 849                 data->dasd_sum_times += tottime;
 850                 data->dasd_sum_time_str += strtime;
 851                 data->dasd_sum_time_irq += irqtime;
 852                 data->dasd_sum_time_end += endtime;
 853                 dasd_profile_end_add_data(device->profile.data,
 854                                           cqr->startdev != block->base,
 855                                           cqr->cpmode == 1,
 856                                           rq_data_dir(req) == READ,
 857                                           sectors, sectors_ind, tottime_ind,
 858                                           tottimeps_ind, strtime_ind,
 859                                           irqtime_ind, irqtimeps_ind,
 860                                           endtime_ind);
 861         }
 862         spin_unlock(&device->profile.lock);
 863 }
 864
 865 void dasd_profile_reset(struct dasd_profile *profile)
 866 {
 867         struct dasd_profile_info *data;
 868
 869         spin_lock_bh(&profile->lock);
 870         data = profile->data;
 871         if (!data) {
 872                 spin_unlock_bh(&profile->lock);
 873                 return;
 874         }
 875         memset(data, 0, sizeof(*data));
 876         ktime_get_real_ts64(&data->starttod);
 877         spin_unlock_bh(&profile->lock);
 878 }
 879
 880 int dasd_profile_on(struct dasd_profile *profile)
 881 {
 882         struct dasd_profile_info *data;
 883
 884         data = kzalloc(sizeof(*data), GFP_KERNEL);
 885         if (!data)
 886                 return -ENOMEM;
 887         spin_lock_bh(&profile->lock);
 888         if (profile->data) {
 889                 spin_unlock_bh(&profile->lock);
 890                 kfree(data);
 891                 return 0;
 892         }
 893         ktime_get_real_ts64(&data->starttod);
 894         profile->data = data;
 895         spin_unlock_bh(&profile->lock);
 896         return 0;
 897 }
 898
 899 void dasd_profile_off(struct dasd_profile *profile)
 900 {
 901         spin_lock_bh(&profile->lock);
 902         kfree(profile->data);
 903         profile->data = NULL;
 904         spin_unlock_bh(&profile->lock);
 905 }
 906
 907 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 908 {
 909         char *buffer;
 910
 911         buffer = vmalloc(user_len + 1);
 912         if (buffer == NULL)
 913                 return ERR_PTR(-ENOMEM);
 914         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 915                 vfree(buffer);
 916                 return ERR_PTR(-EFAULT);
 917         }
 918         /* got the string, now strip linefeed. */
 919         if (buffer[user_len - 1] == '\n')
 920                 buffer[user_len - 1] = 0;
 921         else
 922                 buffer[user_len] = 0;
 923         return buffer;
 924 }
 925
 926 static ssize_t dasd_stats_write(struct file *file,
 927                                 const char __user *user_buf,
 928                                 size_t user_len, loff_t *pos)
 929 {
 930         char *buffer, *str;
 931         int rc;
 932         struct seq_file *m = (struct seq_file *)file->private_data;
 933         struct dasd_profile *prof = m->private;
 934
 935         if (user_len > 65536)
 936                 user_len = 65536;
 937         buffer = dasd_get_user_string(user_buf, user_len);
 938         if (IS_ERR(buffer))
 939                 return PTR_ERR(buffer);
 940
 941         str = skip_spaces(buffer);
 942         rc = user_len;
 943         if (strncmp(str, "reset", 5) == 0) {
 944                 dasd_profile_reset(prof);
 945         } else if (strncmp(str, "on", 2) == 0) {
 946                 rc = dasd_profile_on(prof);
 947                 if (rc)
 948                         goto out;
 949                 rc = user_len;
 950                 if (prof == &dasd_global_profile) {
 951                         dasd_profile_reset(prof);
 952                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 953                 }
 954         } else if (strncmp(str, "off", 3) == 0) {
 955                 if (prof == &dasd_global_profile)
 956                         dasd_global_profile_level = DASD_PROFILE_OFF;
 957                 dasd_profile_off(prof);
 958         } else
 959                 rc = -EINVAL;
 960 out:
 961         vfree(buffer);
 962         return rc;
 963 }
 964
 965 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 966 {
 967         int i;
 968
 969         for (i = 0; i < 32; i++)
 970                 seq_printf(m, "%u ", array[i]);
 971         seq_putc(m, '\n');
 972 }
 973
 974 static void dasd_stats_seq_print(struct seq_file *m,
 975                                  struct dasd_profile_info *data)
 976 {
 977         seq_printf(m, "start_time %lld.%09ld\n",
 978                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
 979         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 980         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 981         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 982         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 983         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
 984                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
 985         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
 986                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
 987         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
 988                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
 989         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
 990                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
 991         seq_puts(m, "histogram_sectors ");
 992         dasd_stats_array(m, data->dasd_io_secs);
 993         seq_puts(m, "histogram_io_times ");
 994         dasd_stats_array(m, data->dasd_io_times);
 995         seq_puts(m, "histogram_io_times_weighted ");
 996         dasd_stats_array(m, data->dasd_io_timps);
 997         seq_puts(m, "histogram_time_build_to_ssch ");
 998         dasd_stats_array(m, data->dasd_io_time1);
 999         seq_puts(m, "histogram_time_ssch_to_irq ");
1000         dasd_stats_array(m, data->dasd_io_time2);
1001         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1002         dasd_stats_array(m, data->dasd_io_time2ps);
1003         seq_puts(m, "histogram_time_irq_to_end ");
1004         dasd_stats_array(m, data->dasd_io_time3);
1005         seq_puts(m, "histogram_ccw_queue_length ");
1006         dasd_stats_array(m, data->dasd_io_nr_req);
1007         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1008         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1009         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1010         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1011         seq_puts(m, "histogram_read_sectors ");
1012         dasd_stats_array(m, data->dasd_read_secs);
1013         seq_puts(m, "histogram_read_times ");
1014         dasd_stats_array(m, data->dasd_read_times);
1015         seq_puts(m, "histogram_read_time_build_to_ssch ");
1016         dasd_stats_array(m, data->dasd_read_time1);
1017         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1018         dasd_stats_array(m, data->dasd_read_time2);
1019         seq_puts(m, "histogram_read_time_irq_to_end ");
1020         dasd_stats_array(m, data->dasd_read_time3);
1021         seq_puts(m, "histogram_read_ccw_queue_length ");
1022         dasd_stats_array(m, data->dasd_read_nr_req);
1023 }
1024
1025 static int dasd_stats_show(struct seq_file *m, void *v)
1026 {
1027         struct dasd_profile *profile;
1028         struct dasd_profile_info *data;
1029
1030         profile = m->private;
1031         spin_lock_bh(&profile->lock);
1032         data = profile->data;
1033         if (!data) {
1034                 spin_unlock_bh(&profile->lock);
1035                 seq_puts(m, "disabled\n");
1036                 return 0;
1037         }
1038         dasd_stats_seq_print(m, data);
1039         spin_unlock_bh(&profile->lock);
1040         return 0;
1041 }
1042
1043 static int dasd_stats_open(struct inode *inode, struct file *file)
1044 {
1045         struct dasd_profile *profile = inode->i_private;
1046         return single_open(file, dasd_stats_show, profile);
1047 }
1048
1049 static const struct file_operations dasd_stats_raw_fops = {
1050         .owner          = THIS_MODULE,
1051         .open           = dasd_stats_open,
1052         .read           = seq_read,
1053         .llseek         = seq_lseek,
1054         .release        = single_release,
1055         .write          = dasd_stats_write,
1056 };
1057
1058 static void dasd_profile_init(struct dasd_profile *profile,
1059                               struct dentry *base_dentry)
1060 {
1061         umode_t mode;
1062         struct dentry *pde;
1063
1064         if (!base_dentry)
1065                 return;
1066         profile->dentry = NULL;
1067         profile->data = NULL;
1068         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1069         pde = debugfs_create_file("statistics", mode, base_dentry,
1070                                   profile, &dasd_stats_raw_fops);
1071         if (pde && !IS_ERR(pde))
1072                 profile->dentry = pde;
1073         return;
1074 }
1075
1076 static void dasd_profile_exit(struct dasd_profile *profile)
1077 {
1078         dasd_profile_off(profile);
1079         debugfs_remove(profile->dentry);
1080         profile->dentry = NULL;
1081 }
1082
1083 static void dasd_statistics_removeroot(void)
1084 {
1085         dasd_global_profile_level = DASD_PROFILE_OFF;
1086         dasd_profile_exit(&dasd_global_profile);
1087         debugfs_remove(dasd_debugfs_global_entry);
1088         debugfs_remove(dasd_debugfs_root_entry);
1089 }
1090
1091 static void dasd_statistics_createroot(void)
1092 {
1093         struct dentry *pde;
1094
1095         dasd_debugfs_root_entry = NULL;
1096         pde = debugfs_create_dir("dasd", NULL);
1097         if (!pde || IS_ERR(pde))
1098                 goto error;
1099         dasd_debugfs_root_entry = pde;
1100         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1101         if (!pde || IS_ERR(pde))
1102                 goto error;
1103         dasd_debugfs_global_entry = pde;
1104         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1105         return;
1106
1107 error:
1108         DBF_EVENT(DBF_ERR, "%s",
1109                   "Creation of the dasd debugfs interface failed");
1110         dasd_statistics_removeroot();
1111         return;
1112 }
1113
1114 #else
1115 #define dasd_profile_start(block, cqr, req) do {} while (0)
1116 #define dasd_profile_end(block, cqr, req) do {} while (0)
1117
1118 static void dasd_statistics_createroot(void)
1119 {
1120         return;
1121 }
1122
1123 static void dasd_statistics_removeroot(void)
1124 {
1125         return;
1126 }
1127
1128 int dasd_stats_generic_show(struct seq_file *m, void *v)
1129 {
1130         seq_puts(m, "Statistics are not activated in this kernel\n");
1131         return 0;
1132 }
1133
1134 static void dasd_profile_init(struct dasd_profile *profile,
1135                               struct dentry *base_dentry)
1136 {
1137         return;
1138 }
1139
1140 static void dasd_profile_exit(struct dasd_profile *profile)
1141 {
1142         return;
1143 }
1144
1145 int dasd_profile_on(struct dasd_profile *profile)
1146 {
1147         return 0;
1148 }
1149
1150 #endif                          /* CONFIG_DASD_PROFILE */
1151
1152 static int dasd_hosts_show(struct seq_file *m, void *v)
1153 {
1154         struct dasd_device *device;
1155         int rc = -EOPNOTSUPP;
1156
1157         device = m->private;
1158         dasd_get_device(device);
1159
1160         if (device->discipline->hosts_print)
1161                 rc = device->discipline->hosts_print(device, m);
1162
1163         dasd_put_device(device);
1164         return rc;
1165 }
1166
1167 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1168
1169 static void dasd_hosts_exit(struct dasd_device *device)
1170 {
1171         debugfs_remove(device->hosts_dentry);
1172         device->hosts_dentry = NULL;
1173 }
1174
1175 static void dasd_hosts_init(struct dentry *base_dentry,
1176                             struct dasd_device *device)
1177 {
1178         struct dentry *pde;
1179         umode_t mode;
1180
1181         if (!base_dentry)
1182                 return;
1183
1184         mode = S_IRUSR | S_IFREG;
1185         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1186                                   device, &dasd_hosts_fops);
1187         if (pde && !IS_ERR(pde))
1188                 device->hosts_dentry = pde;
1189 }
1190
1191 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1192                                           struct dasd_device *device,
1193                                           struct dasd_ccw_req *cqr)
1194 {
1195         unsigned long flags;
1196         char *data, *chunk;
1197         int size = 0;
1198
1199         if (cplength > 0)
1200                 size += cplength * sizeof(struct ccw1);
1201         if (datasize > 0)
1202                 size += datasize;
1203         if (!cqr)
1204                 size += (sizeof(*cqr) + 7L) & -8L;
1205
1206         spin_lock_irqsave(&device->mem_lock, flags);
1207         data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1208         spin_unlock_irqrestore(&device->mem_lock, flags);
1209         if (!chunk)
1210                 return ERR_PTR(-ENOMEM);
1211         if (!cqr) {
1212                 cqr = (void *) data;
1213                 data += (sizeof(*cqr) + 7L) & -8L;
1214         }
1215         memset(cqr, 0, sizeof(*cqr));
1216         cqr->mem_chunk = chunk;
1217         if (cplength > 0) {
1218                 cqr->cpaddr = data;
1219                 data += cplength * sizeof(struct ccw1);
1220                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1221         }
1222         if (datasize > 0) {
1223                 cqr->data = data;
1224                 memset(cqr->data, 0, datasize);
1225         }
1226         cqr->magic = magic;
1227         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1228         dasd_get_device(device);
1229         return cqr;
1230 }
1231 EXPORT_SYMBOL(dasd_smalloc_request);
1232
1233 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1234                                           int datasize,
1235                                           struct dasd_device *device)
1236 {
1237         struct dasd_ccw_req *cqr;
1238         unsigned long flags;
1239         int size, cqr_size;
1240         char *data;
1241
1242         cqr_size = (sizeof(*cqr) + 7L) & -8L;
1243         size = cqr_size;
1244         if (cplength > 0)
1245                 size += cplength * sizeof(struct ccw1);
1246         if (datasize > 0)
1247                 size += datasize;
1248
1249         spin_lock_irqsave(&device->mem_lock, flags);
1250         cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1251         spin_unlock_irqrestore(&device->mem_lock, flags);
1252         if (!cqr)
1253                 return ERR_PTR(-ENOMEM);
1254         memset(cqr, 0, sizeof(*cqr));
1255         data = (char *)cqr + cqr_size;
1256         cqr->cpaddr = NULL;
1257         if (cplength > 0) {
1258                 cqr->cpaddr = data;
1259                 data += cplength * sizeof(struct ccw1);
1260                 memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1261         }
1262         cqr->data = NULL;
1263         if (datasize > 0) {
1264                 cqr->data = data;
1265                 memset(cqr->data, 0, datasize);
1266         }
1267
1268         cqr->magic = magic;
1269         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1270         dasd_get_device(device);
1271
1272         return cqr;
1273 }
1274 EXPORT_SYMBOL(dasd_fmalloc_request);
1275
1276 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1277 {
1278         unsigned long flags;
1279
1280         spin_lock_irqsave(&device->mem_lock, flags);
1281         dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1282         spin_unlock_irqrestore(&device->mem_lock, flags);
1283         dasd_put_device(device);
1284 }
1285 EXPORT_SYMBOL(dasd_sfree_request);
1286
1287 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1288 {
1289         unsigned long flags;
1290
1291         spin_lock_irqsave(&device->mem_lock, flags);
1292         dasd_free_chunk(&device->ese_chunks, cqr);
1293         spin_unlock_irqrestore(&device->mem_lock, flags);
1294         dasd_put_device(device);
1295 }
1296 EXPORT_SYMBOL(dasd_ffree_request);
1297
1298 /*
1299  * Check discipline magic in cqr.
