drivers/s390/block/dasd.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   8  * Copyright IBM Corp. 1999, 2009
   9  */
  10
  11 #define KMSG_COMPONENT "dasd"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kmod.h>
  15 #include <linux/init.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/ctype.h>
  18 #include <linux/major.h>
  19 #include <linux/slab.h>
  20 #include <linux/hdreg.h>
  21 #include <linux/async.h>
  22 #include <linux/mutex.h>
  23 #include <linux/debugfs.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/vmalloc.h>
  26
  27 #include <asm/ccwdev.h>
  28 #include <asm/ebcdic.h>
  29 #include <asm/idals.h>
  30 #include <asm/itcw.h>
  31 #include <asm/diag.h>
  32
  33 /* This is ugly... */
  34 #define PRINTK_HEADER "dasd:"
  35
  36 #include "dasd_int.h"
  37 /*
  38  * SECTION: Constant definitions to be used within this file
  39  */
  40 #define DASD_CHANQ_MAX_SIZE 4
  41
  42 #define DASD_DIAG_MOD           "dasd_diag_mod"
  43
  44 /*
  45  * SECTION: exported variables of dasd.c
  46  */
  47 debug_info_t *dasd_debug_area;
  48 EXPORT_SYMBOL(dasd_debug_area);
  49 static struct dentry *dasd_debugfs_root_entry;
  50 struct dasd_discipline *dasd_diag_discipline_pointer;
  51 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
  52 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
  53
  54 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
  55 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
  56                    " Copyright IBM Corp. 2000");
  57 MODULE_SUPPORTED_DEVICE("dasd");
  58 MODULE_LICENSE("GPL");
  59
  60 /*
  61  * SECTION: prototypes for static functions of dasd.c
  62  */
  63 static int  dasd_alloc_queue(struct dasd_block *);
  64 static void dasd_setup_queue(struct dasd_block *);
  65 static void dasd_free_queue(struct dasd_block *);
  66 static int dasd_flush_block_queue(struct dasd_block *);
  67 static void dasd_device_tasklet(struct dasd_device *);
  68 static void dasd_block_tasklet(struct dasd_block *);
  69 static void do_kick_device(struct work_struct *);
  70 static void do_restore_device(struct work_struct *);
  71 static void do_reload_device(struct work_struct *);
  72 static void do_requeue_requests(struct work_struct *);
  73 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  74 static void dasd_device_timeout(struct timer_list *);
  75 static void dasd_block_timeout(struct timer_list *);
  76 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
  77 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
  78 static void dasd_profile_exit(struct dasd_profile *);
  79 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
  80 static void dasd_hosts_exit(struct dasd_device *);
  81
  82 /*
  83  * SECTION: Operations on the device structure.
  84  */
  85 static wait_queue_head_t dasd_init_waitq;
  86 static wait_queue_head_t dasd_flush_wq;
  87 static wait_queue_head_t generic_waitq;
  88 static wait_queue_head_t shutdown_waitq;
  89
  90 /*
  91  * Allocate memory for a new device structure.
  92  */
  93 struct dasd_device *dasd_alloc_device(void)
  94 {
  95         struct dasd_device *device;
  96
  97         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  98         if (!device)
  99                 return ERR_PTR(-ENOMEM);
 100
 101         /* Get two pages for normal block device operations. */
 102         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 103         if (!device->ccw_mem) {
 104                 kfree(device);
 105                 return ERR_PTR(-ENOMEM);
 106         }
 107         /* Get one page for error recovery. */
 108         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 109         if (!device->erp_mem) {
 110                 free_pages((unsigned long) device->ccw_mem, 1);
 111                 kfree(device);
 112                 return ERR_PTR(-ENOMEM);
 113         }
 114
 115         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 116         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 117         spin_lock_init(&device->mem_lock);
 118         atomic_set(&device->tasklet_scheduled, 0);
 119         tasklet_init(&device->tasklet,
 120                      (void (*)(unsigned long)) dasd_device_tasklet,
 121                      (unsigned long) device);
 122         INIT_LIST_HEAD(&device->ccw_queue);
 123         timer_setup(&device->timer, dasd_device_timeout, 0);
 124         INIT_WORK(&device->kick_work, do_kick_device);
 125         INIT_WORK(&device->restore_device, do_restore_device);
 126         INIT_WORK(&device->reload_device, do_reload_device);
 127         INIT_WORK(&device->requeue_requests, do_requeue_requests);
 128         device->state = DASD_STATE_NEW;
 129         device->target = DASD_STATE_NEW;
 130         mutex_init(&device->state_mutex);
 131         spin_lock_init(&device->profile.lock);
 132         return device;
 133 }
 134
 135 /*
 136  * Free memory of a device structure.
 137  */
 138 void dasd_free_device(struct dasd_device *device)
 139 {
 140         kfree(device->private);
 141         free_page((unsigned long) device->erp_mem);
 142         free_pages((unsigned long) device->ccw_mem, 1);
 143         kfree(device);
 144 }
 145
 146 /*
 147  * Allocate memory for a new device structure.
 148  */
 149 struct dasd_block *dasd_alloc_block(void)
 150 {
 151         struct dasd_block *block;
 152
 153         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 154         if (!block)
 155                 return ERR_PTR(-ENOMEM);
 156         /* open_count = 0 means device online but not in use */
 157         atomic_set(&block->open_count, -1);
 158
 159         atomic_set(&block->tasklet_scheduled, 0);
 160         tasklet_init(&block->tasklet,
 161                      (void (*)(unsigned long)) dasd_block_tasklet,
 162                      (unsigned long) block);
 163         INIT_LIST_HEAD(&block->ccw_queue);
 164         spin_lock_init(&block->queue_lock);
 165         timer_setup(&block->timer, dasd_block_timeout, 0);
 166         spin_lock_init(&block->profile.lock);
 167
 168         return block;
 169 }
 170 EXPORT_SYMBOL_GPL(dasd_alloc_block);
 171
 172 /*
 173  * Free memory of a device structure.
 174  */
 175 void dasd_free_block(struct dasd_block *block)
 176 {
 177         kfree(block);
 178 }
 179 EXPORT_SYMBOL_GPL(dasd_free_block);
 180
 181 /*
 182  * Make a new device known to the system.
 183  */
 184 static int dasd_state_new_to_known(struct dasd_device *device)
 185 {
 186         int rc;
 187
 188         /*
 189          * As long as the device is not in state DASD_STATE_NEW we want to
 190          * keep the reference count > 0.
 191          */
 192         dasd_get_device(device);
 193
 194         if (device->block) {
 195                 rc = dasd_alloc_queue(device->block);
 196                 if (rc) {
 197                         dasd_put_device(device);
 198                         return rc;
 199                 }
 200         }
 201         device->state = DASD_STATE_KNOWN;
 202         return 0;
 203 }
 204
 205 /*
 206  * Let the system forget about a device.
 207  */
 208 static int dasd_state_known_to_new(struct dasd_device *device)
 209 {
 210         /* Disable extended error reporting for this device. */
 211         dasd_eer_disable(device);
 212         device->state = DASD_STATE_NEW;
 213
 214         if (device->block)
 215                 dasd_free_queue(device->block);
 216
 217         /* Give up reference we took in dasd_state_new_to_known. */
 218         dasd_put_device(device);
 219         return 0;
 220 }
 221
 222 static struct dentry *dasd_debugfs_setup(const char *name,
 223                                          struct dentry *base_dentry)
 224 {
 225         struct dentry *pde;
 226
 227         if (!base_dentry)
 228                 return NULL;
 229         pde = debugfs_create_dir(name, base_dentry);
 230         if (!pde || IS_ERR(pde))
 231                 return NULL;
 232         return pde;
 233 }
 234
 235 /*
 236  * Request the irq line for the device.
 237  */
 238 static int dasd_state_known_to_basic(struct dasd_device *device)
 239 {
 240         struct dasd_block *block = device->block;
 241         int rc = 0;
 242
 243         /* Allocate and register gendisk structure. */
 244         if (block) {
 245                 rc = dasd_gendisk_alloc(block);
 246                 if (rc)
 247                         return rc;
 248                 block->debugfs_dentry =
 249                         dasd_debugfs_setup(block->gdp->disk_name,
 250                                            dasd_debugfs_root_entry);
 251                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 252                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 253                         dasd_profile_on(&device->block->profile);
 254         }
 255         device->debugfs_dentry =
 256                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 257                                    dasd_debugfs_root_entry);
 258         dasd_profile_init(&device->profile, device->debugfs_dentry);
 259         dasd_hosts_init(device->debugfs_dentry, device);
 260
 261         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 262         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 263                                             8 * sizeof(long));
 264         debug_register_view(device->debug_area, &debug_sprintf_view);
 265         debug_set_level(device->debug_area, DBF_WARNING);
 266         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 267
 268         device->state = DASD_STATE_BASIC;
 269
 270         return rc;
 271 }
 272
 273 /*
 274  * Release the irq line for the device. Terminate any running i/o.
 275  */
 276 static int dasd_state_basic_to_known(struct dasd_device *device)
 277 {
 278         int rc;
 279
 280         if (device->discipline->basic_to_known) {
 281                 rc = device->discipline->basic_to_known(device);
 282                 if (rc)
 283                         return rc;
 284         }
 285
 286         if (device->block) {
 287                 dasd_profile_exit(&device->block->profile);
 288                 debugfs_remove(device->block->debugfs_dentry);
 289                 dasd_gendisk_free(device->block);
 290                 dasd_block_clear_timer(device->block);
 291         }
 292         rc = dasd_flush_device_queue(device);
 293         if (rc)
 294                 return rc;
 295         dasd_device_clear_timer(device);
 296         dasd_profile_exit(&device->profile);
 297         dasd_hosts_exit(device);
 298         debugfs_remove(device->debugfs_dentry);
 299         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 300         if (device->debug_area != NULL) {
 301                 debug_unregister(device->debug_area);
 302                 device->debug_area = NULL;
 303         }
 304         device->state = DASD_STATE_KNOWN;
 305         return 0;
 306 }
 307
 308 /*
 309  * Do the initial analysis. The do_analysis function may return
 310  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 311  * until the discipline decides to continue the startup sequence
 312  * by calling the function dasd_change_state. The eckd disciplines
 313  * uses this to start a ccw that detects the format. The completion
 314  * interrupt for this detection ccw uses the kernel event daemon to
 315  * trigger the call to dasd_change_state. All this is done in the
 316  * discipline code, see dasd_eckd.c.
 317  * After the analysis ccw is done (do_analysis returned 0) the block
 318  * device is setup.
 319  * In case the analysis returns an error, the device setup is stopped
 320  * (a fake disk was already added to allow formatting).
 321  */
 322 static int dasd_state_basic_to_ready(struct dasd_device *device)
 323 {
 324         int rc;
 325         struct dasd_block *block;
 326         struct gendisk *disk;
 327
 328         rc = 0;
 329         block = device->block;
 330         /* make disk known with correct capacity */
 331         if (block) {
 332                 if (block->base->discipline->do_analysis != NULL)
 333                         rc = block->base->discipline->do_analysis(block);
 334                 if (rc) {
 335                         if (rc != -EAGAIN) {
 336                                 device->state = DASD_STATE_UNFMT;
 337                                 disk = device->block->gdp;
 338                                 kobject_uevent(&disk_to_dev(disk)->kobj,
 339                                                KOBJ_CHANGE);
 340                                 goto out;
 341                         }
 342                         return rc;
 343                 }
 344                 dasd_setup_queue(block);
 345                 set_capacity(block->gdp,
 346                              block->blocks << block->s2b_shift);
 347                 device->state = DASD_STATE_READY;
 348                 rc = dasd_scan_partitions(block);
 349                 if (rc) {
 350                         device->state = DASD_STATE_BASIC;
 351                         return rc;
 352                 }
 353         } else {
 354                 device->state = DASD_STATE_READY;
 355         }
 356 out:
 357         if (device->discipline->basic_to_ready)
 358                 rc = device->discipline->basic_to_ready(device);
 359         return rc;
 360 }
 361
 362 static inline
 363 int _wait_for_empty_queues(struct dasd_device *device)
 364 {
 365         if (device->block)
 366                 return list_empty(&device->ccw_queue) &&
 367                         list_empty(&device->block->ccw_queue);
 368         else
 369                 return list_empty(&device->ccw_queue);
 370 }
 371
 372 /*
 373  * Remove device from block device layer. Destroy dirty buffers.
 374  * Forget format information. Check if the target level is basic
 375  * and if it is create fake disk for formatting.
 376  */
 377 static int dasd_state_ready_to_basic(struct dasd_device *device)
 378 {
 379         int rc;
 380
 381         device->state = DASD_STATE_BASIC;
 382         if (device->block) {
 383                 struct dasd_block *block = device->block;
 384                 rc = dasd_flush_block_queue(block);
 385                 if (rc) {
 386                         device->state = DASD_STATE_READY;
 387                         return rc;
 388                 }
 389                 dasd_destroy_partitions(block);
 390                 block->blocks = 0;
 391                 block->bp_block = 0;
 392                 block->s2b_shift = 0;
 393         }
 394         return 0;
 395 }
 396
 397 /*
 398  * Back to basic.
 399  */
 400 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 401 {
 402         device->state = DASD_STATE_BASIC;
 403         return 0;
 404 }
 405
 406 /*
 407  * Make the device online and schedule the bottom half to start
 408  * the requeueing of requests from the linux request queue to the
 409  * ccw queue.
 410  */
 411 static int
 412 dasd_state_ready_to_online(struct dasd_device * device)
 413 {
 414         struct gendisk *disk;
 415         struct disk_part_iter piter;
 416         struct hd_struct *part;
 417
 418         device->state = DASD_STATE_ONLINE;
 419         if (device->block) {
 420                 dasd_schedule_block_bh(device->block);
 421                 if ((device->features & DASD_FEATURE_USERAW)) {
 422                         disk = device->block->gdp;
 423                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 424                         return 0;
 425                 }
 426                 disk = device->block->bdev->bd_disk;
 427                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 428                 while ((part = disk_part_iter_next(&piter)))
 429                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 430                 disk_part_iter_exit(&piter);
 431         }
 432         return 0;
 433 }
 434
 435 /*
 436  * Stop the requeueing of requests again.
 437  */
 438 static int dasd_state_online_to_ready(struct dasd_device *device)
 439 {
 440         int rc;
 441         struct gendisk *disk;
 442         struct disk_part_iter piter;
 443         struct hd_struct *part;
 444
 445         if (device->discipline->online_to_ready) {
 446                 rc = device->discipline->online_to_ready(device);
 447                 if (rc)
 448                         return rc;
 449         }
 450
 451         device->state = DASD_STATE_READY;
 452         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 453                 disk = device->block->bdev->bd_disk;
 454                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 455                 while ((part = disk_part_iter_next(&piter)))
 456                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 457                 disk_part_iter_exit(&piter);
 458         }
 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  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 606  * event daemon.
 607  */
 608 static void do_restore_device(struct work_struct *work)
 609 {
 610         struct dasd_device *device = container_of(work, struct dasd_device,
 611                                                   restore_device);
 612         device->cdev->drv->restore(device->cdev);
 613         dasd_put_device(device);
 614 }
 615
 616 void dasd_restore_device(struct dasd_device *device)
 617 {
 618         dasd_get_device(device);
 619         /* queue call to dasd_restore_device to the kernel event daemon. */
 620         if (!schedule_work(&device->restore_device))
 621                 dasd_put_device(device);
 622 }
 623
 624 /*
 625  * Set the target state for a device and starts the state change.
 626  */
 627 void dasd_set_target_state(struct dasd_device *device, int target)
 628 {
 629         dasd_get_device(device);
 630         mutex_lock(&device->state_mutex);
 631         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 632         if (dasd_probeonly && target > DASD_STATE_READY)
 633                 target = DASD_STATE_READY;
 634         if (device->target != target) {
 635                 if (device->state == target)
 636                         wake_up(&dasd_init_waitq);
 637                 device->target = target;
 638         }
 639         if (device->state != device->target)
 640                 dasd_change_state(device);
 641         mutex_unlock(&device->state_mutex);
 642         dasd_put_device(device);
 643 }
 644 EXPORT_SYMBOL(dasd_set_target_state);
 645
 646 /*
 647  * Enable devices with device numbers in [from..to].
