drivers/s390/block/dasd.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd.c
   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/buffer_head.h>
  21 #include <linux/hdreg.h>
  22 #include <linux/async.h>
  23 #include <linux/mutex.h>
  24 #include <linux/debugfs.h>
  25 #include <linux/seq_file.h>
  26 #include <linux/vmalloc.h>
  27
  28 #include <asm/ccwdev.h>
  29 #include <asm/ebcdic.h>
  30 #include <asm/idals.h>
  31 #include <asm/itcw.h>
  32 #include <asm/diag.h>
  33
  34 /* This is ugly... */
  35 #define PRINTK_HEADER "dasd:"
  36
  37 #include "dasd_int.h"
  38 /*
  39  * SECTION: Constant definitions to be used within this file
  40  */
  41 #define DASD_CHANQ_MAX_SIZE 4
  42
  43 #define DASD_SLEEPON_START_TAG  (void *) 1
  44 #define DASD_SLEEPON_END_TAG    (void *) 2
  45
  46 /*
  47  * SECTION: exported variables of dasd.c
  48  */
  49 debug_info_t *dasd_debug_area;
  50 static struct dentry *dasd_debugfs_root_entry;
  51 struct dasd_discipline *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 2000 IBM Corporation");
  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 void dasd_flush_request_queue(struct dasd_block *);
  67 static int dasd_flush_block_queue(struct dasd_block *);
  68 static void dasd_device_tasklet(struct dasd_device *);
  69 static void dasd_block_tasklet(struct dasd_block *);
  70 static void do_kick_device(struct work_struct *);
  71 static void do_restore_device(struct work_struct *);
  72 static void do_reload_device(struct work_struct *);
  73 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
  74 static void dasd_device_timeout(unsigned long);
  75 static void dasd_block_timeout(unsigned long);
  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
  80 /*
  81  * SECTION: Operations on the device structure.
  82  */
  83 static wait_queue_head_t dasd_init_waitq;
  84 static wait_queue_head_t dasd_flush_wq;
  85 static wait_queue_head_t generic_waitq;
  86
  87 /*
  88  * Allocate memory for a new device structure.
  89  */
  90 struct dasd_device *dasd_alloc_device(void)
  91 {
  92         struct dasd_device *device;
  93
  94         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
  95         if (!device)
  96                 return ERR_PTR(-ENOMEM);
  97
  98         /* Get two pages for normal block device operations. */
  99         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
 100         if (!device->ccw_mem) {
 101                 kfree(device);
 102                 return ERR_PTR(-ENOMEM);
 103         }
 104         /* Get one page for error recovery. */
 105         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
 106         if (!device->erp_mem) {
 107                 free_pages((unsigned long) device->ccw_mem, 1);
 108                 kfree(device);
 109                 return ERR_PTR(-ENOMEM);
 110         }
 111
 112         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
 113         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
 114         spin_lock_init(&device->mem_lock);
 115         atomic_set(&device->tasklet_scheduled, 0);
 116         tasklet_init(&device->tasklet,
 117                      (void (*)(unsigned long)) dasd_device_tasklet,
 118                      (unsigned long) device);
 119         INIT_LIST_HEAD(&device->ccw_queue);
 120         init_timer(&device->timer);
 121         device->timer.function = dasd_device_timeout;
 122         device->timer.data = (unsigned long) device;
 123         INIT_WORK(&device->kick_work, do_kick_device);
 124         INIT_WORK(&device->restore_device, do_restore_device);
 125         INIT_WORK(&device->reload_device, do_reload_device);
 126         device->state = DASD_STATE_NEW;
 127         device->target = DASD_STATE_NEW;
 128         mutex_init(&device->state_mutex);
 129         spin_lock_init(&device->profile.lock);
 130         return device;
 131 }
 132
 133 /*
 134  * Free memory of a device structure.
 135  */
 136 void dasd_free_device(struct dasd_device *device)
 137 {
 138         kfree(device->private);
 139         free_page((unsigned long) device->erp_mem);
 140         free_pages((unsigned long) device->ccw_mem, 1);
 141         kfree(device);
 142 }
 143
 144 /*
 145  * Allocate memory for a new device structure.
 146  */
 147 struct dasd_block *dasd_alloc_block(void)
 148 {
 149         struct dasd_block *block;
 150
 151         block = kzalloc(sizeof(*block), GFP_ATOMIC);
 152         if (!block)
 153                 return ERR_PTR(-ENOMEM);
 154         /* open_count = 0 means device online but not in use */
 155         atomic_set(&block->open_count, -1);
 156
 157         spin_lock_init(&block->request_queue_lock);
 158         atomic_set(&block->tasklet_scheduled, 0);
 159         tasklet_init(&block->tasklet,
 160                      (void (*)(unsigned long)) dasd_block_tasklet,
 161                      (unsigned long) block);
 162         INIT_LIST_HEAD(&block->ccw_queue);
 163         spin_lock_init(&block->queue_lock);
 164         init_timer(&block->timer);
 165         block->timer.function = dasd_block_timeout;
 166         block->timer.data = (unsigned long) block;
 167         spin_lock_init(&block->profile.lock);
 168
 169         return block;
 170 }
 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
 180 /*
 181  * Make a new device known to the system.
 182  */
 183 static int dasd_state_new_to_known(struct dasd_device *device)
 184 {
 185         int rc;
 186
 187         /*
 188          * As long as the device is not in state DASD_STATE_NEW we want to
 189          * keep the reference count > 0.
 190          */
 191         dasd_get_device(device);
 192
 193         if (device->block) {
 194                 rc = dasd_alloc_queue(device->block);
 195                 if (rc) {
 196                         dasd_put_device(device);
 197                         return rc;
 198                 }
 199         }
 200         device->state = DASD_STATE_KNOWN;
 201         return 0;
 202 }
 203
 204 /*
 205  * Let the system forget about a device.
 206  */
 207 static int dasd_state_known_to_new(struct dasd_device *device)
 208 {
 209         /* Disable extended error reporting for this device. */
 210         dasd_eer_disable(device);
 211         /* Forget the discipline information. */
 212         if (device->discipline) {
 213                 if (device->discipline->uncheck_device)
 214                         device->discipline->uncheck_device(device);
 215                 module_put(device->discipline->owner);
 216         }
 217         device->discipline = NULL;
 218         if (device->base_discipline)
 219                 module_put(device->base_discipline->owner);
 220         device->base_discipline = NULL;
 221         device->state = DASD_STATE_NEW;
 222
 223         if (device->block)
 224                 dasd_free_queue(device->block);
 225
 226         /* Give up reference we took in dasd_state_new_to_known. */
 227         dasd_put_device(device);
 228         return 0;
 229 }
 230
 231 static struct dentry *dasd_debugfs_setup(const char *name,
 232                                          struct dentry *base_dentry)
 233 {
 234         struct dentry *pde;
 235
 236         if (!base_dentry)
 237                 return NULL;
 238         pde = debugfs_create_dir(name, base_dentry);
 239         if (!pde || IS_ERR(pde))
 240                 return NULL;
 241         return pde;
 242 }
 243
 244 /*
 245  * Request the irq line for the device.
 246  */
 247 static int dasd_state_known_to_basic(struct dasd_device *device)
 248 {
 249         struct dasd_block *block = device->block;
 250         int rc;
 251
 252         /* Allocate and register gendisk structure. */
 253         if (block) {
 254                 rc = dasd_gendisk_alloc(block);
 255                 if (rc)
 256                         return rc;
 257                 block->debugfs_dentry =
 258                         dasd_debugfs_setup(block->gdp->disk_name,
 259                                            dasd_debugfs_root_entry);
 260                 dasd_profile_init(&block->profile, block->debugfs_dentry);
 261                 if (dasd_global_profile_level == DASD_PROFILE_ON)
 262                         dasd_profile_on(&device->block->profile);
 263         }
 264         device->debugfs_dentry =
 265                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
 266                                    dasd_debugfs_root_entry);
 267         dasd_profile_init(&device->profile, device->debugfs_dentry);
 268
 269         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
 270         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
 271                                             8 * sizeof(long));
 272         debug_register_view(device->debug_area, &debug_sprintf_view);
 273         debug_set_level(device->debug_area, DBF_WARNING);
 274         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
 275
 276         device->state = DASD_STATE_BASIC;
 277         return 0;
 278 }
 279
 280 /*
 281  * Release the irq line for the device. Terminate any running i/o.
 282  */
 283 static int dasd_state_basic_to_known(struct dasd_device *device)
 284 {
 285         int rc;
 286         if (device->block) {
 287                 dasd_profile_exit(&device->block->profile);
 288                 if (device->block->debugfs_dentry)
 289                         debugfs_remove(device->block->debugfs_dentry);
 290                 dasd_gendisk_free(device->block);
 291                 dasd_block_clear_timer(device->block);
 292         }
 293         rc = dasd_flush_device_queue(device);
 294         if (rc)
 295                 return rc;
 296         dasd_device_clear_timer(device);
 297         dasd_profile_exit(&device->profile);
 298         if (device->debugfs_dentry)
 299                 debugfs_remove(device->debugfs_dentry);
 300
 301         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
 302         if (device->debug_area != NULL) {
 303                 debug_unregister(device->debug_area);
 304                 device->debug_area = NULL;
 305         }
 306         device->state = DASD_STATE_KNOWN;
 307         return 0;
 308 }
 309
 310 /*
 311  * Do the initial analysis. The do_analysis function may return
 312  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 313  * until the discipline decides to continue the startup sequence
 314  * by calling the function dasd_change_state. The eckd disciplines
 315  * uses this to start a ccw that detects the format. The completion
 316  * interrupt for this detection ccw uses the kernel event daemon to
 317  * trigger the call to dasd_change_state. All this is done in the
 318  * discipline code, see dasd_eckd.c.
 319  * After the analysis ccw is done (do_analysis returned 0) the block
 320  * device is setup.
 321  * In case the analysis returns an error, the device setup is stopped
 322  * (a fake disk was already added to allow formatting).
 323  */
 324 static int dasd_state_basic_to_ready(struct dasd_device *device)
 325 {
 326         int rc;
 327         struct dasd_block *block;
 328
 329         rc = 0;
 330         block = device->block;
 331         /* make disk known with correct capacity */
 332         if (block) {
 333                 if (block->base->discipline->do_analysis != NULL)
 334                         rc = block->base->discipline->do_analysis(block);
 335                 if (rc) {
 336                         if (rc != -EAGAIN)
 337                                 device->state = DASD_STATE_UNFMT;
 338                         return rc;
 339                 }
 340                 dasd_setup_queue(block);
 341                 set_capacity(block->gdp,
 342                              block->blocks << block->s2b_shift);
 343                 device->state = DASD_STATE_READY;
 344                 rc = dasd_scan_partitions(block);
 345                 if (rc)
 346                         device->state = DASD_STATE_BASIC;
 347         } else {
 348                 device->state = DASD_STATE_READY;
 349         }
 350         return rc;
 351 }
 352
 353 /*
 354  * Remove device from block device layer. Destroy dirty buffers.
 355  * Forget format information. Check if the target level is basic
 356  * and if it is create fake disk for formatting.
 357  */
 358 static int dasd_state_ready_to_basic(struct dasd_device *device)
 359 {
 360         int rc;
 361
 362         device->state = DASD_STATE_BASIC;
 363         if (device->block) {
 364                 struct dasd_block *block = device->block;
 365                 rc = dasd_flush_block_queue(block);
 366                 if (rc) {
 367                         device->state = DASD_STATE_READY;
 368                         return rc;
 369                 }
 370                 dasd_flush_request_queue(block);
 371                 dasd_destroy_partitions(block);
 372                 block->blocks = 0;
 373                 block->bp_block = 0;
 374                 block->s2b_shift = 0;
 375         }
 376         return 0;
 377 }
 378
 379 /*
 380  * Back to basic.
 381  */
 382 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
 383 {
 384         device->state = DASD_STATE_BASIC;
 385         return 0;
 386 }
 387
 388 /*
 389  * Make the device online and schedule the bottom half to start
 390  * the requeueing of requests from the linux request queue to the
 391  * ccw queue.
 392  */
 393 static int
 394 dasd_state_ready_to_online(struct dasd_device * device)
 395 {
 396         int rc;
 397         struct gendisk *disk;
 398         struct disk_part_iter piter;
 399         struct hd_struct *part;
 400
 401         if (device->discipline->ready_to_online) {
 402                 rc = device->discipline->ready_to_online(device);
 403                 if (rc)
 404                         return rc;
 405         }
 406         device->state = DASD_STATE_ONLINE;
 407         if (device->block) {
 408                 dasd_schedule_block_bh(device->block);
 409                 if ((device->features & DASD_FEATURE_USERAW)) {
 410                         disk = device->block->gdp;
 411                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 412                         return 0;
 413                 }
 414                 disk = device->block->bdev->bd_disk;
 415                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 416                 while ((part = disk_part_iter_next(&piter)))
 417                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 418                 disk_part_iter_exit(&piter);
 419         }
 420         return 0;
 421 }
 422
 423 /*
 424  * Stop the requeueing of requests again.
 425  */
 426 static int dasd_state_online_to_ready(struct dasd_device *device)
 427 {
 428         int rc;
 429         struct gendisk *disk;
 430         struct disk_part_iter piter;
 431         struct hd_struct *part;
 432
 433         if (device->discipline->online_to_ready) {
 434                 rc = device->discipline->online_to_ready(device);
 435                 if (rc)
 436                         return rc;
 437         }
 438         device->state = DASD_STATE_READY;
 439         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
 440                 disk = device->block->bdev->bd_disk;
 441                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
 442                 while ((part = disk_part_iter_next(&piter)))
 443                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
 444                 disk_part_iter_exit(&piter);
 445         }
 446         return 0;
 447 }
 448
 449 /*
 450  * Device startup state changes.
 451  */
 452 static int dasd_increase_state(struct dasd_device *device)
 453 {
 454         int rc;
 455
 456         rc = 0;
 457         if (device->state == DASD_STATE_NEW &&
 458             device->target >= DASD_STATE_KNOWN)
 459                 rc = dasd_state_new_to_known(device);
 460
 461         if (!rc &&
 462             device->state == DASD_STATE_KNOWN &&
 463             device->target >= DASD_STATE_BASIC)
 464                 rc = dasd_state_known_to_basic(device);
 465
 466         if (!rc &&
 467             device->state == DASD_STATE_BASIC &&
 468             device->target >= DASD_STATE_READY)
 469                 rc = dasd_state_basic_to_ready(device);
 470
 471         if (!rc &&
 472             device->state == DASD_STATE_UNFMT &&
 473             device->target > DASD_STATE_UNFMT)
 474                 rc = -EPERM;
 475
 476         if (!rc &&
 477             device->state == DASD_STATE_READY &&
 478             device->target >= DASD_STATE_ONLINE)
 479                 rc = dasd_state_ready_to_online(device);
 480
 481         return rc;
 482 }
 483
 484 /*
 485  * Device shutdown state changes.