1300  */
1301 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1302 {
1303         struct dasd_device *device;
1304
1305         if (cqr == NULL)
1306                 return -EINVAL;
1307         device = cqr->startdev;
1308         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1309                 DBF_DEV_EVENT(DBF_WARNING, device,
1310                             " dasd_ccw_req 0x%08x magic doesn't match"
1311                             " discipline 0x%08x",
1312                             cqr->magic,
1313                             *(unsigned int *) device->discipline->name);
1314                 return -EINVAL;
1315         }
1316         return 0;
1317 }
1318
1319 /*
1320  * Terminate the current i/o and set the request to clear_pending.
1321  * Timer keeps device runnig.
1322  * ccw_device_clear can fail if the i/o subsystem
1323  * is in a bad mood.
1324  */
1325 int dasd_term_IO(struct dasd_ccw_req *cqr)
1326 {
1327         struct dasd_device *device;
1328         int retries, rc;
1329         char errorstring[ERRORLENGTH];
1330
1331         /* Check the cqr */
1332         rc = dasd_check_cqr(cqr);
1333         if (rc)
1334                 return rc;
1335         retries = 0;
1336         device = (struct dasd_device *) cqr->startdev;
1337         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1338                 rc = ccw_device_clear(device->cdev, (long) cqr);
1339                 switch (rc) {
1340                 case 0: /* termination successful */
1341                         cqr->status = DASD_CQR_CLEAR_PENDING;
1342                         cqr->stopclk = get_tod_clock();
1343                         cqr->starttime = 0;
1344                         DBF_DEV_EVENT(DBF_DEBUG, device,
1345                                       "terminate cqr %p successful",
1346                                       cqr);
1347                         break;
1348                 case -ENODEV:
1349                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1350                                       "device gone, retry");
1351                         break;
1352                 case -EINVAL:
1353                         /*
1354                          * device not valid so no I/O could be running
1355                          * handle CQR as termination successful
1356                          */
1357                         cqr->status = DASD_CQR_CLEARED;
1358                         cqr->stopclk = get_tod_clock();
1359                         cqr->starttime = 0;
1360                         /* no retries for invalid devices */
1361                         cqr->retries = -1;
1362                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1363                                       "EINVAL, handle as terminated");
1364                         /* fake rc to success */
1365                         rc = 0;
1366                         break;
1367                 default:
1368                         /* internal error 10 - unknown rc*/
1369                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1370                         dev_err(&device->cdev->dev, "An error occurred in the "
1371                                 "DASD device driver, reason=%s\n", errorstring);
1372                         BUG();
1373                         break;
1374                 }
1375                 retries++;
1376         }
1377         dasd_schedule_device_bh(device);
1378         return rc;
1379 }
1380 EXPORT_SYMBOL(dasd_term_IO);
1381
1382 /*
1383  * Start the i/o. This start_IO can fail if the channel is really busy.
1384  * In that case set up a timer to start the request later.
1385  */
1386 int dasd_start_IO(struct dasd_ccw_req *cqr)
1387 {
1388         struct dasd_device *device;
1389         int rc;
1390         char errorstring[ERRORLENGTH];
1391
1392         /* Check the cqr */
1393         rc = dasd_check_cqr(cqr);
1394         if (rc) {
1395                 cqr->intrc = rc;
1396                 return rc;
1397         }
1398         device = (struct dasd_device *) cqr->startdev;
1399         if (((cqr->block &&
1400               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1401              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1402             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1403                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1404                               "because of stolen lock", cqr);
1405                 cqr->status = DASD_CQR_ERROR;
1406                 cqr->intrc = -EPERM;
1407                 return -EPERM;
1408         }
1409         if (cqr->retries < 0) {
1410                 /* internal error 14 - start_IO run out of retries */
1411                 sprintf(errorstring, "14 %p", cqr);
1412                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1413                         "device driver, reason=%s\n", errorstring);
1414                 cqr->status = DASD_CQR_ERROR;
1415                 return -EIO;
1416         }
1417         cqr->startclk = get_tod_clock();
1418         cqr->starttime = jiffies;
1419         cqr->retries--;
1420         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1421                 cqr->lpm &= dasd_path_get_opm(device);
1422                 if (!cqr->lpm)
1423                         cqr->lpm = dasd_path_get_opm(device);
1424         }
1425         if (cqr->cpmode == 1) {
1426                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1427                                          (long) cqr, cqr->lpm);
1428         } else {
1429                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1430                                       (long) cqr, cqr->lpm, 0);
1431         }
1432         switch (rc) {
1433         case 0:
1434                 cqr->status = DASD_CQR_IN_IO;
1435                 break;
1436         case -EBUSY:
1437                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1438                               "start_IO: device busy, retry later");
1439                 break;
1440         case -EACCES:
1441                 /* -EACCES indicates that the request used only a subset of the
1442                  * available paths and all these paths are gone. If the lpm of
1443                  * this request was only a subset of the opm (e.g. the ppm) then
1444                  * we just do a retry with all available paths.
1445                  * If we already use the full opm, something is amiss, and we
1446                  * need a full path verification.
1447                  */
1448                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1449                         DBF_DEV_EVENT(DBF_WARNING, device,
1450                                       "start_IO: selected paths gone (%x)",
1451                                       cqr->lpm);
1452                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1453                         cqr->lpm = dasd_path_get_opm(device);
1454                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1455                                       "start_IO: selected paths gone,"
1456                                       " retry on all paths");
1457                 } else {
1458                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1459                                       "start_IO: all paths in opm gone,"
1460                                       " do path verification");
1461                         dasd_generic_last_path_gone(device);
1462                         dasd_path_no_path(device);
1463                         dasd_path_set_tbvpm(device,
1464                                           ccw_device_get_path_mask(
1465                                                   device->cdev));
1466                 }
1467                 break;
1468         case -ENODEV:
1469                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1470                               "start_IO: -ENODEV device gone, retry");
1471                 break;
1472         case -EIO:
1473                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1474                               "start_IO: -EIO device gone, retry");
1475                 break;
1476         case -EINVAL:
1477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1478                               "start_IO: -EINVAL device currently "
1479                               "not accessible");
1480                 break;
1481         default:
1482                 /* internal error 11 - unknown rc */
1483                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1484                 dev_err(&device->cdev->dev,
1485                         "An error occurred in the DASD device driver, "
1486                         "reason=%s\n", errorstring);
1487                 BUG();
1488                 break;
1489         }
1490         cqr->intrc = rc;
1491         return rc;
1492 }
1493 EXPORT_SYMBOL(dasd_start_IO);
1494
1495 /*
1496  * Timeout function for dasd devices. This is used for different purposes
1497  *  1) missing interrupt handler for normal operation
1498  *  2) delayed start of request where start_IO failed with -EBUSY
1499  *  3) timeout for missing state change interrupts
1500  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1501  * DASD_CQR_QUEUED for 2) and 3).
1502  */
1503 static void dasd_device_timeout(struct timer_list *t)
1504 {
1505         unsigned long flags;
1506         struct dasd_device *device;
1507
1508         device = from_timer(device, t, timer);
1509         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1510         /* re-activate request queue */
1511         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1512         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1513         dasd_schedule_device_bh(device);
1514 }
1515
1516 /*
1517  * Setup timeout for a device in jiffies.
1518  */
1519 void dasd_device_set_timer(struct dasd_device *device, int expires)
1520 {
1521         if (expires == 0)
1522                 del_timer(&device->timer);
1523         else
1524                 mod_timer(&device->timer, jiffies + expires);
1525 }
1526 EXPORT_SYMBOL(dasd_device_set_timer);
1527
1528 /*
1529  * Clear timeout for a device.
1530  */
1531 void dasd_device_clear_timer(struct dasd_device *device)
1532 {
1533         del_timer(&device->timer);
1534 }
1535 EXPORT_SYMBOL(dasd_device_clear_timer);
1536
1537 static void dasd_handle_killed_request(struct ccw_device *cdev,
1538                                        unsigned long intparm)
1539 {
1540         struct dasd_ccw_req *cqr;
1541         struct dasd_device *device;
1542
1543         if (!intparm)
1544                 return;
1545         cqr = (struct dasd_ccw_req *) intparm;
1546         if (cqr->status != DASD_CQR_IN_IO) {
1547                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1548                                 "invalid status in handle_killed_request: "
1549                                 "%02x", cqr->status);
1550                 return;
1551         }
1552
1553         device = dasd_device_from_cdev_locked(cdev);
1554         if (IS_ERR(device)) {
1555                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1556                                 "unable to get device from cdev");
1557                 return;
1558         }
1559
1560         if (!cqr->startdev ||
1561             device != cqr->startdev ||
1562             strncmp(cqr->startdev->discipline->ebcname,
1563                     (char *) &cqr->magic, 4)) {
1564                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1565                                 "invalid device in request");
1566                 dasd_put_device(device);
1567                 return;
1568         }
1569
1570         /* Schedule request to be retried. */
1571         cqr->status = DASD_CQR_QUEUED;
1572
1573         dasd_device_clear_timer(device);
1574         dasd_schedule_device_bh(device);
1575         dasd_put_device(device);
1576 }
1577
1578 void dasd_generic_handle_state_change(struct dasd_device *device)
1579 {
1580         /* First of all start sense subsystem status request. */
1581         dasd_eer_snss(device);
1582
1583         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1584         dasd_schedule_device_bh(device);
1585         if (device->block) {
1586                 dasd_schedule_block_bh(device->block);
1587                 if (device->block->request_queue)
1588                         blk_mq_run_hw_queues(device->block->request_queue,
1589                                              true);
1590         }
1591 }
1592 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1593
1594 static int dasd_check_hpf_error(struct irb *irb)
1595 {
1596         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1597             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1598              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1599 }
1600
1601 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1602 {
1603         struct dasd_device *device = NULL;
1604         u8 *sense = NULL;
1605
1606         if (!block)
1607                 return 0;
1608         device = block->base;
1609         if (!device || !device->discipline->is_ese)
1610                 return 0;
1611         if (!device->discipline->is_ese(device))
1612                 return 0;
1613
1614         sense = dasd_get_sense(irb);
1615         if (!sense)
1616                 return 0;
1617
1618         return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1619                 !!(sense[1] & SNS1_FILE_PROTECTED) ||
1620                 scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1621 }
1622
1623 static int dasd_ese_oos_cond(u8 *sense)
1624 {
1625         return sense[0] & SNS0_EQUIPMENT_CHECK &&
1626                 sense[1] & SNS1_PERM_ERR &&
1627                 sense[1] & SNS1_WRITE_INHIBITED &&
1628                 sense[25] == 0x01;
1629 }
1630
1631 /*
1632  * Interrupt handler for "normal" ssch-io based dasd devices.
1633  */
1634 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1635                       struct irb *irb)
1636 {
1637         struct dasd_ccw_req *cqr, *next, *fcqr;
1638         struct dasd_device *device;
1639         unsigned long now;
1640         int nrf_suppressed = 0;
1641         int fp_suppressed = 0;
1642         u8 *sense = NULL;
1643         int expires;
1644
1645         cqr = (struct dasd_ccw_req *) intparm;
1646         if (IS_ERR(irb)) {
1647                 switch (PTR_ERR(irb)) {
1648                 case -EIO:
1649                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1650                                 device = cqr->startdev;
1651                                 cqr->status = DASD_CQR_CLEARED;
1652                                 dasd_device_clear_timer(device);
1653                                 wake_up(&dasd_flush_wq);
1654                                 dasd_schedule_device_bh(device);
1655                                 return;
1656                         }
1657                         break;
1658                 case -ETIMEDOUT:
1659                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1660                                         "request timed out\n", __func__);
1661                         break;
1662                 default:
1663                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1664                                         "unknown error %ld\n", __func__,
1665                                         PTR_ERR(irb));
1666                 }
1667                 dasd_handle_killed_request(cdev, intparm);
1668                 return;
1669         }
1670
1671         now = get_tod_clock();
1672         /* check for conditions that should be handled immediately */
1673         if (!cqr ||
1674             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1675               scsw_cstat(&irb->scsw) == 0)) {
1676                 if (cqr)
1677                         memcpy(&cqr->irb, irb, sizeof(*irb));
1678                 device = dasd_device_from_cdev_locked(cdev);
1679                 if (IS_ERR(device))
1680                         return;
1681                 /* ignore unsolicited interrupts for DIAG discipline */
1682                 if (device->discipline == dasd_diag_discipline_pointer) {
1683                         dasd_put_device(device);
1684                         return;
1685                 }
1686
1687                 /*
1688                  * In some cases 'File Protected' or 'No Record Found' errors
1689                  * might be expected and debug log messages for the
1690                  * corresponding interrupts shouldn't be written then.