 648  */
 649 static inline int _wait_for_device(struct dasd_device *device)
 650 {
 651         return (device->state == device->target);
 652 }
 653
 654 void dasd_enable_device(struct dasd_device *device)
 655 {
 656         dasd_set_target_state(device, DASD_STATE_ONLINE);
 657         if (device->state <= DASD_STATE_KNOWN)
 658                 /* No discipline for device found. */
 659                 dasd_set_target_state(device, DASD_STATE_NEW);
 660         /* Now wait for the devices to come up. */
 661         wait_event(dasd_init_waitq, _wait_for_device(device));
 662
 663         dasd_reload_device(device);
 664         if (device->discipline->kick_validate)
 665                 device->discipline->kick_validate(device);
 666 }
 667 EXPORT_SYMBOL(dasd_enable_device);
 668
 669 /*
 670  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 671  */
 672
 673 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 674
 675 #ifdef CONFIG_DASD_PROFILE
 676 struct dasd_profile dasd_global_profile = {
 677         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
 678 };
 679 static struct dentry *dasd_debugfs_global_entry;
 680
 681 /*
 682  * Add profiling information for cqr before execution.
 683  */
 684 static void dasd_profile_start(struct dasd_block *block,
 685                                struct dasd_ccw_req *cqr,
 686                                struct request *req)
 687 {
 688         struct list_head *l;
 689         unsigned int counter;
 690         struct dasd_device *device;
 691
 692         /* count the length of the chanq for statistics */
 693         counter = 0;
 694         if (dasd_global_profile_level || block->profile.data)
 695                 list_for_each(l, &block->ccw_queue)
 696                         if (++counter >= 31)
 697                                 break;
 698
 699         spin_lock(&dasd_global_profile.lock);
 700         if (dasd_global_profile.data) {
 701                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
 702                 if (rq_data_dir(req) == READ)
 703                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
 704         }
 705         spin_unlock(&dasd_global_profile.lock);
 706
 707         spin_lock(&block->profile.lock);
 708         if (block->profile.data) {
 709                 block->profile.data->dasd_io_nr_req[counter]++;
 710                 if (rq_data_dir(req) == READ)
 711                         block->profile.data->dasd_read_nr_req[counter]++;
 712         }
 713         spin_unlock(&block->profile.lock);
 714
 715         /*
 716          * We count the request for the start device, even though it may run on
 717          * some other device due to error recovery. This way we make sure that
 718          * we count each request only once.
 719          */
 720         device = cqr->startdev;
 721         if (device->profile.data) {
 722                 counter = 1; /* request is not yet queued on the start device */
 723                 list_for_each(l, &device->ccw_queue)
 724                         if (++counter >= 31)
 725                                 break;
 726         }
 727         spin_lock(&device->profile.lock);
 728         if (device->profile.data) {
 729                 device->profile.data->dasd_io_nr_req[counter]++;
 730                 if (rq_data_dir(req) == READ)
 731                         device->profile.data->dasd_read_nr_req[counter]++;
 732         }
 733         spin_unlock(&device->profile.lock);
 734 }
 735
 736 /*
 737  * Add profiling information for cqr after execution.
 738  */
 739
 740 #define dasd_profile_counter(value, index)                         \
 741 {                                                                  \
 742         for (index = 0; index < 31 && value >> (2+index); index++) \
 743                 ;                                                  \
 744 }
 745
 746 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 747                                       int is_alias,
 748                                       int is_tpm,
 749                                       int is_read,
 750                                       long sectors,
 751                                       int sectors_ind,
 752                                       int tottime_ind,
 753                                       int tottimeps_ind,
 754                                       int strtime_ind,
 755                                       int irqtime_ind,
 756                                       int irqtimeps_ind,
 757                                       int endtime_ind)
 758 {
 759         /* in case of an overflow, reset the whole profile */
 760         if (data->dasd_io_reqs == UINT_MAX) {
 761                         memset(data, 0, sizeof(*data));
 762                         ktime_get_real_ts64(&data->starttod);
 763         }
 764         data->dasd_io_reqs++;
 765         data->dasd_io_sects += sectors;
 766         if (is_alias)
 767                 data->dasd_io_alias++;
 768         if (is_tpm)
 769                 data->dasd_io_tpm++;
 770
 771         data->dasd_io_secs[sectors_ind]++;
 772         data->dasd_io_times[tottime_ind]++;
 773         data->dasd_io_timps[tottimeps_ind]++;
 774         data->dasd_io_time1[strtime_ind]++;
 775         data->dasd_io_time2[irqtime_ind]++;
 776         data->dasd_io_time2ps[irqtimeps_ind]++;
 777         data->dasd_io_time3[endtime_ind]++;
 778
 779         if (is_read) {
 780                 data->dasd_read_reqs++;
 781                 data->dasd_read_sects += sectors;
 782                 if (is_alias)
 783                         data->dasd_read_alias++;
 784                 if (is_tpm)
 785                         data->dasd_read_tpm++;
 786                 data->dasd_read_secs[sectors_ind]++;
 787                 data->dasd_read_times[tottime_ind]++;
 788                 data->dasd_read_time1[strtime_ind]++;
 789                 data->dasd_read_time2[irqtime_ind]++;
 790                 data->dasd_read_time3[endtime_ind]++;
 791         }
 792 }
 793
 794 static void dasd_profile_end(struct dasd_block *block,
 795                              struct dasd_ccw_req *cqr,
 796                              struct request *req)
 797 {
 798         unsigned long strtime, irqtime, endtime, tottime;
 799         unsigned long tottimeps, sectors;
 800         struct dasd_device *device;
 801         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 802         int irqtime_ind, irqtimeps_ind, endtime_ind;
 803         struct dasd_profile_info *data;
 804
 805         device = cqr->startdev;
 806         if (!(dasd_global_profile_level ||
 807               block->profile.data ||
 808               device->profile.data))
 809                 return;
 810
 811         sectors = blk_rq_sectors(req);
 812         if (!cqr->buildclk || !cqr->startclk ||
 813             !cqr->stopclk || !cqr->endclk ||
 814             !sectors)
 815                 return;
 816
 817         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 818         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 819         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 820         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 821         tottimeps = tottime / sectors;
 822
 823         dasd_profile_counter(sectors, sectors_ind);
 824         dasd_profile_counter(tottime, tottime_ind);
 825         dasd_profile_counter(tottimeps, tottimeps_ind);
 826         dasd_profile_counter(strtime, strtime_ind);
 827         dasd_profile_counter(irqtime, irqtime_ind);
 828         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 829         dasd_profile_counter(endtime, endtime_ind);
 830
 831         spin_lock(&dasd_global_profile.lock);
 832         if (dasd_global_profile.data) {
 833                 data = dasd_global_profile.data;
 834                 data->dasd_sum_times += tottime;
 835                 data->dasd_sum_time_str += strtime;
 836                 data->dasd_sum_time_irq += irqtime;
 837                 data->dasd_sum_time_end += endtime;
 838                 dasd_profile_end_add_data(dasd_global_profile.data,
 839                                           cqr->startdev != block->base,
 840                                           cqr->cpmode == 1,
 841                                           rq_data_dir(req) == READ,
 842                                           sectors, sectors_ind, tottime_ind,
 843                                           tottimeps_ind, strtime_ind,
 844                                           irqtime_ind, irqtimeps_ind,
 845                                           endtime_ind);
 846         }
 847         spin_unlock(&dasd_global_profile.lock);
 848
 849         spin_lock(&block->profile.lock);
 850         if (block->profile.data) {
 851                 data = block->profile.data;
 852                 data->dasd_sum_times += tottime;
 853                 data->dasd_sum_time_str += strtime;
 854                 data->dasd_sum_time_irq += irqtime;
 855                 data->dasd_sum_time_end += endtime;
 856                 dasd_profile_end_add_data(block->profile.data,
 857                                           cqr->startdev != block->base,
 858                                           cqr->cpmode == 1,
 859                                           rq_data_dir(req) == READ,
 860                                           sectors, sectors_ind, tottime_ind,
 861                                           tottimeps_ind, strtime_ind,
 862                                           irqtime_ind, irqtimeps_ind,
 863                                           endtime_ind);
 864         }
 865         spin_unlock(&block->profile.lock);
 866
 867         spin_lock(&device->profile.lock);
 868         if (device->profile.data) {
 869                 data = device->profile.data;
 870                 data->dasd_sum_times += tottime;
 871                 data->dasd_sum_time_str += strtime;
 872                 data->dasd_sum_time_irq += irqtime;
 873                 data->dasd_sum_time_end += endtime;
 874                 dasd_profile_end_add_data(device->profile.data,
 875                                           cqr->startdev != block->base,
 876                                           cqr->cpmode == 1,
 877                                           rq_data_dir(req) == READ,
 878                                           sectors, sectors_ind, tottime_ind,
 879                                           tottimeps_ind, strtime_ind,
 880                                           irqtime_ind, irqtimeps_ind,
 881                                           endtime_ind);
 882         }
 883         spin_unlock(&device->profile.lock);
 884 }
 885
 886 void dasd_profile_reset(struct dasd_profile *profile)
 887 {
 888         struct dasd_profile_info *data;
 889
 890         spin_lock_bh(&profile->lock);
 891         data = profile->data;
 892         if (!data) {
 893                 spin_unlock_bh(&profile->lock);
 894                 return;
 895         }
 896         memset(data, 0, sizeof(*data));
 897         ktime_get_real_ts64(&data->starttod);
 898         spin_unlock_bh(&profile->lock);
 899 }
 900
 901 int dasd_profile_on(struct dasd_profile *profile)
 902 {
 903         struct dasd_profile_info *data;
 904
 905         data = kzalloc(sizeof(*data), GFP_KERNEL);
 906         if (!data)
 907                 return -ENOMEM;
 908         spin_lock_bh(&profile->lock);
 909         if (profile->data) {
 910                 spin_unlock_bh(&profile->lock);
 911                 kfree(data);
 912                 return 0;
 913         }
 914         ktime_get_real_ts64(&data->starttod);
 915         profile->data = data;
 916         spin_unlock_bh(&profile->lock);
 917         return 0;
 918 }
 919
 920 void dasd_profile_off(struct dasd_profile *profile)
 921 {
 922         spin_lock_bh(&profile->lock);
 923         kfree(profile->data);
 924         profile->data = NULL;
 925         spin_unlock_bh(&profile->lock);
 926 }
 927
 928 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 929 {
 930         char *buffer;
 931
 932         buffer = vmalloc(user_len + 1);
 933         if (buffer == NULL)
 934                 return ERR_PTR(-ENOMEM);
 935         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 936                 vfree(buffer);
 937                 return ERR_PTR(-EFAULT);
 938         }
 939         /* got the string, now strip linefeed. */
 940         if (buffer[user_len - 1] == '\n')
 941                 buffer[user_len - 1] = 0;
 942         else
 943                 buffer[user_len] = 0;
 944         return buffer;
 945 }
 946
 947 static ssize_t dasd_stats_write(struct file *file,
 948                                 const char __user *user_buf,
 949                                 size_t user_len, loff_t *pos)
 950 {
 951         char *buffer, *str;
 952         int rc;
 953         struct seq_file *m = (struct seq_file *)file->private_data;
 954         struct dasd_profile *prof = m->private;
 955
 956         if (user_len > 65536)
 957                 user_len = 65536;
 958         buffer = dasd_get_user_string(user_buf, user_len);
 959         if (IS_ERR(buffer))
 960                 return PTR_ERR(buffer);
 961
 962         str = skip_spaces(buffer);
 963         rc = user_len;
 964         if (strncmp(str, "reset", 5) == 0) {
 965                 dasd_profile_reset(prof);
 966         } else if (strncmp(str, "on", 2) == 0) {
 967                 rc = dasd_profile_on(prof);
 968                 if (rc)
 969                         goto out;
 970                 rc = user_len;
 971                 if (prof == &dasd_global_profile) {
 972                         dasd_profile_reset(prof);
 973                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
 974                 }
 975         } else if (strncmp(str, "off", 3) == 0) {
 976                 if (prof == &dasd_global_profile)
 977                         dasd_global_profile_level = DASD_PROFILE_OFF;
 978                 dasd_profile_off(prof);
 979         } else
 980                 rc = -EINVAL;
 981 out:
 982         vfree(buffer);
 983         return rc;
 984 }
 985
 986 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 987 {
 988         int i;
 989
 990         for (i = 0; i < 32; i++)
 991                 seq_printf(m, "%u ", array[i]);
 992         seq_putc(m, '\n');
 993 }
 994
 995 static void dasd_stats_seq_print(struct seq_file *m,
 996                                  struct dasd_profile_info *data)
 997 {
 998         seq_printf(m, "start_time %lld.%09ld\n",
 999                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1000         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1001         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1002         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1003         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1004         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1005                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1006         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1007                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1008         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1009                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1010         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1011                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1012         seq_puts(m, "histogram_sectors ");
1013         dasd_stats_array(m, data->dasd_io_secs);
1014         seq_puts(m, "histogram_io_times ");
1015         dasd_stats_array(m, data->dasd_io_times);
1016         seq_puts(m, "histogram_io_times_weighted ");
1017         dasd_stats_array(m, data->dasd_io_timps);
1018         seq_puts(m, "histogram_time_build_to_ssch ");
1019         dasd_stats_array(m, data->dasd_io_time1);
1020         seq_puts(m, "histogram_time_ssch_to_irq ");
1021         dasd_stats_array(m, data->dasd_io_time2);
1022         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1023         dasd_stats_array(m, data->dasd_io_time2ps);
1024         seq_puts(m, "histogram_time_irq_to_end ");
1025         dasd_stats_array(m, data->dasd_io_time3);
1026         seq_puts(m, "histogram_ccw_queue_length ");
1027         dasd_stats_array(m, data->dasd_io_nr_req);
1028         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1029         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1030         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1031         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1032         seq_puts(m, "histogram_read_sectors ");
1033         dasd_stats_array(m, data->dasd_read_secs);
1034         seq_puts(m, "histogram_read_times ");
1035         dasd_stats_array(m, data->dasd_read_times);
1036         seq_puts(m, "histogram_read_time_build_to_ssch ");
1037         dasd_stats_array(m, data->dasd_read_time1);
1038         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1039         dasd_stats_array(m, data->dasd_read_time2);
1040         seq_puts(m, "histogram_read_time_irq_to_end ");
1041         dasd_stats_array(m, data->dasd_read_time3);
1042         seq_puts(m, "histogram_read_ccw_queue_length ");
1043         dasd_stats_array(m, data->dasd_read_nr_req);
1044 }
1045
1046 static int dasd_stats_show(struct seq_file *m, void *v)
1047 {
1048         struct dasd_profile *profile;
1049         struct dasd_profile_info *data;
1050
1051         profile = m->private;
1052         spin_lock_bh(&profile->lock);
1053         data = profile->data;
1054         if (!data) {
1055                 spin_unlock_bh(&profile->lock);
1056                 seq_puts(m, "disabled\n");
1057                 return 0;
1058         }
1059         dasd_stats_seq_print(m, data);
1060         spin_unlock_bh(&profile->lock);
1061         return 0;
1062 }
1063
1064 static int dasd_stats_open(struct inode *inode, struct file *file)
1065 {
1066         struct dasd_profile *profile = inode->i_private;
1067         return single_open(file, dasd_stats_show, profile);
1068 }
1069
1070 static const struct file_operations dasd_stats_raw_fops = {
1071         .owner          = THIS_MODULE,
1072         .open           = dasd_stats_open,
1073         .read           = seq_read,
1074         .llseek         = seq_lseek,
1075         .release        = single_release,
1076         .write          = dasd_stats_write,
1077 };
1078
1079 static void dasd_profile_init(struct dasd_profile *profile,
1080                               struct dentry *base_dentry)
1081 {
1082         umode_t mode;
1083         struct dentry *pde;
1084
1085         if (!base_dentry)
1086                 return;
1087         profile->dentry = NULL;
1088         profile->data = NULL;
1089         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1090         pde = debugfs_create_file("statistics", mode, base_dentry,
1091                                   profile, &dasd_stats_raw_fops);
1092         if (pde && !IS_ERR(pde))
1093                 profile->dentry = pde;
1094         return;
1095 }
1096
1097 static void dasd_profile_exit(struct dasd_profile *profile)
1098 {
1099         dasd_profile_off(profile);
1100         debugfs_remove(profile->dentry);
1101         profile->dentry = NULL;
1102 }
1103
1104 static void dasd_statistics_removeroot(void)
1105 {
1106         dasd_global_profile_level = DASD_PROFILE_OFF;
1107         dasd_profile_exit(&dasd_global_profile);
1108         debugfs_remove(dasd_debugfs_global_entry);
1109         debugfs_remove(dasd_debugfs_root_entry);
1110 }
1111
1112 static void dasd_statistics_createroot(void)
1113 {
1114         struct dentry *pde;
1115
1116         dasd_debugfs_root_entry = NULL;
1117         pde = debugfs_create_dir("dasd", NULL);
1118         if (!pde || IS_ERR(pde))
1119                 goto error;
1120         dasd_debugfs_root_entry = pde;
1121         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1122         if (!pde || IS_ERR(pde))
1123                 goto error;
1124         dasd_debugfs_global_entry = pde;
1125         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1126         return;
1127
1128 error:
1129         DBF_EVENT(DBF_ERR, "%s",
1130                   "Creation of the dasd debugfs interface failed");
1131         dasd_statistics_removeroot();
1132         return;
1133 }
1134
1135 #else
1136 #define dasd_profile_start(block, cqr, req) do {} while (0)
1137 #define dasd_profile_end(block, cqr, req) do {} while (0)
1138
1139 static void dasd_statistics_createroot(void)
1140 {
1141         return;
1142 }
1143
1144 static void dasd_statistics_removeroot(void)
1145 {
1146         return;
1147 }
1148
1149 int dasd_stats_generic_show(struct seq_file *m, void *v)
1150 {
1151         seq_puts(m, "Statistics are not activated in this kernel\n");
1152         return 0;
1153 }
1154
1155 static void dasd_profile_init(struct dasd_profile *profile,
1156                               struct dentry *base_dentry)
1157 {
1158         return;
1159 }
1160
1161 static void dasd_profile_exit(struct dasd_profile *profile)
1162 {
1163         return;
1164 }
1165
1166 int dasd_profile_on(struct dasd_profile *profile)
1167 {
1168         return 0;
1169 }
1170
1171 #endif                          /* CONFIG_DASD_PROFILE */
1172
1173 static int dasd_hosts_show(struct seq_file *m, void *v)
1174 {
1175         struct dasd_device *device;
1176         int rc = -EOPNOTSUPP;
1177
1178         device = m->private;
1179         dasd_get_device(device);
1180
1181         if (device->discipline->hosts_print)
1182                 rc = device->discipline->hosts_print(device, m);
1183
1184         dasd_put_device(device);
1185         return rc;
1186 }
1187
1188 static int dasd_hosts_open(struct inode *inode, struct file *file)
1189 {
1190         struct dasd_device *device = inode->i_private;
1191
1192         return single_open(file, dasd_hosts_show, device);
1193 }
1194
1195 static const struct file_operations dasd_hosts_fops = {
1196         .owner          = THIS_MODULE,
1197         .open           = dasd_hosts_open,
1198         .read           = seq_read,
1199         .llseek         = seq_lseek,
1200         .release        = single_release,
1201 };
1202
1203 static void dasd_hosts_exit(struct dasd_device *device)
1204 {
1205         debugfs_remove(device->hosts_dentry);
1206         device->hosts_dentry = NULL;
1207 }
1208
1209 static void dasd_hosts_init(struct dentry *base_dentry,
1210                             struct dasd_device *device)
1211 {
1212         struct dentry *pde;
1213         umode_t mode;
1214
1215         if (!base_dentry)
1216                 return;
1217
1218         mode = S_IRUSR | S_IFREG;
1219         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1220                                   device, &dasd_hosts_fops);
1221         if (pde && !IS_ERR(pde))
1222                 device->hosts_dentry = pde;
1223 }
1224
1225 /*
1226  * Allocate memory for a channel program with 'cplength' channel
1227  * command words and 'datasize' additional space. There are two
1228  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1229  * memory and 2) dasd_smalloc_request uses the static ccw memory
1230  * that gets allocated for each device.