 486  */
 487 static int dasd_decrease_state(struct dasd_device *device)
 488 {
 489         int rc;
 490
 491         rc = 0;
 492         if (device->state == DASD_STATE_ONLINE &&
 493             device->target <= DASD_STATE_READY)
 494                 rc = dasd_state_online_to_ready(device);
 495
 496         if (!rc &&
 497             device->state == DASD_STATE_READY &&
 498             device->target <= DASD_STATE_BASIC)
 499                 rc = dasd_state_ready_to_basic(device);
 500
 501         if (!rc &&
 502             device->state == DASD_STATE_UNFMT &&
 503             device->target <= DASD_STATE_BASIC)
 504                 rc = dasd_state_unfmt_to_basic(device);
 505
 506         if (!rc &&
 507             device->state == DASD_STATE_BASIC &&
 508             device->target <= DASD_STATE_KNOWN)
 509                 rc = dasd_state_basic_to_known(device);
 510
 511         if (!rc &&
 512             device->state == DASD_STATE_KNOWN &&
 513             device->target <= DASD_STATE_NEW)
 514                 rc = dasd_state_known_to_new(device);
 515
 516         return rc;
 517 }
 518
 519 /*
 520  * This is the main startup/shutdown routine.
 521  */
 522 static void dasd_change_state(struct dasd_device *device)
 523 {
 524         int rc;
 525
 526         if (device->state == device->target)
 527                 /* Already where we want to go today... */
 528                 return;
 529         if (device->state < device->target)
 530                 rc = dasd_increase_state(device);
 531         else
 532                 rc = dasd_decrease_state(device);
 533         if (rc == -EAGAIN)
 534                 return;
 535         if (rc)
 536                 device->target = device->state;
 537
 538         if (device->state == device->target)
 539                 wake_up(&dasd_init_waitq);
 540
 541         /* let user-space know that the device status changed */
 542         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
 543 }
 544
 545 /*
 546  * Kick starter for devices that did not complete the startup/shutdown
 547  * procedure or were sleeping because of a pending state.
 548  * dasd_kick_device will schedule a call do do_kick_device to the kernel
 549  * event daemon.
 550  */
 551 static void do_kick_device(struct work_struct *work)
 552 {
 553         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
 554         mutex_lock(&device->state_mutex);
 555         dasd_change_state(device);
 556         mutex_unlock(&device->state_mutex);
 557         dasd_schedule_device_bh(device);
 558         dasd_put_device(device);
 559 }
 560
 561 void dasd_kick_device(struct dasd_device *device)
 562 {
 563         dasd_get_device(device);
 564         /* queue call to dasd_kick_device to the kernel event daemon. */
 565         schedule_work(&device->kick_work);
 566 }
 567
 568 /*
 569  * dasd_reload_device will schedule a call do do_reload_device to the kernel
 570  * event daemon.
 571  */
 572 static void do_reload_device(struct work_struct *work)
 573 {
 574         struct dasd_device *device = container_of(work, struct dasd_device,
 575                                                   reload_device);
 576         device->discipline->reload(device);
 577         dasd_put_device(device);
 578 }
 579
 580 void dasd_reload_device(struct dasd_device *device)
 581 {
 582         dasd_get_device(device);
 583         /* queue call to dasd_reload_device to the kernel event daemon. */
 584         schedule_work(&device->reload_device);
 585 }
 586 EXPORT_SYMBOL(dasd_reload_device);
 587
 588 /*
 589  * dasd_restore_device will schedule a call do do_restore_device to the kernel
 590  * event daemon.
 591  */
 592 static void do_restore_device(struct work_struct *work)
 593 {
 594         struct dasd_device *device = container_of(work, struct dasd_device,
 595                                                   restore_device);
 596         device->cdev->drv->restore(device->cdev);
 597         dasd_put_device(device);
 598 }
 599
 600 void dasd_restore_device(struct dasd_device *device)
 601 {
 602         dasd_get_device(device);
 603         /* queue call to dasd_restore_device to the kernel event daemon. */
 604         schedule_work(&device->restore_device);
 605 }
 606
 607 /*
 608  * Set the target state for a device and starts the state change.
 609  */
 610 void dasd_set_target_state(struct dasd_device *device, int target)
 611 {
 612         dasd_get_device(device);
 613         mutex_lock(&device->state_mutex);
 614         /* If we are in probeonly mode stop at DASD_STATE_READY. */
 615         if (dasd_probeonly && target > DASD_STATE_READY)
 616                 target = DASD_STATE_READY;
 617         if (device->target != target) {
 618                 if (device->state == target)
 619                         wake_up(&dasd_init_waitq);
 620                 device->target = target;
 621         }
 622         if (device->state != device->target)
 623                 dasd_change_state(device);
 624         mutex_unlock(&device->state_mutex);
 625         dasd_put_device(device);
 626 }
 627
 628 /*
 629  * Enable devices with device numbers in [from..to].
 630  */
 631 static inline int _wait_for_device(struct dasd_device *device)
 632 {
 633         return (device->state == device->target);
 634 }
 635
 636 void dasd_enable_device(struct dasd_device *device)
 637 {
 638         dasd_set_target_state(device, DASD_STATE_ONLINE);
 639         if (device->state <= DASD_STATE_KNOWN)
 640                 /* No discipline for device found. */
 641                 dasd_set_target_state(device, DASD_STATE_NEW);
 642         /* Now wait for the devices to come up. */
 643         wait_event(dasd_init_waitq, _wait_for_device(device));
 644 }
 645
 646 /*
 647  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 648  */
 649
 650 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
 651
 652 #ifdef CONFIG_DASD_PROFILE
 653 struct dasd_profile_info dasd_global_profile_data;
 654 static struct dentry *dasd_global_profile_dentry;
 655 static struct dentry *dasd_debugfs_global_entry;
 656
 657 /*
 658  * Add profiling information for cqr before execution.
 659  */
 660 static void dasd_profile_start(struct dasd_block *block,
 661                                struct dasd_ccw_req *cqr,
 662                                struct request *req)
 663 {
 664         struct list_head *l;
 665         unsigned int counter;
 666         struct dasd_device *device;
 667
 668         /* count the length of the chanq for statistics */
 669         counter = 0;
 670         if (dasd_global_profile_level || block->profile.data)
 671                 list_for_each(l, &block->ccw_queue)
 672                         if (++counter >= 31)
 673                                 break;
 674
 675         if (dasd_global_profile_level) {
 676                 dasd_global_profile_data.dasd_io_nr_req[counter]++;
 677                 if (rq_data_dir(req) == READ)
 678                         dasd_global_profile_data.dasd_read_nr_req[counter]++;
 679         }
 680
 681         spin_lock(&block->profile.lock);
 682         if (block->profile.data)
 683                 block->profile.data->dasd_io_nr_req[counter]++;
 684                 if (rq_data_dir(req) == READ)
 685                         block->profile.data->dasd_read_nr_req[counter]++;
 686         spin_unlock(&block->profile.lock);
 687
 688         /*
 689          * We count the request for the start device, even though it may run on
 690          * some other device due to error recovery. This way we make sure that
 691          * we count each request only once.
 692          */
 693         device = cqr->startdev;
 694         if (device->profile.data) {
 695                 counter = 1; /* request is not yet queued on the start device */
 696                 list_for_each(l, &device->ccw_queue)
 697                         if (++counter >= 31)
 698                                 break;
 699         }
 700         spin_lock(&device->profile.lock);
 701         if (device->profile.data) {
 702                 device->profile.data->dasd_io_nr_req[counter]++;
 703                 if (rq_data_dir(req) == READ)
 704                         device->profile.data->dasd_read_nr_req[counter]++;
 705         }
 706         spin_unlock(&device->profile.lock);
 707 }
 708
 709 /*
 710  * Add profiling information for cqr after execution.
 711  */
 712
 713 #define dasd_profile_counter(value, index)                         \
 714 {                                                                  \
 715         for (index = 0; index < 31 && value >> (2+index); index++) \
 716                 ;                                                  \
 717 }
 718
 719 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
 720                                       int is_alias,
 721                                       int is_tpm,
 722                                       int is_read,
 723                                       long sectors,
 724                                       int sectors_ind,
 725                                       int tottime_ind,
 726                                       int tottimeps_ind,
 727                                       int strtime_ind,
 728                                       int irqtime_ind,
 729                                       int irqtimeps_ind,
 730                                       int endtime_ind)
 731 {
 732         /* in case of an overflow, reset the whole profile */
 733         if (data->dasd_io_reqs == UINT_MAX) {
 734                         memset(data, 0, sizeof(*data));
 735                         getnstimeofday(&data->starttod);
 736         }
 737         data->dasd_io_reqs++;
 738         data->dasd_io_sects += sectors;
 739         if (is_alias)
 740                 data->dasd_io_alias++;
 741         if (is_tpm)
 742                 data->dasd_io_tpm++;
 743
 744         data->dasd_io_secs[sectors_ind]++;
 745         data->dasd_io_times[tottime_ind]++;
 746         data->dasd_io_timps[tottimeps_ind]++;
 747         data->dasd_io_time1[strtime_ind]++;
 748         data->dasd_io_time2[irqtime_ind]++;
 749         data->dasd_io_time2ps[irqtimeps_ind]++;
 750         data->dasd_io_time3[endtime_ind]++;
 751
 752         if (is_read) {
 753                 data->dasd_read_reqs++;
 754                 data->dasd_read_sects += sectors;
 755                 if (is_alias)
 756                         data->dasd_read_alias++;
 757                 if (is_tpm)
 758                         data->dasd_read_tpm++;
 759                 data->dasd_read_secs[sectors_ind]++;
 760                 data->dasd_read_times[tottime_ind]++;
 761                 data->dasd_read_time1[strtime_ind]++;
 762                 data->dasd_read_time2[irqtime_ind]++;
 763                 data->dasd_read_time3[endtime_ind]++;
 764         }
 765 }
 766
 767 static void dasd_profile_end(struct dasd_block *block,
 768                              struct dasd_ccw_req *cqr,
 769                              struct request *req)
 770 {
 771         long strtime, irqtime, endtime, tottime;        /* in microseconds */
 772         long tottimeps, sectors;
 773         struct dasd_device *device;
 774         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
 775         int irqtime_ind, irqtimeps_ind, endtime_ind;
 776
 777         device = cqr->startdev;
 778         if (!(dasd_global_profile_level ||
 779               block->profile.data ||
 780               device->profile.data))
 781                 return;
 782
 783         sectors = blk_rq_sectors(req);
 784         if (!cqr->buildclk || !cqr->startclk ||
 785             !cqr->stopclk || !cqr->endclk ||
 786             !sectors)
 787                 return;
 788
 789         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
 790         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
 791         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
 792         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
 793         tottimeps = tottime / sectors;
 794
 795         dasd_profile_counter(sectors, sectors_ind);
 796         dasd_profile_counter(tottime, tottime_ind);
 797         dasd_profile_counter(tottimeps, tottimeps_ind);
 798         dasd_profile_counter(strtime, strtime_ind);
 799         dasd_profile_counter(irqtime, irqtime_ind);
 800         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
 801         dasd_profile_counter(endtime, endtime_ind);
 802
 803         if (dasd_global_profile_level) {
 804                 dasd_profile_end_add_data(&dasd_global_profile_data,
 805                                           cqr->startdev != block->base,
 806                                           cqr->cpmode == 1,
 807                                           rq_data_dir(req) == READ,
 808                                           sectors, sectors_ind, tottime_ind,
 809                                           tottimeps_ind, strtime_ind,
 810                                           irqtime_ind, irqtimeps_ind,
 811                                           endtime_ind);
 812         }
 813
 814         spin_lock(&block->profile.lock);
 815         if (block->profile.data)
 816                 dasd_profile_end_add_data(block->profile.data,
 817                                           cqr->startdev != block->base,
 818                                           cqr->cpmode == 1,
 819                                           rq_data_dir(req) == READ,
 820                                           sectors, sectors_ind, tottime_ind,
 821                                           tottimeps_ind, strtime_ind,
 822                                           irqtime_ind, irqtimeps_ind,
 823                                           endtime_ind);
 824         spin_unlock(&block->profile.lock);
 825
 826         spin_lock(&device->profile.lock);
 827         if (device->profile.data)
 828                 dasd_profile_end_add_data(device->profile.data,
 829                                           cqr->startdev != block->base,
 830                                           cqr->cpmode == 1,
 831                                           rq_data_dir(req) == READ,
 832                                           sectors, sectors_ind, tottime_ind,
 833                                           tottimeps_ind, strtime_ind,
 834                                           irqtime_ind, irqtimeps_ind,
 835                                           endtime_ind);
 836         spin_unlock(&device->profile.lock);
 837 }
 838
 839 void dasd_profile_reset(struct dasd_profile *profile)
 840 {
 841         struct dasd_profile_info *data;
 842
 843         spin_lock_bh(&profile->lock);
 844         data = profile->data;
 845         if (!data) {
 846                 spin_unlock_bh(&profile->lock);
 847                 return;
 848         }
 849         memset(data, 0, sizeof(*data));
 850         getnstimeofday(&data->starttod);
 851         spin_unlock_bh(&profile->lock);
 852 }
 853
 854 void dasd_global_profile_reset(void)
 855 {
 856         memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
 857         getnstimeofday(&dasd_global_profile_data.starttod);
 858 }
 859
 860 int dasd_profile_on(struct dasd_profile *profile)
 861 {
 862         struct dasd_profile_info *data;
 863
 864         data = kzalloc(sizeof(*data), GFP_KERNEL);
 865         if (!data)
 866                 return -ENOMEM;
 867         spin_lock_bh(&profile->lock);
 868         if (profile->data) {
 869                 spin_unlock_bh(&profile->lock);
 870                 kfree(data);
 871                 return 0;
 872         }
 873         getnstimeofday(&data->starttod);
 874         profile->data = data;
 875         spin_unlock_bh(&profile->lock);
 876         return 0;
 877 }
 878
 879 void dasd_profile_off(struct dasd_profile *profile)
 880 {
 881         spin_lock_bh(&profile->lock);
 882         kfree(profile->data);
 883         profile->data = NULL;
 884         spin_unlock_bh(&profile->lock);
 885 }
 886
 887 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
 888 {
 889         char *buffer;
 890
 891         buffer = vmalloc(user_len + 1);