1691                  * Check if either of the according suppress bits is set.
1692                  */
1693                 sense = dasd_get_sense(irb);
1694                 if (sense) {
1695                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1696                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1697                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1698                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1699
1700                         /*
1701                          * Extent pool probably out-of-space.
1702                          * Stop device and check exhaust level.
1703                          */
1704                         if (dasd_ese_oos_cond(sense)) {
1705                                 dasd_generic_space_exhaust(device, cqr);
1706                                 device->discipline->ext_pool_exhaust(device, cqr);
1707                                 dasd_put_device(device);
1708                                 return;
1709                         }
1710                 }
1711                 if (!(fp_suppressed || nrf_suppressed))
1712                         device->discipline->dump_sense_dbf(device, irb, "int");
1713
1714                 if (device->features & DASD_FEATURE_ERPLOG)
1715                         device->discipline->dump_sense(device, cqr, irb);
1716                 device->discipline->check_for_device_change(device, cqr, irb);
1717                 dasd_put_device(device);
1718         }
1719
1720         /* check for for attention message */
1721         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1722                 device = dasd_device_from_cdev_locked(cdev);
1723                 if (!IS_ERR(device)) {
1724                         device->discipline->check_attention(device,
1725                                                             irb->esw.esw1.lpum);
1726                         dasd_put_device(device);
1727                 }
1728         }
1729
1730         if (!cqr)
1731                 return;
1732
1733         device = (struct dasd_device *) cqr->startdev;
1734         if (!device ||
1735             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1736                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1737                                 "invalid device in request");
1738                 return;
1739         }
1740
1741         if (dasd_ese_needs_format(cqr->block, irb)) {
1742                 if (rq_data_dir((struct request *)cqr->callback_data) == READ) {
1743                         device->discipline->ese_read(cqr, irb);
1744                         cqr->status = DASD_CQR_SUCCESS;
1745                         cqr->stopclk = now;
1746                         dasd_device_clear_timer(device);
1747                         dasd_schedule_device_bh(device);
1748                         return;
1749                 }
1750                 fcqr = device->discipline->ese_format(device, cqr, irb);
1751                 if (IS_ERR(fcqr)) {
1752                         if (PTR_ERR(fcqr) == -EINVAL) {
1753                                 cqr->status = DASD_CQR_ERROR;
1754                                 return;
1755                         }
1756                         /*
1757                          * If we can't format now, let the request go
1758                          * one extra round. Maybe we can format later.
1759                          */
1760                         cqr->status = DASD_CQR_QUEUED;
1761                         dasd_schedule_device_bh(device);
1762                         return;
1763                 } else {
1764                         fcqr->status = DASD_CQR_QUEUED;
1765                         cqr->status = DASD_CQR_QUEUED;
1766                         list_add(&fcqr->devlist, &device->ccw_queue);
1767                         dasd_schedule_device_bh(device);
1768                         return;
1769                 }
1770         }
1771
1772         /* Check for clear pending */
1773         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1774             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1775                 cqr->status = DASD_CQR_CLEARED;
1776                 dasd_device_clear_timer(device);
1777                 wake_up(&dasd_flush_wq);
1778                 dasd_schedule_device_bh(device);
1779                 return;
1780         }
1781
1782         /* check status - the request might have been killed by dyn detach */
1783         if (cqr->status != DASD_CQR_IN_IO) {
1784                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1785                               "status %02x", dev_name(&cdev->dev), cqr->status);
1786                 return;
1787         }
1788
1789         next = NULL;
1790         expires = 0;
1791         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1792             scsw_cstat(&irb->scsw) == 0) {
1793                 /* request was completed successfully */
1794                 cqr->status = DASD_CQR_SUCCESS;
1795                 cqr->stopclk = now;
1796                 /* Start first request on queue if possible -> fast_io. */
1797                 if (cqr->devlist.next != &device->ccw_queue) {
1798                         next = list_entry(cqr->devlist.next,
1799                                           struct dasd_ccw_req, devlist);
1800                 }
1801         } else {  /* error */
1802                 /* check for HPF error
1803                  * call discipline function to requeue all requests
1804                  * and disable HPF accordingly
1805                  */
1806                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1807                     device->discipline->handle_hpf_error)
1808                         device->discipline->handle_hpf_error(device, irb);
1809                 /*
1810                  * If we don't want complex ERP for this request, then just
1811                  * reset this and retry it in the fastpath
1812                  */
1813                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1814                     cqr->retries > 0) {
1815                         if (cqr->lpm == dasd_path_get_opm(device))
1816                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1817                                               "default ERP in fastpath "
1818                                               "(%i retries left)",
1819                                               cqr->retries);
1820                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1821                                 cqr->lpm = dasd_path_get_opm(device);
1822                         cqr->status = DASD_CQR_QUEUED;
1823                         next = cqr;
1824                 } else
1825                         cqr->status = DASD_CQR_ERROR;
1826         }
1827         if (next && (next->status == DASD_CQR_QUEUED) &&
1828             (!device->stopped)) {
1829                 if (device->discipline->start_IO(next) == 0)
1830                         expires = next->expires;
1831         }
1832         if (expires != 0)
1833                 dasd_device_set_timer(device, expires);
1834         else
1835                 dasd_device_clear_timer(device);
1836         dasd_schedule_device_bh(device);
1837 }
1838 EXPORT_SYMBOL(dasd_int_handler);
1839
1840 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1841 {
1842         struct dasd_device *device;
1843
1844         device = dasd_device_from_cdev_locked(cdev);
1845
1846         if (IS_ERR(device))
1847                 goto out;
1848         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1849            device->state != device->target ||
1850            !device->discipline->check_for_device_change){
1851                 dasd_put_device(device);
1852                 goto out;
1853         }
1854         if (device->discipline->dump_sense_dbf)
1855                 device->discipline->dump_sense_dbf(device, irb, "uc");
1856         device->discipline->check_for_device_change(device, NULL, irb);
1857         dasd_put_device(device);
1858 out:
1859         return UC_TODO_RETRY;
1860 }
1861 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1862
1863 /*
1864  * If we have an error on a dasd_block layer request then we cancel
1865  * and return all further requests from the same dasd_block as well.
1866  */
1867 static void __dasd_device_recovery(struct dasd_device *device,
1868                                    struct dasd_ccw_req *ref_cqr)
1869 {
1870         struct list_head *l, *n;
1871         struct dasd_ccw_req *cqr;
1872
1873         /*
1874          * only requeue request that came from the dasd_block layer
1875          */
1876         if (!ref_cqr->block)
1877                 return;
1878
1879         list_for_each_safe(l, n, &device->ccw_queue) {
1880                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1881                 if (cqr->status == DASD_CQR_QUEUED &&
1882                     ref_cqr->block == cqr->block) {
1883                         cqr->status = DASD_CQR_CLEARED;
1884                 }
1885         }
1886 };
1887
1888 /*
1889  * Remove those ccw requests from the queue that need to be returned
1890  * to the upper layer.
1891  */
1892 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1893                                             struct list_head *final_queue)
1894 {
1895         struct list_head *l, *n;
1896         struct dasd_ccw_req *cqr;
1897
1898         /* Process request with final status. */
1899         list_for_each_safe(l, n, &device->ccw_queue) {
1900                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1901
1902                 /* Skip any non-final request. */
1903                 if (cqr->status == DASD_CQR_QUEUED ||
1904                     cqr->status == DASD_CQR_IN_IO ||
1905                     cqr->status == DASD_CQR_CLEAR_PENDING)
1906                         continue;
1907                 if (cqr->status == DASD_CQR_ERROR) {
1908                         __dasd_device_recovery(device, cqr);
1909                 }
1910                 /* Rechain finished requests to final queue */
1911                 list_move_tail(&cqr->devlist, final_queue);
1912         }
1913 }
1914
1915 static void __dasd_process_cqr(struct dasd_device *device,
1916                                struct dasd_ccw_req *cqr)
1917 {
1918         char errorstring[ERRORLENGTH];
1919
1920         switch (cqr->status) {
1921         case DASD_CQR_SUCCESS:
1922                 cqr->status = DASD_CQR_DONE;
1923                 break;
1924         case DASD_CQR_ERROR:
1925                 cqr->status = DASD_CQR_NEED_ERP;
1926                 break;
1927         case DASD_CQR_CLEARED:
1928                 cqr->status = DASD_CQR_TERMINATED;
1929                 break;
1930         default:
1931                 /* internal error 12 - wrong cqr status*/
1932                 snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1933                 dev_err(&device->cdev->dev,
1934                         "An error occurred in the DASD device driver, "
1935                         "reason=%s\n", errorstring);
1936                 BUG();
1937         }
1938         if (cqr->callback)
1939                 cqr->callback(cqr, cqr->callback_data);
1940 }
1941
1942 /*
1943  * the cqrs from the final queue are returned to the upper layer
1944  * by setting a dasd_block state and calling the callback function
1945  */
1946 static void __dasd_device_process_final_queue(struct dasd_device *device,
1947                                               struct list_head *final_queue)
1948 {
1949         struct list_head *l, *n;
1950         struct dasd_ccw_req *cqr;
1951         struct dasd_block *block;
1952
1953         list_for_each_safe(l, n, final_queue) {
1954                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1955                 list_del_init(&cqr->devlist);
1956                 block = cqr->block;
1957                 if (!block) {
1958                         __dasd_process_cqr(device, cqr);
1959                 } else {
1960                         spin_lock_bh(&block->queue_lock);
1961                         __dasd_process_cqr(device, cqr);
1962                         spin_unlock_bh(&block->queue_lock);
1963                 }
1964         }
1965 }
1966
1967 /*
1968  * Take a look at the first request on the ccw queue and check
1969  * if it reached its expire time. If so, terminate the IO.
1970  */
1971 static void __dasd_device_check_expire(struct dasd_device *device)
1972 {
1973         struct dasd_ccw_req *cqr;
1974
1975         if (list_empty(&device->ccw_queue))
1976                 return;
1977         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1978         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1979             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1980                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1981                         /*
1982                          * IO in safe offline processing should not
1983                          * run out of retries
1984                          */
1985                         cqr->retries++;
1986                 }
1987                 if (device->discipline->term_IO(cqr) != 0) {
1988                         /* Hmpf, try again in 5 sec */
1989                         dev_err(&device->cdev->dev,
1990                                 "cqr %p timed out (%lus) but cannot be "
1991                                 "ended, retrying in 5 s\n",
1992                                 cqr, (cqr->expires/HZ));
1993                         cqr->expires += 5*HZ;
1994                         dasd_device_set_timer(device, 5*HZ);
1995                 } else {
1996                         dev_err(&device->cdev->dev,
1997                                 "cqr %p timed out (%lus), %i retries "
1998                                 "remaining\n", cqr, (cqr->expires/HZ),
1999                                 cqr->retries);
2000                 }
2001         }
2002 }
2003
2004 /*
2005  * return 1 when device is not eligible for IO
2006  */
2007 static int __dasd_device_is_unusable(struct dasd_device *device,
2008                                      struct dasd_ccw_req *cqr)
2009 {
2010         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
2011
2012         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2013             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2014                 /*
2015                  * dasd is being set offline
2016                  * but it is no safe offline where we have to allow I/O
2017                  */
2018                 return 1;
2019         }
2020         if (device->stopped) {
2021                 if (device->stopped & mask) {
2022                         /* stopped and CQR will not change that. */
2023                         return 1;
2024                 }
2025                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2026                         /* CQR is not able to change device to
2027                          * operational. */
2028                         return 1;
2029                 }
2030                 /* CQR required to get device operational. */
2031         }
2032         return 0;
2033 }
2034
2035 /*
2036  * Take a look at the first request on the ccw queue and check
2037  * if it needs to be started.