1231  */
1232 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1233                                           int datasize,
1234                                           struct dasd_device *device)
1235 {
1236         struct dasd_ccw_req *cqr;
1237
1238         /* Sanity checks */
1239         BUG_ON(datasize > PAGE_SIZE ||
1240              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1241
1242         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1243         if (cqr == NULL)
1244                 return ERR_PTR(-ENOMEM);
1245         cqr->cpaddr = NULL;
1246         if (cplength > 0) {
1247                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1248                                       GFP_ATOMIC | GFP_DMA);
1249                 if (cqr->cpaddr == NULL) {
1250                         kfree(cqr);
1251                         return ERR_PTR(-ENOMEM);
1252                 }
1253         }
1254         cqr->data = NULL;
1255         if (datasize > 0) {
1256                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1257                 if (cqr->data == NULL) {
1258                         kfree(cqr->cpaddr);
1259                         kfree(cqr);
1260                         return ERR_PTR(-ENOMEM);
1261                 }
1262         }
1263         cqr->magic =  magic;
1264         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1265         dasd_get_device(device);
1266         return cqr;
1267 }
1268 EXPORT_SYMBOL(dasd_kmalloc_request);
1269
1270 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1271                                           int datasize,
1272                                           struct dasd_device *device)
1273 {
1274         unsigned long flags;
1275         struct dasd_ccw_req *cqr;
1276         char *data;
1277         int size;
1278
1279         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1280         if (cplength > 0)
1281                 size += cplength * sizeof(struct ccw1);
1282         if (datasize > 0)
1283                 size += datasize;
1284         spin_lock_irqsave(&device->mem_lock, flags);
1285         cqr = (struct dasd_ccw_req *)
1286                 dasd_alloc_chunk(&device->ccw_chunks, size);
1287         spin_unlock_irqrestore(&device->mem_lock, flags);
1288         if (cqr == NULL)
1289                 return ERR_PTR(-ENOMEM);
1290         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1291         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1292         cqr->cpaddr = NULL;
1293         if (cplength > 0) {
1294                 cqr->cpaddr = (struct ccw1 *) data;
1295                 data += cplength*sizeof(struct ccw1);
1296                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1297         }
1298         cqr->data = NULL;
1299         if (datasize > 0) {
1300                 cqr->data = data;
1301                 memset(cqr->data, 0, datasize);
1302         }
1303         cqr->magic = magic;
1304         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1305         dasd_get_device(device);
1306         return cqr;
1307 }
1308 EXPORT_SYMBOL(dasd_smalloc_request);
1309
1310 /*
1311  * Free memory of a channel program. This function needs to free all the
1312  * idal lists that might have been created by dasd_set_cda and the
1313  * struct dasd_ccw_req itself.
1314  */
1315 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1316 {
1317         struct ccw1 *ccw;
1318
1319         /* Clear any idals used for the request. */
1320         ccw = cqr->cpaddr;
1321         do {
1322                 clear_normalized_cda(ccw);
1323         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1324         kfree(cqr->cpaddr);
1325         kfree(cqr->data);
1326         kfree(cqr);
1327         dasd_put_device(device);
1328 }
1329 EXPORT_SYMBOL(dasd_kfree_request);
1330
1331 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1332 {
1333         unsigned long flags;
1334
1335         spin_lock_irqsave(&device->mem_lock, flags);
1336         dasd_free_chunk(&device->ccw_chunks, cqr);
1337         spin_unlock_irqrestore(&device->mem_lock, flags);
1338         dasd_put_device(device);
1339 }
1340 EXPORT_SYMBOL(dasd_sfree_request);
1341
1342 /*
1343  * Check discipline magic in cqr.
1344  */
1345 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1346 {
1347         struct dasd_device *device;
1348
1349         if (cqr == NULL)
1350                 return -EINVAL;
1351         device = cqr->startdev;
1352         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1353                 DBF_DEV_EVENT(DBF_WARNING, device,
1354                             " dasd_ccw_req 0x%08x magic doesn't match"
1355                             " discipline 0x%08x",
1356                             cqr->magic,
1357                             *(unsigned int *) device->discipline->name);
1358                 return -EINVAL;
1359         }
1360         return 0;
1361 }
1362
1363 /*
1364  * Terminate the current i/o and set the request to clear_pending.
1365  * Timer keeps device runnig.
1366  * ccw_device_clear can fail if the i/o subsystem
1367  * is in a bad mood.
1368  */
1369 int dasd_term_IO(struct dasd_ccw_req *cqr)
1370 {
1371         struct dasd_device *device;
1372         int retries, rc;
1373         char errorstring[ERRORLENGTH];
1374
1375         /* Check the cqr */
1376         rc = dasd_check_cqr(cqr);
1377         if (rc)
1378                 return rc;
1379         retries = 0;
1380         device = (struct dasd_device *) cqr->startdev;
1381         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1382                 rc = ccw_device_clear(device->cdev, (long) cqr);
1383                 switch (rc) {
1384                 case 0: /* termination successful */
1385                         cqr->status = DASD_CQR_CLEAR_PENDING;
1386                         cqr->stopclk = get_tod_clock();
1387                         cqr->starttime = 0;
1388                         DBF_DEV_EVENT(DBF_DEBUG, device,
1389                                       "terminate cqr %p successful",
1390                                       cqr);
1391                         break;
1392                 case -ENODEV:
1393                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1394                                       "device gone, retry");
1395                         break;
1396                 case -EIO:
1397                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1398                                       "I/O error, retry");
1399                         break;
1400                 case -EINVAL:
1401                         /*
1402                          * device not valid so no I/O could be running
1403                          * handle CQR as termination successful
1404                          */
1405                         cqr->status = DASD_CQR_CLEARED;
1406                         cqr->stopclk = get_tod_clock();
1407                         cqr->starttime = 0;
1408                         /* no retries for invalid devices */
1409                         cqr->retries = -1;
1410                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1411                                       "EINVAL, handle as terminated");
1412                         /* fake rc to success */
1413                         rc = 0;
1414                         break;
1415                 case -EBUSY:
1416                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1417                                       "device busy, retry later");
1418                         break;
1419                 default:
1420                         /* internal error 10 - unknown rc*/
1421                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1422                         dev_err(&device->cdev->dev, "An error occurred in the "
1423                                 "DASD device driver, reason=%s\n", errorstring);
1424                         BUG();
1425                         break;
1426                 }
1427                 retries++;
1428         }
1429         dasd_schedule_device_bh(device);
1430         return rc;
1431 }
1432 EXPORT_SYMBOL(dasd_term_IO);
1433
1434 /*
1435  * Start the i/o. This start_IO can fail if the channel is really busy.
1436  * In that case set up a timer to start the request later.
1437  */
1438 int dasd_start_IO(struct dasd_ccw_req *cqr)
1439 {
1440         struct dasd_device *device;
1441         int rc;
1442         char errorstring[ERRORLENGTH];
1443
1444         /* Check the cqr */
1445         rc = dasd_check_cqr(cqr);
1446         if (rc) {
1447                 cqr->intrc = rc;
1448                 return rc;
1449         }
1450         device = (struct dasd_device *) cqr->startdev;
1451         if (((cqr->block &&
1452               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1453              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1454             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1455                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1456                               "because of stolen lock", cqr);
1457                 cqr->status = DASD_CQR_ERROR;
1458                 cqr->intrc = -EPERM;
1459                 return -EPERM;
1460         }
1461         if (cqr->retries < 0) {
1462                 /* internal error 14 - start_IO run out of retries */
1463                 sprintf(errorstring, "14 %p", cqr);
1464                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1465                         "device driver, reason=%s\n", errorstring);
1466                 cqr->status = DASD_CQR_ERROR;
1467                 return -EIO;
1468         }
1469         cqr->startclk = get_tod_clock();
1470         cqr->starttime = jiffies;
1471         cqr->retries--;
1472         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1473                 cqr->lpm &= dasd_path_get_opm(device);
1474                 if (!cqr->lpm)
1475                         cqr->lpm = dasd_path_get_opm(device);
1476         }
1477         if (cqr->cpmode == 1) {
1478                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1479                                          (long) cqr, cqr->lpm);
1480         } else {
1481                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1482                                       (long) cqr, cqr->lpm, 0);
1483         }
1484         switch (rc) {
1485         case 0:
1486                 cqr->status = DASD_CQR_IN_IO;
1487                 break;
1488         case -EBUSY:
1489                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1490                               "start_IO: device busy, retry later");
1491                 break;
1492         case -ETIMEDOUT:
1493                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1494                               "start_IO: request timeout, retry later");
1495                 break;
1496         case -EACCES:
1497                 /* -EACCES indicates that the request used only a subset of the
1498                  * available paths and all these paths are gone. If the lpm of
1499                  * this request was only a subset of the opm (e.g. the ppm) then
1500                  * we just do a retry with all available paths.
1501                  * If we already use the full opm, something is amiss, and we
1502                  * need a full path verification.
1503                  */
1504                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1505                         DBF_DEV_EVENT(DBF_WARNING, device,
1506                                       "start_IO: selected paths gone (%x)",
1507                                       cqr->lpm);
1508                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1509                         cqr->lpm = dasd_path_get_opm(device);
1510                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1511                                       "start_IO: selected paths gone,"
1512                                       " retry on all paths");
1513                 } else {
1514                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1515                                       "start_IO: all paths in opm gone,"
1516                                       " do path verification");
1517                         dasd_generic_last_path_gone(device);
1518                         dasd_path_no_path(device);
1519                         dasd_path_set_tbvpm(device,
1520                                           ccw_device_get_path_mask(
1521                                                   device->cdev));
1522                 }
1523                 break;
1524         case -ENODEV:
1525                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1526                               "start_IO: -ENODEV device gone, retry");
1527                 break;
1528         case -EIO:
1529                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1530                               "start_IO: -EIO device gone, retry");
1531                 break;
1532         case -EINVAL:
1533                 /* most likely caused in power management context */
1534                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1535                               "start_IO: -EINVAL device currently "
1536                               "not accessible");
1537                 break;
1538         default:
1539                 /* internal error 11 - unknown rc */
1540                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1541                 dev_err(&device->cdev->dev,
1542                         "An error occurred in the DASD device driver, "
1543                         "reason=%s\n", errorstring);
1544                 BUG();
1545                 break;
1546         }
1547         cqr->intrc = rc;
1548         return rc;
1549 }
1550 EXPORT_SYMBOL(dasd_start_IO);
1551
1552 /*
1553  * Timeout function for dasd devices. This is used for different purposes
1554  *  1) missing interrupt handler for normal operation
1555  *  2) delayed start of request where start_IO failed with -EBUSY
1556  *  3) timeout for missing state change interrupts
1557  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1558  * DASD_CQR_QUEUED for 2) and 3).
1559  */
1560 static void dasd_device_timeout(struct timer_list *t)
1561 {
1562         unsigned long flags;
1563         struct dasd_device *device;
1564
1565         device = from_timer(device, t, timer);
1566         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1567         /* re-activate request queue */
1568         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1569         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1570         dasd_schedule_device_bh(device);
1571 }
1572
1573 /*
1574  * Setup timeout for a device in jiffies.
1575  */
1576 void dasd_device_set_timer(struct dasd_device *device, int expires)
1577 {
1578         if (expires == 0)
1579                 del_timer(&device->timer);
1580         else
1581                 mod_timer(&device->timer, jiffies + expires);
1582 }
1583 EXPORT_SYMBOL(dasd_device_set_timer);
1584
1585 /*
1586  * Clear timeout for a device.
1587  */
1588 void dasd_device_clear_timer(struct dasd_device *device)
1589 {
1590         del_timer(&device->timer);
1591 }
1592 EXPORT_SYMBOL(dasd_device_clear_timer);
1593
1594 static void dasd_handle_killed_request(struct ccw_device *cdev,
1595                                        unsigned long intparm)
1596 {
1597         struct dasd_ccw_req *cqr;
1598         struct dasd_device *device;
1599
1600         if (!intparm)
1601                 return;
1602         cqr = (struct dasd_ccw_req *) intparm;
1603         if (cqr->status != DASD_CQR_IN_IO) {
1604                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1605                                 "invalid status in handle_killed_request: "
1606                                 "%02x", cqr->status);
1607                 return;
1608         }
1609
1610         device = dasd_device_from_cdev_locked(cdev);
1611         if (IS_ERR(device)) {
1612                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1613                                 "unable to get device from cdev");
1614                 return;
1615         }
1616
1617         if (!cqr->startdev ||
1618             device != cqr->startdev ||
1619             strncmp(cqr->startdev->discipline->ebcname,
1620                     (char *) &cqr->magic, 4)) {
1621                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1622                                 "invalid device in request");
1623                 dasd_put_device(device);
1624                 return;
1625         }
1626
1627         /* Schedule request to be retried. */
1628         cqr->status = DASD_CQR_QUEUED;
1629
1630         dasd_device_clear_timer(device);
1631         dasd_schedule_device_bh(device);
1632         dasd_put_device(device);
1633 }
1634
1635 void dasd_generic_handle_state_change(struct dasd_device *device)
1636 {
1637         /* First of all start sense subsystem status request. */
1638         dasd_eer_snss(device);
1639
1640         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1641         dasd_schedule_device_bh(device);
1642         if (device->block) {
1643                 dasd_schedule_block_bh(device->block);
1644                 if (device->block->request_queue)
1645                         blk_mq_run_hw_queues(device->block->request_queue,
1646                                              true);
1647         }
1648 }
1649 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1650
1651 static int dasd_check_hpf_error(struct irb *irb)
1652 {
1653         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1654             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1655              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1656 }
1657
1658 /*
1659  * Interrupt handler for "normal" ssch-io based dasd devices.