 892         if (buffer == NULL)
 893                 return ERR_PTR(-ENOMEM);
 894         if (copy_from_user(buffer, user_buf, user_len) != 0) {
 895                 vfree(buffer);
 896                 return ERR_PTR(-EFAULT);
 897         }
 898         /* got the string, now strip linefeed. */
 899         if (buffer[user_len - 1] == '\n')
 900                 buffer[user_len - 1] = 0;
 901         else
 902                 buffer[user_len] = 0;
 903         return buffer;
 904 }
 905
 906 static ssize_t dasd_stats_write(struct file *file,
 907                                 const char __user *user_buf,
 908                                 size_t user_len, loff_t *pos)
 909 {
 910         char *buffer, *str;
 911         int rc;
 912         struct seq_file *m = (struct seq_file *)file->private_data;
 913         struct dasd_profile *prof = m->private;
 914
 915         if (user_len > 65536)
 916                 user_len = 65536;
 917         buffer = dasd_get_user_string(user_buf, user_len);
 918         if (IS_ERR(buffer))
 919                 return PTR_ERR(buffer);
 920
 921         str = skip_spaces(buffer);
 922         rc = user_len;
 923         if (strncmp(str, "reset", 5) == 0) {
 924                 dasd_profile_reset(prof);
 925         } else if (strncmp(str, "on", 2) == 0) {
 926                 rc = dasd_profile_on(prof);
 927                 if (!rc)
 928                         rc = user_len;
 929         } else if (strncmp(str, "off", 3) == 0) {
 930                 dasd_profile_off(prof);
 931         } else
 932                 rc = -EINVAL;
 933         vfree(buffer);
 934         return rc;
 935 }
 936
 937 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
 938 {
 939         int i;
 940
 941         for (i = 0; i < 32; i++)
 942                 seq_printf(m, "%u ", array[i]);
 943         seq_putc(m, '\n');
 944 }
 945
 946 static void dasd_stats_seq_print(struct seq_file *m,
 947                                  struct dasd_profile_info *data)
 948 {
 949         seq_printf(m, "start_time %ld.%09ld\n",
 950                    data->starttod.tv_sec, data->starttod.tv_nsec);
 951         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
 952         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
 953         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
 954         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
 955         seq_printf(m, "histogram_sectors ");
 956         dasd_stats_array(m, data->dasd_io_secs);
 957         seq_printf(m, "histogram_io_times ");
 958         dasd_stats_array(m, data->dasd_io_times);
 959         seq_printf(m, "histogram_io_times_weighted ");
 960         dasd_stats_array(m, data->dasd_io_timps);
 961         seq_printf(m, "histogram_time_build_to_ssch ");
 962         dasd_stats_array(m, data->dasd_io_time1);
 963         seq_printf(m, "histogram_time_ssch_to_irq ");
 964         dasd_stats_array(m, data->dasd_io_time2);
 965         seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
 966         dasd_stats_array(m, data->dasd_io_time2ps);
 967         seq_printf(m, "histogram_time_irq_to_end ");
 968         dasd_stats_array(m, data->dasd_io_time3);
 969         seq_printf(m, "histogram_ccw_queue_length ");
 970         dasd_stats_array(m, data->dasd_io_nr_req);
 971         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
 972         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
 973         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
 974         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
 975         seq_printf(m, "histogram_read_sectors ");
 976         dasd_stats_array(m, data->dasd_read_secs);
 977         seq_printf(m, "histogram_read_times ");
 978         dasd_stats_array(m, data->dasd_read_times);
 979         seq_printf(m, "histogram_read_time_build_to_ssch ");
 980         dasd_stats_array(m, data->dasd_read_time1);
 981         seq_printf(m, "histogram_read_time_ssch_to_irq ");
 982         dasd_stats_array(m, data->dasd_read_time2);
 983         seq_printf(m, "histogram_read_time_irq_to_end ");
 984         dasd_stats_array(m, data->dasd_read_time3);
 985         seq_printf(m, "histogram_read_ccw_queue_length ");
 986         dasd_stats_array(m, data->dasd_read_nr_req);
 987 }
 988
 989 static int dasd_stats_show(struct seq_file *m, void *v)
 990 {
 991         struct dasd_profile *profile;
 992         struct dasd_profile_info *data;
 993
 994         profile = m->private;
 995         spin_lock_bh(&profile->lock);
 996         data = profile->data;
 997         if (!data) {
 998                 spin_unlock_bh(&profile->lock);
 999                 seq_printf(m, "disabled\n");
1000                 return 0;
1001         }
1002         dasd_stats_seq_print(m, data);
1003         spin_unlock_bh(&profile->lock);
1004         return 0;
1005 }
1006
1007 static int dasd_stats_open(struct inode *inode, struct file *file)
1008 {
1009         struct dasd_profile *profile = inode->i_private;
1010         return single_open(file, dasd_stats_show, profile);
1011 }
1012
1013 static const struct file_operations dasd_stats_raw_fops = {
1014         .owner          = THIS_MODULE,
1015         .open           = dasd_stats_open,
1016         .read           = seq_read,
1017         .llseek         = seq_lseek,
1018         .release        = single_release,
1019         .write          = dasd_stats_write,
1020 };
1021
1022 static ssize_t dasd_stats_global_write(struct file *file,
1023                                        const char __user *user_buf,
1024                                        size_t user_len, loff_t *pos)
1025 {
1026         char *buffer, *str;
1027         ssize_t rc;
1028
1029         if (user_len > 65536)
1030                 user_len = 65536;
1031         buffer = dasd_get_user_string(user_buf, user_len);
1032         if (IS_ERR(buffer))
1033                 return PTR_ERR(buffer);
1034         str = skip_spaces(buffer);
1035         rc = user_len;
1036         if (strncmp(str, "reset", 5) == 0) {
1037                 dasd_global_profile_reset();
1038         } else if (strncmp(str, "on", 2) == 0) {
1039                 dasd_global_profile_reset();
1040                 dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
1041         } else if (strncmp(str, "off", 3) == 0) {
1042                 dasd_global_profile_level = DASD_PROFILE_OFF;
1043         } else
1044                 rc = -EINVAL;
1045         vfree(buffer);
1046         return rc;
1047 }
1048
1049 static int dasd_stats_global_show(struct seq_file *m, void *v)
1050 {
1051         if (!dasd_global_profile_level) {
1052                 seq_printf(m, "disabled\n");
1053                 return 0;
1054         }
1055         dasd_stats_seq_print(m, &dasd_global_profile_data);
1056         return 0;
1057 }
1058
1059 static int dasd_stats_global_open(struct inode *inode, struct file *file)
1060 {
1061         return single_open(file, dasd_stats_global_show, NULL);
1062 }
1063
1064 static const struct file_operations dasd_stats_global_fops = {
1065         .owner          = THIS_MODULE,
1066         .open           = dasd_stats_global_open,
1067         .read           = seq_read,
1068         .llseek         = seq_lseek,
1069         .release        = single_release,
1070         .write          = dasd_stats_global_write,
1071 };
1072
1073 static void dasd_profile_init(struct dasd_profile *profile,
1074                               struct dentry *base_dentry)
1075 {
1076         umode_t mode;
1077         struct dentry *pde;
1078
1079         if (!base_dentry)
1080                 return;
1081         profile->dentry = NULL;
1082         profile->data = NULL;
1083         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1084         pde = debugfs_create_file("statistics", mode, base_dentry,
1085                                   profile, &dasd_stats_raw_fops);
1086         if (pde && !IS_ERR(pde))
1087                 profile->dentry = pde;
1088         return;
1089 }
1090
1091 static void dasd_profile_exit(struct dasd_profile *profile)
1092 {
1093         dasd_profile_off(profile);
1094         if (profile->dentry) {
1095                 debugfs_remove(profile->dentry);
1096                 profile->dentry = NULL;
1097         }
1098 }
1099
1100 static void dasd_statistics_removeroot(void)
1101 {
1102         dasd_global_profile_level = DASD_PROFILE_OFF;
1103         if (dasd_global_profile_dentry) {
1104                 debugfs_remove(dasd_global_profile_dentry);
1105                 dasd_global_profile_dentry = NULL;
1106         }
1107         if (dasd_debugfs_global_entry)
1108                 debugfs_remove(dasd_debugfs_global_entry);
1109         if (dasd_debugfs_root_entry)
1110                 debugfs_remove(dasd_debugfs_root_entry);
1111 }
1112
1113 static void dasd_statistics_createroot(void)
1114 {
1115         umode_t mode;
1116         struct dentry *pde;
1117
1118         dasd_debugfs_root_entry = NULL;
1119         dasd_debugfs_global_entry = NULL;
1120         dasd_global_profile_dentry = NULL;
1121         pde = debugfs_create_dir("dasd", NULL);
1122         if (!pde || IS_ERR(pde))
1123                 goto error;
1124         dasd_debugfs_root_entry = pde;
1125         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1126         if (!pde || IS_ERR(pde))
1127                 goto error;
1128         dasd_debugfs_global_entry = pde;
1129
1130         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1131         pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
1132                                   NULL, &dasd_stats_global_fops);
1133         if (!pde || IS_ERR(pde))
1134                 goto error;
1135         dasd_global_profile_dentry = pde;
1136         return;
1137
1138 error:
1139         DBF_EVENT(DBF_ERR, "%s",
1140                   "Creation of the dasd debugfs interface failed");
1141         dasd_statistics_removeroot();
1142         return;
1143 }
1144
1145 #else
1146 #define dasd_profile_start(block, cqr, req) do {} while (0)
1147 #define dasd_profile_end(block, cqr, req) do {} while (0)
1148
1149 static void dasd_statistics_createroot(void)
1150 {
1151         return;
1152 }
1153
1154 static void dasd_statistics_removeroot(void)
1155 {
1156         return;
1157 }
1158
1159 int dasd_stats_generic_show(struct seq_file *m, void *v)
1160 {
1161         seq_printf(m, "Statistics are not activated in this kernel\n");
1162         return 0;
1163 }
1164
1165 static void dasd_profile_init(struct dasd_profile *profile,
1166                               struct dentry *base_dentry)
1167 {
1168         return;
1169 }
1170
1171 static void dasd_profile_exit(struct dasd_profile *profile)
1172 {
1173         return;
1174 }
1175
1176 int dasd_profile_on(struct dasd_profile *profile)
1177 {
1178         return 0;
1179 }
1180
1181 #endif                          /* CONFIG_DASD_PROFILE */
1182
1183 /*
1184  * Allocate memory for a channel program with 'cplength' channel
1185  * command words and 'datasize' additional space. There are two
1186  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1187  * memory and 2) dasd_smalloc_request uses the static ccw memory
1188  * that gets allocated for each device.
1189  */
1190 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1191                                           int datasize,
1192                                           struct dasd_device *device)
1193 {
1194         struct dasd_ccw_req *cqr;
1195
1196         /* Sanity checks */
1197         BUG_ON(datasize > PAGE_SIZE ||
1198              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1199
1200         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1201         if (cqr == NULL)
1202                 return ERR_PTR(-ENOMEM);
1203         cqr->cpaddr = NULL;
1204         if (cplength > 0) {
1205                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1206                                       GFP_ATOMIC | GFP_DMA);
1207                 if (cqr->cpaddr == NULL) {
1208                         kfree(cqr);
1209                         return ERR_PTR(-ENOMEM);
1210                 }
1211         }
1212         cqr->data = NULL;
1213         if (datasize > 0) {
1214                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1215                 if (cqr->data == NULL) {
1216                         kfree(cqr->cpaddr);
1217                         kfree(cqr);
1218                         return ERR_PTR(-ENOMEM);
1219                 }
1220         }
1221         cqr->magic =  magic;
1222         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1223         dasd_get_device(device);
1224         return cqr;
1225 }
1226
1227 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1228                                           int datasize,
1229                                           struct dasd_device *device)
1230 {
1231         unsigned long flags;
1232         struct dasd_ccw_req *cqr;
1233         char *data;
1234         int size;
1235
1236         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1237         if (cplength > 0)
1238                 size += cplength * sizeof(struct ccw1);
1239         if (datasize > 0)
1240                 size += datasize;
1241         spin_lock_irqsave(&device->mem_lock, flags);
1242         cqr = (struct dasd_ccw_req *)
1243                 dasd_alloc_chunk(&device->ccw_chunks, size);
1244         spin_unlock_irqrestore(&device->mem_lock, flags);
1245         if (cqr == NULL)
1246                 return ERR_PTR(-ENOMEM);
1247         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1248         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1249         cqr->cpaddr = NULL;
1250         if (cplength > 0) {
1251                 cqr->cpaddr = (struct ccw1 *) data;
1252                 data += cplength*sizeof(struct ccw1);
1253                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1254         }
1255         cqr->data = NULL;
1256         if (datasize > 0) {
1257                 cqr->data = data;
1258                 memset(cqr->data, 0, datasize);
1259         }
1260         cqr->magic = magic;
1261         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1262         dasd_get_device(device);
1263         return cqr;
1264 }
1265
1266 /*
1267  * Free memory of a channel program. This function needs to free all the
1268  * idal lists that might have been created by dasd_set_cda and the
1269  * struct dasd_ccw_req itself.
1270  */
1271 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1272 {
1273 #ifdef CONFIG_64BIT
1274         struct ccw1 *ccw;
1275
1276         /* Clear any idals used for the request. */
1277         ccw = cqr->cpaddr;
1278         do {
1279                 clear_normalized_cda(ccw);
1280         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1281 #endif
1282         kfree(cqr->cpaddr);
1283         kfree(cqr->data);
1284         kfree(cqr);
1285         dasd_put_device(device);
1286 }
1287
1288 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1289 {
1290         unsigned long flags;
1291
1292         spin_lock_irqsave(&device->mem_lock, flags);
1293         dasd_free_chunk(&device->ccw_chunks, cqr);
1294         spin_unlock_irqrestore(&device->mem_lock, flags);
1295         dasd_put_device(device);
1296 }
1297
1298 /*
1299  * Check discipline magic in cqr.
1300  */
1301 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1302 {
1303         struct dasd_device *device;
1304
1305         if (cqr == NULL)
1306                 return -EINVAL;
1307         device = cqr->startdev;
1308         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1309                 DBF_DEV_EVENT(DBF_WARNING, device,
1310                             " dasd_ccw_req 0x%08x magic doesn't match"
1311                             " discipline 0x%08x",
1312                             cqr->magic,
1313                             *(unsigned int *) device->discipline->name);
1314                 return -EINVAL;
1315         }
1316         return 0;
1317 }
1318
1319 /*
1320  * Terminate the current i/o and set the request to clear_pending.
1321  * Timer keeps device runnig.
1322  * ccw_device_clear can fail if the i/o subsystem
1323  * is in a bad mood.