2038  */
2039 static void __dasd_device_start_head(struct dasd_device *device)
2040 {
2041         struct dasd_ccw_req *cqr;
2042         int rc;
2043
2044         if (list_empty(&device->ccw_queue))
2045                 return;
2046         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2047         if (cqr->status != DASD_CQR_QUEUED)
2048                 return;
2049         /* if device is not usable return request to upper layer */
2050         if (__dasd_device_is_unusable(device, cqr)) {
2051                 cqr->intrc = -EAGAIN;
2052                 cqr->status = DASD_CQR_CLEARED;
2053                 dasd_schedule_device_bh(device);
2054                 return;
2055         }
2056
2057         rc = device->discipline->start_IO(cqr);
2058         if (rc == 0)
2059                 dasd_device_set_timer(device, cqr->expires);
2060         else if (rc == -EACCES) {
2061                 dasd_schedule_device_bh(device);
2062         } else
2063                 /* Hmpf, try again in 1/2 sec */
2064                 dasd_device_set_timer(device, 50);
2065 }
2066
2067 static void __dasd_device_check_path_events(struct dasd_device *device)
2068 {
2069         __u8 tbvpm, fcsecpm;
2070         int rc;
2071
2072         tbvpm = dasd_path_get_tbvpm(device);
2073         fcsecpm = dasd_path_get_fcsecpm(device);
2074
2075         if (!tbvpm && !fcsecpm)
2076                 return;
2077
2078         if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2079                 return;
2080         rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
2081         if (rc) {
2082                 dasd_device_set_timer(device, 50);
2083         } else {
2084                 dasd_path_clear_all_verify(device);
2085                 dasd_path_clear_all_fcsec(device);
2086         }
2087 };
2088
2089 /*
2090  * Go through all request on the dasd_device request queue,
2091  * terminate them on the cdev if necessary, and return them to the
2092  * submitting layer via callback.
2093  * Note:
2094  * Make sure that all 'submitting layers' still exist when
2095  * this function is called!. In other words, when 'device' is a base
2096  * device then all block layer requests must have been removed before
2097  * via dasd_flush_block_queue.
2098  */
2099 int dasd_flush_device_queue(struct dasd_device *device)
2100 {
2101         struct dasd_ccw_req *cqr, *n;
2102         int rc;
2103         struct list_head flush_queue;
2104
2105         INIT_LIST_HEAD(&flush_queue);
2106         spin_lock_irq(get_ccwdev_lock(device->cdev));
2107         rc = 0;
2108         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2109                 /* Check status and move request to flush_queue */
2110                 switch (cqr->status) {
2111                 case DASD_CQR_IN_IO:
2112                         rc = device->discipline->term_IO(cqr);
2113                         if (rc) {
2114                                 /* unable to terminate requeust */
2115                                 dev_err(&device->cdev->dev,
2116                                         "Flushing the DASD request queue "
2117                                         "failed for request %p\n", cqr);
2118                                 /* stop flush processing */
2119                                 goto finished;
2120                         }
2121                         break;
2122                 case DASD_CQR_QUEUED:
2123                         cqr->stopclk = get_tod_clock();
2124                         cqr->status = DASD_CQR_CLEARED;
2125                         break;
2126                 default: /* no need to modify the others */
2127                         break;
2128                 }
2129                 list_move_tail(&cqr->devlist, &flush_queue);
2130         }
2131 finished:
2132         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2133         /*
2134          * After this point all requests must be in state CLEAR_PENDING,
2135          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2136          * one of the others.
2137          */
2138         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2139                 wait_event(dasd_flush_wq,
2140                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2141         /*
2142          * Now set each request back to TERMINATED, DONE or NEED_ERP
2143          * and call the callback function of flushed requests
2144          */
2145         __dasd_device_process_final_queue(device, &flush_queue);
2146         return rc;
2147 }
2148 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2149
2150 /*
2151  * Acquire the device lock and process queues for the device.
2152  */
2153 static void dasd_device_tasklet(unsigned long data)
2154 {
2155         struct dasd_device *device = (struct dasd_device *) data;
2156         struct list_head final_queue;
2157
2158         atomic_set (&device->tasklet_scheduled, 0);
2159         INIT_LIST_HEAD(&final_queue);
2160         spin_lock_irq(get_ccwdev_lock(device->cdev));
2161         /* Check expire time of first request on the ccw queue. */
2162         __dasd_device_check_expire(device);
2163         /* find final requests on ccw queue */
2164         __dasd_device_process_ccw_queue(device, &final_queue);
2165         __dasd_device_check_path_events(device);
2166         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2167         /* Now call the callback function of requests with final status */
2168         __dasd_device_process_final_queue(device, &final_queue);
2169         spin_lock_irq(get_ccwdev_lock(device->cdev));
2170         /* Now check if the head of the ccw queue needs to be started. */
2171         __dasd_device_start_head(device);
2172         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2173         if (waitqueue_active(&shutdown_waitq))
2174                 wake_up(&shutdown_waitq);
2175         dasd_put_device(device);
2176 }
2177
2178 /*
2179  * Schedules a call to dasd_tasklet over the device tasklet.
2180  */
2181 void dasd_schedule_device_bh(struct dasd_device *device)
2182 {
2183         /* Protect against rescheduling. */
2184         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2185                 return;
2186         dasd_get_device(device);
2187         tasklet_hi_schedule(&device->tasklet);
2188 }
2189 EXPORT_SYMBOL(dasd_schedule_device_bh);
2190
2191 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2192 {
2193         device->stopped |= bits;
2194 }
2195 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2196
2197 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2198 {
2199         device->stopped &= ~bits;
2200         if (!device->stopped)
2201                 wake_up(&generic_waitq);
2202 }
2203 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2204
2205 /*
2206  * Queue a request to the head of the device ccw_queue.
2207  * Start the I/O if possible.
2208  */
2209 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2210 {
2211         struct dasd_device *device;
2212         unsigned long flags;
2213
2214         device = cqr->startdev;
2215         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2216         cqr->status = DASD_CQR_QUEUED;
2217         list_add(&cqr->devlist, &device->ccw_queue);
2218         /* let the bh start the request to keep them in order */
2219         dasd_schedule_device_bh(device);
2220         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2221 }
2222 EXPORT_SYMBOL(dasd_add_request_head);
2223
2224 /*
2225  * Queue a request to the tail of the device ccw_queue.
2226  * Start the I/O if possible.
2227  */
2228 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2229 {
2230         struct dasd_device *device;
2231         unsigned long flags;
2232
2233         device = cqr->startdev;
2234         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2235         cqr->status = DASD_CQR_QUEUED;
2236         list_add_tail(&cqr->devlist, &device->ccw_queue);
2237         /* let the bh start the request to keep them in order */
2238         dasd_schedule_device_bh(device);
2239         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2240 }
2241 EXPORT_SYMBOL(dasd_add_request_tail);
2242
2243 /*
2244  * Wakeup helper for the 'sleep_on' functions.
2245  */
2246 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2247 {
2248         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2249         cqr->callback_data = DASD_SLEEPON_END_TAG;
2250         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2251         wake_up(&generic_waitq);
2252 }
2253 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2254
2255 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2256 {
2257         struct dasd_device *device;
2258         int rc;
2259
2260         device = cqr->startdev;
2261         spin_lock_irq(get_ccwdev_lock(device->cdev));
2262         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2263         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2264         return rc;
2265 }
2266
2267 /*
2268  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2269  */
2270 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2271 {
2272         struct dasd_device *device;
2273         dasd_erp_fn_t erp_fn;
2274
2275         if (cqr->status == DASD_CQR_FILLED)
2276                 return 0;
2277         device = cqr->startdev;
2278         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2279                 if (cqr->status == DASD_CQR_TERMINATED) {
2280                         device->discipline->handle_terminated_request(cqr);
2281                         return 1;
2282                 }
2283                 if (cqr->status == DASD_CQR_NEED_ERP) {
2284                         erp_fn = device->discipline->erp_action(cqr);
2285                         erp_fn(cqr);
2286                         return 1;
2287                 }
2288                 if (cqr->status == DASD_CQR_FAILED)
2289                         dasd_log_sense(cqr, &cqr->irb);
2290                 if (cqr->refers) {
2291                         __dasd_process_erp(device, cqr);
2292                         return 1;
2293                 }
2294         }
2295         return 0;
2296 }
2297
2298 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2299 {
2300         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2301                 if (cqr->refers) /* erp is not done yet */
2302                         return 1;
2303                 return ((cqr->status != DASD_CQR_DONE) &&
2304                         (cqr->status != DASD_CQR_FAILED));
2305         } else
2306                 return (cqr->status == DASD_CQR_FILLED);
2307 }
2308
2309 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2310 {
2311         struct dasd_device *device;
2312         int rc;
2313         struct list_head ccw_queue;
2314         struct dasd_ccw_req *cqr;
2315
2316         INIT_LIST_HEAD(&ccw_queue);
2317         maincqr->status = DASD_CQR_FILLED;
2318         device = maincqr->startdev;
2319         list_add(&maincqr->blocklist, &ccw_queue);
2320         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2321              cqr = list_first_entry(&ccw_queue,
2322                                     struct dasd_ccw_req, blocklist)) {
2323
2324                 if (__dasd_sleep_on_erp(cqr))
2325                         continue;
2326                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2327                         continue;
2328                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2329                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2330                         cqr->status = DASD_CQR_FAILED;
2331                         cqr->intrc = -EPERM;
2332                         continue;
2333                 }
2334                 /* Non-temporary stop condition will trigger fail fast */
2335                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2336                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2337                     (!dasd_eer_enabled(device))) {
2338                         cqr->status = DASD_CQR_FAILED;
2339                         cqr->intrc = -ENOLINK;
2340                         continue;
2341                 }
2342                 /*
2343                  * Don't try to start requests if device is in
2344                  * offline processing, it might wait forever
2345                  */
2346                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2347                         cqr->status = DASD_CQR_FAILED;
2348                         cqr->intrc = -ENODEV;
2349                         continue;
2350                 }
2351                 /*
2352                  * Don't try to start requests if device is stopped
2353                  * except path verification requests
2354                  */
2355                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2356                         if (interruptible) {
2357                                 rc = wait_event_interruptible(
2358                                         generic_waitq, !(device->stopped));
2359                                 if (rc == -ERESTARTSYS) {
2360                                         cqr->status = DASD_CQR_FAILED;
2361                                         maincqr->intrc = rc;
2362                                         continue;
2363                                 }
2364                         } else
2365                                 wait_event(generic_waitq, !(device->stopped));
2366                 }
2367                 if (!cqr->callback)
2368                         cqr->callback = dasd_wakeup_cb;
2369
2370                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2371                 dasd_add_request_tail(cqr);
2372                 if (interruptible) {
2373                         rc = wait_event_interruptible(
2374                                 generic_waitq, _wait_for_wakeup(cqr));
2375                         if (rc == -ERESTARTSYS) {
2376                                 dasd_cancel_req(cqr);
2377                                 /* wait (non-interruptible) for final status */
2378                                 wait_event(generic_waitq,
2379                                            _wait_for_wakeup(cqr));
2380                                 cqr->status = DASD_CQR_FAILED;
2381                                 maincqr->intrc = rc;
2382                                 continue;
2383                         }
2384                 } else
2385                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2386         }
2387
2388         maincqr->endclk = get_tod_clock();
2389         if ((maincqr->status != DASD_CQR_DONE) &&
2390             (maincqr->intrc != -ERESTARTSYS))
2391                 dasd_log_sense(maincqr, &maincqr->irb);
2392         if (maincqr->status == DASD_CQR_DONE)
2393                 rc = 0;
2394         else if (maincqr->intrc)
2395                 rc = maincqr->intrc;
2396         else
2397                 rc = -EIO;
2398         return rc;
2399 }
2400
2401 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2402 {
2403         struct dasd_ccw_req *cqr;
2404
2405         list_for_each_entry(cqr, ccw_queue, blocklist) {
2406                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2407                         return 0;
2408         }
2409
2410         return 1;
2411 }
2412
2413 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2414 {
2415         struct dasd_device *device;
2416         struct dasd_ccw_req *cqr, *n;
2417         u8 *sense = NULL;
2418         int rc;
2419
2420 retry:
2421         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2422                 device = cqr->startdev;
2423                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2424                         continue;
2425
2426                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2427                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2428                         cqr->status = DASD_CQR_FAILED;
2429                         cqr->intrc = -EPERM;
2430                         continue;
2431                 }
2432                 /*Non-temporary stop condition will trigger fail fast*/
2433                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2434                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2435                     !dasd_eer_enabled(device)) {
2436                         cqr->status = DASD_CQR_FAILED;
2437                         cqr->intrc = -EAGAIN;
2438                         continue;
2439                 }
2440
2441                 /*Don't try to start requests if device is stopped*/
2442                 if (interruptible) {
2443                         rc = wait_event_interruptible(
2444                                 generic_waitq, !device->stopped);
2445                         if (rc == -ERESTARTSYS) {
2446                                 cqr->status = DASD_CQR_FAILED;
2447                                 cqr->intrc = rc;
2448                                 continue;
2449                         }
2450                 } else
2451                         wait_event(generic_waitq, !(device->stopped));
2452
2453                 if (!cqr->callback)
2454                         cqr->callback = dasd_wakeup_cb;
2455                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2456                 dasd_add_request_tail(cqr);
2457         }
2458
2459         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2460
2461         rc = 0;
2462         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2463                 /*
2464                  * In some cases the 'File Protected' or 'Incorrect Length'
2465                  * error might be expected and error recovery would be
2466                  * unnecessary in these cases.  Check if the according suppress
2467                  * bit is set.
2468                  */
2469                 sense = dasd_get_sense(&cqr->irb);
2470                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2471                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2472                         continue;
2473                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2474                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2475                         continue;
2476
2477                 /*
2478                  * for alias devices simplify error recovery and
2479                  * return to upper layer
2480                  * do not skip ERP requests
2481                  */
2482                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2483                     (cqr->status == DASD_CQR_TERMINATED ||
2484                      cqr->status == DASD_CQR_NEED_ERP))
2485                         return -EAGAIN;
2486
2487                 /* normal recovery for basedev IO */
2488                 if (__dasd_sleep_on_erp(cqr))
2489                         /* handle erp first */
2490                         goto retry;
2491         }
2492
2493         return 0;
2494 }
2495
2496 /*
2497  * Queue a request to the tail of the device ccw_queue and wait for
2498  * it's completion.