1660  */
1661 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1662                       struct irb *irb)
1663 {
1664         struct dasd_ccw_req *cqr, *next;
1665         struct dasd_device *device;
1666         unsigned long now;
1667         int nrf_suppressed = 0;
1668         int fp_suppressed = 0;
1669         u8 *sense = NULL;
1670         int expires;
1671
1672         cqr = (struct dasd_ccw_req *) intparm;
1673         if (IS_ERR(irb)) {
1674                 switch (PTR_ERR(irb)) {
1675                 case -EIO:
1676                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1677                                 device = cqr->startdev;
1678                                 cqr->status = DASD_CQR_CLEARED;
1679                                 dasd_device_clear_timer(device);
1680                                 wake_up(&dasd_flush_wq);
1681                                 dasd_schedule_device_bh(device);
1682                                 return;
1683                         }
1684                         break;
1685                 case -ETIMEDOUT:
1686                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1687                                         "request timed out\n", __func__);
1688                         break;
1689                 default:
1690                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1691                                         "unknown error %ld\n", __func__,
1692                                         PTR_ERR(irb));
1693                 }
1694                 dasd_handle_killed_request(cdev, intparm);
1695                 return;
1696         }
1697
1698         now = get_tod_clock();
1699         /* check for conditions that should be handled immediately */
1700         if (!cqr ||
1701             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1702               scsw_cstat(&irb->scsw) == 0)) {
1703                 if (cqr)
1704                         memcpy(&cqr->irb, irb, sizeof(*irb));
1705                 device = dasd_device_from_cdev_locked(cdev);
1706                 if (IS_ERR(device))
1707                         return;
1708                 /* ignore unsolicited interrupts for DIAG discipline */
1709                 if (device->discipline == dasd_diag_discipline_pointer) {
1710                         dasd_put_device(device);
1711                         return;
1712                 }
1713
1714                 /*
1715                  * In some cases 'File Protected' or 'No Record Found' errors
1716                  * might be expected and debug log messages for the
1717                  * corresponding interrupts shouldn't be written then.
1718                  * Check if either of the according suppress bits is set.
1719                  */
1720                 sense = dasd_get_sense(irb);
1721                 if (sense) {
1722                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1723                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1724                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1725                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1726                 }
1727                 if (!(fp_suppressed || nrf_suppressed))
1728                         device->discipline->dump_sense_dbf(device, irb, "int");
1729
1730                 if (device->features & DASD_FEATURE_ERPLOG)
1731                         device->discipline->dump_sense(device, cqr, irb);
1732                 device->discipline->check_for_device_change(device, cqr, irb);
1733                 dasd_put_device(device);
1734         }
1735
1736         /* check for for attention message */
1737         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1738                 device = dasd_device_from_cdev_locked(cdev);
1739                 if (!IS_ERR(device)) {
1740                         device->discipline->check_attention(device,
1741                                                             irb->esw.esw1.lpum);
1742                         dasd_put_device(device);
1743                 }
1744         }
1745
1746         if (!cqr)
1747                 return;
1748
1749         device = (struct dasd_device *) cqr->startdev;
1750         if (!device ||
1751             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1752                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1753                                 "invalid device in request");
1754                 return;
1755         }
1756
1757         /* Check for clear pending */
1758         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1759             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1760                 cqr->status = DASD_CQR_CLEARED;
1761                 dasd_device_clear_timer(device);
1762                 wake_up(&dasd_flush_wq);
1763                 dasd_schedule_device_bh(device);
1764                 return;
1765         }
1766
1767         /* check status - the request might have been killed by dyn detach */
1768         if (cqr->status != DASD_CQR_IN_IO) {
1769                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1770                               "status %02x", dev_name(&cdev->dev), cqr->status);
1771                 return;
1772         }
1773
1774         next = NULL;
1775         expires = 0;
1776         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1777             scsw_cstat(&irb->scsw) == 0) {
1778                 /* request was completed successfully */
1779                 cqr->status = DASD_CQR_SUCCESS;
1780                 cqr->stopclk = now;
1781                 /* Start first request on queue if possible -> fast_io. */
1782                 if (cqr->devlist.next != &device->ccw_queue) {
1783                         next = list_entry(cqr->devlist.next,
1784                                           struct dasd_ccw_req, devlist);
1785                 }
1786         } else {  /* error */
1787                 /* check for HPF error
1788                  * call discipline function to requeue all requests
1789                  * and disable HPF accordingly
1790                  */
1791                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1792                     device->discipline->handle_hpf_error)
1793                         device->discipline->handle_hpf_error(device, irb);
1794                 /*
1795                  * If we don't want complex ERP for this request, then just
1796                  * reset this and retry it in the fastpath
1797                  */
1798                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1799                     cqr->retries > 0) {
1800                         if (cqr->lpm == dasd_path_get_opm(device))
1801                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1802                                               "default ERP in fastpath "
1803                                               "(%i retries left)",
1804                                               cqr->retries);
1805                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1806                                 cqr->lpm = dasd_path_get_opm(device);
1807                         cqr->status = DASD_CQR_QUEUED;
1808                         next = cqr;
1809                 } else
1810                         cqr->status = DASD_CQR_ERROR;
1811         }
1812         if (next && (next->status == DASD_CQR_QUEUED) &&
1813             (!device->stopped)) {
1814                 if (device->discipline->start_IO(next) == 0)
1815                         expires = next->expires;
1816         }
1817         if (expires != 0)
1818                 dasd_device_set_timer(device, expires);
1819         else
1820                 dasd_device_clear_timer(device);
1821         dasd_schedule_device_bh(device);
1822 }
1823 EXPORT_SYMBOL(dasd_int_handler);
1824
1825 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1826 {
1827         struct dasd_device *device;
1828
1829         device = dasd_device_from_cdev_locked(cdev);
1830
1831         if (IS_ERR(device))
1832                 goto out;
1833         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1834            device->state != device->target ||
1835            !device->discipline->check_for_device_change){
1836                 dasd_put_device(device);
1837                 goto out;
1838         }
1839         if (device->discipline->dump_sense_dbf)
1840                 device->discipline->dump_sense_dbf(device, irb, "uc");
1841         device->discipline->check_for_device_change(device, NULL, irb);
1842         dasd_put_device(device);
1843 out:
1844         return UC_TODO_RETRY;
1845 }
1846 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1847
1848 /*
1849  * If we have an error on a dasd_block layer request then we cancel
1850  * and return all further requests from the same dasd_block as well.
1851  */
1852 static void __dasd_device_recovery(struct dasd_device *device,
1853                                    struct dasd_ccw_req *ref_cqr)
1854 {
1855         struct list_head *l, *n;
1856         struct dasd_ccw_req *cqr;
1857
1858         /*
1859          * only requeue request that came from the dasd_block layer
1860          */
1861         if (!ref_cqr->block)
1862                 return;
1863
1864         list_for_each_safe(l, n, &device->ccw_queue) {
1865                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1866                 if (cqr->status == DASD_CQR_QUEUED &&
1867                     ref_cqr->block == cqr->block) {
1868                         cqr->status = DASD_CQR_CLEARED;
1869                 }
1870         }
1871 };
1872
1873 /*
1874  * Remove those ccw requests from the queue that need to be returned
1875  * to the upper layer.
1876  */
1877 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1878                                             struct list_head *final_queue)
1879 {
1880         struct list_head *l, *n;
1881         struct dasd_ccw_req *cqr;
1882
1883         /* Process request with final status. */
1884         list_for_each_safe(l, n, &device->ccw_queue) {
1885                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1886
1887                 /* Skip any non-final request. */
1888                 if (cqr->status == DASD_CQR_QUEUED ||
1889                     cqr->status == DASD_CQR_IN_IO ||
1890                     cqr->status == DASD_CQR_CLEAR_PENDING)
1891                         continue;
1892                 if (cqr->status == DASD_CQR_ERROR) {
1893                         __dasd_device_recovery(device, cqr);
1894                 }
1895                 /* Rechain finished requests to final queue */
1896                 list_move_tail(&cqr->devlist, final_queue);
1897         }
1898 }
1899
1900 /*
1901  * the cqrs from the final queue are returned to the upper layer
1902  * by setting a dasd_block state and calling the callback function
1903  */
1904 static void __dasd_device_process_final_queue(struct dasd_device *device,
1905                                               struct list_head *final_queue)
1906 {
1907         struct list_head *l, *n;
1908         struct dasd_ccw_req *cqr;
1909         struct dasd_block *block;
1910         void (*callback)(struct dasd_ccw_req *, void *data);
1911         void *callback_data;
1912         char errorstring[ERRORLENGTH];
1913
1914         list_for_each_safe(l, n, final_queue) {
1915                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1916                 list_del_init(&cqr->devlist);
1917                 block = cqr->block;
1918                 callback = cqr->callback;
1919                 callback_data = cqr->callback_data;
1920                 if (block)
1921                         spin_lock_bh(&block->queue_lock);
1922                 switch (cqr->status) {
1923                 case DASD_CQR_SUCCESS:
1924                         cqr->status = DASD_CQR_DONE;
1925                         break;
1926                 case DASD_CQR_ERROR:
1927                         cqr->status = DASD_CQR_NEED_ERP;
1928                         break;
1929                 case DASD_CQR_CLEARED:
1930                         cqr->status = DASD_CQR_TERMINATED;
1931                         break;
1932                 default:
1933                         /* internal error 12 - wrong cqr status*/
1934                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1935                         dev_err(&device->cdev->dev,
1936                                 "An error occurred in the DASD device driver, "
1937                                 "reason=%s\n", errorstring);
1938                         BUG();
1939                 }
1940                 if (cqr->callback != NULL)
1941                         (callback)(cqr, callback_data);
1942                 if (block)
1943                         spin_unlock_bh(&block->queue_lock);
1944         }
1945 }
1946
1947 /*
1948  * Take a look at the first request on the ccw queue and check
1949  * if it reached its expire time. If so, terminate the IO.
1950  */
1951 static void __dasd_device_check_expire(struct dasd_device *device)
1952 {
1953         struct dasd_ccw_req *cqr;
1954
1955         if (list_empty(&device->ccw_queue))
1956                 return;
1957         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1958         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1959             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1960                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1961                         /*
1962                          * IO in safe offline processing should not
1963                          * run out of retries
1964                          */
1965                         cqr->retries++;
1966                 }
1967                 if (device->discipline->term_IO(cqr) != 0) {
1968                         /* Hmpf, try again in 5 sec */
1969                         dev_err(&device->cdev->dev,
1970                                 "cqr %p timed out (%lus) but cannot be "
1971                                 "ended, retrying in 5 s\n",
1972                                 cqr, (cqr->expires/HZ));
1973                         cqr->expires += 5*HZ;
1974                         dasd_device_set_timer(device, 5*HZ);
1975                 } else {
1976                         dev_err(&device->cdev->dev,
1977                                 "cqr %p timed out (%lus), %i retries "
1978                                 "remaining\n", cqr, (cqr->expires/HZ),
1979                                 cqr->retries);
1980                 }
1981         }
1982 }
1983
1984 /*
1985  * return 1 when device is not eligible for IO
1986  */
1987 static int __dasd_device_is_unusable(struct dasd_device *device,
1988                                      struct dasd_ccw_req *cqr)
1989 {
1990         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1991
1992         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1993             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1994                 /*
1995                  * dasd is being set offline
1996                  * but it is no safe offline where we have to allow I/O
1997                  */
1998                 return 1;
1999         }
2000         if (device->stopped) {
2001                 if (device->stopped & mask) {
2002                         /* stopped and CQR will not change that. */
2003                         return 1;
2004                 }
2005                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2006                         /* CQR is not able to change device to
2007                          * operational. */
2008                         return 1;
2009                 }
2010                 /* CQR required to get device operational. */
2011         }
2012         return 0;
2013 }
2014
2015 /*
2016  * Take a look at the first request on the ccw queue and check
2017  * if it needs to be started.
2018  */
2019 static void __dasd_device_start_head(struct dasd_device *device)
2020 {
2021         struct dasd_ccw_req *cqr;
2022         int rc;
2023
2024         if (list_empty(&device->ccw_queue))
2025                 return;
2026         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2027         if (cqr->status != DASD_CQR_QUEUED)
2028                 return;
2029         /* if device is not usable return request to upper layer */
2030         if (__dasd_device_is_unusable(device, cqr)) {
2031                 cqr->intrc = -EAGAIN;
2032                 cqr->status = DASD_CQR_CLEARED;
2033                 dasd_schedule_device_bh(device);
2034                 return;
2035         }
2036
2037         rc = device->discipline->start_IO(cqr);
2038         if (rc == 0)
2039                 dasd_device_set_timer(device, cqr->expires);
2040         else if (rc == -EACCES) {
2041                 dasd_schedule_device_bh(device);
2042         } else
2043                 /* Hmpf, try again in 1/2 sec */
2044                 dasd_device_set_timer(device, 50);
2045 }
2046
2047 static void __dasd_device_check_path_events(struct dasd_device *device)
2048 {
2049         int rc;
2050
2051         if (!dasd_path_get_tbvpm(device))
2052                 return;
2053
2054         if (device->stopped &
2055             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2056                 return;
2057         rc = device->discipline->verify_path(device,
2058                                              dasd_path_get_tbvpm(device));
2059         if (rc)
2060                 dasd_device_set_timer(device, 50);
2061         else
2062                 dasd_path_clear_all_verify(device);
2063 };
2064
2065 /*
2066  * Go through all request on the dasd_device request queue,
2067  * terminate them on the cdev if necessary, and return them to the
2068  * submitting layer via callback.
2069  * Note:
2070  * Make sure that all 'submitting layers' still exist when
2071  * this function is called!. In other words, when 'device' is a base
2072  * device then all block layer requests must have been removed before
2073  * via dasd_flush_block_queue.
2074  */
2075 int dasd_flush_device_queue(struct dasd_device *device)
2076 {
2077         struct dasd_ccw_req *cqr, *n;
2078         int rc;
2079         struct list_head flush_queue;
2080
2081         INIT_LIST_HEAD(&flush_queue);
2082         spin_lock_irq(get_ccwdev_lock(device->cdev));
2083         rc = 0;
2084         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2085                 /* Check status and move request to flush_queue */
2086                 switch (cqr->status) {
2087                 case DASD_CQR_IN_IO:
2088                         rc = device->discipline->term_IO(cqr);
2089                         if (rc) {
2090                                 /* unable to terminate requeust */
2091                                 dev_err(&device->cdev->dev,
2092                                         "Flushing the DASD request queue "
2093                                         "failed for request %p\n", cqr);
2094                                 /* stop flush processing */
2095                                 goto finished;
2096                         }
2097                         break;
2098                 case DASD_CQR_QUEUED:
2099                         cqr->stopclk = get_tod_clock();
2100                         cqr->status = DASD_CQR_CLEARED;
2101                         break;
2102                 default: /* no need to modify the others */
2103                         break;
2104                 }
2105                 list_move_tail(&cqr->devlist, &flush_queue);
2106         }
2107 finished:
2108         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2109         /*
2110          * After this point all requests must be in state CLEAR_PENDING,
2111          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2112          * one of the others.
2113          */
2114         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2115                 wait_event(dasd_flush_wq,
2116                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2117         /*
2118          * Now set each request back to TERMINATED, DONE or NEED_ERP
2119          * and call the callback function of flushed requests
2120          */
2121         __dasd_device_process_final_queue(device, &flush_queue);
2122         return rc;
2123 }
2124 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2125
2126 /*
2127  * Acquire the device lock and process queues for the device.