1324  */
1325 int dasd_term_IO(struct dasd_ccw_req *cqr)
1326 {
1327         struct dasd_device *device;
1328         int retries, rc;
1329         char errorstring[ERRORLENGTH];
1330
1331         /* Check the cqr */
1332         rc = dasd_check_cqr(cqr);
1333         if (rc)
1334                 return rc;
1335         retries = 0;
1336         device = (struct dasd_device *) cqr->startdev;
1337         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1338                 rc = ccw_device_clear(device->cdev, (long) cqr);
1339                 switch (rc) {
1340                 case 0: /* termination successful */
1341                         cqr->status = DASD_CQR_CLEAR_PENDING;
1342                         cqr->stopclk = get_clock();
1343                         cqr->starttime = 0;
1344                         DBF_DEV_EVENT(DBF_DEBUG, device,
1345                                       "terminate cqr %p successful",
1346                                       cqr);
1347                         break;
1348                 case -ENODEV:
1349                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1350                                       "device gone, retry");
1351                         break;
1352                 case -EIO:
1353                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1354                                       "I/O error, retry");
1355                         break;
1356                 case -EINVAL:
1357                 case -EBUSY:
1358                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1359                                       "device busy, retry later");
1360                         break;
1361                 default:
1362                         /* internal error 10 - unknown rc*/
1363                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1364                         dev_err(&device->cdev->dev, "An error occurred in the "
1365                                 "DASD device driver, reason=%s\n", errorstring);
1366                         BUG();
1367                         break;
1368                 }
1369                 retries++;
1370         }
1371         dasd_schedule_device_bh(device);
1372         return rc;
1373 }
1374
1375 /*
1376  * Start the i/o. This start_IO can fail if the channel is really busy.
1377  * In that case set up a timer to start the request later.
1378  */
1379 int dasd_start_IO(struct dasd_ccw_req *cqr)
1380 {
1381         struct dasd_device *device;
1382         int rc;
1383         char errorstring[ERRORLENGTH];
1384
1385         /* Check the cqr */
1386         rc = dasd_check_cqr(cqr);
1387         if (rc) {
1388                 cqr->intrc = rc;
1389                 return rc;
1390         }
1391         device = (struct dasd_device *) cqr->startdev;
1392         if (((cqr->block &&
1393               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1394              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1395             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1396                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1397                               "because of stolen lock", cqr);
1398                 cqr->status = DASD_CQR_ERROR;
1399                 cqr->intrc = -EPERM;
1400                 return -EPERM;
1401         }
1402         if (cqr->retries < 0) {
1403                 /* internal error 14 - start_IO run out of retries */
1404                 sprintf(errorstring, "14 %p", cqr);
1405                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1406                         "device driver, reason=%s\n", errorstring);
1407                 cqr->status = DASD_CQR_ERROR;
1408                 return -EIO;
1409         }
1410         cqr->startclk = get_clock();
1411         cqr->starttime = jiffies;
1412         cqr->retries--;
1413         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1414                 cqr->lpm &= device->path_data.opm;
1415                 if (!cqr->lpm)
1416                         cqr->lpm = device->path_data.opm;
1417         }
1418         if (cqr->cpmode == 1) {
1419                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1420                                          (long) cqr, cqr->lpm);
1421         } else {
1422                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1423                                       (long) cqr, cqr->lpm, 0);
1424         }
1425         switch (rc) {
1426         case 0:
1427                 cqr->status = DASD_CQR_IN_IO;
1428                 break;
1429         case -EBUSY:
1430                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1431                               "start_IO: device busy, retry later");
1432                 break;
1433         case -ETIMEDOUT:
1434                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1435                               "start_IO: request timeout, retry later");
1436                 break;
1437         case -EACCES:
1438                 /* -EACCES indicates that the request used only a subset of the
1439                  * available paths and all these paths are gone. If the lpm of
1440                  * this request was only a subset of the opm (e.g. the ppm) then
1441                  * we just do a retry with all available paths.
1442                  * If we already use the full opm, something is amiss, and we
1443                  * need a full path verification.
1444                  */
1445                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1446                         DBF_DEV_EVENT(DBF_WARNING, device,
1447                                       "start_IO: selected paths gone (%x)",
1448                                       cqr->lpm);
1449                 } else if (cqr->lpm != device->path_data.opm) {
1450                         cqr->lpm = device->path_data.opm;
1451                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1452                                       "start_IO: selected paths gone,"
1453                                       " retry on all paths");
1454                 } else {
1455                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1456                                       "start_IO: all paths in opm gone,"
1457                                       " do path verification");
1458                         dasd_generic_last_path_gone(device);
1459                         device->path_data.opm = 0;
1460                         device->path_data.ppm = 0;
1461                         device->path_data.npm = 0;
1462                         device->path_data.tbvpm =
1463                                 ccw_device_get_path_mask(device->cdev);
1464                 }
1465                 break;
1466         case -ENODEV:
1467                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1468                               "start_IO: -ENODEV device gone, retry");
1469                 break;
1470         case -EIO:
1471                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1472                               "start_IO: -EIO device gone, retry");
1473                 break;
1474         case -EINVAL:
1475                 /* most likely caused in power management context */
1476                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1477                               "start_IO: -EINVAL device currently "
1478                               "not accessible");
1479                 break;
1480         default:
1481                 /* internal error 11 - unknown rc */
1482                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1483                 dev_err(&device->cdev->dev,
1484                         "An error occurred in the DASD device driver, "
1485                         "reason=%s\n", errorstring);
1486                 BUG();
1487                 break;
1488         }
1489         cqr->intrc = rc;
1490         return rc;
1491 }
1492
1493 /*
1494  * Timeout function for dasd devices. This is used for different purposes
1495  *  1) missing interrupt handler for normal operation
1496  *  2) delayed start of request where start_IO failed with -EBUSY
1497  *  3) timeout for missing state change interrupts
1498  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1499  * DASD_CQR_QUEUED for 2) and 3).
1500  */
1501 static void dasd_device_timeout(unsigned long ptr)
1502 {
1503         unsigned long flags;
1504         struct dasd_device *device;
1505
1506         device = (struct dasd_device *) ptr;
1507         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1508         /* re-activate request queue */
1509         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1510         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1511         dasd_schedule_device_bh(device);
1512 }
1513
1514 /*
1515  * Setup timeout for a device in jiffies.
1516  */
1517 void dasd_device_set_timer(struct dasd_device *device, int expires)
1518 {
1519         if (expires == 0)
1520                 del_timer(&device->timer);
1521         else
1522                 mod_timer(&device->timer, jiffies + expires);
1523 }
1524
1525 /*
1526  * Clear timeout for a device.
1527  */
1528 void dasd_device_clear_timer(struct dasd_device *device)
1529 {
1530         del_timer(&device->timer);
1531 }
1532
1533 static void dasd_handle_killed_request(struct ccw_device *cdev,
1534                                        unsigned long intparm)
1535 {
1536         struct dasd_ccw_req *cqr;
1537         struct dasd_device *device;
1538
1539         if (!intparm)
1540                 return;
1541         cqr = (struct dasd_ccw_req *) intparm;
1542         if (cqr->status != DASD_CQR_IN_IO) {
1543                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1544                                 "invalid status in handle_killed_request: "
1545                                 "%02x", cqr->status);
1546                 return;
1547         }
1548
1549         device = dasd_device_from_cdev_locked(cdev);
1550         if (IS_ERR(device)) {
1551                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1552                                 "unable to get device from cdev");
1553                 return;
1554         }
1555
1556         if (!cqr->startdev ||
1557             device != cqr->startdev ||
1558             strncmp(cqr->startdev->discipline->ebcname,
1559                     (char *) &cqr->magic, 4)) {
1560                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1561                                 "invalid device in request");
1562                 dasd_put_device(device);
1563                 return;
1564         }
1565
1566         /* Schedule request to be retried. */
1567         cqr->status = DASD_CQR_QUEUED;
1568
1569         dasd_device_clear_timer(device);
1570         dasd_schedule_device_bh(device);
1571         dasd_put_device(device);
1572 }
1573
1574 void dasd_generic_handle_state_change(struct dasd_device *device)
1575 {
1576         /* First of all start sense subsystem status request. */
1577         dasd_eer_snss(device);
1578
1579         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1580         dasd_schedule_device_bh(device);
1581         if (device->block)
1582                 dasd_schedule_block_bh(device->block);
1583 }
1584
1585 /*
1586  * Interrupt handler for "normal" ssch-io based dasd devices.
1587  */
1588 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1589                       struct irb *irb)
1590 {
1591         struct dasd_ccw_req *cqr, *next;
1592         struct dasd_device *device;
1593         unsigned long long now;
1594         int expires;
1595
1596         if (IS_ERR(irb)) {
1597                 switch (PTR_ERR(irb)) {
1598                 case -EIO:
1599                         break;
1600                 case -ETIMEDOUT:
1601                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1602                                         "request timed out\n", __func__);
1603                         break;
1604                 default:
1605                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1606                                         "unknown error %ld\n", __func__,
1607                                         PTR_ERR(irb));
1608                 }
1609                 dasd_handle_killed_request(cdev, intparm);
1610                 return;
1611         }
1612
1613         now = get_clock();
1614         cqr = (struct dasd_ccw_req *) intparm;
1615         /* check for conditions that should be handled immediately */
1616         if (!cqr ||
1617             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1618               scsw_cstat(&irb->scsw) == 0)) {
1619                 if (cqr)
1620                         memcpy(&cqr->irb, irb, sizeof(*irb));
1621                 device = dasd_device_from_cdev_locked(cdev);
1622                 if (IS_ERR(device))
1623                         return;
1624                 /* ignore unsolicited interrupts for DIAG discipline */
1625                 if (device->discipline == dasd_diag_discipline_pointer) {
1626                         dasd_put_device(device);
1627                         return;
1628                 }
1629                 device->discipline->dump_sense_dbf(device, irb, "int");
1630                 if (device->features & DASD_FEATURE_ERPLOG)
1631                         device->discipline->dump_sense(device, cqr, irb);
1632                 device->discipline->check_for_device_change(device, cqr, irb);
1633                 dasd_put_device(device);
1634         }
1635         if (!cqr)
1636                 return;
1637
1638         device = (struct dasd_device *) cqr->startdev;
1639         if (!device ||
1640             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1641                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1642                                 "invalid device in request");
1643                 return;
1644         }
1645
1646         /* Check for clear pending */
1647         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1648             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1649                 cqr->status = DASD_CQR_CLEARED;
1650                 dasd_device_clear_timer(device);
1651                 wake_up(&dasd_flush_wq);
1652                 dasd_schedule_device_bh(device);
1653                 return;
1654         }
1655
1656         /* check status - the request might have been killed by dyn detach */
1657         if (cqr->status != DASD_CQR_IN_IO) {
1658                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1659                               "status %02x", dev_name(&cdev->dev), cqr->status);
1660                 return;
1661         }
1662
1663         next = NULL;
1664         expires = 0;
1665         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1666             scsw_cstat(&irb->scsw) == 0) {
1667                 /* request was completed successfully */
1668                 cqr->status = DASD_CQR_SUCCESS;
1669                 cqr->stopclk = now;
1670                 /* Start first request on queue if possible -> fast_io. */
1671                 if (cqr->devlist.next != &device->ccw_queue) {
1672                         next = list_entry(cqr->devlist.next,
1673                                           struct dasd_ccw_req, devlist);
1674                 }
1675         } else {  /* error */
1676                 /*
1677                  * If we don't want complex ERP for this request, then just
1678                  * reset this and retry it in the fastpath
1679                  */
1680                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1681                     cqr->retries > 0) {
1682                         if (cqr->lpm == device->path_data.opm)
1683                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1684                                               "default ERP in fastpath "
1685                                               "(%i retries left)",
1686                                               cqr->retries);
1687                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1688                                 cqr->lpm = device->path_data.opm;
1689                         cqr->status = DASD_CQR_QUEUED;
1690                         next = cqr;
1691                 } else
1692                         cqr->status = DASD_CQR_ERROR;
1693         }
1694         if (next && (next->status == DASD_CQR_QUEUED) &&
1695             (!device->stopped)) {
1696                 if (device->discipline->start_IO(next) == 0)
1697                         expires = next->expires;
1698         }
1699         if (expires != 0)
1700                 dasd_device_set_timer(device, expires);
1701         else
1702                 dasd_device_clear_timer(device);
1703         dasd_schedule_device_bh(device);
1704 }
1705
1706 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1707 {
1708         struct dasd_device *device;
1709
1710         device = dasd_device_from_cdev_locked(cdev);
1711
1712         if (IS_ERR(device))
1713                 goto out;
1714         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1715            device->state != device->target ||
1716            !device->discipline->check_for_device_change){
1717                 dasd_put_device(device);
1718                 goto out;
1719         }
1720         if (device->discipline->dump_sense_dbf)
1721                 device->discipline->dump_sense_dbf(device, irb, "uc");
1722         device->discipline->check_for_device_change(device, NULL, irb);
1723         dasd_put_device(device);
1724 out:
1725         return UC_TODO_RETRY;
1726 }
1727 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1728
1729 /*
1730  * If we have an error on a dasd_block layer request then we cancel
1731  * and return all further requests from the same dasd_block as well.
1732  */
1733 static void __dasd_device_recovery(struct dasd_device *device,
1734                                    struct dasd_ccw_req *ref_cqr)
1735 {
1736         struct list_head *l, *n;
1737         struct dasd_ccw_req *cqr;
1738
1739         /*
1740          * only requeue request that came from the dasd_block layer
1741          */
1742         if (!ref_cqr->block)
1743                 return;
1744
1745         list_for_each_safe(l, n, &device->ccw_queue) {
1746                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1747                 if (cqr->status == DASD_CQR_QUEUED &&
1748                     ref_cqr->block == cqr->block) {
1749                         cqr->status = DASD_CQR_CLEARED;
1750                 }
1751         }
1752 };
1753
1754 /*
1755  * Remove those ccw requests from the queue that need to be returned
1756  * to the upper layer.