2499  */
2500 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2501 {
2502         return _dasd_sleep_on(cqr, 0);
2503 }
2504 EXPORT_SYMBOL(dasd_sleep_on);
2505
2506 /*
2507  * Start requests from a ccw_queue and wait for their completion.
2508  */
2509 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2510 {
2511         return _dasd_sleep_on_queue(ccw_queue, 0);
2512 }
2513 EXPORT_SYMBOL(dasd_sleep_on_queue);
2514
2515 /*
2516  * Start requests from a ccw_queue and wait interruptible for their completion.
2517  */
2518 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2519 {
2520         return _dasd_sleep_on_queue(ccw_queue, 1);
2521 }
2522 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2523
2524 /*
2525  * Queue a request to the tail of the device ccw_queue and wait
2526  * interruptible for it's completion.
2527  */
2528 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2529 {
2530         return _dasd_sleep_on(cqr, 1);
2531 }
2532 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2533
2534 /*
2535  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2536  * for eckd devices) the currently running request has to be terminated
2537  * and be put back to status queued, before the special request is added
2538  * to the head of the queue. Then the special request is waited on normally.
2539  */
2540 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2541 {
2542         struct dasd_ccw_req *cqr;
2543         int rc;
2544
2545         if (list_empty(&device->ccw_queue))
2546                 return 0;
2547         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2548         rc = device->discipline->term_IO(cqr);
2549         if (!rc)
2550                 /*
2551                  * CQR terminated because a more important request is pending.
2552                  * Undo decreasing of retry counter because this is
2553                  * not an error case.
2554                  */
2555                 cqr->retries++;
2556         return rc;
2557 }
2558
2559 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2560 {
2561         struct dasd_device *device;
2562         int rc;
2563
2564         device = cqr->startdev;
2565         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2566             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2567                 cqr->status = DASD_CQR_FAILED;
2568                 cqr->intrc = -EPERM;
2569                 return -EIO;
2570         }
2571         spin_lock_irq(get_ccwdev_lock(device->cdev));
2572         rc = _dasd_term_running_cqr(device);
2573         if (rc) {
2574                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2575                 return rc;
2576         }
2577         cqr->callback = dasd_wakeup_cb;
2578         cqr->callback_data = DASD_SLEEPON_START_TAG;
2579         cqr->status = DASD_CQR_QUEUED;
2580         /*
2581          * add new request as second
2582          * first the terminated cqr needs to be finished
2583          */
2584         list_add(&cqr->devlist, device->ccw_queue.next);
2585
2586         /* let the bh start the request to keep them in order */
2587         dasd_schedule_device_bh(device);
2588
2589         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2590
2591         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2592
2593         if (cqr->status == DASD_CQR_DONE)
2594                 rc = 0;
2595         else if (cqr->intrc)
2596                 rc = cqr->intrc;
2597         else
2598                 rc = -EIO;
2599
2600         /* kick tasklets */
2601         dasd_schedule_device_bh(device);
2602         if (device->block)
2603                 dasd_schedule_block_bh(device->block);
2604
2605         return rc;
2606 }
2607 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2608
2609 /*
2610  * Cancels a request that was started with dasd_sleep_on_req.
2611  * This is useful to timeout requests. The request will be
2612  * terminated if it is currently in i/o.
2613  * Returns 0 if request termination was successful
2614  *         negative error code if termination failed
2615  * Cancellation of a request is an asynchronous operation! The calling
2616  * function has to wait until the request is properly returned via callback.
2617  */
2618 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2619 {
2620         struct dasd_device *device = cqr->startdev;
2621         int rc = 0;
2622
2623         switch (cqr->status) {
2624         case DASD_CQR_QUEUED:
2625                 /* request was not started - just set to cleared */
2626                 cqr->status = DASD_CQR_CLEARED;
2627                 break;
2628         case DASD_CQR_IN_IO:
2629                 /* request in IO - terminate IO and release again */
2630                 rc = device->discipline->term_IO(cqr);
2631                 if (rc) {
2632                         dev_err(&device->cdev->dev,
2633                                 "Cancelling request %p failed with rc=%d\n",
2634                                 cqr, rc);
2635                 } else {
2636                         cqr->stopclk = get_tod_clock();
2637                 }
2638                 break;
2639         default: /* already finished or clear pending - do nothing */
2640                 break;
2641         }
2642         dasd_schedule_device_bh(device);
2643         return rc;
2644 }
2645
2646 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2647 {
2648         struct dasd_device *device = cqr->startdev;
2649         unsigned long flags;
2650         int rc;
2651
2652         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2653         rc = __dasd_cancel_req(cqr);
2654         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2655         return rc;
2656 }
2657
2658 /*
2659  * SECTION: Operations of the dasd_block layer.
2660  */
2661
2662 /*
2663  * Timeout function for dasd_block. This is used when the block layer
2664  * is waiting for something that may not come reliably, (e.g. a state
2665  * change interrupt)
2666  */
2667 static void dasd_block_timeout(struct timer_list *t)
2668 {
2669         unsigned long flags;
2670         struct dasd_block *block;
2671
2672         block = from_timer(block, t, timer);
2673         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2674         /* re-activate request queue */
2675         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2676         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2677         dasd_schedule_block_bh(block);
2678         blk_mq_run_hw_queues(block->request_queue, true);
2679 }
2680
2681 /*
2682  * Setup timeout for a dasd_block in jiffies.
2683  */
2684 void dasd_block_set_timer(struct dasd_block *block, int expires)
2685 {
2686         if (expires == 0)
2687                 del_timer(&block->timer);
2688         else
2689                 mod_timer(&block->timer, jiffies + expires);
2690 }
2691 EXPORT_SYMBOL(dasd_block_set_timer);
2692
2693 /*
2694  * Clear timeout for a dasd_block.
2695  */
2696 void dasd_block_clear_timer(struct dasd_block *block)
2697 {
2698         del_timer(&block->timer);
2699 }
2700 EXPORT_SYMBOL(dasd_block_clear_timer);
2701
2702 /*
2703  * Process finished error recovery ccw.
2704  */
2705 static void __dasd_process_erp(struct dasd_device *device,
2706                                struct dasd_ccw_req *cqr)
2707 {
2708         dasd_erp_fn_t erp_fn;
2709
2710         if (cqr->status == DASD_CQR_DONE)
2711                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2712         else
2713                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2714         erp_fn = device->discipline->erp_postaction(cqr);
2715         erp_fn(cqr);
2716 }
2717
2718 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2719 {
2720         struct request *req;
2721         blk_status_t error = BLK_STS_OK;
2722         unsigned int proc_bytes;
2723         int status;
2724
2725         req = (struct request *) cqr->callback_data;
2726         dasd_profile_end(cqr->block, cqr, req);
2727
2728         proc_bytes = cqr->proc_bytes;
2729         status = cqr->block->base->discipline->free_cp(cqr, req);
2730         if (status < 0)
2731                 error = errno_to_blk_status(status);
2732         else if (status == 0) {
2733                 switch (cqr->intrc) {
2734                 case -EPERM:
2735                         error = BLK_STS_NEXUS;
2736                         break;
2737                 case -ENOLINK:
2738                         error = BLK_STS_TRANSPORT;
2739                         break;
2740                 case -ETIMEDOUT:
2741                         error = BLK_STS_TIMEOUT;
2742                         break;
2743                 default:
2744                         error = BLK_STS_IOERR;
2745                         break;
2746                 }
2747         }
2748
2749         /*
2750          * We need to take care for ETIMEDOUT errors here since the
2751          * complete callback does not get called in this case.
2752          * Take care of all errors here and avoid additional code to
2753          * transfer the error value to the complete callback.
2754          */
2755         if (error) {
2756                 blk_mq_end_request(req, error);
2757                 blk_mq_run_hw_queues(req->q, true);
2758         } else {
2759                 /*
2760                  * Partial completed requests can happen with ESE devices.
2761                  * During read we might have gotten a NRF error and have to
2762                  * complete a request partially.
2763                  */
2764                 if (proc_bytes) {
2765                         blk_update_request(req, BLK_STS_OK,
2766                                            blk_rq_bytes(req) - proc_bytes);
2767                         blk_mq_requeue_request(req, true);
2768                 } else if (likely(!blk_should_fake_timeout(req->q))) {
2769                         blk_mq_complete_request(req);
2770                 }
2771         }
2772 }
2773
2774 /*
2775  * Process ccw request queue.
2776  */
2777 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2778                                            struct list_head *final_queue)
2779 {
2780         struct list_head *l, *n;
2781         struct dasd_ccw_req *cqr;
2782         dasd_erp_fn_t erp_fn;
2783         unsigned long flags;
2784         struct dasd_device *base = block->base;
2785
2786 restart:
2787         /* Process request with final status. */
2788         list_for_each_safe(l, n, &block->ccw_queue) {
2789                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2790                 if (cqr->status != DASD_CQR_DONE &&
2791                     cqr->status != DASD_CQR_FAILED &&
2792                     cqr->status != DASD_CQR_NEED_ERP &&
2793                     cqr->status != DASD_CQR_TERMINATED)
2794                         continue;
2795
2796                 if (cqr->status == DASD_CQR_TERMINATED) {
2797                         base->discipline->handle_terminated_request(cqr);
2798                         goto restart;
2799                 }
2800
2801                 /*  Process requests that may be recovered */
2802                 if (cqr->status == DASD_CQR_NEED_ERP) {
2803                         erp_fn = base->discipline->erp_action(cqr);
2804                         if (IS_ERR(erp_fn(cqr)))
2805                                 continue;
2806                         goto restart;
2807                 }
2808
2809                 /* log sense for fatal error */
2810                 if (cqr->status == DASD_CQR_FAILED) {
2811                         dasd_log_sense(cqr, &cqr->irb);
2812                 }
2813
2814                 /* First of all call extended error reporting. */
2815                 if (dasd_eer_enabled(base) &&
2816                     cqr->status == DASD_CQR_FAILED) {
2817                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2818
2819                         /* restart request  */
2820                         cqr->status = DASD_CQR_FILLED;
2821                         cqr->retries = 255;
2822                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2823                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2824                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2825                                                flags);
2826                         goto restart;
2827                 }
2828
2829                 /* Process finished ERP request. */
2830                 if (cqr->refers) {
2831                         __dasd_process_erp(base, cqr);
2832                         goto restart;
2833                 }
2834
2835                 /* Rechain finished requests to final queue */
2836                 cqr->endclk = get_tod_clock();
2837                 list_move_tail(&cqr->blocklist, final_queue);
2838         }
2839 }
2840
2841 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2842 {
2843         dasd_schedule_block_bh(cqr->block);
2844 }
2845
2846 static void __dasd_block_start_head(struct dasd_block *block)
2847 {
2848         struct dasd_ccw_req *cqr;
2849
2850         if (list_empty(&block->ccw_queue))
2851                 return;
2852         /* We allways begin with the first requests on the queue, as some
2853          * of previously started requests have to be enqueued on a
2854          * dasd_device again for error recovery.
2855          */
2856         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2857                 if (cqr->status != DASD_CQR_FILLED)
2858                         continue;
2859                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2860                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2861                         cqr->status = DASD_CQR_FAILED;
2862                         cqr->intrc = -EPERM;
2863                         dasd_schedule_block_bh(block);
2864                         continue;
2865                 }
2866                 /* Non-temporary stop condition will trigger fail fast */
2867                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2868                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2869                     (!dasd_eer_enabled(block->base))) {
2870                         cqr->status = DASD_CQR_FAILED;
2871                         cqr->intrc = -ENOLINK;
2872                         dasd_schedule_block_bh(block);
2873                         continue;
2874                 }
2875                 /* Don't try to start requests if device is stopped */
2876                 if (block->base->stopped)
2877                         return;
2878
2879                 /* just a fail safe check, should not happen */
2880                 if (!cqr->startdev)
2881                         cqr->startdev = block->base;
2882
2883                 /* make sure that the requests we submit find their way back */
2884                 cqr->callback = dasd_return_cqr_cb;
2885
2886                 dasd_add_request_tail(cqr);
2887         }
2888 }
2889
2890 /*
2891  * Central dasd_block layer routine. Takes requests from the generic
2892  * block layer request queue, creates ccw requests, enqueues them on
2893  * a dasd_device and processes ccw requests that have been returned.