2128  */
2129 static void dasd_device_tasklet(struct dasd_device *device)
2130 {
2131         struct list_head final_queue;
2132
2133         atomic_set (&device->tasklet_scheduled, 0);
2134         INIT_LIST_HEAD(&final_queue);
2135         spin_lock_irq(get_ccwdev_lock(device->cdev));
2136         /* Check expire time of first request on the ccw queue. */
2137         __dasd_device_check_expire(device);
2138         /* find final requests on ccw queue */
2139         __dasd_device_process_ccw_queue(device, &final_queue);
2140         __dasd_device_check_path_events(device);
2141         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2142         /* Now call the callback function of requests with final status */
2143         __dasd_device_process_final_queue(device, &final_queue);
2144         spin_lock_irq(get_ccwdev_lock(device->cdev));
2145         /* Now check if the head of the ccw queue needs to be started. */
2146         __dasd_device_start_head(device);
2147         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2148         if (waitqueue_active(&shutdown_waitq))
2149                 wake_up(&shutdown_waitq);
2150         dasd_put_device(device);
2151 }
2152
2153 /*
2154  * Schedules a call to dasd_tasklet over the device tasklet.
2155  */
2156 void dasd_schedule_device_bh(struct dasd_device *device)
2157 {
2158         /* Protect against rescheduling. */
2159         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2160                 return;
2161         dasd_get_device(device);
2162         tasklet_hi_schedule(&device->tasklet);
2163 }
2164 EXPORT_SYMBOL(dasd_schedule_device_bh);
2165
2166 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2167 {
2168         device->stopped |= bits;
2169 }
2170 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2171
2172 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2173 {
2174         device->stopped &= ~bits;
2175         if (!device->stopped)
2176                 wake_up(&generic_waitq);
2177 }
2178 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2179
2180 /*
2181  * Queue a request to the head of the device ccw_queue.
2182  * Start the I/O if possible.
2183  */
2184 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2185 {
2186         struct dasd_device *device;
2187         unsigned long flags;
2188
2189         device = cqr->startdev;
2190         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2191         cqr->status = DASD_CQR_QUEUED;
2192         list_add(&cqr->devlist, &device->ccw_queue);
2193         /* let the bh start the request to keep them in order */
2194         dasd_schedule_device_bh(device);
2195         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2196 }
2197 EXPORT_SYMBOL(dasd_add_request_head);
2198
2199 /*
2200  * Queue a request to the tail of the device ccw_queue.
2201  * Start the I/O if possible.
2202  */
2203 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2204 {
2205         struct dasd_device *device;
2206         unsigned long flags;
2207
2208         device = cqr->startdev;
2209         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2210         cqr->status = DASD_CQR_QUEUED;
2211         list_add_tail(&cqr->devlist, &device->ccw_queue);
2212         /* let the bh start the request to keep them in order */
2213         dasd_schedule_device_bh(device);
2214         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2215 }
2216 EXPORT_SYMBOL(dasd_add_request_tail);
2217
2218 /*
2219  * Wakeup helper for the 'sleep_on' functions.
2220  */
2221 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2222 {
2223         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2224         cqr->callback_data = DASD_SLEEPON_END_TAG;
2225         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2226         wake_up(&generic_waitq);
2227 }
2228 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2229
2230 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2231 {
2232         struct dasd_device *device;
2233         int rc;
2234
2235         device = cqr->startdev;
2236         spin_lock_irq(get_ccwdev_lock(device->cdev));
2237         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2238         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2239         return rc;
2240 }
2241
2242 /*
2243  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2244  */
2245 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2246 {
2247         struct dasd_device *device;
2248         dasd_erp_fn_t erp_fn;
2249
2250         if (cqr->status == DASD_CQR_FILLED)
2251                 return 0;
2252         device = cqr->startdev;
2253         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2254                 if (cqr->status == DASD_CQR_TERMINATED) {
2255                         device->discipline->handle_terminated_request(cqr);
2256                         return 1;
2257                 }
2258                 if (cqr->status == DASD_CQR_NEED_ERP) {
2259                         erp_fn = device->discipline->erp_action(cqr);
2260                         erp_fn(cqr);
2261                         return 1;
2262                 }
2263                 if (cqr->status == DASD_CQR_FAILED)
2264                         dasd_log_sense(cqr, &cqr->irb);
2265                 if (cqr->refers) {
2266                         __dasd_process_erp(device, cqr);
2267                         return 1;
2268                 }
2269         }
2270         return 0;
2271 }
2272
2273 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2274 {
2275         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2276                 if (cqr->refers) /* erp is not done yet */
2277                         return 1;
2278                 return ((cqr->status != DASD_CQR_DONE) &&
2279                         (cqr->status != DASD_CQR_FAILED));
2280         } else
2281                 return (cqr->status == DASD_CQR_FILLED);
2282 }
2283
2284 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2285 {
2286         struct dasd_device *device;
2287         int rc;
2288         struct list_head ccw_queue;
2289         struct dasd_ccw_req *cqr;
2290
2291         INIT_LIST_HEAD(&ccw_queue);
2292         maincqr->status = DASD_CQR_FILLED;
2293         device = maincqr->startdev;
2294         list_add(&maincqr->blocklist, &ccw_queue);
2295         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2296              cqr = list_first_entry(&ccw_queue,
2297                                     struct dasd_ccw_req, blocklist)) {
2298
2299                 if (__dasd_sleep_on_erp(cqr))
2300                         continue;
2301                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2302                         continue;
2303                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2304                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2305                         cqr->status = DASD_CQR_FAILED;
2306                         cqr->intrc = -EPERM;
2307                         continue;
2308                 }
2309                 /* Non-temporary stop condition will trigger fail fast */
2310                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2311                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2312                     (!dasd_eer_enabled(device))) {
2313                         cqr->status = DASD_CQR_FAILED;
2314                         cqr->intrc = -ENOLINK;
2315                         continue;
2316                 }
2317                 /*
2318                  * Don't try to start requests if device is in
2319                  * offline processing, it might wait forever
2320                  */
2321                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2322                         cqr->status = DASD_CQR_FAILED;
2323                         cqr->intrc = -ENODEV;
2324                         continue;
2325                 }
2326                 /*
2327                  * Don't try to start requests if device is stopped
2328                  * except path verification requests
2329                  */
2330                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2331                         if (interruptible) {
2332                                 rc = wait_event_interruptible(
2333                                         generic_waitq, !(device->stopped));
2334                                 if (rc == -ERESTARTSYS) {
2335                                         cqr->status = DASD_CQR_FAILED;
2336                                         maincqr->intrc = rc;
2337                                         continue;
2338                                 }
2339                         } else
2340                                 wait_event(generic_waitq, !(device->stopped));
2341                 }
2342                 if (!cqr->callback)
2343                         cqr->callback = dasd_wakeup_cb;
2344
2345                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2346                 dasd_add_request_tail(cqr);
2347                 if (interruptible) {
2348                         rc = wait_event_interruptible(
2349                                 generic_waitq, _wait_for_wakeup(cqr));
2350                         if (rc == -ERESTARTSYS) {
2351                                 dasd_cancel_req(cqr);
2352                                 /* wait (non-interruptible) for final status */
2353                                 wait_event(generic_waitq,
2354                                            _wait_for_wakeup(cqr));
2355                                 cqr->status = DASD_CQR_FAILED;
2356                                 maincqr->intrc = rc;
2357                                 continue;
2358                         }
2359                 } else
2360                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2361         }
2362
2363         maincqr->endclk = get_tod_clock();
2364         if ((maincqr->status != DASD_CQR_DONE) &&
2365             (maincqr->intrc != -ERESTARTSYS))
2366                 dasd_log_sense(maincqr, &maincqr->irb);
2367         if (maincqr->status == DASD_CQR_DONE)
2368                 rc = 0;
2369         else if (maincqr->intrc)
2370                 rc = maincqr->intrc;
2371         else
2372                 rc = -EIO;
2373         return rc;
2374 }
2375
2376 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2377 {
2378         struct dasd_ccw_req *cqr;
2379
2380         list_for_each_entry(cqr, ccw_queue, blocklist) {
2381                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2382                         return 0;
2383         }
2384
2385         return 1;
2386 }
2387
2388 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2389 {
2390         struct dasd_device *device;
2391         struct dasd_ccw_req *cqr, *n;
2392         u8 *sense = NULL;
2393         int rc;
2394
2395 retry:
2396         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2397                 device = cqr->startdev;
2398                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2399                         continue;
2400
2401                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2402                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2403                         cqr->status = DASD_CQR_FAILED;
2404                         cqr->intrc = -EPERM;
2405                         continue;
2406                 }
2407                 /*Non-temporary stop condition will trigger fail fast*/
2408                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2409                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2410                     !dasd_eer_enabled(device)) {
2411                         cqr->status = DASD_CQR_FAILED;
2412                         cqr->intrc = -EAGAIN;
2413                         continue;
2414                 }
2415
2416                 /*Don't try to start requests if device is stopped*/
2417                 if (interruptible) {
2418                         rc = wait_event_interruptible(
2419                                 generic_waitq, !device->stopped);
2420                         if (rc == -ERESTARTSYS) {
2421                                 cqr->status = DASD_CQR_FAILED;
2422                                 cqr->intrc = rc;
2423                                 continue;
2424                         }
2425                 } else
2426                         wait_event(generic_waitq, !(device->stopped));
2427
2428                 if (!cqr->callback)
2429                         cqr->callback = dasd_wakeup_cb;
2430                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2431                 dasd_add_request_tail(cqr);
2432         }
2433
2434         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2435
2436         rc = 0;
2437         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2438                 /*
2439                  * In some cases the 'File Protected' or 'Incorrect Length'
2440                  * error might be expected and error recovery would be
2441                  * unnecessary in these cases.  Check if the according suppress
2442                  * bit is set.
2443                  */
2444                 sense = dasd_get_sense(&cqr->irb);
2445                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2446                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2447                         continue;
2448                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2449                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2450                         continue;
2451
2452                 /*
2453                  * for alias devices simplify error recovery and
2454                  * return to upper layer
2455                  * do not skip ERP requests
2456                  */
2457                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2458                     (cqr->status == DASD_CQR_TERMINATED ||
2459                      cqr->status == DASD_CQR_NEED_ERP))
2460                         return -EAGAIN;
2461
2462                 /* normal recovery for basedev IO */
2463                 if (__dasd_sleep_on_erp(cqr))
2464                         /* handle erp first */
2465                         goto retry;
2466         }
2467
2468         return 0;
2469 }
2470
2471 /*
2472  * Queue a request to the tail of the device ccw_queue and wait for
2473  * it's completion.
2474  */
2475 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2476 {
2477         return _dasd_sleep_on(cqr, 0);
2478 }
2479 EXPORT_SYMBOL(dasd_sleep_on);
2480
2481 /*
2482  * Start requests from a ccw_queue and wait for their completion.
2483  */
2484 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2485 {
2486         return _dasd_sleep_on_queue(ccw_queue, 0);
2487 }
2488 EXPORT_SYMBOL(dasd_sleep_on_queue);
2489
2490 /*
2491  * Queue a request to the tail of the device ccw_queue and wait
2492  * interruptible for it's completion.
2493  */
2494 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2495 {
2496         return _dasd_sleep_on(cqr, 1);
2497 }
2498 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2499
2500 /*
2501  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2502  * for eckd devices) the currently running request has to be terminated
2503  * and be put back to status queued, before the special request is added
2504  * to the head of the queue. Then the special request is waited on normally.
2505  */
2506 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2507 {
2508         struct dasd_ccw_req *cqr;
2509         int rc;
2510
2511         if (list_empty(&device->ccw_queue))
2512                 return 0;
2513         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2514         rc = device->discipline->term_IO(cqr);
2515         if (!rc)
2516                 /*
2517                  * CQR terminated because a more important request is pending.
2518                  * Undo decreasing of retry counter because this is
2519                  * not an error case.
2520                  */
2521                 cqr->retries++;
2522         return rc;
2523 }
2524
2525 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2526 {
2527         struct dasd_device *device;
2528         int rc;
2529
2530         device = cqr->startdev;
2531         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2532             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2533                 cqr->status = DASD_CQR_FAILED;
2534                 cqr->intrc = -EPERM;
2535                 return -EIO;
2536         }
2537         spin_lock_irq(get_ccwdev_lock(device->cdev));
2538         rc = _dasd_term_running_cqr(device);
2539         if (rc) {
2540                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2541                 return rc;
2542         }
2543         cqr->callback = dasd_wakeup_cb;
2544         cqr->callback_data = DASD_SLEEPON_START_TAG;
2545         cqr->status = DASD_CQR_QUEUED;
2546         /*
2547          * add new request as second
2548          * first the terminated cqr needs to be finished
2549          */
2550         list_add(&cqr->devlist, device->ccw_queue.next);
2551
2552         /* let the bh start the request to keep them in order */
2553         dasd_schedule_device_bh(device);
2554
2555         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2556
2557         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2558
2559         if (cqr->status == DASD_CQR_DONE)
2560                 rc = 0;
2561         else if (cqr->intrc)
2562                 rc = cqr->intrc;
2563         else
2564                 rc = -EIO;
2565
2566         /* kick tasklets */
2567         dasd_schedule_device_bh(device);
2568         if (device->block)
2569                 dasd_schedule_block_bh(device->block);
2570
2571         return rc;
2572 }
2573 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2574
2575 /*
2576  * Cancels a request that was started with dasd_sleep_on_req.
2577  * This is useful to timeout requests. The request will be
2578  * terminated if it is currently in i/o.
2579  * Returns 0 if request termination was successful
2580  *         negative error code if termination failed
2581  * Cancellation of a request is an asynchronous operation! The calling
2582  * function has to wait until the request is properly returned via callback.
2583  */
2584 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2585 {
2586         struct dasd_device *device = cqr->startdev;
2587         unsigned long flags;
2588         int rc;
2589
2590         rc = 0;
2591         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2592         switch (cqr->status) {
2593         case DASD_CQR_QUEUED:
2594                 /* request was not started - just set to cleared */
2595                 cqr->status = DASD_CQR_CLEARED;
2596                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2597                         cqr->callback_data = DASD_SLEEPON_END_TAG;
2598                 break;
2599         case DASD_CQR_IN_IO:
2600                 /* request in IO - terminate IO and release again */
2601                 rc = device->discipline->term_IO(cqr);
2602                 if (rc) {
2603                         dev_err(&device->cdev->dev,
2604                                 "Cancelling request %p failed with rc=%d\n",
2605                                 cqr, rc);
2606                 } else {
2607                         cqr->stopclk = get_tod_clock();
2608                 }
2609                 break;
2610         default: /* already finished or clear pending - do nothing */
2611                 break;
2612         }
2613         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2614         dasd_schedule_device_bh(device);
2615         return rc;
2616 }
2617 EXPORT_SYMBOL(dasd_cancel_req);
2618
2619 /*
2620  * SECTION: Operations of the dasd_block layer.
2621  */
2622
2623 /*
2624  * Timeout function for dasd_block. This is used when the block layer
2625  * is waiting for something that may not come reliably, (e.g. a state
2626  * change interrupt)
2627  */
2628 static void dasd_block_timeout(struct timer_list *t)
2629 {
2630         unsigned long flags;
2631         struct dasd_block *block;
2632
2633         block = from_timer(block, t, timer);
2634         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2635         /* re-activate request queue */
2636         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2637         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2638         dasd_schedule_block_bh(block);
2639         blk_mq_run_hw_queues(block->request_queue, true);
2640 }
2641
2642 /*
2643  * Setup timeout for a dasd_block in jiffies.
2644  */
2645 void dasd_block_set_timer(struct dasd_block *block, int expires)
2646 {
2647         if (expires == 0)
2648                 del_timer(&block->timer);
2649         else
2650                 mod_timer(&block->timer, jiffies + expires);
2651 }
2652 EXPORT_SYMBOL(dasd_block_set_timer);
2653
2654 /*
2655  * Clear timeout for a dasd_block.
2656  */
2657 void dasd_block_clear_timer(struct dasd_block *block)
2658 {
2659         del_timer(&block->timer);
2660 }
2661 EXPORT_SYMBOL(dasd_block_clear_timer);
2662
2663 /*
2664  * Process finished error recovery ccw.