1757  */
1758 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1759                                             struct list_head *final_queue)
1760 {
1761         struct list_head *l, *n;
1762         struct dasd_ccw_req *cqr;
1763
1764         /* Process request with final status. */
1765         list_for_each_safe(l, n, &device->ccw_queue) {
1766                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1767
1768                 /* Stop list processing at the first non-final request. */
1769                 if (cqr->status == DASD_CQR_QUEUED ||
1770                     cqr->status == DASD_CQR_IN_IO ||
1771                     cqr->status == DASD_CQR_CLEAR_PENDING)
1772                         break;
1773                 if (cqr->status == DASD_CQR_ERROR) {
1774                         __dasd_device_recovery(device, cqr);
1775                 }
1776                 /* Rechain finished requests to final queue */
1777                 list_move_tail(&cqr->devlist, final_queue);
1778         }
1779 }
1780
1781 /*
1782  * the cqrs from the final queue are returned to the upper layer
1783  * by setting a dasd_block state and calling the callback function
1784  */
1785 static void __dasd_device_process_final_queue(struct dasd_device *device,
1786                                               struct list_head *final_queue)
1787 {
1788         struct list_head *l, *n;
1789         struct dasd_ccw_req *cqr;
1790         struct dasd_block *block;
1791         void (*callback)(struct dasd_ccw_req *, void *data);
1792         void *callback_data;
1793         char errorstring[ERRORLENGTH];
1794
1795         list_for_each_safe(l, n, final_queue) {
1796                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1797                 list_del_init(&cqr->devlist);
1798                 block = cqr->block;
1799                 callback = cqr->callback;
1800                 callback_data = cqr->callback_data;
1801                 if (block)
1802                         spin_lock_bh(&block->queue_lock);
1803                 switch (cqr->status) {
1804                 case DASD_CQR_SUCCESS:
1805                         cqr->status = DASD_CQR_DONE;
1806                         break;
1807                 case DASD_CQR_ERROR:
1808                         cqr->status = DASD_CQR_NEED_ERP;
1809                         break;
1810                 case DASD_CQR_CLEARED:
1811                         cqr->status = DASD_CQR_TERMINATED;
1812                         break;
1813                 default:
1814                         /* internal error 12 - wrong cqr status*/
1815                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1816                         dev_err(&device->cdev->dev,
1817                                 "An error occurred in the DASD device driver, "
1818                                 "reason=%s\n", errorstring);
1819                         BUG();
1820                 }
1821                 if (cqr->callback != NULL)
1822                         (callback)(cqr, callback_data);
1823                 if (block)
1824                         spin_unlock_bh(&block->queue_lock);
1825         }
1826 }
1827
1828 /*
1829  * Take a look at the first request on the ccw queue and check
1830  * if it reached its expire time. If so, terminate the IO.
1831  */
1832 static void __dasd_device_check_expire(struct dasd_device *device)
1833 {
1834         struct dasd_ccw_req *cqr;
1835
1836         if (list_empty(&device->ccw_queue))
1837                 return;
1838         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1839         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1840             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1841                 if (device->discipline->term_IO(cqr) != 0) {
1842                         /* Hmpf, try again in 5 sec */
1843                         dev_err(&device->cdev->dev,
1844                                 "cqr %p timed out (%lus) but cannot be "
1845                                 "ended, retrying in 5 s\n",
1846                                 cqr, (cqr->expires/HZ));
1847                         cqr->expires += 5*HZ;
1848                         dasd_device_set_timer(device, 5*HZ);
1849                 } else {
1850                         dev_err(&device->cdev->dev,
1851                                 "cqr %p timed out (%lus), %i retries "
1852                                 "remaining\n", cqr, (cqr->expires/HZ),
1853                                 cqr->retries);
1854                 }
1855         }
1856 }
1857
1858 /*
1859  * Take a look at the first request on the ccw queue and check
1860  * if it needs to be started.
1861  */
1862 static void __dasd_device_start_head(struct dasd_device *device)
1863 {
1864         struct dasd_ccw_req *cqr;
1865         int rc;
1866
1867         if (list_empty(&device->ccw_queue))
1868                 return;
1869         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1870         if (cqr->status != DASD_CQR_QUEUED)
1871                 return;
1872         /* when device is stopped, return request to previous layer
1873          * exception: only the disconnect or unresumed bits are set and the
1874          * cqr is a path verification request
1875          */
1876         if (device->stopped &&
1877             !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
1878               && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
1879                 cqr->intrc = -EAGAIN;
1880                 cqr->status = DASD_CQR_CLEARED;
1881                 dasd_schedule_device_bh(device);
1882                 return;
1883         }
1884
1885         rc = device->discipline->start_IO(cqr);
1886         if (rc == 0)
1887                 dasd_device_set_timer(device, cqr->expires);
1888         else if (rc == -EACCES) {
1889                 dasd_schedule_device_bh(device);
1890         } else
1891                 /* Hmpf, try again in 1/2 sec */
1892                 dasd_device_set_timer(device, 50);
1893 }
1894
1895 static void __dasd_device_check_path_events(struct dasd_device *device)
1896 {
1897         int rc;
1898
1899         if (device->path_data.tbvpm) {
1900                 if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
1901                                         DASD_UNRESUMED_PM))
1902                         return;
1903                 rc = device->discipline->verify_path(
1904                         device, device->path_data.tbvpm);
1905                 if (rc)
1906                         dasd_device_set_timer(device, 50);
1907                 else
1908                         device->path_data.tbvpm = 0;
1909         }
1910 };
1911
1912 /*
1913  * Go through all request on the dasd_device request queue,
1914  * terminate them on the cdev if necessary, and return them to the
1915  * submitting layer via callback.
1916  * Note:
1917  * Make sure that all 'submitting layers' still exist when
1918  * this function is called!. In other words, when 'device' is a base
1919  * device then all block layer requests must have been removed before
1920  * via dasd_flush_block_queue.
1921  */
1922 int dasd_flush_device_queue(struct dasd_device *device)
1923 {
1924         struct dasd_ccw_req *cqr, *n;
1925         int rc;
1926         struct list_head flush_queue;
1927
1928         INIT_LIST_HEAD(&flush_queue);
1929         spin_lock_irq(get_ccwdev_lock(device->cdev));
1930         rc = 0;
1931         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1932                 /* Check status and move request to flush_queue */
1933                 switch (cqr->status) {
1934                 case DASD_CQR_IN_IO:
1935                         rc = device->discipline->term_IO(cqr);
1936                         if (rc) {
1937                                 /* unable to terminate requeust */
1938                                 dev_err(&device->cdev->dev,
1939                                         "Flushing the DASD request queue "
1940                                         "failed for request %p\n", cqr);
1941                                 /* stop flush processing */
1942                                 goto finished;
1943                         }
1944                         break;
1945                 case DASD_CQR_QUEUED:
1946                         cqr->stopclk = get_clock();
1947                         cqr->status = DASD_CQR_CLEARED;
1948                         break;
1949                 default: /* no need to modify the others */
1950                         break;
1951                 }
1952                 list_move_tail(&cqr->devlist, &flush_queue);
1953         }
1954 finished:
1955         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1956         /*
1957          * After this point all requests must be in state CLEAR_PENDING,
1958          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
1959          * one of the others.
1960          */
1961         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
1962                 wait_event(dasd_flush_wq,
1963                            (cqr->status != DASD_CQR_CLEAR_PENDING));
1964         /*
1965          * Now set each request back to TERMINATED, DONE or NEED_ERP
1966          * and call the callback function of flushed requests
1967          */
1968         __dasd_device_process_final_queue(device, &flush_queue);
1969         return rc;
1970 }
1971
1972 /*
1973  * Acquire the device lock and process queues for the device.
1974  */
1975 static void dasd_device_tasklet(struct dasd_device *device)
1976 {
1977         struct list_head final_queue;
1978
1979         atomic_set (&device->tasklet_scheduled, 0);
1980         INIT_LIST_HEAD(&final_queue);
1981         spin_lock_irq(get_ccwdev_lock(device->cdev));
1982         /* Check expire time of first request on the ccw queue. */
1983         __dasd_device_check_expire(device);
1984         /* find final requests on ccw queue */
1985         __dasd_device_process_ccw_queue(device, &final_queue);
1986         __dasd_device_check_path_events(device);
1987         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1988         /* Now call the callback function of requests with final status */
1989         __dasd_device_process_final_queue(device, &final_queue);
1990         spin_lock_irq(get_ccwdev_lock(device->cdev));
1991         /* Now check if the head of the ccw queue needs to be started. */
1992         __dasd_device_start_head(device);
1993         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1994         dasd_put_device(device);
1995 }
1996
1997 /*
1998  * Schedules a call to dasd_tasklet over the device tasklet.
1999  */
2000 void dasd_schedule_device_bh(struct dasd_device *device)
2001 {
2002         /* Protect against rescheduling. */
2003         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2004                 return;
2005         dasd_get_device(device);
2006         tasklet_hi_schedule(&device->tasklet);
2007 }
2008
2009 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2010 {
2011         device->stopped |= bits;
2012 }
2013 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2014
2015 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2016 {
2017         device->stopped &= ~bits;
2018         if (!device->stopped)
2019                 wake_up(&generic_waitq);
2020 }
2021 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2022
2023 /*
2024  * Queue a request to the head of the device ccw_queue.
2025  * Start the I/O if possible.
2026  */
2027 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2028 {
2029         struct dasd_device *device;
2030         unsigned long flags;
2031
2032         device = cqr->startdev;
2033         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2034         cqr->status = DASD_CQR_QUEUED;
2035         list_add(&cqr->devlist, &device->ccw_queue);
2036         /* let the bh start the request to keep them in order */
2037         dasd_schedule_device_bh(device);
2038         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2039 }
2040
2041 /*
2042  * Queue a request to the tail of the device ccw_queue.
2043  * Start the I/O if possible.
2044  */
2045 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2046 {
2047         struct dasd_device *device;
2048         unsigned long flags;
2049
2050         device = cqr->startdev;
2051         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2052         cqr->status = DASD_CQR_QUEUED;
2053         list_add_tail(&cqr->devlist, &device->ccw_queue);
2054         /* let the bh start the request to keep them in order */
2055         dasd_schedule_device_bh(device);
2056         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2057 }
2058
2059 /*
2060  * Wakeup helper for the 'sleep_on' functions.
2061  */
2062 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2063 {
2064         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2065         cqr->callback_data = DASD_SLEEPON_END_TAG;
2066         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2067         wake_up(&generic_waitq);
2068 }
2069 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2070
2071 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2072 {
2073         struct dasd_device *device;
2074         int rc;
2075
2076         device = cqr->startdev;
2077         spin_lock_irq(get_ccwdev_lock(device->cdev));
2078         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2079         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2080         return rc;
2081 }
2082
2083 /*
2084  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2085  */
2086 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2087 {
2088         struct dasd_device *device;
2089         dasd_erp_fn_t erp_fn;
2090
2091         if (cqr->status == DASD_CQR_FILLED)
2092                 return 0;
2093         device = cqr->startdev;
2094         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2095                 if (cqr->status == DASD_CQR_TERMINATED) {
2096                         device->discipline->handle_terminated_request(cqr);
2097                         return 1;
2098                 }
2099                 if (cqr->status == DASD_CQR_NEED_ERP) {
2100                         erp_fn = device->discipline->erp_action(cqr);
2101                         erp_fn(cqr);
2102                         return 1;
2103                 }
2104                 if (cqr->status == DASD_CQR_FAILED)
2105                         dasd_log_sense(cqr, &cqr->irb);
2106                 if (cqr->refers) {
2107                         __dasd_process_erp(device, cqr);
2108                         return 1;
2109                 }
2110         }
2111         return 0;
2112 }
2113
2114 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2115 {
2116         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2117                 if (cqr->refers) /* erp is not done yet */
2118                         return 1;
2119                 return ((cqr->status != DASD_CQR_DONE) &&
2120                         (cqr->status != DASD_CQR_FAILED));
2121         } else
2122                 return (cqr->status == DASD_CQR_FILLED);
2123 }
2124
2125 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2126 {
2127         struct dasd_device *device;
2128         int rc;
2129         struct list_head ccw_queue;
2130         struct dasd_ccw_req *cqr;
2131
2132         INIT_LIST_HEAD(&ccw_queue);
2133         maincqr->status = DASD_CQR_FILLED;
2134         device = maincqr->startdev;
2135         list_add(&maincqr->blocklist, &ccw_queue);
2136         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2137              cqr = list_first_entry(&ccw_queue,
2138                                     struct dasd_ccw_req, blocklist)) {
2139
2140                 if (__dasd_sleep_on_erp(cqr))
2141                         continue;
2142                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2143                         continue;
2144                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2145                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2146                         cqr->status = DASD_CQR_FAILED;
2147                         cqr->intrc = -EPERM;
2148                         continue;
2149                 }
2150                 /* Non-temporary stop condition will trigger fail fast */
2151                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2152                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2153                     (!dasd_eer_enabled(device))) {
2154                         cqr->status = DASD_CQR_FAILED;
2155                         continue;
2156                 }
2157                 /* Don't try to start requests if device is stopped */
2158                 if (interruptible) {
2159                         rc = wait_event_interruptible(
2160                                 generic_waitq, !(device->stopped));
2161                         if (rc == -ERESTARTSYS) {
2162                                 cqr->status = DASD_CQR_FAILED;
2163                                 maincqr->intrc = rc;
2164                                 continue;
2165                         }
2166                 } else
2167                         wait_event(generic_waitq, !(device->stopped));
2168
2169                 if (!cqr->callback)
2170                         cqr->callback = dasd_wakeup_cb;
2171
2172                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2173                 dasd_add_request_tail(cqr);
2174                 if (interruptible) {
2175                         rc = wait_event_interruptible(
2176                                 generic_waitq, _wait_for_wakeup(cqr));
2177                         if (rc == -ERESTARTSYS) {
2178                                 dasd_cancel_req(cqr);
2179                                 /* wait (non-interruptible) for final status */
2180                                 wait_event(generic_waitq,
2181                                            _wait_for_wakeup(cqr));
2182                                 cqr->status = DASD_CQR_FAILED;
2183                                 maincqr->intrc = rc;
2184                                 continue;
2185                         }
2186                 } else
2187                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2188         }
2189
2190         maincqr->endclk = get_clock();
2191         if ((maincqr->status != DASD_CQR_DONE) &&
2192             (maincqr->intrc != -ERESTARTSYS))
2193                 dasd_log_sense(maincqr, &maincqr->irb);
2194         if (maincqr->status == DASD_CQR_DONE)
2195                 rc = 0;
2196         else if (maincqr->intrc)
2197                 rc = maincqr->intrc;
2198         else
2199                 rc = -EIO;
2200         return rc;
2201 }
2202
2203 /*
2204  * Queue a request to the tail of the device ccw_queue and wait for
2205  * it's completion.
2206  */
2207 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2208 {
2209         return _dasd_sleep_on(cqr, 0);
2210 }
2211
2212 /*
2213  * Queue a request to the tail of the device ccw_queue and wait
2214  * interruptible for it's completion.
2215  */
2216 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2217 {
2218         return _dasd_sleep_on(cqr, 1);
2219 }
2220
2221 /*
2222  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2223  * for eckd devices) the currently running request has to be terminated
2224  * and be put back to status queued, before the special request is added
2225  * to the head of the queue. Then the special request is waited on normally.