2894  */
2895 static void dasd_block_tasklet(unsigned long data)
2896 {
2897         struct dasd_block *block = (struct dasd_block *) data;
2898         struct list_head final_queue;
2899         struct list_head *l, *n;
2900         struct dasd_ccw_req *cqr;
2901         struct dasd_queue *dq;
2902
2903         atomic_set(&block->tasklet_scheduled, 0);
2904         INIT_LIST_HEAD(&final_queue);
2905         spin_lock_irq(&block->queue_lock);
2906         /* Finish off requests on ccw queue */
2907         __dasd_process_block_ccw_queue(block, &final_queue);
2908         spin_unlock_irq(&block->queue_lock);
2909
2910         /* Now call the callback function of requests with final status */
2911         list_for_each_safe(l, n, &final_queue) {
2912                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2913                 dq = cqr->dq;
2914                 spin_lock_irq(&dq->lock);
2915                 list_del_init(&cqr->blocklist);
2916                 __dasd_cleanup_cqr(cqr);
2917                 spin_unlock_irq(&dq->lock);
2918         }
2919
2920         spin_lock_irq(&block->queue_lock);
2921         /* Now check if the head of the ccw queue needs to be started. */
2922         __dasd_block_start_head(block);
2923         spin_unlock_irq(&block->queue_lock);
2924
2925         if (waitqueue_active(&shutdown_waitq))
2926                 wake_up(&shutdown_waitq);
2927         dasd_put_device(block->base);
2928 }
2929
2930 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2931 {
2932         wake_up(&dasd_flush_wq);
2933 }
2934
2935 /*
2936  * Requeue a request back to the block request queue
2937  * only works for block requests
2938  */
2939 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2940 {
2941         struct dasd_block *block = cqr->block;
2942         struct request *req;
2943
2944         if (!block)
2945                 return -EINVAL;
2946         /*
2947          * If the request is an ERP request there is nothing to requeue.
2948          * This will be done with the remaining original request.
2949          */
2950         if (cqr->refers)
2951                 return 0;
2952         spin_lock_irq(&cqr->dq->lock);
2953         req = (struct request *) cqr->callback_data;
2954         blk_mq_requeue_request(req, false);
2955         spin_unlock_irq(&cqr->dq->lock);
2956
2957         return 0;
2958 }
2959
2960 /*
2961  * Go through all request on the dasd_block request queue, cancel them
2962  * on the respective dasd_device, and return them to the generic
2963  * block layer.
2964  */
2965 static int dasd_flush_block_queue(struct dasd_block *block)
2966 {
2967         struct dasd_ccw_req *cqr, *n;
2968         int rc, i;
2969         struct list_head flush_queue;
2970         unsigned long flags;
2971
2972         INIT_LIST_HEAD(&flush_queue);
2973         spin_lock_bh(&block->queue_lock);
2974         rc = 0;
2975 restart:
2976         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2977                 /* if this request currently owned by a dasd_device cancel it */
2978                 if (cqr->status >= DASD_CQR_QUEUED)
2979                         rc = dasd_cancel_req(cqr);
2980                 if (rc < 0)
2981                         break;
2982                 /* Rechain request (including erp chain) so it won't be
2983                  * touched by the dasd_block_tasklet anymore.
2984                  * Replace the callback so we notice when the request
2985                  * is returned from the dasd_device layer.
2986                  */
2987                 cqr->callback = _dasd_wake_block_flush_cb;
2988                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2989                         list_move_tail(&cqr->blocklist, &flush_queue);
2990                 if (i > 1)
2991                         /* moved more than one request - need to restart */
2992                         goto restart;
2993         }
2994         spin_unlock_bh(&block->queue_lock);
2995         /* Now call the callback function of flushed requests */
2996 restart_cb:
2997         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2998                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2999                 /* Process finished ERP request. */
3000                 if (cqr->refers) {
3001                         spin_lock_bh(&block->queue_lock);
3002                         __dasd_process_erp(block->base, cqr);
3003                         spin_unlock_bh(&block->queue_lock);
3004                         /* restart list_for_xx loop since dasd_process_erp
3005                          * might remove multiple elements */
3006                         goto restart_cb;
3007                 }
3008                 /* call the callback function */
3009                 spin_lock_irqsave(&cqr->dq->lock, flags);
3010                 cqr->endclk = get_tod_clock();
3011                 list_del_init(&cqr->blocklist);
3012                 __dasd_cleanup_cqr(cqr);
3013                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3014         }
3015         return rc;
3016 }
3017
3018 /*
3019  * Schedules a call to dasd_tasklet over the device tasklet.
3020  */
3021 void dasd_schedule_block_bh(struct dasd_block *block)
3022 {
3023         /* Protect against rescheduling. */
3024         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3025                 return;
3026         /* life cycle of block is bound to it's base device */
3027         dasd_get_device(block->base);
3028         tasklet_hi_schedule(&block->tasklet);
3029 }
3030 EXPORT_SYMBOL(dasd_schedule_block_bh);
3031
3032
3033 /*
3034  * SECTION: external block device operations
3035  * (request queue handling, open, release, etc.)
3036  */
3037
3038 /*
3039  * Dasd request queue function. Called from ll_rw_blk.c
3040  */
3041 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3042                                     const struct blk_mq_queue_data *qd)
3043 {
3044         struct dasd_block *block = hctx->queue->queuedata;
3045         struct dasd_queue *dq = hctx->driver_data;
3046         struct request *req = qd->rq;
3047         struct dasd_device *basedev;
3048         struct dasd_ccw_req *cqr;
3049         blk_status_t rc = BLK_STS_OK;
3050
3051         basedev = block->base;
3052         spin_lock_irq(&dq->lock);
3053         if (basedev->state < DASD_STATE_READY ||
3054             test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3055                 DBF_DEV_EVENT(DBF_ERR, basedev,
3056                               "device not ready for request %p", req);
3057                 rc = BLK_STS_IOERR;
3058                 goto out;
3059         }
3060
3061         /*
3062          * if device is stopped do not fetch new requests
3063          * except failfast is active which will let requests fail
3064          * immediately in __dasd_block_start_head()
3065          */
3066         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3067                 DBF_DEV_EVENT(DBF_ERR, basedev,
3068                               "device stopped request %p", req);
3069                 rc = BLK_STS_RESOURCE;
3070                 goto out;
3071         }
3072
3073         if (basedev->features & DASD_FEATURE_READONLY &&
3074             rq_data_dir(req) == WRITE) {
3075                 DBF_DEV_EVENT(DBF_ERR, basedev,
3076                               "Rejecting write request %p", req);
3077                 rc = BLK_STS_IOERR;
3078                 goto out;
3079         }
3080
3081         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3082             (basedev->features & DASD_FEATURE_FAILFAST ||
3083              blk_noretry_request(req))) {
3084                 DBF_DEV_EVENT(DBF_ERR, basedev,
3085                               "Rejecting failfast request %p", req);
3086                 rc = BLK_STS_IOERR;
3087                 goto out;
3088         }
3089
3090         cqr = basedev->discipline->build_cp(basedev, block, req);
3091         if (IS_ERR(cqr)) {
3092                 if (PTR_ERR(cqr) == -EBUSY ||
3093                     PTR_ERR(cqr) == -ENOMEM ||
3094                     PTR_ERR(cqr) == -EAGAIN) {
3095                         rc = BLK_STS_RESOURCE;
3096                         goto out;
3097                 }
3098                 DBF_DEV_EVENT(DBF_ERR, basedev,
3099                               "CCW creation failed (rc=%ld) on request %p",
3100                               PTR_ERR(cqr), req);
3101                 rc = BLK_STS_IOERR;
3102                 goto out;
3103         }
3104         /*
3105          *  Note: callback is set to dasd_return_cqr_cb in
3106          * __dasd_block_start_head to cover erp requests as well
3107          */
3108         cqr->callback_data = req;
3109         cqr->status = DASD_CQR_FILLED;
3110         cqr->dq = dq;
3111
3112         blk_mq_start_request(req);
3113         spin_lock(&block->queue_lock);
3114         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3115         INIT_LIST_HEAD(&cqr->devlist);
3116         dasd_profile_start(block, cqr, req);
3117         dasd_schedule_block_bh(block);
3118         spin_unlock(&block->queue_lock);
3119
3120 out:
3121         spin_unlock_irq(&dq->lock);
3122         return rc;
3123 }
3124
3125 /*
3126  * Block timeout callback, called from the block layer
3127  *
3128  * Return values:
3129  * BLK_EH_RESET_TIMER if the request should be left running
3130  * BLK_EH_DONE if the request is handled or terminated
3131  *                    by the driver.
3132  */
3133 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3134 {
3135         struct dasd_block *block = req->q->queuedata;
3136         struct dasd_device *device;
3137         struct dasd_ccw_req *cqr;
3138         unsigned long flags;
3139         int rc = 0;
3140
3141         cqr = blk_mq_rq_to_pdu(req);
3142         if (!cqr)
3143                 return BLK_EH_DONE;
3144
3145         spin_lock_irqsave(&cqr->dq->lock, flags);
3146         device = cqr->startdev ? cqr->startdev : block->base;
3147         if (!device->blk_timeout) {
3148                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3149                 return BLK_EH_RESET_TIMER;
3150         }
3151         DBF_DEV_EVENT(DBF_WARNING, device,
3152                       " dasd_times_out cqr %p status %x",
3153                       cqr, cqr->status);
3154
3155         spin_lock(&block->queue_lock);
3156         spin_lock(get_ccwdev_lock(device->cdev));
3157         cqr->retries = -1;
3158         cqr->intrc = -ETIMEDOUT;
3159         if (cqr->status >= DASD_CQR_QUEUED) {
3160                 rc = __dasd_cancel_req(cqr);
3161         } else if (cqr->status == DASD_CQR_FILLED ||
3162                    cqr->status == DASD_CQR_NEED_ERP) {
3163                 cqr->status = DASD_CQR_TERMINATED;
3164         } else if (cqr->status == DASD_CQR_IN_ERP) {
3165                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3166
3167                 list_for_each_entry_safe(searchcqr, nextcqr,
3168                                          &block->ccw_queue, blocklist) {
3169                         tmpcqr = searchcqr;
3170                         while (tmpcqr->refers)
3171                                 tmpcqr = tmpcqr->refers;
3172                         if (tmpcqr != cqr)
3173                                 continue;
3174                         /* searchcqr is an ERP request for cqr */
3175                         searchcqr->retries = -1;
3176                         searchcqr->intrc = -ETIMEDOUT;
3177                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3178                                 rc = __dasd_cancel_req(searchcqr);
3179                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3180                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3181                                 searchcqr->status = DASD_CQR_TERMINATED;
3182                                 rc = 0;
3183                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3184                                 /*
3185                                  * Shouldn't happen; most recent ERP
3186                                  * request is at the front of queue
3187                                  */
3188                                 continue;
3189                         }
3190                         break;
3191                 }
3192         }
3193         spin_unlock(get_ccwdev_lock(device->cdev));
3194         dasd_schedule_block_bh(block);
3195         spin_unlock(&block->queue_lock);
3196         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3197
3198         return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3199 }
3200
3201 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3202                           unsigned int idx)
3203 {
3204         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3205
3206         if (!dq)
3207                 return -ENOMEM;
3208
3209         spin_lock_init(&dq->lock);
3210         hctx->driver_data = dq;
3211
3212         return 0;
3213 }
3214
3215 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3216 {
3217         kfree(hctx->driver_data);
3218         hctx->driver_data = NULL;
3219 }
3220
3221 static void dasd_request_done(struct request *req)
3222 {
3223         blk_mq_end_request(req, 0);
3224         blk_mq_run_hw_queues(req->q, true);
3225 }
3226
3227 static struct blk_mq_ops dasd_mq_ops = {
3228         .queue_rq = do_dasd_request,
3229         .complete = dasd_request_done,
3230         .timeout = dasd_times_out,
3231         .init_hctx = dasd_init_hctx,
3232         .exit_hctx = dasd_exit_hctx,
3233 };
3234
3235 /*
3236  * Allocate and initialize request queue and default I/O scheduler.
3237  */
3238 static int dasd_alloc_queue(struct dasd_block *block)
3239 {
3240         int rc;
3241
3242         block->tag_set.ops = &dasd_mq_ops;
3243         block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3244         block->tag_set.nr_hw_queues = nr_hw_queues;
3245         block->tag_set.queue_depth = queue_depth;
3246         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3247         block->tag_set.numa_node = NUMA_NO_NODE;
3248
3249         rc = blk_mq_alloc_tag_set(&block->tag_set);
3250         if (rc)
3251                 return rc;
3252
3253         block->request_queue = blk_mq_init_queue(&block->tag_set);
3254         if (IS_ERR(block->request_queue))
3255                 return PTR_ERR(block->request_queue);
3256
3257         block->request_queue->queuedata = block;
3258
3259         return 0;
3260 }
3261
3262 /*
3263  * Deactivate and free request queue.
3264  */
3265 static void dasd_free_queue(struct dasd_block *block)
3266 {
3267         if (block->request_queue) {
3268                 blk_cleanup_queue(block->request_queue);
3269                 blk_mq_free_tag_set(&block->tag_set);
3270                 block->request_queue = NULL;
3271         }
3272 }
3273
3274 static int dasd_open(struct block_device *bdev, fmode_t mode)
3275 {
3276         struct dasd_device *base;
3277         int rc;
3278
3279         base = dasd_device_from_gendisk(bdev->bd_disk);
3280         if (!base)
3281                 return -ENODEV;
3282
3283         atomic_inc(&base->block->open_count);
3284         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3285                 rc = -ENODEV;
3286                 goto unlock;
3287         }
3288
3289         if (!try_module_get(base->discipline->owner)) {
3290                 rc = -EINVAL;
3291                 goto unlock;
3292         }
3293
3294         if (dasd_probeonly) {
3295                 dev_info(&base->cdev->dev,
3296                          "Accessing the DASD failed because it is in "
3297                          "probeonly mode\n");
3298                 rc = -EPERM;
3299                 goto out;
3300         }
3301
3302         if (base->state <= DASD_STATE_BASIC) {
3303                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3304                               " Cannot open unrecognized device");
3305                 rc = -ENODEV;
3306                 goto out;
3307         }
3308
3309         if ((mode & FMODE_WRITE) &&
3310             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3311              (base->features & DASD_FEATURE_READONLY))) {
3312                 rc = -EROFS;
3313                 goto out;
3314         }
3315
3316         dasd_put_device(base);
3317         return 0;
3318
3319 out:
3320         module_put(base->discipline->owner);
3321 unlock:
3322         atomic_dec(&base->block->open_count);
3323         dasd_put_device(base);
3324         return rc;
3325 }
3326
3327 static void dasd_release(struct gendisk *disk, fmode_t mode)
3328 {
3329         struct dasd_device *base = dasd_device_from_gendisk(disk);
3330         if (base) {
3331                 atomic_dec(&base->block->open_count);
3332                 module_put(base->discipline->owner);
3333                 dasd_put_device(base);
3334         }
3335 }
3336
3337 /*
3338  * Return disk geometry.