2665  */
2666 static void __dasd_process_erp(struct dasd_device *device,
2667                                struct dasd_ccw_req *cqr)
2668 {
2669         dasd_erp_fn_t erp_fn;
2670
2671         if (cqr->status == DASD_CQR_DONE)
2672                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2673         else
2674                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2675         erp_fn = device->discipline->erp_postaction(cqr);
2676         erp_fn(cqr);
2677 }
2678
2679 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2680 {
2681         struct request *req;
2682         blk_status_t error = BLK_STS_OK;
2683         int status;
2684
2685         req = (struct request *) cqr->callback_data;
2686         dasd_profile_end(cqr->block, cqr, req);
2687
2688         status = cqr->block->base->discipline->free_cp(cqr, req);
2689         if (status < 0)
2690                 error = errno_to_blk_status(status);
2691         else if (status == 0) {
2692                 switch (cqr->intrc) {
2693                 case -EPERM:
2694                         error = BLK_STS_NEXUS;
2695                         break;
2696                 case -ENOLINK:
2697                         error = BLK_STS_TRANSPORT;
2698                         break;
2699                 case -ETIMEDOUT:
2700                         error = BLK_STS_TIMEOUT;
2701                         break;
2702                 default:
2703                         error = BLK_STS_IOERR;
2704                         break;
2705                 }
2706         }
2707
2708         /*
2709          * We need to take care for ETIMEDOUT errors here since the
2710          * complete callback does not get called in this case.
2711          * Take care of all errors here and avoid additional code to
2712          * transfer the error value to the complete callback.
2713          */
2714         if (error) {
2715                 blk_mq_end_request(req, error);
2716                 blk_mq_run_hw_queues(req->q, true);
2717         } else {
2718                 blk_mq_complete_request(req);
2719         }
2720 }
2721
2722 /*
2723  * Process ccw request queue.
2724  */
2725 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2726                                            struct list_head *final_queue)
2727 {
2728         struct list_head *l, *n;
2729         struct dasd_ccw_req *cqr;
2730         dasd_erp_fn_t erp_fn;
2731         unsigned long flags;
2732         struct dasd_device *base = block->base;
2733
2734 restart:
2735         /* Process request with final status. */
2736         list_for_each_safe(l, n, &block->ccw_queue) {
2737                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2738                 if (cqr->status != DASD_CQR_DONE &&
2739                     cqr->status != DASD_CQR_FAILED &&
2740                     cqr->status != DASD_CQR_NEED_ERP &&
2741                     cqr->status != DASD_CQR_TERMINATED)
2742                         continue;
2743
2744                 if (cqr->status == DASD_CQR_TERMINATED) {
2745                         base->discipline->handle_terminated_request(cqr);
2746                         goto restart;
2747                 }
2748
2749                 /*  Process requests that may be recovered */
2750                 if (cqr->status == DASD_CQR_NEED_ERP) {
2751                         erp_fn = base->discipline->erp_action(cqr);
2752                         if (IS_ERR(erp_fn(cqr)))
2753                                 continue;
2754                         goto restart;
2755                 }
2756
2757                 /* log sense for fatal error */
2758                 if (cqr->status == DASD_CQR_FAILED) {
2759                         dasd_log_sense(cqr, &cqr->irb);
2760                 }
2761
2762                 /* First of all call extended error reporting. */
2763                 if (dasd_eer_enabled(base) &&
2764                     cqr->status == DASD_CQR_FAILED) {
2765                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2766
2767                         /* restart request  */
2768                         cqr->status = DASD_CQR_FILLED;
2769                         cqr->retries = 255;
2770                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2771                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2772                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2773                                                flags);
2774                         goto restart;
2775                 }
2776
2777                 /* Process finished ERP request. */
2778                 if (cqr->refers) {
2779                         __dasd_process_erp(base, cqr);
2780                         goto restart;
2781                 }
2782
2783                 /* Rechain finished requests to final queue */
2784                 cqr->endclk = get_tod_clock();
2785                 list_move_tail(&cqr->blocklist, final_queue);
2786         }
2787 }
2788
2789 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2790 {
2791         dasd_schedule_block_bh(cqr->block);
2792 }
2793
2794 static void __dasd_block_start_head(struct dasd_block *block)
2795 {
2796         struct dasd_ccw_req *cqr;
2797
2798         if (list_empty(&block->ccw_queue))
2799                 return;
2800         /* We allways begin with the first requests on the queue, as some
2801          * of previously started requests have to be enqueued on a
2802          * dasd_device again for error recovery.
2803          */
2804         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2805                 if (cqr->status != DASD_CQR_FILLED)
2806                         continue;
2807                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2808                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2809                         cqr->status = DASD_CQR_FAILED;
2810                         cqr->intrc = -EPERM;
2811                         dasd_schedule_block_bh(block);
2812                         continue;
2813                 }
2814                 /* Non-temporary stop condition will trigger fail fast */
2815                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2816                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2817                     (!dasd_eer_enabled(block->base))) {
2818                         cqr->status = DASD_CQR_FAILED;
2819                         cqr->intrc = -ENOLINK;
2820                         dasd_schedule_block_bh(block);
2821                         continue;
2822                 }
2823                 /* Don't try to start requests if device is stopped */
2824                 if (block->base->stopped)
2825                         return;
2826
2827                 /* just a fail safe check, should not happen */
2828                 if (!cqr->startdev)
2829                         cqr->startdev = block->base;
2830
2831                 /* make sure that the requests we submit find their way back */
2832                 cqr->callback = dasd_return_cqr_cb;
2833
2834                 dasd_add_request_tail(cqr);
2835         }
2836 }
2837
2838 /*
2839  * Central dasd_block layer routine. Takes requests from the generic
2840  * block layer request queue, creates ccw requests, enqueues them on
2841  * a dasd_device and processes ccw requests that have been returned.
2842  */
2843 static void dasd_block_tasklet(struct dasd_block *block)
2844 {
2845         struct list_head final_queue;
2846         struct list_head *l, *n;
2847         struct dasd_ccw_req *cqr;
2848         struct dasd_queue *dq;
2849
2850         atomic_set(&block->tasklet_scheduled, 0);
2851         INIT_LIST_HEAD(&final_queue);
2852         spin_lock_irq(&block->queue_lock);
2853         /* Finish off requests on ccw queue */
2854         __dasd_process_block_ccw_queue(block, &final_queue);
2855         spin_unlock_irq(&block->queue_lock);
2856
2857         /* Now call the callback function of requests with final status */
2858         list_for_each_safe(l, n, &final_queue) {
2859                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2860                 dq = cqr->dq;
2861                 spin_lock_irq(&dq->lock);
2862                 list_del_init(&cqr->blocklist);
2863                 __dasd_cleanup_cqr(cqr);
2864                 spin_unlock_irq(&dq->lock);
2865         }
2866
2867         spin_lock_irq(&block->queue_lock);
2868         /* Now check if the head of the ccw queue needs to be started. */
2869         __dasd_block_start_head(block);
2870         spin_unlock_irq(&block->queue_lock);
2871
2872         if (waitqueue_active(&shutdown_waitq))
2873                 wake_up(&shutdown_waitq);
2874         dasd_put_device(block->base);
2875 }
2876
2877 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2878 {
2879         wake_up(&dasd_flush_wq);
2880 }
2881
2882 /*
2883  * Requeue a request back to the block request queue
2884  * only works for block requests
2885  */
2886 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2887 {
2888         struct dasd_block *block = cqr->block;
2889         struct request *req;
2890
2891         if (!block)
2892                 return -EINVAL;
2893         spin_lock_irq(&cqr->dq->lock);
2894         req = (struct request *) cqr->callback_data;
2895         blk_mq_requeue_request(req, false);
2896         spin_unlock_irq(&cqr->dq->lock);
2897
2898         return 0;
2899 }
2900
2901 /*
2902  * Go through all request on the dasd_block request queue, cancel them
2903  * on the respective dasd_device, and return them to the generic
2904  * block layer.
2905  */
2906 static int dasd_flush_block_queue(struct dasd_block *block)
2907 {
2908         struct dasd_ccw_req *cqr, *n;
2909         int rc, i;
2910         struct list_head flush_queue;
2911         unsigned long flags;
2912
2913         INIT_LIST_HEAD(&flush_queue);
2914         spin_lock_bh(&block->queue_lock);
2915         rc = 0;
2916 restart:
2917         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2918                 /* if this request currently owned by a dasd_device cancel it */
2919                 if (cqr->status >= DASD_CQR_QUEUED)
2920                         rc = dasd_cancel_req(cqr);
2921                 if (rc < 0)
2922                         break;
2923                 /* Rechain request (including erp chain) so it won't be
2924                  * touched by the dasd_block_tasklet anymore.
2925                  * Replace the callback so we notice when the request
2926                  * is returned from the dasd_device layer.
2927                  */
2928                 cqr->callback = _dasd_wake_block_flush_cb;
2929                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2930                         list_move_tail(&cqr->blocklist, &flush_queue);
2931                 if (i > 1)
2932                         /* moved more than one request - need to restart */
2933                         goto restart;
2934         }
2935         spin_unlock_bh(&block->queue_lock);
2936         /* Now call the callback function of flushed requests */
2937 restart_cb:
2938         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2939                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2940                 /* Process finished ERP request. */
2941                 if (cqr->refers) {
2942                         spin_lock_bh(&block->queue_lock);
2943                         __dasd_process_erp(block->base, cqr);
2944                         spin_unlock_bh(&block->queue_lock);
2945                         /* restart list_for_xx loop since dasd_process_erp
2946                          * might remove multiple elements */
2947                         goto restart_cb;
2948                 }
2949                 /* call the callback function */
2950                 spin_lock_irqsave(&cqr->dq->lock, flags);
2951                 cqr->endclk = get_tod_clock();
2952                 list_del_init(&cqr->blocklist);
2953                 __dasd_cleanup_cqr(cqr);
2954                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
2955         }
2956         return rc;
2957 }
2958
2959 /*
2960  * Schedules a call to dasd_tasklet over the device tasklet.
2961  */
2962 void dasd_schedule_block_bh(struct dasd_block *block)
2963 {
2964         /* Protect against rescheduling. */
2965         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2966                 return;
2967         /* life cycle of block is bound to it's base device */
2968         dasd_get_device(block->base);
2969         tasklet_hi_schedule(&block->tasklet);
2970 }
2971 EXPORT_SYMBOL(dasd_schedule_block_bh);
2972
2973
2974 /*
2975  * SECTION: external block device operations
2976  * (request queue handling, open, release, etc.)
2977  */
2978
2979 /*
2980  * Dasd request queue function. Called from ll_rw_blk.c
2981  */
2982 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
2983                                     const struct blk_mq_queue_data *qd)
2984 {
2985         struct dasd_block *block = hctx->queue->queuedata;
2986         struct dasd_queue *dq = hctx->driver_data;
2987         struct request *req = qd->rq;
2988         struct dasd_device *basedev;
2989         struct dasd_ccw_req *cqr;
2990         blk_status_t rc = BLK_STS_OK;
2991
2992         basedev = block->base;
2993         spin_lock_irq(&dq->lock);
2994         if (basedev->state < DASD_STATE_READY) {
2995                 DBF_DEV_EVENT(DBF_ERR, basedev,
2996                               "device not ready for request %p", req);
2997                 rc = BLK_STS_IOERR;
2998                 goto out;
2999         }
3000
3001         /*
3002          * if device is stopped do not fetch new requests
3003          * except failfast is active which will let requests fail
3004          * immediately in __dasd_block_start_head()
3005          */
3006         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3007                 DBF_DEV_EVENT(DBF_ERR, basedev,
3008                               "device stopped request %p", req);
3009                 rc = BLK_STS_RESOURCE;
3010                 goto out;
3011         }
3012
3013         if (basedev->features & DASD_FEATURE_READONLY &&
3014             rq_data_dir(req) == WRITE) {
3015                 DBF_DEV_EVENT(DBF_ERR, basedev,
3016                               "Rejecting write request %p", req);
3017                 rc = BLK_STS_IOERR;
3018                 goto out;
3019         }
3020
3021         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3022             (basedev->features & DASD_FEATURE_FAILFAST ||
3023              blk_noretry_request(req))) {
3024                 DBF_DEV_EVENT(DBF_ERR, basedev,
3025                               "Rejecting failfast request %p", req);
3026                 rc = BLK_STS_IOERR;
3027                 goto out;
3028         }
3029
3030         cqr = basedev->discipline->build_cp(basedev, block, req);
3031         if (IS_ERR(cqr)) {
3032                 if (PTR_ERR(cqr) == -EBUSY ||
3033                     PTR_ERR(cqr) == -ENOMEM ||
3034                     PTR_ERR(cqr) == -EAGAIN) {
3035                         rc = BLK_STS_RESOURCE;
3036                         goto out;
3037                 }
3038                 DBF_DEV_EVENT(DBF_ERR, basedev,
3039                               "CCW creation failed (rc=%ld) on request %p",
3040                               PTR_ERR(cqr), req);
3041                 rc = BLK_STS_IOERR;
3042                 goto out;
3043         }
3044         /*
3045          *  Note: callback is set to dasd_return_cqr_cb in
3046          * __dasd_block_start_head to cover erp requests as well
3047          */
3048         cqr->callback_data = req;
3049         cqr->status = DASD_CQR_FILLED;
3050         cqr->dq = dq;
3051         req->completion_data = cqr;
3052         blk_mq_start_request(req);
3053         spin_lock(&block->queue_lock);
3054         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3055         INIT_LIST_HEAD(&cqr->devlist);
3056         dasd_profile_start(block, cqr, req);
3057         dasd_schedule_block_bh(block);
3058         spin_unlock(&block->queue_lock);
3059
3060 out:
3061         spin_unlock_irq(&dq->lock);
3062         return rc;
3063 }
3064
3065 /*
3066  * Block timeout callback, called from the block layer
3067  *
3068  * Return values:
3069  * BLK_EH_RESET_TIMER if the request should be left running
3070  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3071  *                    by the driver.
3072  */
3073 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3074 {
3075         struct dasd_ccw_req *cqr = req->completion_data;
3076         struct dasd_block *block = req->q->queuedata;
3077         struct dasd_device *device;
3078         unsigned long flags;
3079         int rc = 0;
3080
3081         if (!cqr)
3082                 return BLK_EH_NOT_HANDLED;
3083
3084         spin_lock_irqsave(&cqr->dq->lock, flags);
3085         device = cqr->startdev ? cqr->startdev : block->base;
3086         if (!device->blk_timeout) {
3087                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3088                 return BLK_EH_RESET_TIMER;
3089         }
3090         DBF_DEV_EVENT(DBF_WARNING, device,
3091                       " dasd_times_out cqr %p status %x",
3092                       cqr, cqr->status);
3093
3094         spin_lock(&block->queue_lock);
3095         spin_lock(get_ccwdev_lock(device->cdev));
3096         cqr->retries = -1;
3097         cqr->intrc = -ETIMEDOUT;
3098         if (cqr->status >= DASD_CQR_QUEUED) {
3099                 spin_unlock(get_ccwdev_lock(device->cdev));
3100                 rc = dasd_cancel_req(cqr);
3101         } else if (cqr->status == DASD_CQR_FILLED ||
3102                    cqr->status == DASD_CQR_NEED_ERP) {
3103                 cqr->status = DASD_CQR_TERMINATED;
3104                 spin_unlock(get_ccwdev_lock(device->cdev));
3105         } else if (cqr->status == DASD_CQR_IN_ERP) {
3106                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3107
3108                 list_for_each_entry_safe(searchcqr, nextcqr,
3109                                          &block->ccw_queue, blocklist) {
3110                         tmpcqr = searchcqr;
3111                         while (tmpcqr->refers)
3112                                 tmpcqr = tmpcqr->refers;
3113                         if (tmpcqr != cqr)
3114                                 continue;
3115                         /* searchcqr is an ERP request for cqr */
3116                         searchcqr->retries = -1;
3117                         searchcqr->intrc = -ETIMEDOUT;
3118                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3119                                 spin_unlock(get_ccwdev_lock(device->cdev));
3120                                 rc = dasd_cancel_req(searchcqr);
3121                                 spin_lock(get_ccwdev_lock(device->cdev));
3122                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3123                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3124                                 searchcqr->status = DASD_CQR_TERMINATED;
3125                                 rc = 0;
3126                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3127                                 /*
3128                                  * Shouldn't happen; most recent ERP
3129                                  * request is at the front of queue
3130                                  */
3131                                 continue;
3132                         }
3133                         break;
3134                 }
3135                 spin_unlock(get_ccwdev_lock(device->cdev));
3136         }
3137         dasd_schedule_block_bh(block);
3138         spin_unlock(&block->queue_lock);
3139         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3140
3141         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3142 }
3143
3144 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3145                           unsigned int idx)
3146 {
3147         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3148
3149         if (!dq)
3150                 return -ENOMEM;
3151
3152         spin_lock_init(&dq->lock);
3153         hctx->driver_data = dq;
3154
3155         return 0;
3156 }
3157
3158 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3159 {
3160         kfree(hctx->driver_data);
3161         hctx->driver_data = NULL;
3162 }
3163
3164 static void dasd_request_done(struct request *req)
3165 {
3166         blk_mq_end_request(req, 0);
3167         blk_mq_run_hw_queues(req->q, true);
3168 }
3169
3170 static struct blk_mq_ops dasd_mq_ops = {
3171         .queue_rq = do_dasd_request,
3172         .complete = dasd_request_done,
3173         .timeout = dasd_times_out,
3174         .init_hctx = dasd_init_hctx,
3175         .exit_hctx = dasd_exit_hctx,
3176 };
3177
3178 /*
3179  * Allocate and initialize request queue and default I/O scheduler.