2226  */
2227 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2228 {
2229         struct dasd_ccw_req *cqr;
2230         int rc;
2231
2232         if (list_empty(&device->ccw_queue))
2233                 return 0;
2234         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2235         rc = device->discipline->term_IO(cqr);
2236         if (!rc)
2237                 /*
2238                  * CQR terminated because a more important request is pending.
2239                  * Undo decreasing of retry counter because this is
2240                  * not an error case.
2241                  */
2242                 cqr->retries++;
2243         return rc;
2244 }
2245
2246 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2247 {
2248         struct dasd_device *device;
2249         int rc;
2250
2251         device = cqr->startdev;
2252         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2253             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2254                 cqr->status = DASD_CQR_FAILED;
2255                 cqr->intrc = -EPERM;
2256                 return -EIO;
2257         }
2258         spin_lock_irq(get_ccwdev_lock(device->cdev));
2259         rc = _dasd_term_running_cqr(device);
2260         if (rc) {
2261                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2262                 return rc;
2263         }
2264         cqr->callback = dasd_wakeup_cb;
2265         cqr->callback_data = DASD_SLEEPON_START_TAG;
2266         cqr->status = DASD_CQR_QUEUED;
2267         /*
2268          * add new request as second
2269          * first the terminated cqr needs to be finished
2270          */
2271         list_add(&cqr->devlist, device->ccw_queue.next);
2272
2273         /* let the bh start the request to keep them in order */
2274         dasd_schedule_device_bh(device);
2275
2276         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2277
2278         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2279
2280         if (cqr->status == DASD_CQR_DONE)
2281                 rc = 0;
2282         else if (cqr->intrc)
2283                 rc = cqr->intrc;
2284         else
2285                 rc = -EIO;
2286         return rc;
2287 }
2288
2289 /*
2290  * Cancels a request that was started with dasd_sleep_on_req.
2291  * This is useful to timeout requests. The request will be
2292  * terminated if it is currently in i/o.
2293  * Returns 1 if the request has been terminated.
2294  *         0 if there was no need to terminate the request (not started yet)
2295  *         negative error code if termination failed
2296  * Cancellation of a request is an asynchronous operation! The calling
2297  * function has to wait until the request is properly returned via callback.
2298  */
2299 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2300 {
2301         struct dasd_device *device = cqr->startdev;
2302         unsigned long flags;
2303         int rc;
2304
2305         rc = 0;
2306         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2307         switch (cqr->status) {
2308         case DASD_CQR_QUEUED:
2309                 /* request was not started - just set to cleared */
2310                 cqr->status = DASD_CQR_CLEARED;
2311                 break;
2312         case DASD_CQR_IN_IO:
2313                 /* request in IO - terminate IO and release again */
2314                 rc = device->discipline->term_IO(cqr);
2315                 if (rc) {
2316                         dev_err(&device->cdev->dev,
2317                                 "Cancelling request %p failed with rc=%d\n",
2318                                 cqr, rc);
2319                 } else {
2320                         cqr->stopclk = get_clock();
2321                 }
2322                 break;
2323         default: /* already finished or clear pending - do nothing */
2324                 break;
2325         }
2326         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2327         dasd_schedule_device_bh(device);
2328         return rc;
2329 }
2330
2331
2332 /*
2333  * SECTION: Operations of the dasd_block layer.
2334  */
2335
2336 /*
2337  * Timeout function for dasd_block. This is used when the block layer
2338  * is waiting for something that may not come reliably, (e.g. a state
2339  * change interrupt)
2340  */
2341 static void dasd_block_timeout(unsigned long ptr)
2342 {
2343         unsigned long flags;
2344         struct dasd_block *block;
2345
2346         block = (struct dasd_block *) ptr;
2347         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2348         /* re-activate request queue */
2349         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2350         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2351         dasd_schedule_block_bh(block);
2352 }
2353
2354 /*
2355  * Setup timeout for a dasd_block in jiffies.
2356  */
2357 void dasd_block_set_timer(struct dasd_block *block, int expires)
2358 {
2359         if (expires == 0)
2360                 del_timer(&block->timer);
2361         else
2362                 mod_timer(&block->timer, jiffies + expires);
2363 }
2364
2365 /*
2366  * Clear timeout for a dasd_block.
2367  */
2368 void dasd_block_clear_timer(struct dasd_block *block)
2369 {
2370         del_timer(&block->timer);
2371 }
2372
2373 /*
2374  * Process finished error recovery ccw.
2375  */
2376 static void __dasd_process_erp(struct dasd_device *device,
2377                                struct dasd_ccw_req *cqr)
2378 {
2379         dasd_erp_fn_t erp_fn;
2380
2381         if (cqr->status == DASD_CQR_DONE)
2382                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2383         else
2384                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2385         erp_fn = device->discipline->erp_postaction(cqr);
2386         erp_fn(cqr);
2387 }
2388
2389 /*
2390  * Fetch requests from the block device queue.
2391  */
2392 static void __dasd_process_request_queue(struct dasd_block *block)
2393 {
2394         struct request_queue *queue;
2395         struct request *req;
2396         struct dasd_ccw_req *cqr;
2397         struct dasd_device *basedev;
2398         unsigned long flags;
2399         queue = block->request_queue;
2400         basedev = block->base;
2401         /* No queue ? Then there is nothing to do. */
2402         if (queue == NULL)
2403                 return;
2404
2405         /*
2406          * We requeue request from the block device queue to the ccw
2407          * queue only in two states. In state DASD_STATE_READY the
2408          * partition detection is done and we need to requeue requests
2409          * for that. State DASD_STATE_ONLINE is normal block device
2410          * operation.
2411          */
2412         if (basedev->state < DASD_STATE_READY) {
2413                 while ((req = blk_fetch_request(block->request_queue)))
2414                         __blk_end_request_all(req, -EIO);
2415                 return;
2416         }
2417         /* Now we try to fetch requests from the request queue */
2418         while ((req = blk_peek_request(queue))) {
2419                 if (basedev->features & DASD_FEATURE_READONLY &&
2420                     rq_data_dir(req) == WRITE) {
2421                         DBF_DEV_EVENT(DBF_ERR, basedev,
2422                                       "Rejecting write request %p",
2423                                       req);
2424                         blk_start_request(req);
2425                         __blk_end_request_all(req, -EIO);
2426                         continue;
2427                 }
2428                 cqr = basedev->discipline->build_cp(basedev, block, req);
2429                 if (IS_ERR(cqr)) {
2430                         if (PTR_ERR(cqr) == -EBUSY)
2431                                 break;  /* normal end condition */
2432                         if (PTR_ERR(cqr) == -ENOMEM)
2433                                 break;  /* terminate request queue loop */
2434                         if (PTR_ERR(cqr) == -EAGAIN) {
2435                                 /*
2436                                  * The current request cannot be build right
2437                                  * now, we have to try later. If this request
2438                                  * is the head-of-queue we stop the device
2439                                  * for 1/2 second.
2440                                  */
2441                                 if (!list_empty(&block->ccw_queue))
2442                                         break;
2443                                 spin_lock_irqsave(
2444                                         get_ccwdev_lock(basedev->cdev), flags);
2445                                 dasd_device_set_stop_bits(basedev,
2446                                                           DASD_STOPPED_PENDING);
2447                                 spin_unlock_irqrestore(
2448                                         get_ccwdev_lock(basedev->cdev), flags);
2449                                 dasd_block_set_timer(block, HZ/2);
2450                                 break;
2451                         }
2452                         DBF_DEV_EVENT(DBF_ERR, basedev,
2453                                       "CCW creation failed (rc=%ld) "
2454                                       "on request %p",
2455                                       PTR_ERR(cqr), req);
2456                         blk_start_request(req);
2457                         __blk_end_request_all(req, -EIO);
2458                         continue;
2459                 }
2460                 /*
2461                  *  Note: callback is set to dasd_return_cqr_cb in
2462                  * __dasd_block_start_head to cover erp requests as well
2463                  */
2464                 cqr->callback_data = (void *) req;
2465                 cqr->status = DASD_CQR_FILLED;
2466                 blk_start_request(req);
2467                 list_add_tail(&cqr->blocklist, &block->ccw_queue);
2468                 dasd_profile_start(block, cqr, req);
2469         }
2470 }
2471
2472 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2473 {
2474         struct request *req;
2475         int status;
2476         int error = 0;
2477
2478         req = (struct request *) cqr->callback_data;
2479         dasd_profile_end(cqr->block, cqr, req);
2480         status = cqr->block->base->discipline->free_cp(cqr, req);
2481         if (status <= 0)
2482                 error = status ? status : -EIO;
2483         __blk_end_request_all(req, error);
2484 }
2485
2486 /*
2487  * Process ccw request queue.
2488  */
2489 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2490                                            struct list_head *final_queue)
2491 {
2492         struct list_head *l, *n;
2493         struct dasd_ccw_req *cqr;
2494         dasd_erp_fn_t erp_fn;
2495         unsigned long flags;
2496         struct dasd_device *base = block->base;
2497
2498 restart:
2499         /* Process request with final status. */
2500         list_for_each_safe(l, n, &block->ccw_queue) {
2501                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2502                 if (cqr->status != DASD_CQR_DONE &&
2503                     cqr->status != DASD_CQR_FAILED &&
2504                     cqr->status != DASD_CQR_NEED_ERP &&
2505                     cqr->status != DASD_CQR_TERMINATED)
2506                         continue;
2507
2508                 if (cqr->status == DASD_CQR_TERMINATED) {
2509                         base->discipline->handle_terminated_request(cqr);
2510                         goto restart;
2511                 }
2512
2513                 /*  Process requests that may be recovered */
2514                 if (cqr->status == DASD_CQR_NEED_ERP) {
2515                         erp_fn = base->discipline->erp_action(cqr);
2516                         if (IS_ERR(erp_fn(cqr)))
2517                                 continue;
2518                         goto restart;
2519                 }
2520
2521                 /* log sense for fatal error */
2522                 if (cqr->status == DASD_CQR_FAILED) {
2523                         dasd_log_sense(cqr, &cqr->irb);
2524                 }
2525
2526                 /* First of all call extended error reporting. */
2527                 if (dasd_eer_enabled(base) &&
2528                     cqr->status == DASD_CQR_FAILED) {
2529                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2530
2531                         /* restart request  */
2532                         cqr->status = DASD_CQR_FILLED;
2533                         cqr->retries = 255;
2534                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2535                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2536                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2537                                                flags);
2538                         goto restart;
2539                 }
2540
2541                 /* Process finished ERP request. */
2542                 if (cqr->refers) {
2543                         __dasd_process_erp(base, cqr);
2544                         goto restart;
2545                 }
2546
2547                 /* Rechain finished requests to final queue */
2548                 cqr->endclk = get_clock();
2549                 list_move_tail(&cqr->blocklist, final_queue);
2550         }
2551 }
2552
2553 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2554 {
2555         dasd_schedule_block_bh(cqr->block);
2556 }
2557
2558 static void __dasd_block_start_head(struct dasd_block *block)
2559 {
2560         struct dasd_ccw_req *cqr;
2561
2562         if (list_empty(&block->ccw_queue))
2563                 return;
2564         /* We allways begin with the first requests on the queue, as some
2565          * of previously started requests have to be enqueued on a
2566          * dasd_device again for error recovery.
2567          */
2568         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2569                 if (cqr->status != DASD_CQR_FILLED)
2570                         continue;
2571                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2572                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2573                         cqr->status = DASD_CQR_FAILED;
2574                         cqr->intrc = -EPERM;
2575                         dasd_schedule_block_bh(block);
2576                         continue;
2577                 }
2578                 /* Non-temporary stop condition will trigger fail fast */
2579                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2580                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2581                     (!dasd_eer_enabled(block->base))) {
2582                         cqr->status = DASD_CQR_FAILED;
2583                         dasd_schedule_block_bh(block);
2584                         continue;
2585                 }
2586                 /* Don't try to start requests if device is stopped */
2587                 if (block->base->stopped)
2588                         return;
2589
2590                 /* just a fail safe check, should not happen */
2591                 if (!cqr->startdev)
2592                         cqr->startdev = block->base;
2593
2594                 /* make sure that the requests we submit find their way back */
2595                 cqr->callback = dasd_return_cqr_cb;
2596
2597                 dasd_add_request_tail(cqr);
2598         }
2599 }
2600
2601 /*
2602  * Central dasd_block layer routine. Takes requests from the generic
2603  * block layer request queue, creates ccw requests, enqueues them on
2604  * a dasd_device and processes ccw requests that have been returned.
2605  */
2606 static void dasd_block_tasklet(struct dasd_block *block)
2607 {
2608         struct list_head final_queue;
2609         struct list_head *l, *n;
2610         struct dasd_ccw_req *cqr;
2611
2612         atomic_set(&block->tasklet_scheduled, 0);
2613         INIT_LIST_HEAD(&final_queue);
2614         spin_lock(&block->queue_lock);
2615         /* Finish off requests on ccw queue */
2616         __dasd_process_block_ccw_queue(block, &final_queue);
2617         spin_unlock(&block->queue_lock);
2618         /* Now call the callback function of requests with final status */
2619         spin_lock_irq(&block->request_queue_lock);
2620         list_for_each_safe(l, n, &final_queue) {
2621                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2622                 list_del_init(&cqr->blocklist);
2623                 __dasd_cleanup_cqr(cqr);
2624         }
2625         spin_lock(&block->queue_lock);
2626         /* Get new request from the block device request queue */
2627         __dasd_process_request_queue(block);
2628         /* Now check if the head of the ccw queue needs to be started. */
2629         __dasd_block_start_head(block);
2630         spin_unlock(&block->queue_lock);
2631         spin_unlock_irq(&block->request_queue_lock);
2632         dasd_put_device(block->base);
2633 }
2634
2635 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2636 {
2637         wake_up(&dasd_flush_wq);
2638 }
2639
2640 /*
2641  * Go through all request on the dasd_block request queue, cancel them
2642  * on the respective dasd_device, and return them to the generic
2643  * block layer.
2644  */
2645 static int dasd_flush_block_queue(struct dasd_block *block)
2646 {
2647         struct dasd_ccw_req *cqr, *n;
2648         int rc, i;
2649         struct list_head flush_queue;
2650
2651         INIT_LIST_HEAD(&flush_queue);
2652         spin_lock_bh(&block->queue_lock);
2653         rc = 0;
2654 restart:
2655         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2656                 /* if this request currently owned by a dasd_device cancel it */
2657                 if (cqr->status >= DASD_CQR_QUEUED)
2658                         rc = dasd_cancel_req(cqr);
2659                 if (rc < 0)
2660                         break;
2661                 /* Rechain request (including erp chain) so it won't be
2662                  * touched by the dasd_block_tasklet anymore.
2663                  * Replace the callback so we notice when the request
2664                  * is returned from the dasd_device layer.