3339  */
3340 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3341 {
3342         struct dasd_device *base;
3343
3344         base = dasd_device_from_gendisk(bdev->bd_disk);
3345         if (!base)
3346                 return -ENODEV;
3347
3348         if (!base->discipline ||
3349             !base->discipline->fill_geometry) {
3350                 dasd_put_device(base);
3351                 return -EINVAL;
3352         }
3353         base->discipline->fill_geometry(base->block, geo);
3354         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3355         dasd_put_device(base);
3356         return 0;
3357 }
3358
3359 const struct block_device_operations
3360 dasd_device_operations = {
3361         .owner          = THIS_MODULE,
3362         .open           = dasd_open,
3363         .release        = dasd_release,
3364         .ioctl          = dasd_ioctl,
3365         .compat_ioctl   = dasd_ioctl,
3366         .getgeo         = dasd_getgeo,
3367         .set_read_only  = dasd_set_read_only,
3368 };
3369
3370 /*******************************************************************************
3371  * end of block device operations
3372  */
3373
3374 static void
3375 dasd_exit(void)
3376 {
3377 #ifdef CONFIG_PROC_FS
3378         dasd_proc_exit();
3379 #endif
3380         dasd_eer_exit();
3381         kmem_cache_destroy(dasd_page_cache);
3382         dasd_page_cache = NULL;
3383         dasd_gendisk_exit();
3384         dasd_devmap_exit();
3385         if (dasd_debug_area != NULL) {
3386                 debug_unregister(dasd_debug_area);
3387                 dasd_debug_area = NULL;
3388         }
3389         dasd_statistics_removeroot();
3390 }
3391
3392 /*
3393  * SECTION: common functions for ccw_driver use
3394  */
3395
3396 /*
3397  * Is the device read-only?
3398  * Note that this function does not report the setting of the
3399  * readonly device attribute, but how it is configured in z/VM.
3400  */
3401 int dasd_device_is_ro(struct dasd_device *device)
3402 {
3403         struct ccw_dev_id dev_id;
3404         struct diag210 diag_data;
3405         int rc;
3406
3407         if (!MACHINE_IS_VM)
3408                 return 0;
3409         ccw_device_get_id(device->cdev, &dev_id);
3410         memset(&diag_data, 0, sizeof(diag_data));
3411         diag_data.vrdcdvno = dev_id.devno;
3412         diag_data.vrdclen = sizeof(diag_data);
3413         rc = diag210(&diag_data);
3414         if (rc == 0 || rc == 2) {
3415                 return diag_data.vrdcvfla & 0x80;
3416         } else {
3417                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3418                           dev_id.devno, rc);
3419                 return 0;
3420         }
3421 }
3422 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3423
3424 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3425 {
3426         struct ccw_device *cdev = data;
3427         int ret;
3428
3429         ret = ccw_device_set_online(cdev);
3430         if (ret)
3431                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3432                         dev_name(&cdev->dev), ret);
3433 }
3434
3435 /*
3436  * Initial attempt at a probe function. this can be simplified once
3437  * the other detection code is gone.
3438  */
3439 int dasd_generic_probe(struct ccw_device *cdev)
3440 {
3441         cdev->handler = &dasd_int_handler;
3442
3443         /*
3444          * Automatically online either all dasd devices (dasd_autodetect)
3445          * or all devices specified with dasd= parameters during
3446          * initial probe.
3447          */
3448         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3449             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3450                 async_schedule(dasd_generic_auto_online, cdev);
3451         return 0;
3452 }
3453 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3454
3455 void dasd_generic_free_discipline(struct dasd_device *device)
3456 {
3457         /* Forget the discipline information. */
3458         if (device->discipline) {
3459                 if (device->discipline->uncheck_device)
3460                         device->discipline->uncheck_device(device);
3461                 module_put(device->discipline->owner);
3462                 device->discipline = NULL;
3463         }
3464         if (device->base_discipline) {
3465                 module_put(device->base_discipline->owner);
3466                 device->base_discipline = NULL;
3467         }
3468 }
3469 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3470
3471 /*
3472  * This will one day be called from a global not_oper handler.
3473  * It is also used by driver_unregister during module unload.
3474  */
3475 void dasd_generic_remove(struct ccw_device *cdev)
3476 {
3477         struct dasd_device *device;
3478         struct dasd_block *block;
3479
3480         device = dasd_device_from_cdev(cdev);
3481         if (IS_ERR(device))
3482                 return;
3483
3484         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3485             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3486                 /* Already doing offline processing */
3487                 dasd_put_device(device);
3488                 return;
3489         }
3490         /*
3491          * This device is removed unconditionally. Set offline
3492          * flag to prevent dasd_open from opening it while it is
3493          * no quite down yet.
3494          */
3495         dasd_set_target_state(device, DASD_STATE_NEW);
3496         cdev->handler = NULL;
3497         /* dasd_delete_device destroys the device reference. */
3498         block = device->block;
3499         dasd_delete_device(device);
3500         /*
3501          * life cycle of block is bound to device, so delete it after
3502          * device was safely removed
3503          */
3504         if (block)
3505                 dasd_free_block(block);
3506 }
3507 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3508
3509 /*
3510  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3511  * the device is detected for the first time and is supposed to be used
3512  * or the user has started activation through sysfs.
3513  */
3514 int dasd_generic_set_online(struct ccw_device *cdev,
3515                             struct dasd_discipline *base_discipline)
3516 {
3517         struct dasd_discipline *discipline;
3518         struct dasd_device *device;
3519         int rc;
3520
3521         /* first online clears initial online feature flag */
3522         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3523         device = dasd_create_device(cdev);
3524         if (IS_ERR(device))
3525                 return PTR_ERR(device);
3526
3527         discipline = base_discipline;
3528         if (device->features & DASD_FEATURE_USEDIAG) {
3529                 if (!dasd_diag_discipline_pointer) {
3530                         /* Try to load the required module. */
3531                         rc = request_module(DASD_DIAG_MOD);
3532                         if (rc) {
3533                                 pr_warn("%s Setting the DASD online failed "
3534                                         "because the required module %s "
3535                                         "could not be loaded (rc=%d)\n",
3536                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3537                                         rc);
3538                                 dasd_delete_device(device);
3539                                 return -ENODEV;
3540                         }
3541                 }
3542                 /* Module init could have failed, so check again here after
3543                  * request_module(). */
3544                 if (!dasd_diag_discipline_pointer) {
3545                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3546                                 dev_name(&cdev->dev));
3547                         dasd_delete_device(device);
3548                         return -ENODEV;
3549                 }
3550                 discipline = dasd_diag_discipline_pointer;
3551         }
3552         if (!try_module_get(base_discipline->owner)) {
3553                 dasd_delete_device(device);
3554                 return -EINVAL;
3555         }
3556         if (!try_module_get(discipline->owner)) {
3557                 module_put(base_discipline->owner);
3558                 dasd_delete_device(device);
3559                 return -EINVAL;
3560         }
3561         device->base_discipline = base_discipline;
3562         device->discipline = discipline;
3563
3564         /* check_device will allocate block device if necessary */
3565         rc = discipline->check_device(device);
3566         if (rc) {
3567                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3568                         dev_name(&cdev->dev), discipline->name, rc);
3569                 module_put(discipline->owner);
3570                 module_put(base_discipline->owner);
3571                 dasd_delete_device(device);
3572                 return rc;
3573         }
3574
3575         dasd_set_target_state(device, DASD_STATE_ONLINE);
3576         if (device->state <= DASD_STATE_KNOWN) {
3577                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3578                         dev_name(&cdev->dev));
3579                 rc = -ENODEV;
3580                 dasd_set_target_state(device, DASD_STATE_NEW);
3581                 if (device->block)
3582                         dasd_free_block(device->block);
3583                 dasd_delete_device(device);
3584         } else
3585                 pr_debug("dasd_generic device %s found\n",
3586                                 dev_name(&cdev->dev));
3587
3588         wait_event(dasd_init_waitq, _wait_for_device(device));
3589
3590         dasd_put_device(device);
3591         return rc;
3592 }
3593 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3594
3595 int dasd_generic_set_offline(struct ccw_device *cdev)
3596 {
3597         struct dasd_device *device;
3598         struct dasd_block *block;
3599         int max_count, open_count, rc;
3600         unsigned long flags;
3601
3602         rc = 0;
3603         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3604         device = dasd_device_from_cdev_locked(cdev);
3605         if (IS_ERR(device)) {
3606                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3607                 return PTR_ERR(device);
3608         }
3609
3610         /*
3611          * We must make sure that this device is currently not in use.
3612          * The open_count is increased for every opener, that includes
3613          * the blkdev_get in dasd_scan_partitions. We are only interested
3614          * in the other openers.
3615          */
3616         if (device->block) {
3617                 max_count = device->block->bdev ? 0 : -1;
3618                 open_count = atomic_read(&device->block->open_count);
3619                 if (open_count > max_count) {
3620                         if (open_count > 0)
3621                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3622                                         dev_name(&cdev->dev), open_count);
3623                         else
3624                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3625                                         dev_name(&cdev->dev));
3626                         rc = -EBUSY;
3627                         goto out_err;
3628                 }
3629         }
3630
3631         /*
3632          * Test if the offline processing is already running and exit if so.