3180  */
3181 static int dasd_alloc_queue(struct dasd_block *block)
3182 {
3183         int rc;
3184
3185         block->tag_set.ops = &dasd_mq_ops;
3186         block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
3187         block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
3188         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3189
3190         rc = blk_mq_alloc_tag_set(&block->tag_set);
3191         if (rc)
3192                 return rc;
3193
3194         block->request_queue = blk_mq_init_queue(&block->tag_set);
3195         if (IS_ERR(block->request_queue))
3196                 return PTR_ERR(block->request_queue);
3197
3198         block->request_queue->queuedata = block;
3199
3200         return 0;
3201 }
3202
3203 /*
3204  * Allocate and initialize request queue.
3205  */
3206 static void dasd_setup_queue(struct dasd_block *block)
3207 {
3208         unsigned int logical_block_size = block->bp_block;
3209         struct request_queue *q = block->request_queue;
3210         unsigned int max_bytes, max_discard_sectors;
3211         int max;
3212
3213         if (block->base->features & DASD_FEATURE_USERAW) {
3214                 /*
3215                  * the max_blocks value for raw_track access is 256
3216                  * it is higher than the native ECKD value because we
3217                  * only need one ccw per track
3218                  * so the max_hw_sectors are
3219                  * 2048 x 512B = 1024kB = 16 tracks
3220                  */
3221                 max = 2048;
3222         } else {
3223                 max = block->base->discipline->max_blocks << block->s2b_shift;
3224         }
3225         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
3226         q->limits.max_dev_sectors = max;
3227         blk_queue_logical_block_size(q, logical_block_size);
3228         blk_queue_max_hw_sectors(q, max);
3229         blk_queue_max_segments(q, USHRT_MAX);
3230         /* with page sized segments we can translate each segement into
3231          * one idaw/tidaw
3232          */
3233         blk_queue_max_segment_size(q, PAGE_SIZE);
3234         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
3235
3236         /* Only activate blocklayer discard support for devices that support it */
3237         if (block->base->features & DASD_FEATURE_DISCARD) {
3238                 q->limits.discard_granularity = logical_block_size;
3239                 q->limits.discard_alignment = PAGE_SIZE;
3240
3241                 /* Calculate max_discard_sectors and make it PAGE aligned */
3242                 max_bytes = USHRT_MAX * logical_block_size;
3243                 max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
3244                 max_discard_sectors = max_bytes / logical_block_size;
3245
3246                 blk_queue_max_discard_sectors(q, max_discard_sectors);
3247                 blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
3248                 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
3249         }
3250 }
3251
3252 /*
3253  * Deactivate and free request queue.
3254  */
3255 static void dasd_free_queue(struct dasd_block *block)
3256 {
3257         if (block->request_queue) {
3258                 blk_cleanup_queue(block->request_queue);
3259                 blk_mq_free_tag_set(&block->tag_set);
3260                 block->request_queue = NULL;
3261         }
3262 }
3263
3264 static int dasd_open(struct block_device *bdev, fmode_t mode)
3265 {
3266         struct dasd_device *base;
3267         int rc;
3268
3269         base = dasd_device_from_gendisk(bdev->bd_disk);
3270         if (!base)
3271                 return -ENODEV;
3272
3273         atomic_inc(&base->block->open_count);
3274         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3275                 rc = -ENODEV;
3276                 goto unlock;
3277         }
3278
3279         if (!try_module_get(base->discipline->owner)) {
3280                 rc = -EINVAL;
3281                 goto unlock;
3282         }
3283
3284         if (dasd_probeonly) {
3285                 dev_info(&base->cdev->dev,
3286                          "Accessing the DASD failed because it is in "
3287                          "probeonly mode\n");
3288                 rc = -EPERM;
3289                 goto out;
3290         }
3291
3292         if (base->state <= DASD_STATE_BASIC) {
3293                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3294                               " Cannot open unrecognized device");
3295                 rc = -ENODEV;
3296                 goto out;
3297         }
3298
3299         if ((mode & FMODE_WRITE) &&
3300             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3301              (base->features & DASD_FEATURE_READONLY))) {
3302                 rc = -EROFS;
3303                 goto out;
3304         }
3305
3306         dasd_put_device(base);
3307         return 0;
3308
3309 out:
3310         module_put(base->discipline->owner);
3311 unlock:
3312         atomic_dec(&base->block->open_count);
3313         dasd_put_device(base);
3314         return rc;
3315 }
3316
3317 static void dasd_release(struct gendisk *disk, fmode_t mode)
3318 {
3319         struct dasd_device *base = dasd_device_from_gendisk(disk);
3320         if (base) {
3321                 atomic_dec(&base->block->open_count);
3322                 module_put(base->discipline->owner);
3323                 dasd_put_device(base);
3324         }
3325 }
3326
3327 /*
3328  * Return disk geometry.
3329  */
3330 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3331 {
3332         struct dasd_device *base;
3333
3334         base = dasd_device_from_gendisk(bdev->bd_disk);
3335         if (!base)
3336                 return -ENODEV;
3337
3338         if (!base->discipline ||
3339             !base->discipline->fill_geometry) {
3340                 dasd_put_device(base);
3341                 return -EINVAL;
3342         }
3343         base->discipline->fill_geometry(base->block, geo);
3344         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3345         dasd_put_device(base);
3346         return 0;
3347 }
3348
3349 const struct block_device_operations
3350 dasd_device_operations = {
3351         .owner          = THIS_MODULE,
3352         .open           = dasd_open,
3353         .release        = dasd_release,
3354         .ioctl          = dasd_ioctl,
3355         .compat_ioctl   = dasd_ioctl,
3356         .getgeo         = dasd_getgeo,
3357 };
3358
3359 /*******************************************************************************
3360  * end of block device operations
3361  */
3362
3363 static void
3364 dasd_exit(void)
3365 {
3366 #ifdef CONFIG_PROC_FS
3367         dasd_proc_exit();
3368 #endif
3369         dasd_eer_exit();
3370         if (dasd_page_cache != NULL) {
3371                 kmem_cache_destroy(dasd_page_cache);
3372                 dasd_page_cache = NULL;
3373         }
3374         dasd_gendisk_exit();
3375         dasd_devmap_exit();
3376         if (dasd_debug_area != NULL) {
3377                 debug_unregister(dasd_debug_area);
3378                 dasd_debug_area = NULL;
3379         }
3380         dasd_statistics_removeroot();
3381 }
3382
3383 /*
3384  * SECTION: common functions for ccw_driver use
3385  */
3386
3387 /*
3388  * Is the device read-only?
3389  * Note that this function does not report the setting of the
3390  * readonly device attribute, but how it is configured in z/VM.
3391  */
3392 int dasd_device_is_ro(struct dasd_device *device)
3393 {
3394         struct ccw_dev_id dev_id;
3395         struct diag210 diag_data;
3396         int rc;
3397
3398         if (!MACHINE_IS_VM)
3399                 return 0;
3400         ccw_device_get_id(device->cdev, &dev_id);
3401         memset(&diag_data, 0, sizeof(diag_data));
3402         diag_data.vrdcdvno = dev_id.devno;
3403         diag_data.vrdclen = sizeof(diag_data);
3404         rc = diag210(&diag_data);
3405         if (rc == 0 || rc == 2) {
3406                 return diag_data.vrdcvfla & 0x80;
3407         } else {
3408                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3409                           dev_id.devno, rc);
3410                 return 0;
3411         }
3412 }
3413 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3414
3415 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3416 {
3417         struct ccw_device *cdev = data;
3418         int ret;
3419
3420         ret = ccw_device_set_online(cdev);
3421         if (ret)
3422                 pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3423                         dev_name(&cdev->dev), ret);
3424 }
3425
3426 /*
3427  * Initial attempt at a probe function. this can be simplified once
3428  * the other detection code is gone.
3429  */
3430 int dasd_generic_probe(struct ccw_device *cdev,
3431                        struct dasd_discipline *discipline)
3432 {
3433         int ret;
3434
3435         ret = dasd_add_sysfs_files(cdev);
3436         if (ret) {
3437                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3438                                 "dasd_generic_probe: could not add "
3439                                 "sysfs entries");
3440                 return ret;
3441         }
3442         cdev->handler = &dasd_int_handler;
3443
3444         /*
3445          * Automatically online either all dasd devices (dasd_autodetect)
3446          * or all devices specified with dasd= parameters during
3447          * initial probe.
3448          */
3449         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3450             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3451                 async_schedule(dasd_generic_auto_online, cdev);
3452         return 0;
3453 }
3454 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3455
3456 void dasd_generic_free_discipline(struct dasd_device *device)
3457 {
3458         /* Forget the discipline information. */
3459         if (device->discipline) {
3460                 if (device->discipline->uncheck_device)
3461                         device->discipline->uncheck_device(device);
3462                 module_put(device->discipline->owner);
3463                 device->discipline = NULL;
3464         }
3465         if (device->base_discipline) {
3466                 module_put(device->base_discipline->owner);
3467                 device->base_discipline = NULL;
3468         }
3469 }
3470 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3471
3472 /*
3473  * This will one day be called from a global not_oper handler.
3474  * It is also used by driver_unregister during module unload.
3475  */
3476 void dasd_generic_remove(struct ccw_device *cdev)
3477 {
3478         struct dasd_device *device;
3479         struct dasd_block *block;
3480
3481         cdev->handler = NULL;
3482
3483         device = dasd_device_from_cdev(cdev);
3484         if (IS_ERR(device)) {
3485                 dasd_remove_sysfs_files(cdev);
3486                 return;
3487         }
3488         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3489             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3490                 /* Already doing offline processing */
3491                 dasd_put_device(device);
3492                 dasd_remove_sysfs_files(cdev);
3493                 return;
3494         }
3495         /*
3496          * This device is removed unconditionally. Set offline
3497          * flag to prevent dasd_open from opening it while it is
3498          * no quite down yet.
3499          */
3500         dasd_set_target_state(device, DASD_STATE_NEW);
3501         /* dasd_delete_device destroys the device reference. */
3502         block = device->block;
3503         dasd_delete_device(device);
3504         /*
3505          * life cycle of block is bound to device, so delete it after
3506          * device was safely removed
3507          */
3508         if (block)
3509                 dasd_free_block(block);
3510
3511         dasd_remove_sysfs_files(cdev);
3512 }
3513 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3514
3515 /*
3516  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3517  * the device is detected for the first time and is supposed to be used
3518  * or the user has started activation through sysfs.
3519  */
3520 int dasd_generic_set_online(struct ccw_device *cdev,
3521                             struct dasd_discipline *base_discipline)
3522 {
3523         struct dasd_discipline *discipline;
3524         struct dasd_device *device;
3525         int rc;
3526
3527         /* first online clears initial online feature flag */
3528         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3529         device = dasd_create_device(cdev);
3530         if (IS_ERR(device))
3531                 return PTR_ERR(device);
3532
3533         discipline = base_discipline;
3534         if (device->features & DASD_FEATURE_USEDIAG) {
3535                 if (!dasd_diag_discipline_pointer) {
3536                         /* Try to load the required module. */
3537                         rc = request_module(DASD_DIAG_MOD);
3538                         if (rc) {
3539                                 pr_warn("%s Setting the DASD online failed "
3540                                         "because the required module %s "
3541                                         "could not be loaded (rc=%d)\n",
3542                                         dev_name(&cdev->dev), DASD_DIAG_MOD,
3543                                         rc);
3544                                 dasd_delete_device(device);
3545                                 return -ENODEV;
3546                         }
3547                 }
3548                 /* Module init could have failed, so check again here after
3549                  * request_module(). */
3550                 if (!dasd_diag_discipline_pointer) {
3551                         pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3552                                 dev_name(&cdev->dev));
3553                         dasd_delete_device(device);
3554                         return -ENODEV;
3555                 }
3556                 discipline = dasd_diag_discipline_pointer;
3557         }
3558         if (!try_module_get(base_discipline->owner)) {
3559                 dasd_delete_device(device);
3560                 return -EINVAL;
3561         }
3562         if (!try_module_get(discipline->owner)) {
3563                 module_put(base_discipline->owner);
3564                 dasd_delete_device(device);
3565                 return -EINVAL;
3566         }
3567         device->base_discipline = base_discipline;
3568         device->discipline = discipline;
3569
3570         /* check_device will allocate block device if necessary */
3571         rc = discipline->check_device(device);
3572         if (rc) {
3573                 pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3574                         dev_name(&cdev->dev), discipline->name, rc);
3575                 module_put(discipline->owner);
3576                 module_put(base_discipline->owner);
3577                 dasd_delete_device(device);
3578                 return rc;
3579         }
3580
3581         dasd_set_target_state(device, DASD_STATE_ONLINE);
3582         if (device->state <= DASD_STATE_KNOWN) {
3583                 pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3584                         dev_name(&cdev->dev));
3585                 rc = -ENODEV;
3586                 dasd_set_target_state(device, DASD_STATE_NEW);
3587                 if (device->block)
3588                         dasd_free_block(device->block);
3589                 dasd_delete_device(device);
3590         } else
3591                 pr_debug("dasd_generic device %s found\n",
3592                                 dev_name(&cdev->dev));
3593
3594         wait_event(dasd_init_waitq, _wait_for_device(device));
3595
3596         dasd_put_device(device);
3597         return rc;
3598 }
3599 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3600
3601 int dasd_generic_set_offline(struct ccw_device *cdev)
3602 {
3603         struct dasd_device *device;
3604         struct dasd_block *block;
3605         int max_count, open_count, rc;
3606         unsigned long flags;
3607
3608         rc = 0;
3609         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3610         device = dasd_device_from_cdev_locked(cdev);
3611         if (IS_ERR(device)) {
3612                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3613                 return PTR_ERR(device);
3614         }
3615
3616         /*
3617          * We must make sure that this device is currently not in use.
3618          * The open_count is increased for every opener, that includes
3619          * the blkdev_get in dasd_scan_partitions. We are only interested
3620          * in the other openers.
3621          */
3622         if (device->block) {
3623                 max_count = device->block->bdev ? 0 : -1;
3624                 open_count = atomic_read(&device->block->open_count);
3625                 if (open_count > max_count) {
3626                         if (open_count > 0)
3627                                 pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3628                                         dev_name(&cdev->dev), open_count);
3629                         else
3630                                 pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3631                                         dev_name(&cdev->dev));
3632                         rc = -EBUSY;
3633                         goto out_err;
3634                 }
3635         }
3636
3637         /*
3638          * Test if the offline processing is already running and exit if so.