2665                  */
2666                 cqr->callback = _dasd_wake_block_flush_cb;
2667                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2668                         list_move_tail(&cqr->blocklist, &flush_queue);
2669                 if (i > 1)
2670                         /* moved more than one request - need to restart */
2671                         goto restart;
2672         }
2673         spin_unlock_bh(&block->queue_lock);
2674         /* Now call the callback function of flushed requests */
2675 restart_cb:
2676         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2677                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2678                 /* Process finished ERP request. */
2679                 if (cqr->refers) {
2680                         spin_lock_bh(&block->queue_lock);
2681                         __dasd_process_erp(block->base, cqr);
2682                         spin_unlock_bh(&block->queue_lock);
2683                         /* restart list_for_xx loop since dasd_process_erp
2684                          * might remove multiple elements */
2685                         goto restart_cb;
2686                 }
2687                 /* call the callback function */
2688                 spin_lock_irq(&block->request_queue_lock);
2689                 cqr->endclk = get_clock();
2690                 list_del_init(&cqr->blocklist);
2691                 __dasd_cleanup_cqr(cqr);
2692                 spin_unlock_irq(&block->request_queue_lock);
2693         }
2694         return rc;
2695 }
2696
2697 /*
2698  * Schedules a call to dasd_tasklet over the device tasklet.
2699  */
2700 void dasd_schedule_block_bh(struct dasd_block *block)
2701 {
2702         /* Protect against rescheduling. */
2703         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2704                 return;
2705         /* life cycle of block is bound to it's base device */
2706         dasd_get_device(block->base);
2707         tasklet_hi_schedule(&block->tasklet);
2708 }
2709
2710
2711 /*
2712  * SECTION: external block device operations
2713  * (request queue handling, open, release, etc.)
2714  */
2715
2716 /*
2717  * Dasd request queue function. Called from ll_rw_blk.c
2718  */
2719 static void do_dasd_request(struct request_queue *queue)
2720 {
2721         struct dasd_block *block;
2722
2723         block = queue->queuedata;
2724         spin_lock(&block->queue_lock);
2725         /* Get new request from the block device request queue */
2726         __dasd_process_request_queue(block);
2727         /* Now check if the head of the ccw queue needs to be started. */
2728         __dasd_block_start_head(block);
2729         spin_unlock(&block->queue_lock);
2730 }
2731
2732 /*
2733  * Allocate and initialize request queue and default I/O scheduler.
2734  */
2735 static int dasd_alloc_queue(struct dasd_block *block)
2736 {
2737         int rc;
2738
2739         block->request_queue = blk_init_queue(do_dasd_request,
2740                                                &block->request_queue_lock);
2741         if (block->request_queue == NULL)
2742                 return -ENOMEM;
2743
2744         block->request_queue->queuedata = block;
2745
2746         elevator_exit(block->request_queue->elevator);
2747         block->request_queue->elevator = NULL;
2748         rc = elevator_init(block->request_queue, "deadline");
2749         if (rc) {
2750                 blk_cleanup_queue(block->request_queue);
2751                 return rc;
2752         }
2753         return 0;
2754 }
2755
2756 /*
2757  * Allocate and initialize request queue.
2758  */
2759 static void dasd_setup_queue(struct dasd_block *block)
2760 {
2761         int max;
2762
2763         if (block->base->features & DASD_FEATURE_USERAW) {
2764                 /*
2765                  * the max_blocks value for raw_track access is 256
2766                  * it is higher than the native ECKD value because we
2767                  * only need one ccw per track
2768                  * so the max_hw_sectors are
2769                  * 2048 x 512B = 1024kB = 16 tracks
2770                  */
2771                 max = 2048;
2772         } else {
2773                 max = block->base->discipline->max_blocks << block->s2b_shift;
2774         }
2775         blk_queue_logical_block_size(block->request_queue,
2776                                      block->bp_block);
2777         blk_queue_max_hw_sectors(block->request_queue, max);
2778         blk_queue_max_segments(block->request_queue, -1L);
2779         /* with page sized segments we can translate each segement into
2780          * one idaw/tidaw
2781          */
2782         blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
2783         blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
2784 }
2785
2786 /*
2787  * Deactivate and free request queue.
2788  */
2789 static void dasd_free_queue(struct dasd_block *block)
2790 {
2791         if (block->request_queue) {
2792                 blk_cleanup_queue(block->request_queue);
2793                 block->request_queue = NULL;
2794         }
2795 }
2796
2797 /*
2798  * Flush request on the request queue.
2799  */
2800 static void dasd_flush_request_queue(struct dasd_block *block)
2801 {
2802         struct request *req;
2803
2804         if (!block->request_queue)
2805                 return;
2806
2807         spin_lock_irq(&block->request_queue_lock);
2808         while ((req = blk_fetch_request(block->request_queue)))
2809                 __blk_end_request_all(req, -EIO);
2810         spin_unlock_irq(&block->request_queue_lock);
2811 }
2812
2813 static int dasd_open(struct block_device *bdev, fmode_t mode)
2814 {
2815         struct dasd_device *base;
2816         int rc;
2817
2818         base = dasd_device_from_gendisk(bdev->bd_disk);
2819         if (!base)
2820                 return -ENODEV;
2821
2822         atomic_inc(&base->block->open_count);
2823         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
2824                 rc = -ENODEV;
2825                 goto unlock;
2826         }
2827
2828         if (!try_module_get(base->discipline->owner)) {
2829                 rc = -EINVAL;
2830                 goto unlock;
2831         }
2832
2833         if (dasd_probeonly) {
2834                 dev_info(&base->cdev->dev,
2835                          "Accessing the DASD failed because it is in "
2836                          "probeonly mode\n");
2837                 rc = -EPERM;
2838                 goto out;
2839         }
2840
2841         if (base->state <= DASD_STATE_BASIC) {
2842                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
2843                               " Cannot open unrecognized device");
2844                 rc = -ENODEV;
2845                 goto out;
2846         }
2847
2848         if ((mode & FMODE_WRITE) &&
2849             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
2850              (base->features & DASD_FEATURE_READONLY))) {
2851                 rc = -EROFS;
2852                 goto out;
2853         }
2854
2855         dasd_put_device(base);
2856         return 0;
2857
2858 out:
2859         module_put(base->discipline->owner);
2860 unlock:
2861         atomic_dec(&base->block->open_count);
2862         dasd_put_device(base);
2863         return rc;
2864 }
2865
2866 static int dasd_release(struct gendisk *disk, fmode_t mode)
2867 {
2868         struct dasd_device *base;
2869
2870         base = dasd_device_from_gendisk(disk);
2871         if (!base)
2872                 return -ENODEV;
2873
2874         atomic_dec(&base->block->open_count);
2875         module_put(base->discipline->owner);
2876         dasd_put_device(base);
2877         return 0;
2878 }
2879
2880 /*
2881  * Return disk geometry.
2882  */
2883 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2884 {
2885         struct dasd_device *base;
2886
2887         base = dasd_device_from_gendisk(bdev->bd_disk);
2888         if (!base)
2889                 return -ENODEV;
2890
2891         if (!base->discipline ||
2892             !base->discipline->fill_geometry) {
2893                 dasd_put_device(base);
2894                 return -EINVAL;
2895         }
2896         base->discipline->fill_geometry(base->block, geo);
2897         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
2898         dasd_put_device(base);
2899         return 0;
2900 }
2901
2902 const struct block_device_operations
2903 dasd_device_operations = {
2904         .owner          = THIS_MODULE,
2905         .open           = dasd_open,
2906         .release        = dasd_release,
2907         .ioctl          = dasd_ioctl,
2908         .compat_ioctl   = dasd_ioctl,
2909         .getgeo         = dasd_getgeo,
2910 };
2911
2912 /*******************************************************************************
2913  * end of block device operations
2914  */
2915
2916 static void
2917 dasd_exit(void)
2918 {
2919 #ifdef CONFIG_PROC_FS
2920         dasd_proc_exit();
2921 #endif
2922         dasd_eer_exit();
2923         if (dasd_page_cache != NULL) {
2924                 kmem_cache_destroy(dasd_page_cache);
2925                 dasd_page_cache = NULL;
2926         }
2927         dasd_gendisk_exit();
2928         dasd_devmap_exit();
2929         if (dasd_debug_area != NULL) {
2930                 debug_unregister(dasd_debug_area);
2931                 dasd_debug_area = NULL;
2932         }
2933         dasd_statistics_removeroot();
2934 }
2935
2936 /*
2937  * SECTION: common functions for ccw_driver use
2938  */
2939
2940 /*
2941  * Is the device read-only?
2942  * Note that this function does not report the setting of the
2943  * readonly device attribute, but how it is configured in z/VM.
2944  */
2945 int dasd_device_is_ro(struct dasd_device *device)
2946 {
2947         struct ccw_dev_id dev_id;
2948         struct diag210 diag_data;
2949         int rc;
2950
2951         if (!MACHINE_IS_VM)
2952                 return 0;
2953         ccw_device_get_id(device->cdev, &dev_id);
2954         memset(&diag_data, 0, sizeof(diag_data));
2955         diag_data.vrdcdvno = dev_id.devno;
2956         diag_data.vrdclen = sizeof(diag_data);
2957         rc = diag210(&diag_data);
2958         if (rc == 0 || rc == 2) {
2959                 return diag_data.vrdcvfla & 0x80;
2960         } else {
2961                 DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
2962                           dev_id.devno, rc);
2963                 return 0;
2964         }
2965 }
2966 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
2967
2968 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
2969 {
2970         struct ccw_device *cdev = data;
2971         int ret;
2972
2973         ret = ccw_device_set_online(cdev);
2974         if (ret)
2975                 pr_warning("%s: Setting the DASD online failed with rc=%d\n",
2976                            dev_name(&cdev->dev), ret);
2977 }
2978
2979 /*
2980  * Initial attempt at a probe function. this can be simplified once
2981  * the other detection code is gone.
2982  */
2983 int dasd_generic_probe(struct ccw_device *cdev,
2984                        struct dasd_discipline *discipline)
2985 {
2986         int ret;
2987
2988         ret = dasd_add_sysfs_files(cdev);
2989         if (ret) {
2990                 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
2991                                 "dasd_generic_probe: could not add "
2992                                 "sysfs entries");
2993                 return ret;
2994         }
2995         cdev->handler = &dasd_int_handler;
2996
2997         /*
2998          * Automatically online either all dasd devices (dasd_autodetect)
2999          * or all devices specified with dasd= parameters during
3000          * initial probe.
3001          */
3002         if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3003             (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3004                 async_schedule(dasd_generic_auto_online, cdev);
3005         return 0;
3006 }
3007
3008 /*
3009  * This will one day be called from a global not_oper handler.
3010  * It is also used by driver_unregister during module unload.
3011  */
3012 void dasd_generic_remove(struct ccw_device *cdev)
3013 {
3014         struct dasd_device *device;
3015         struct dasd_block *block;
3016
3017         cdev->handler = NULL;
3018
3019         dasd_remove_sysfs_files(cdev);
3020         device = dasd_device_from_cdev(cdev);
3021         if (IS_ERR(device))
3022                 return;
3023         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3024                 /* Already doing offline processing */
3025                 dasd_put_device(device);
3026                 return;
3027         }
3028         /*
3029          * This device is removed unconditionally. Set offline
3030          * flag to prevent dasd_open from opening it while it is
3031          * no quite down yet.
3032          */
3033         dasd_set_target_state(device, DASD_STATE_NEW);
3034         /* dasd_delete_device destroys the device reference. */
3035         block = device->block;
3036         dasd_delete_device(device);
3037         /*
3038          * life cycle of block is bound to device, so delete it after
3039          * device was safely removed
3040          */
3041         if (block)
3042                 dasd_free_block(block);
3043 }
3044
3045 /*
3046  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3047  * the device is detected for the first time and is supposed to be used
3048  * or the user has started activation through sysfs.
3049  */
3050 int dasd_generic_set_online(struct ccw_device *cdev,
3051                             struct dasd_discipline *base_discipline)
3052 {
3053         struct dasd_discipline *discipline;
3054         struct dasd_device *device;
3055         int rc;
3056
3057         /* first online clears initial online feature flag */
3058         dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3059         device = dasd_create_device(cdev);
3060         if (IS_ERR(device))
3061                 return PTR_ERR(device);
3062
3063         discipline = base_discipline;
3064         if (device->features & DASD_FEATURE_USEDIAG) {
3065                 if (!dasd_diag_discipline_pointer) {
3066                         pr_warning("%s Setting the DASD online failed because "
3067                                    "of missing DIAG discipline\n",
3068                                    dev_name(&cdev->dev));
3069                         dasd_delete_device(device);
3070                         return -ENODEV;
3071                 }
3072                 discipline = dasd_diag_discipline_pointer;
3073         }
3074         if (!try_module_get(base_discipline->owner)) {
3075                 dasd_delete_device(device);
3076                 return -EINVAL;
3077         }
3078         if (!try_module_get(discipline->owner)) {
3079                 module_put(base_discipline->owner);
3080                 dasd_delete_device(device);
3081                 return -EINVAL;
3082         }
3083         device->base_discipline = base_discipline;
3084         device->discipline = discipline;
3085
3086         /* check_device will allocate block device if necessary */
3087         rc = discipline->check_device(device);
3088         if (rc) {
3089                 pr_warning("%s Setting the DASD online with discipline %s "
3090                            "failed with rc=%i\n",
3091                            dev_name(&cdev->dev), discipline->name, rc);
3092                 module_put(discipline->owner);
3093                 module_put(base_discipline->owner);
3094                 dasd_delete_device(device);
3095                 return rc;
3096         }
3097
3098         dasd_set_target_state(device, DASD_STATE_ONLINE);
3099         if (device->state <= DASD_STATE_KNOWN) {
3100                 pr_warning("%s Setting the DASD online failed because of a "
3101                            "missing discipline\n", dev_name(&cdev->dev));
3102                 rc = -ENODEV;
3103                 dasd_set_target_state(device, DASD_STATE_NEW);
3104                 if (device->block)
3105                         dasd_free_block(device->block);
3106                 dasd_delete_device(device);
3107         } else
3108                 pr_debug("dasd_generic device %s found\n",
3109                                 dev_name(&cdev->dev));
3110
3111         wait_event(dasd_init_waitq, _wait_for_device(device));
3112
3113         dasd_put_device(device);
3114         return rc;
3115 }
3116
3117 int dasd_generic_set_offline(struct ccw_device *cdev)
3118 {
3119         struct dasd_device *device;
3120         struct dasd_block *block;
3121         int max_count, open_count;
3122
3123         device = dasd_device_from_cdev(cdev);
3124         if (IS_ERR(device))
3125                 return PTR_ERR(device);
3126         if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3127                 /* Already doing offline processing */
3128                 dasd_put_device(device);
3129                 return 0;
3130         }
3131         /*
3132          * We must make sure that this device is currently not in use.