3633          * If a safe offline is being processed this could only be a normal
3634          * offline that should be able to overtake the safe offline and
3635          * cancel any I/O we do not want to wait for any longer
3636          */
3637         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3638                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3639                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3640                                   &device->flags);
3641                 } else {
3642                         rc = -EBUSY;
3643                         goto out_err;
3644                 }
3645         }
3646         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3647
3648         /*
3649          * if safe_offline is called set safe_offline_running flag and
3650          * clear safe_offline so that a call to normal offline
3651          * can overrun safe_offline processing
3652          */
3653         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3654             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3655                 /* need to unlock here to wait for outstanding I/O */
3656                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3657                 /*
3658                  * If we want to set the device safe offline all IO operations
3659                  * should be finished before continuing the offline process
3660                  * so sync bdev first and then wait for our queues to become
3661                  * empty
3662                  */
3663                 if (device->block) {
3664                         rc = fsync_bdev(device->block->bdev);
3665                         if (rc != 0)
3666                                 goto interrupted;
3667                 }
3668                 dasd_schedule_device_bh(device);
3669                 rc = wait_event_interruptible(shutdown_waitq,
3670                                               _wait_for_empty_queues(device));
3671                 if (rc != 0)
3672                         goto interrupted;
3673
3674                 /*
3675                  * check if a normal offline process overtook the offline
3676                  * processing in this case simply do nothing beside returning
3677                  * that we got interrupted
3678                  * otherwise mark safe offline as not running any longer and
3679                  * continue with normal offline
3680                  */
3681                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3682                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3683                         rc = -ERESTARTSYS;
3684                         goto out_err;
3685                 }
3686                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3687         }
3688         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3689
3690         dasd_set_target_state(device, DASD_STATE_NEW);
3691         /* dasd_delete_device destroys the device reference. */
3692         block = device->block;
3693         dasd_delete_device(device);
3694         /*
3695          * life cycle of block is bound to device, so delete it after
3696          * device was safely removed
3697          */
3698         if (block)
3699                 dasd_free_block(block);
3700
3701         return 0;
3702
3703 interrupted:
3704         /* interrupted by signal */
3705         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3706         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3707         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3708 out_err:
3709         dasd_put_device(device);
3710         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3711         return rc;
3712 }
3713 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3714
3715 int dasd_generic_last_path_gone(struct dasd_device *device)
3716 {
3717         struct dasd_ccw_req *cqr;
3718
3719         dev_warn(&device->cdev->dev, "No operational channel path is left "
3720                  "for the device\n");
3721         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3722         /* First of all call extended error reporting. */
3723         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3724
3725         if (device->state < DASD_STATE_BASIC)
3726                 return 0;
3727         /* Device is active. We want to keep it. */
3728         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3729                 if ((cqr->status == DASD_CQR_IN_IO) ||
3730                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3731                         cqr->status = DASD_CQR_QUEUED;
3732                         cqr->retries++;
3733                 }
3734         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3735         dasd_device_clear_timer(device);
3736         dasd_schedule_device_bh(device);
3737         return 1;
3738 }
3739 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3740
3741 int dasd_generic_path_operational(struct dasd_device *device)
3742 {
3743         dev_info(&device->cdev->dev, "A channel path to the device has become "
3744                  "operational\n");
3745         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3746         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3747         dasd_schedule_device_bh(device);
3748         if (device->block) {
3749                 dasd_schedule_block_bh(device->block);
3750                 if (device->block->request_queue)
3751                         blk_mq_run_hw_queues(device->block->request_queue,
3752                                              true);
3753                 }
3754
3755         if (!device->stopped)
3756                 wake_up(&generic_waitq);
3757
3758         return 1;
3759 }
3760 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3761
3762 int dasd_generic_notify(struct ccw_device *cdev, int event)
3763 {
3764         struct dasd_device *device;
3765         int ret;
3766
3767         device = dasd_device_from_cdev_locked(cdev);
3768         if (IS_ERR(device))
3769                 return 0;
3770         ret = 0;
3771         switch (event) {
3772         case CIO_GONE:
3773         case CIO_BOXED:
3774         case CIO_NO_PATH:
3775                 dasd_path_no_path(device);
3776                 ret = dasd_generic_last_path_gone(device);
3777                 break;
3778         case CIO_OPER:
3779                 ret = 1;
3780                 if (dasd_path_get_opm(device))
3781                         ret = dasd_generic_path_operational(device);
3782                 break;
3783         }
3784         dasd_put_device(device);
3785         return ret;
3786 }
3787 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3788
3789 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3790 {
3791         struct dasd_device *device;
3792         int chp, oldopm, hpfpm, ifccpm;
3793
3794         device = dasd_device_from_cdev_locked(cdev);
3795         if (IS_ERR(device))
3796                 return;
3797
3798         oldopm = dasd_path_get_opm(device);
3799         for (chp = 0; chp < 8; chp++) {
3800                 if (path_event[chp] & PE_PATH_GONE) {
3801                         dasd_path_notoper(device, chp);
3802                 }
3803                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3804                         dasd_path_available(device, chp);
3805                         dasd_schedule_device_bh(device);
3806                 }
3807                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3808                         if (!dasd_path_is_operational(device, chp) &&
3809                             !dasd_path_need_verify(device, chp)) {
3810                                 /*
3811                                  * we can not establish a pathgroup on an
3812                                  * unavailable path, so trigger a path
3813                                  * verification first
3814                                  */
3815                         dasd_path_available(device, chp);
3816                         dasd_schedule_device_bh(device);
3817                         }
3818                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3819                                       "Pathgroup re-established\n");
3820                         if (device->discipline->kick_validate)
3821                                 device->discipline->kick_validate(device);
3822                 }
3823                 if (path_event[chp] & PE_PATH_FCES_EVENT) {
3824                         dasd_path_fcsec_update(device, chp);
3825                         dasd_schedule_device_bh(device);
3826                 }
3827         }
3828         hpfpm = dasd_path_get_hpfpm(device);
3829         ifccpm = dasd_path_get_ifccpm(device);
3830         if (!dasd_path_get_opm(device) && hpfpm) {
3831                 /*
3832                  * device has no operational paths but at least one path is
3833                  * disabled due to HPF errors
3834                  * disable HPF at all and use the path(s) again
3835                  */
3836                 if (device->discipline->disable_hpf)
3837                         device->discipline->disable_hpf(device);
3838                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3839                 dasd_path_set_tbvpm(device, hpfpm);
3840                 dasd_schedule_device_bh(device);
3841                 dasd_schedule_requeue(device);
3842         } else if (!dasd_path_get_opm(device) && ifccpm) {
3843                 /*
3844                  * device has no operational paths but at least one path is
3845                  * disabled due to IFCC errors
3846                  * trigger path verification on paths with IFCC errors
3847                  */
3848                 dasd_path_set_tbvpm(device, ifccpm);
3849                 dasd_schedule_device_bh(device);
3850         }
3851         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3852                 dev_warn(&device->cdev->dev,
3853                          "No verified channel paths remain for the device\n");
3854                 DBF_DEV_EVENT(DBF_WARNING, device,
3855                               "%s", "last verified path gone");
3856                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3857                 dasd_device_set_stop_bits(device,
3858                                           DASD_STOPPED_DC_WAIT);
3859         }
3860         dasd_put_device(device);
3861 }
3862 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3863
3864 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3865 {
3866         if (!dasd_path_get_opm(device) && lpm) {
3867                 dasd_path_set_opm(device, lpm);
3868                 dasd_generic_path_operational(device);
3869         } else
3870                 dasd_path_add_opm(device, lpm);
3871         return 0;
3872 }
3873 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3874
3875 void dasd_generic_space_exhaust(struct dasd_device *device,
3876                                 struct dasd_ccw_req *cqr)
3877 {
3878         dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3879
3880         if (device->state < DASD_STATE_BASIC)
3881                 return;
3882
3883         if (cqr->status == DASD_CQR_IN_IO ||
3884             cqr->status == DASD_CQR_CLEAR_PENDING) {
3885                 cqr->status = DASD_CQR_QUEUED;
3886                 cqr->retries++;
3887         }
3888         dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3889         dasd_device_clear_timer(device);
3890         dasd_schedule_device_bh(device);
3891 }
3892 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3893
3894 void dasd_generic_space_avail(struct dasd_device *device)
3895 {
3896         dev_info(&device->cdev->dev, "Extent pool space is available\n");
3897         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3898
3899         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3900         dasd_schedule_device_bh(device);
3901
3902         if (device->block) {
3903                 dasd_schedule_block_bh(device->block);
3904                 if (device->block->request_queue)
3905                         blk_mq_run_hw_queues(device->block->request_queue, true);
3906         }
3907         if (!device->stopped)
3908                 wake_up(&generic_waitq);
3909 }
3910 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3911
3912 /*
3913  * clear active requests and requeue them to block layer if possible
3914  */
3915 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3916 {
3917         struct list_head requeue_queue;
3918         struct dasd_ccw_req *cqr, *n;
3919         struct dasd_ccw_req *refers;
3920         int rc;
3921
3922         INIT_LIST_HEAD(&requeue_queue);
3923         spin_lock_irq(get_ccwdev_lock(device->cdev));
3924         rc = 0;
3925         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3926                 /* Check status and move request to flush_queue */
3927                 if (cqr->status == DASD_CQR_IN_IO) {
3928                         rc = device->discipline->term_IO(cqr);
3929                         if (rc) {
3930                                 /* unable to terminate requeust */
3931                                 dev_err(&device->cdev->dev,
3932                                         "Unable to terminate request %p "
3933                                         "on suspend\n", cqr);
3934                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3935                                 dasd_put_device(device);
3936                                 return rc;
3937                         }
3938                 }
3939                 list_move_tail(&cqr->devlist, &requeue_queue);
3940         }
3941         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3942
3943         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3944                 wait_event(dasd_flush_wq,
3945                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3946
3947                 /*
3948                  * requeue requests to blocklayer will only work
3949                  * for block device requests
3950                  */
3951                 if (_dasd_requeue_request(cqr))
3952                         continue;
3953
3954                 /* remove requests from device and block queue */
3955                 list_del_init(&cqr->devlist);
3956                 while (cqr->refers != NULL) {
3957                         refers = cqr->refers;
3958                         /* remove the request from the block queue */
3959                         list_del(&cqr->blocklist);
3960                         /* free the finished erp request */
3961                         dasd_free_erp_request(cqr, cqr->memdev);
3962                         cqr = refers;
3963                 }
3964
3965                 /*
3966                  * _dasd_requeue_request already checked for a valid
3967                  * blockdevice, no need to check again
3968                  * all erp requests (cqr->refers) have a cqr->block
3969                  * pointer copy from the original cqr
3970                  */
3971                 list_del_init(&cqr->blocklist);
3972                 cqr->block->base->discipline->free_cp(
3973                         cqr, (struct request *) cqr->callback_data);
3974         }
3975
3976         /*
3977          * if requests remain then they are internal request
3978          * and go back to the device queue
3979          */
3980         if (!list_empty(&requeue_queue)) {
3981                 /* move freeze_queue to start of the ccw_queue */
3982                 spin_lock_irq(get_ccwdev_lock(device->cdev));
3983                 list_splice_tail(&requeue_queue, &device->ccw_queue);
3984                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3985         }
3986         dasd_schedule_device_bh(device);
3987         return rc;
3988 }
3989
3990 static void do_requeue_requests(struct work_struct *work)
3991 {
3992         struct dasd_device *device = container_of(work, struct dasd_device,
3993                                                   requeue_requests);
3994         dasd_generic_requeue_all_requests(device);
3995         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3996         if (device->block)
3997                 dasd_schedule_block_bh(device->block);
3998         dasd_put_device(device);
3999 }
4000
4001 void dasd_schedule_requeue(struct dasd_device *device)
4002 {
4003         dasd_get_device(device);
4004         /* queue call to dasd_reload_device to the kernel event daemon. */
4005         if (!schedule_work(&device->requeue_requests))
4006                 dasd_put_device(device);
4007 }
4008 EXPORT_SYMBOL(dasd_schedule_requeue);
4009
4010 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4011                                                    int rdc_buffer_size,
4012                                                    int magic)
4013 {
4014         struct dasd_ccw_req *cqr;
4015         struct ccw1 *ccw;
4016
4017         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
4018                                    NULL);
4019
4020         if (IS_ERR(cqr)) {
4021                 /* internal error 13 - Allocating the RDC request failed*/
4022                 dev_err(&device->cdev->dev,
4023                          "An error occurred in the DASD device driver, "
4024                          "reason=%s\n", "13");
4025                 return cqr;
4026         }
4027
4028         ccw = cqr->cpaddr;
4029         ccw->cmd_code = CCW_CMD_RDC;
4030         ccw->cda = (__u32)(addr_t) cqr->data;
4031         ccw->flags = 0;
4032         ccw->count = rdc_buffer_size;
4033         cqr->startdev = device;
4034         cqr->memdev = device;
4035         cqr->expires = 10*HZ;
4036         cqr->retries = 256;
4037         cqr->buildclk = get_tod_clock();
4038         cqr->status = DASD_CQR_FILLED;
4039         return cqr;
4040 }
4041
4042
4043 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4044                                 void *rdc_buffer, int rdc_buffer_size)
4045 {
4046         int ret;
4047         struct dasd_ccw_req *cqr;
4048
4049         cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4050         if (IS_ERR(cqr))
4051                 return PTR_ERR(cqr);
4052
4053         ret = dasd_sleep_on(cqr);
4054         if (ret == 0)
4055                 memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4056         dasd_sfree_request(cqr, cqr->memdev);
4057         return ret;
4058 }
4059 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4060
4061 /*
4062  *   In command mode and transport mode we need to look for sense
4063  *   data in different places. The sense data itself is allways
4064  *   an array of 32 bytes, so we can unify the sense data access
4065  *   for both modes.
4066  */
4067 char *dasd_get_sense(struct irb *irb)
4068 {
4069         struct tsb *tsb = NULL;
4070         char *sense = NULL;
4071
4072         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4073                 if (irb->scsw.tm.tcw)
4074                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4075                                           irb->scsw.tm.tcw);
4076                 if (tsb && tsb->length == 64 && tsb->flags)
4077                         switch (tsb->flags & 0x07) {
4078                         case 1: /* tsa_iostat */
4079                                 sense = tsb->tsa.iostat.sense;
4080                                 break;
4081                         case 2: /* tsa_ddpc */
4082                                 sense = tsb->tsa.ddpc.sense;
4083                                 break;
4084                         default:
4085                                 /* currently we don't use interrogate data */
4086                                 break;
4087                         }
4088         } else if (irb->esw.esw0.erw.cons) {
4089                 sense = irb->ecw;
4090         }
4091         return sense;
4092 }
4093 EXPORT_SYMBOL_GPL(dasd_get_sense);
4094
4095 void dasd_generic_shutdown(struct ccw_device *cdev)
4096 {
4097         struct dasd_device *device;
4098
4099         device = dasd_device_from_cdev(cdev);
4100         if (IS_ERR(device))
4101                 return;
4102
4103         if (device->block)
4104                 dasd_schedule_block_bh(device->block);
4105
4106         dasd_schedule_device_bh(device);
4107
4108         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4109 }
4110 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4111
4112 static int __init dasd_init(void)
4113 {
4114         int rc;
4115
4116         init_waitqueue_head(&dasd_init_waitq);
4117         init_waitqueue_head(&dasd_flush_wq);
4118         init_waitqueue_head(&generic_waitq);
4119         init_waitqueue_head(&shutdown_waitq);
4120
4121         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4122         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4123         if (dasd_debug_area == NULL) {
4124                 rc = -ENOMEM;
4125                 goto failed;
4126         }
4127         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4128         debug_set_level(dasd_debug_area, DBF_WARNING);
4129
4130         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4131
4132         dasd_diag_discipline_pointer = NULL;
4133
4134         dasd_statistics_createroot();
4135
4136         rc = dasd_devmap_init();
4137         if (rc)
4138                 goto failed;
4139         rc = dasd_gendisk_init();
4140         if (rc)
4141                 goto failed;
4142         rc = dasd_parse();
4143         if (rc)
4144                 goto failed;
4145         rc = dasd_eer_init();
4146         if (rc)
4147                 goto failed;
4148 #ifdef CONFIG_PROC_FS
4149         rc = dasd_proc_init();
4150         if (rc)
4151                 goto failed;
4152 #endif
4153
4154         return 0;
4155 failed:
4156         pr_info("The DASD device driver could not be initialized\n");
4157         dasd_exit();
4158         return rc;
4159 }
4160
4161 module_init(dasd_init);
4162 module_exit(dasd_exit);