3639          * If a safe offline is being processed this could only be a normal
3640          * offline that should be able to overtake the safe offline and
3641          * cancel any I/O we do not want to wait for any longer
3642          */
3643         if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3644                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3645                         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3646                                   &device->flags);
3647                 } else {
3648                         rc = -EBUSY;
3649                         goto out_err;
3650                 }
3651         }
3652         set_bit(DASD_FLAG_OFFLINE, &device->flags);
3653
3654         /*
3655          * if safe_offline is called set safe_offline_running flag and
3656          * clear safe_offline so that a call to normal offline
3657          * can overrun safe_offline processing
3658          */
3659         if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3660             !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3661                 /* need to unlock here to wait for outstanding I/O */
3662                 spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3663                 /*
3664                  * If we want to set the device safe offline all IO operations
3665                  * should be finished before continuing the offline process
3666                  * so sync bdev first and then wait for our queues to become
3667                  * empty
3668                  */
3669                 if (device->block) {
3670                         rc = fsync_bdev(device->block->bdev);
3671                         if (rc != 0)
3672                                 goto interrupted;
3673                 }
3674                 dasd_schedule_device_bh(device);
3675                 rc = wait_event_interruptible(shutdown_waitq,
3676                                               _wait_for_empty_queues(device));
3677                 if (rc != 0)
3678                         goto interrupted;
3679
3680                 /*
3681                  * check if a normal offline process overtook the offline
3682                  * processing in this case simply do nothing beside returning
3683                  * that we got interrupted
3684                  * otherwise mark safe offline as not running any longer and
3685                  * continue with normal offline
3686                  */
3687                 spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3688                 if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3689                         rc = -ERESTARTSYS;
3690                         goto out_err;
3691                 }
3692                 clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3693         }
3694         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3695
3696         dasd_set_target_state(device, DASD_STATE_NEW);
3697         /* dasd_delete_device destroys the device reference. */
3698         block = device->block;
3699         dasd_delete_device(device);
3700         /*
3701          * life cycle of block is bound to device, so delete it after
3702          * device was safely removed
3703          */
3704         if (block)
3705                 dasd_free_block(block);
3706
3707         return 0;
3708
3709 interrupted:
3710         /* interrupted by signal */
3711         spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3712         clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3713         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3714 out_err:
3715         dasd_put_device(device);
3716         spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3717         return rc;
3718 }
3719 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3720
3721 int dasd_generic_last_path_gone(struct dasd_device *device)
3722 {
3723         struct dasd_ccw_req *cqr;
3724
3725         dev_warn(&device->cdev->dev, "No operational channel path is left "
3726                  "for the device\n");
3727         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3728         /* First of all call extended error reporting. */
3729         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3730
3731         if (device->state < DASD_STATE_BASIC)
3732                 return 0;
3733         /* Device is active. We want to keep it. */
3734         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3735                 if ((cqr->status == DASD_CQR_IN_IO) ||
3736                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3737                         cqr->status = DASD_CQR_QUEUED;
3738                         cqr->retries++;
3739                 }
3740         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3741         dasd_device_clear_timer(device);
3742         dasd_schedule_device_bh(device);
3743         return 1;
3744 }
3745 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3746
3747 int dasd_generic_path_operational(struct dasd_device *device)
3748 {
3749         dev_info(&device->cdev->dev, "A channel path to the device has become "
3750                  "operational\n");
3751         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3752         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3753         if (device->stopped & DASD_UNRESUMED_PM) {
3754                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3755                 dasd_restore_device(device);
3756                 return 1;
3757         }
3758         dasd_schedule_device_bh(device);
3759         if (device->block) {
3760                 dasd_schedule_block_bh(device->block);
3761                 if (device->block->request_queue)
3762                         blk_mq_run_hw_queues(device->block->request_queue,
3763                                              true);
3764                 }
3765
3766         if (!device->stopped)
3767                 wake_up(&generic_waitq);
3768
3769         return 1;
3770 }
3771 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3772
3773 int dasd_generic_notify(struct ccw_device *cdev, int event)
3774 {
3775         struct dasd_device *device;
3776         int ret;
3777
3778         device = dasd_device_from_cdev_locked(cdev);
3779         if (IS_ERR(device))
3780                 return 0;
3781         ret = 0;
3782         switch (event) {
3783         case CIO_GONE:
3784         case CIO_BOXED:
3785         case CIO_NO_PATH:
3786                 dasd_path_no_path(device);
3787                 ret = dasd_generic_last_path_gone(device);
3788                 break;
3789         case CIO_OPER:
3790                 ret = 1;
3791                 if (dasd_path_get_opm(device))
3792                         ret = dasd_generic_path_operational(device);
3793                 break;
3794         }
3795         dasd_put_device(device);
3796         return ret;
3797 }
3798 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3799
3800 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3801 {
3802         struct dasd_device *device;
3803         int chp, oldopm, hpfpm, ifccpm;
3804
3805         device = dasd_device_from_cdev_locked(cdev);
3806         if (IS_ERR(device))
3807                 return;
3808
3809         oldopm = dasd_path_get_opm(device);
3810         for (chp = 0; chp < 8; chp++) {
3811                 if (path_event[chp] & PE_PATH_GONE) {
3812                         dasd_path_notoper(device, chp);
3813                 }
3814                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3815                         dasd_path_available(device, chp);
3816                         dasd_schedule_device_bh(device);
3817                 }
3818                 if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3819                         if (!dasd_path_is_operational(device, chp) &&
3820                             !dasd_path_need_verify(device, chp)) {
3821                                 /*
3822                                  * we can not establish a pathgroup on an
3823                                  * unavailable path, so trigger a path
3824                                  * verification first
3825                                  */
3826                         dasd_path_available(device, chp);
3827                         dasd_schedule_device_bh(device);
3828                         }
3829                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3830                                       "Pathgroup re-established\n");
3831                         if (device->discipline->kick_validate)
3832                                 device->discipline->kick_validate(device);
3833                 }
3834         }
3835         hpfpm = dasd_path_get_hpfpm(device);
3836         ifccpm = dasd_path_get_ifccpm(device);
3837         if (!dasd_path_get_opm(device) && hpfpm) {
3838                 /*
3839                  * device has no operational paths but at least one path is
3840                  * disabled due to HPF errors
3841                  * disable HPF at all and use the path(s) again
3842                  */
3843                 if (device->discipline->disable_hpf)
3844                         device->discipline->disable_hpf(device);
3845                 dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3846                 dasd_path_set_tbvpm(device, hpfpm);
3847                 dasd_schedule_device_bh(device);
3848                 dasd_schedule_requeue(device);
3849         } else if (!dasd_path_get_opm(device) && ifccpm) {
3850                 /*
3851                  * device has no operational paths but at least one path is
3852                  * disabled due to IFCC errors
3853                  * trigger path verification on paths with IFCC errors
3854                  */
3855                 dasd_path_set_tbvpm(device, ifccpm);
3856                 dasd_schedule_device_bh(device);
3857         }
3858         if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3859                 dev_warn(&device->cdev->dev,
3860                          "No verified channel paths remain for the device\n");
3861                 DBF_DEV_EVENT(DBF_WARNING, device,
3862                               "%s", "last verified path gone");
3863                 dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3864                 dasd_device_set_stop_bits(device,
3865                                           DASD_STOPPED_DC_WAIT);
3866         }
3867         dasd_put_device(device);
3868 }
3869 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3870
3871 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3872 {
3873         if (!dasd_path_get_opm(device) && lpm) {
3874                 dasd_path_set_opm(device, lpm);
3875                 dasd_generic_path_operational(device);
3876         } else
3877                 dasd_path_add_opm(device, lpm);
3878         return 0;
3879 }
3880 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3881
3882 /*
3883  * clear active requests and requeue them to block layer if possible
3884  */
3885 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3886 {
3887         struct list_head requeue_queue;
3888         struct dasd_ccw_req *cqr, *n;
3889         struct dasd_ccw_req *refers;
3890         int rc;
3891
3892         INIT_LIST_HEAD(&requeue_queue);
3893         spin_lock_irq(get_ccwdev_lock(device->cdev));
3894         rc = 0;
3895         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3896                 /* Check status and move request to flush_queue */
3897                 if (cqr->status == DASD_CQR_IN_IO) {
3898                         rc = device->discipline->term_IO(cqr);
3899                         if (rc) {
3900                                 /* unable to terminate requeust */
3901                                 dev_err(&device->cdev->dev,
3902                                         "Unable to terminate request %p "
3903                                         "on suspend\n", cqr);
3904                                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3905                                 dasd_put_device(device);
3906                                 return rc;
3907                         }
3908                 }
3909                 list_move_tail(&cqr->devlist, &requeue_queue);
3910         }
3911         spin_unlock_irq(get_ccwdev_lock(device->cdev));
3912
3913         list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3914                 wait_event(dasd_flush_wq,
3915                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3916
3917                 /* mark sleepon requests as ended */
3918                 if (cqr->callback_data == DASD_SLEEPON_START_TAG)
3919                         cqr->callback_data = DASD_SLEEPON_END_TAG;
3920
3921                 /* remove requests from device and block queue */
3922                 list_del_init(&cqr->devlist);
3923                 while (cqr->refers != NULL) {
3924                         refers = cqr->refers;
3925                         /* remove the request from the block queue */
3926                         list_del(&cqr->blocklist);
3927                         /* free the finished erp request */
3928                         dasd_free_erp_request(cqr, cqr->memdev);
3929                         cqr = refers;
3930                 }
3931
3932                 /*
3933                  * requeue requests to blocklayer will only work
3934                  * for block device requests
3935                  */
3936                 if (_dasd_requeue_request(cqr))
3937                         continue;
3938
3939                 if (cqr->block)
3940                         list_del_init(&cqr->blocklist);
3941                 cqr->block->base->discipline->free_cp(
3942                         cqr, (struct request *) cqr->callback_data);
3943         }
3944
3945         /*
3946          * if requests remain then they are internal request
3947          * and go back to the device queue
3948          */
3949         if (!list_empty(&requeue_queue)) {
3950                 /* move freeze_queue to start of the ccw_queue */
3951                 spin_lock_irq(get_ccwdev_lock(device->cdev));
3952                 list_splice_tail(&requeue_queue, &device->ccw_queue);
3953                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
3954         }
3955         /* wake up generic waitqueue for eventually ended sleepon requests */
3956         wake_up(&generic_waitq);
3957         return rc;
3958 }
3959
3960 static void do_requeue_requests(struct work_struct *work)
3961 {
3962         struct dasd_device *device = container_of(work, struct dasd_device,
3963                                                   requeue_requests);
3964         dasd_generic_requeue_all_requests(device);
3965         dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3966         if (device->block)
3967                 dasd_schedule_block_bh(device->block);
3968         dasd_put_device(device);
3969 }
3970
3971 void dasd_schedule_requeue(struct dasd_device *device)
3972 {
3973         dasd_get_device(device);
3974         /* queue call to dasd_reload_device to the kernel event daemon. */
3975         if (!schedule_work(&device->requeue_requests))
3976                 dasd_put_device(device);
3977 }
3978 EXPORT_SYMBOL(dasd_schedule_requeue);
3979
3980 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3981 {
3982         struct dasd_device *device = dasd_device_from_cdev(cdev);
3983
3984         if (IS_ERR(device))
3985                 return PTR_ERR(device);
3986
3987         /* mark device as suspended */
3988         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3989
3990         if (device->discipline->freeze)
3991                 device->discipline->freeze(device);
3992
3993         /* disallow new I/O  */
3994         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3995
3996         return dasd_generic_requeue_all_requests(device);
3997 }
3998 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3999
4000 int dasd_generic_restore_device(struct ccw_device *cdev)
4001 {
4002         struct dasd_device *device = dasd_device_from_cdev(cdev);
4003         int rc = 0;
4004
4005         if (IS_ERR(device))
4006                 return PTR_ERR(device);
4007
4008         /* allow new IO again */
4009         dasd_device_remove_stop_bits(device,
4010                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4011
4012         dasd_schedule_device_bh(device);
4013
4014         /*
4015          * call discipline restore function
4016          * if device is stopped do nothing e.g. for disconnected devices
4017          */
4018         if (device->discipline->restore && !(device->stopped))
4019                 rc = device->discipline->restore(device);
4020         if (rc || device->stopped)
4021                 /*
4022                  * if the resume failed for the DASD we put it in
4023                  * an UNRESUMED stop state
4024                  */
4025                 device->stopped |= DASD_UNRESUMED_PM;
4026
4027         if (device->block) {
4028                 dasd_schedule_block_bh(device->block);
4029                 if (device->block->request_queue)
4030                         blk_mq_run_hw_queues(device->block->request_queue,
4031                                              true);
4032         }
4033
4034         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4035         dasd_put_device(device);
4036         return 0;
4037 }
4038 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4039
4040 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4041                                                    void *rdc_buffer,
4042                                                    int rdc_buffer_size,
4043                                                    int magic)
4044 {
4045         struct dasd_ccw_req *cqr;
4046         struct ccw1 *ccw;
4047         unsigned long *idaw;
4048
4049         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
4050
4051         if (IS_ERR(cqr)) {
4052                 /* internal error 13 - Allocating the RDC request failed*/
4053                 dev_err(&device->cdev->dev,
4054                          "An error occurred in the DASD device driver, "
4055                          "reason=%s\n", "13");
4056                 return cqr;
4057         }
4058
4059         ccw = cqr->cpaddr;
4060         ccw->cmd_code = CCW_CMD_RDC;
4061         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
4062                 idaw = (unsigned long *) (cqr->data);
4063                 ccw->cda = (__u32)(addr_t) idaw;
4064                 ccw->flags = CCW_FLAG_IDA;
4065                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
4066         } else {
4067                 ccw->cda = (__u32)(addr_t) rdc_buffer;
4068                 ccw->flags = 0;
4069         }
4070
4071         ccw->count = rdc_buffer_size;
4072         cqr->startdev = device;
4073         cqr->memdev = device;
4074         cqr->expires = 10*HZ;
4075         cqr->retries = 256;
4076         cqr->buildclk = get_tod_clock();
4077         cqr->status = DASD_CQR_FILLED;
4078         return cqr;
4079 }
4080
4081
4082 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4083                                 void *rdc_buffer, int rdc_buffer_size)
4084 {
4085         int ret;
4086         struct dasd_ccw_req *cqr;
4087
4088         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
4089                                      magic);
4090         if (IS_ERR(cqr))
4091                 return PTR_ERR(cqr);
4092
4093         ret = dasd_sleep_on(cqr);
4094         dasd_sfree_request(cqr, cqr->memdev);
4095         return ret;
4096 }
4097 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4098
4099 /*
4100  *   In command mode and transport mode we need to look for sense
4101  *   data in different places. The sense data itself is allways
4102  *   an array of 32 bytes, so we can unify the sense data access
4103  *   for both modes.
4104  */
4105 char *dasd_get_sense(struct irb *irb)
4106 {
4107         struct tsb *tsb = NULL;
4108         char *sense = NULL;
4109
4110         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4111                 if (irb->scsw.tm.tcw)
4112                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4113                                           irb->scsw.tm.tcw);
4114                 if (tsb && tsb->length == 64 && tsb->flags)
4115                         switch (tsb->flags & 0x07) {
4116                         case 1: /* tsa_iostat */
4117                                 sense = tsb->tsa.iostat.sense;
4118                                 break;
4119                         case 2: /* tsa_ddpc */
4120                                 sense = tsb->tsa.ddpc.sense;
4121                                 break;
4122                         default:
4123                                 /* currently we don't use interrogate data */
4124                                 break;
4125                         }
4126         } else if (irb->esw.esw0.erw.cons) {
4127                 sense = irb->ecw;
4128         }
4129         return sense;
4130 }
4131 EXPORT_SYMBOL_GPL(dasd_get_sense);
4132
4133 void dasd_generic_shutdown(struct ccw_device *cdev)
4134 {
4135         struct dasd_device *device;
4136
4137         device = dasd_device_from_cdev(cdev);
4138         if (IS_ERR(device))
4139                 return;
4140
4141         if (device->block)
4142                 dasd_schedule_block_bh(device->block);
4143
4144         dasd_schedule_device_bh(device);
4145
4146         wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4147 }
4148 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4149
4150 static int __init dasd_init(void)
4151 {
4152         int rc;
4153
4154         init_waitqueue_head(&dasd_init_waitq);
4155         init_waitqueue_head(&dasd_flush_wq);
4156         init_waitqueue_head(&generic_waitq);
4157         init_waitqueue_head(&shutdown_waitq);
4158
4159         /* register 'common' DASD debug area, used for all DBF_XXX calls */
4160         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4161         if (dasd_debug_area == NULL) {
4162                 rc = -ENOMEM;
4163                 goto failed;
4164         }
4165         debug_register_view(dasd_debug_area, &debug_sprintf_view);
4166         debug_set_level(dasd_debug_area, DBF_WARNING);
4167
4168         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4169
4170         dasd_diag_discipline_pointer = NULL;
4171
4172         dasd_statistics_createroot();
4173
4174         rc = dasd_devmap_init();
4175         if (rc)
4176                 goto failed;
4177         rc = dasd_gendisk_init();
4178         if (rc)
4179                 goto failed;
4180         rc = dasd_parse();
4181         if (rc)
4182                 goto failed;
4183         rc = dasd_eer_init();
4184         if (rc)
4185                 goto failed;
4186 #ifdef CONFIG_PROC_FS
4187         rc = dasd_proc_init();
4188         if (rc)
4189                 goto failed;
4190 #endif
4191
4192         return 0;
4193 failed:
4194         pr_info("The DASD device driver could not be initialized\n");
4195         dasd_exit();
4196         return rc;
4197 }
4198
4199 module_init(dasd_init);
4200 module_exit(dasd_exit);