3133          * The open_count is increased for every opener, that includes
3134          * the blkdev_get in dasd_scan_partitions. We are only interested
3135          * in the other openers.
3136          */
3137         if (device->block) {
3138                 max_count = device->block->bdev ? 0 : -1;
3139                 open_count = atomic_read(&device->block->open_count);
3140                 if (open_count > max_count) {
3141                         if (open_count > 0)
3142                                 pr_warning("%s: The DASD cannot be set offline "
3143                                            "with open count %i\n",
3144                                            dev_name(&cdev->dev), open_count);
3145                         else
3146                                 pr_warning("%s: The DASD cannot be set offline "
3147                                            "while it is in use\n",
3148                                            dev_name(&cdev->dev));
3149                         clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3150                         dasd_put_device(device);
3151                         return -EBUSY;
3152                 }
3153         }
3154         dasd_set_target_state(device, DASD_STATE_NEW);
3155         /* dasd_delete_device destroys the device reference. */
3156         block = device->block;
3157         dasd_delete_device(device);
3158         /*
3159          * life cycle of block is bound to device, so delete it after
3160          * device was safely removed
3161          */
3162         if (block)
3163                 dasd_free_block(block);
3164         return 0;
3165 }
3166
3167 int dasd_generic_last_path_gone(struct dasd_device *device)
3168 {
3169         struct dasd_ccw_req *cqr;
3170
3171         dev_warn(&device->cdev->dev, "No operational channel path is left "
3172                  "for the device\n");
3173         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3174         /* First of all call extended error reporting. */
3175         dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3176
3177         if (device->state < DASD_STATE_BASIC)
3178                 return 0;
3179         /* Device is active. We want to keep it. */
3180         list_for_each_entry(cqr, &device->ccw_queue, devlist)
3181                 if ((cqr->status == DASD_CQR_IN_IO) ||
3182                     (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3183                         cqr->status = DASD_CQR_QUEUED;
3184                         cqr->retries++;
3185                 }
3186         dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3187         dasd_device_clear_timer(device);
3188         dasd_schedule_device_bh(device);
3189         return 1;
3190 }
3191 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3192
3193 int dasd_generic_path_operational(struct dasd_device *device)
3194 {
3195         dev_info(&device->cdev->dev, "A channel path to the device has become "
3196                  "operational\n");
3197         DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3198         dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3199         if (device->stopped & DASD_UNRESUMED_PM) {
3200                 dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3201                 dasd_restore_device(device);
3202                 return 1;
3203         }
3204         dasd_schedule_device_bh(device);
3205         if (device->block)
3206                 dasd_schedule_block_bh(device->block);
3207         return 1;
3208 }
3209 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3210
3211 int dasd_generic_notify(struct ccw_device *cdev, int event)
3212 {
3213         struct dasd_device *device;
3214         int ret;
3215
3216         device = dasd_device_from_cdev_locked(cdev);
3217         if (IS_ERR(device))
3218                 return 0;
3219         ret = 0;
3220         switch (event) {
3221         case CIO_GONE:
3222         case CIO_BOXED:
3223         case CIO_NO_PATH:
3224                 device->path_data.opm = 0;
3225                 device->path_data.ppm = 0;
3226                 device->path_data.npm = 0;
3227                 ret = dasd_generic_last_path_gone(device);
3228                 break;
3229         case CIO_OPER:
3230                 ret = 1;
3231                 if (device->path_data.opm)
3232                         ret = dasd_generic_path_operational(device);
3233                 break;
3234         }
3235         dasd_put_device(device);
3236         return ret;
3237 }
3238
3239 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3240 {
3241         int chp;
3242         __u8 oldopm, eventlpm;
3243         struct dasd_device *device;
3244
3245         device = dasd_device_from_cdev_locked(cdev);
3246         if (IS_ERR(device))
3247                 return;
3248         for (chp = 0; chp < 8; chp++) {
3249                 eventlpm = 0x80 >> chp;
3250                 if (path_event[chp] & PE_PATH_GONE) {
3251                         oldopm = device->path_data.opm;
3252                         device->path_data.opm &= ~eventlpm;
3253                         device->path_data.ppm &= ~eventlpm;
3254                         device->path_data.npm &= ~eventlpm;
3255                         if (oldopm && !device->path_data.opm)
3256                                 dasd_generic_last_path_gone(device);
3257                 }
3258                 if (path_event[chp] & PE_PATH_AVAILABLE) {
3259                         device->path_data.opm &= ~eventlpm;
3260                         device->path_data.ppm &= ~eventlpm;
3261                         device->path_data.npm &= ~eventlpm;
3262                         device->path_data.tbvpm |= eventlpm;
3263                         dasd_schedule_device_bh(device);
3264                 }
3265         }
3266         dasd_put_device(device);
3267 }
3268 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3269
3270 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3271 {
3272         if (!device->path_data.opm && lpm) {
3273                 device->path_data.opm = lpm;
3274                 dasd_generic_path_operational(device);
3275         } else
3276                 device->path_data.opm |= lpm;
3277         return 0;
3278 }
3279 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3280
3281
3282 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3283 {
3284         struct dasd_ccw_req *cqr, *n;
3285         int rc;
3286         struct list_head freeze_queue;
3287         struct dasd_device *device = dasd_device_from_cdev(cdev);
3288
3289         if (IS_ERR(device))
3290                 return PTR_ERR(device);
3291
3292         /* mark device as suspended */
3293         set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3294
3295         if (device->discipline->freeze)
3296                 rc = device->discipline->freeze(device);
3297
3298         /* disallow new I/O  */
3299         dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3300         /* clear active requests */
3301         INIT_LIST_HEAD(&freeze_queue);
3302         spin_lock_irq(get_ccwdev_lock(cdev));
3303         rc = 0;
3304         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3305                 /* Check status and move request to flush_queue */
3306                 if (cqr->status == DASD_CQR_IN_IO) {
3307                         rc = device->discipline->term_IO(cqr);
3308                         if (rc) {
3309                                 /* unable to terminate requeust */
3310                                 dev_err(&device->cdev->dev,
3311                                         "Unable to terminate request %p "
3312                                         "on suspend\n", cqr);
3313                                 spin_unlock_irq(get_ccwdev_lock(cdev));
3314                                 dasd_put_device(device);
3315                                 return rc;
3316                         }
3317                 }
3318                 list_move_tail(&cqr->devlist, &freeze_queue);
3319         }
3320
3321         spin_unlock_irq(get_ccwdev_lock(cdev));
3322
3323         list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
3324                 wait_event(dasd_flush_wq,
3325                            (cqr->status != DASD_CQR_CLEAR_PENDING));
3326                 if (cqr->status == DASD_CQR_CLEARED)
3327                         cqr->status = DASD_CQR_QUEUED;
3328         }
3329         /* move freeze_queue to start of the ccw_queue */
3330         spin_lock_irq(get_ccwdev_lock(cdev));
3331         list_splice_tail(&freeze_queue, &device->ccw_queue);
3332         spin_unlock_irq(get_ccwdev_lock(cdev));
3333
3334         dasd_put_device(device);
3335         return rc;
3336 }
3337 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
3338
3339 int dasd_generic_restore_device(struct ccw_device *cdev)
3340 {
3341         struct dasd_device *device = dasd_device_from_cdev(cdev);
3342         int rc = 0;
3343
3344         if (IS_ERR(device))
3345                 return PTR_ERR(device);
3346
3347         /* allow new IO again */
3348         dasd_device_remove_stop_bits(device,
3349                                      (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3350
3351         dasd_schedule_device_bh(device);
3352
3353         /*
3354          * call discipline restore function
3355          * if device is stopped do nothing e.g. for disconnected devices
3356          */
3357         if (device->discipline->restore && !(device->stopped))
3358                 rc = device->discipline->restore(device);
3359         if (rc || device->stopped)
3360                 /*
3361                  * if the resume failed for the DASD we put it in
3362                  * an UNRESUMED stop state
3363                  */
3364                 device->stopped |= DASD_UNRESUMED_PM;
3365
3366         if (device->block)
3367                 dasd_schedule_block_bh(device->block);
3368
3369         clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3370         dasd_put_device(device);
3371         return 0;
3372 }
3373 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
3374
3375 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3376                                                    void *rdc_buffer,
3377                                                    int rdc_buffer_size,
3378                                                    int magic)
3379 {
3380         struct dasd_ccw_req *cqr;
3381         struct ccw1 *ccw;
3382         unsigned long *idaw;
3383
3384         cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
3385
3386         if (IS_ERR(cqr)) {
3387                 /* internal error 13 - Allocating the RDC request failed*/
3388                 dev_err(&device->cdev->dev,
3389                          "An error occurred in the DASD device driver, "
3390                          "reason=%s\n", "13");
3391                 return cqr;
3392         }
3393
3394         ccw = cqr->cpaddr;
3395         ccw->cmd_code = CCW_CMD_RDC;
3396         if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
3397                 idaw = (unsigned long *) (cqr->data);
3398                 ccw->cda = (__u32)(addr_t) idaw;
3399                 ccw->flags = CCW_FLAG_IDA;
3400                 idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
3401         } else {
3402                 ccw->cda = (__u32)(addr_t) rdc_buffer;
3403                 ccw->flags = 0;
3404         }
3405
3406         ccw->count = rdc_buffer_size;
3407         cqr->startdev = device;
3408         cqr->memdev = device;
3409         cqr->expires = 10*HZ;
3410         cqr->retries = 256;
3411         cqr->buildclk = get_clock();
3412         cqr->status = DASD_CQR_FILLED;
3413         return cqr;
3414 }
3415
3416
3417 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3418                                 void *rdc_buffer, int rdc_buffer_size)
3419 {
3420         int ret;
3421         struct dasd_ccw_req *cqr;
3422
3423         cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3424                                      magic);
3425         if (IS_ERR(cqr))
3426                 return PTR_ERR(cqr);
3427
3428         ret = dasd_sleep_on(cqr);
3429         dasd_sfree_request(cqr, cqr->memdev);
3430         return ret;
3431 }
3432 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3433
3434 /*
3435  *   In command mode and transport mode we need to look for sense
3436  *   data in different places. The sense data itself is allways
3437  *   an array of 32 bytes, so we can unify the sense data access
3438  *   for both modes.
3439  */
3440 char *dasd_get_sense(struct irb *irb)
3441 {
3442         struct tsb *tsb = NULL;
3443         char *sense = NULL;
3444
3445         if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
3446                 if (irb->scsw.tm.tcw)
3447                         tsb = tcw_get_tsb((struct tcw *)(unsigned long)
3448                                           irb->scsw.tm.tcw);
3449                 if (tsb && tsb->length == 64 && tsb->flags)
3450                         switch (tsb->flags & 0x07) {
3451                         case 1: /* tsa_iostat */
3452                                 sense = tsb->tsa.iostat.sense;
3453                                 break;
3454                         case 2: /* tsa_ddpc */
3455                                 sense = tsb->tsa.ddpc.sense;
3456                                 break;
3457                         default:
3458                                 /* currently we don't use interrogate data */
3459                                 break;
3460                         }
3461         } else if (irb->esw.esw0.erw.cons) {
3462                 sense = irb->ecw;
3463         }
3464         return sense;
3465 }
3466 EXPORT_SYMBOL_GPL(dasd_get_sense);
3467
3468 static int __init dasd_init(void)
3469 {
3470         int rc;
3471
3472         init_waitqueue_head(&dasd_init_waitq);
3473         init_waitqueue_head(&dasd_flush_wq);
3474         init_waitqueue_head(&generic_waitq);
3475
3476         /* register 'common' DASD debug area, used for all DBF_XXX calls */
3477         dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
3478         if (dasd_debug_area == NULL) {
3479                 rc = -ENOMEM;
3480                 goto failed;
3481         }
3482         debug_register_view(dasd_debug_area, &debug_sprintf_view);
3483         debug_set_level(dasd_debug_area, DBF_WARNING);
3484
3485         DBF_EVENT(DBF_EMERG, "%s", "debug area created");
3486
3487         dasd_diag_discipline_pointer = NULL;
3488
3489         dasd_statistics_createroot();
3490
3491         rc = dasd_devmap_init();
3492         if (rc)
3493                 goto failed;
3494         rc = dasd_gendisk_init();
3495         if (rc)
3496                 goto failed;
3497         rc = dasd_parse();
3498         if (rc)
3499                 goto failed;
3500         rc = dasd_eer_init();
3501         if (rc)
3502                 goto failed;
3503 #ifdef CONFIG_PROC_FS
3504         rc = dasd_proc_init();
3505         if (rc)
3506                 goto failed;
3507 #endif
3508
3509         return 0;
3510 failed:
3511         pr_info("The DASD device driver could not be initialized\n");
3512         dasd_exit();
3513         return rc;
3514 }
3515
3516 module_init(dasd_init);
3517 module_exit(dasd_exit);
3518
3519 EXPORT_SYMBOL(dasd_debug_area);
3520 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
3521
3522 EXPORT_SYMBOL(dasd_add_request_head);
3523 EXPORT_SYMBOL(dasd_add_request_tail);
3524 EXPORT_SYMBOL(dasd_cancel_req);
3525 EXPORT_SYMBOL(dasd_device_clear_timer);
3526 EXPORT_SYMBOL(dasd_block_clear_timer);
3527 EXPORT_SYMBOL(dasd_enable_device);
3528 EXPORT_SYMBOL(dasd_int_handler);
3529 EXPORT_SYMBOL(dasd_kfree_request);
3530 EXPORT_SYMBOL(dasd_kick_device);
3531 EXPORT_SYMBOL(dasd_kmalloc_request);
3532 EXPORT_SYMBOL(dasd_schedule_device_bh);
3533 EXPORT_SYMBOL(dasd_schedule_block_bh);
3534 EXPORT_SYMBOL(dasd_set_target_state);
3535 EXPORT_SYMBOL(dasd_device_set_timer);
3536 EXPORT_SYMBOL(dasd_block_set_timer);
3537 EXPORT_SYMBOL(dasd_sfree_request);
3538 EXPORT_SYMBOL(dasd_sleep_on);
3539 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
3540 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
3541 EXPORT_SYMBOL(dasd_smalloc_request);
3542 EXPORT_SYMBOL(dasd_start_IO);
3543 EXPORT_SYMBOL(dasd_term_IO);
3544
3545 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3546 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3547 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3548 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3549 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3550 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
3551 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
3552 EXPORT_SYMBOL_GPL(dasd_alloc_block);
3553 EXPORT_SYMBOL_GPL(dasd_free_block);