Pileus Git - ~andy/linux/blob - drivers/s390/char/tape_core.c

   1 /*
   2  *  drivers/s390/char/tape_core.c
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright IBM Corp. 2001, 2009
   7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Michael Holzheu <holzheu@de.ibm.com>
   9  *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
  10  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
  11  *               Stefan Bader <shbader@de.ibm.com>
  12  */
  13
  14 #define KMSG_COMPONENT "tape"
  15 #include <linux/module.h>
  16 #include <linux/init.h>      // for kernel parameters
  17 #include <linux/kmod.h>      // for requesting modules
  18 #include <linux/spinlock.h>  // for locks
  19 #include <linux/vmalloc.h>
  20 #include <linux/list.h>
  21
  22 #include <asm/types.h>       // for variable types
  23
  24 #define TAPE_DBF_AREA   tape_core_dbf
  25
  26 #include "tape.h"
  27 #include "tape_std.h"
  28
  29 #define LONG_BUSY_TIMEOUT 180 /* seconds */
  30
  31 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  32 static void tape_delayed_next_request(struct work_struct *);
  33 static void tape_long_busy_timeout(unsigned long data);
  34
  35 /*
  36  * One list to contain all tape devices of all disciplines, so
  37  * we can assign the devices to minor numbers of the same major
  38  * The list is protected by the rwlock
  39  */
  40 static LIST_HEAD(tape_device_list);
  41 static DEFINE_RWLOCK(tape_device_lock);
  42
  43 /*
  44  * Pointer to debug area.
  45  */
  46 debug_info_t *TAPE_DBF_AREA = NULL;
  47 EXPORT_SYMBOL(TAPE_DBF_AREA);
  48
  49 /*
  50  * Printable strings for tape enumerations.
  51  */
  52 const char *tape_state_verbose[TS_SIZE] =
  53 {
  54         [TS_UNUSED]   = "UNUSED",
  55         [TS_IN_USE]   = "IN_USE",
  56         [TS_BLKUSE]   = "BLKUSE",
  57         [TS_INIT]     = "INIT  ",
  58         [TS_NOT_OPER] = "NOT_OP"
  59 };
  60
  61 const char *tape_op_verbose[TO_SIZE] =
  62 {
  63         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  64         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  65         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  66         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  67         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  68         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  69         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  70         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  71         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  72         [TO_READ_ATTMSG] = "RAT",
  73         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  74         [TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
  75         [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
  76         [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
  77 };
  78
  79 static int devid_to_int(struct ccw_dev_id *dev_id)
  80 {
  81         return dev_id->devno + (dev_id->ssid << 16);
  82 }
  83
  84 /*
  85  * Some channel attached tape specific attributes.
  86  *
  87  * FIXME: In the future the first_minor and blocksize attribute should be
  88  *        replaced by a link to the cdev tree.
  89  */
  90 static ssize_t
  91 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
  92 {
  93         struct tape_device *tdev;
  94
  95         tdev = dev_get_drvdata(dev);
  96         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
  97 }
  98
  99 static
 100 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 101
 102 static ssize_t
 103 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 104 {
 105         struct tape_device *tdev;
 106
 107         tdev = dev_get_drvdata(dev);
 108         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 109 }
 110
 111 static
 112 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 113
 114 static ssize_t
 115 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 116 {
 117         struct tape_device *tdev;
 118
 119         tdev = dev_get_drvdata(dev);
 120         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 121                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 122 }
 123
 124 static
 125 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 126
 127 static ssize_t
 128 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 129 {
 130         struct tape_device *tdev;
 131         ssize_t rc;
 132
 133         tdev = dev_get_drvdata(dev);
 134         if (tdev->first_minor < 0)
 135                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 136
 137         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 138         if (list_empty(&tdev->req_queue))
 139                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 140         else {
 141                 struct tape_request *req;
 142
 143                 req = list_entry(tdev->req_queue.next, struct tape_request,
 144                         list);
 145                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 146         }
 147         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 148         return rc;
 149 }
 150
 151 static
 152 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 153
 154 static ssize_t
 155 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 156 {
 157         struct tape_device *tdev;
 158
 159         tdev = dev_get_drvdata(dev);
 160
 161         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 162 }
 163
 164 static
 165 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 166
 167 static struct attribute *tape_attrs[] = {
 168         &dev_attr_medium_state.attr,
 169         &dev_attr_first_minor.attr,
 170         &dev_attr_state.attr,
 171         &dev_attr_operation.attr,
 172         &dev_attr_blocksize.attr,
 173         NULL
 174 };
 175
 176 static struct attribute_group tape_attr_group = {
 177         .attrs = tape_attrs,
 178 };
 179
 180 /*
 181  * Tape state functions
 182  */
 183 void
 184 tape_state_set(struct tape_device *device, enum tape_state newstate)
 185 {
 186         const char *str;
 187
 188         if (device->tape_state == TS_NOT_OPER) {
 189                 DBF_EVENT(3, "ts_set err: not oper\n");
 190                 return;
 191         }
 192         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 193         DBF_EVENT(4, "old ts:\t\n");
 194         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 195                 str = tape_state_verbose[device->tape_state];
 196         else
 197                 str = "UNKNOWN TS";
 198         DBF_EVENT(4, "%s\n", str);
 199         DBF_EVENT(4, "new ts:\t\n");
 200         if (newstate < TS_SIZE && newstate >= 0)
 201                 str = tape_state_verbose[newstate];
 202         else
 203                 str = "UNKNOWN TS";
 204         DBF_EVENT(4, "%s\n", str);
 205         device->tape_state = newstate;
 206         wake_up(&device->state_change_wq);
 207 }
 208
 209 void
 210 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 211 {
 212         if (device->medium_state == newstate)
 213                 return;
 214         switch(newstate){
 215         case MS_UNLOADED:
 216                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 217                 if (device->medium_state == MS_LOADED)
 218                         pr_info("%s: The tape cartridge has been successfully "
 219                                 "unloaded\n", dev_name(&device->cdev->dev));
 220                 break;
 221         case MS_LOADED:
 222                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 223                 if (device->medium_state == MS_UNLOADED)
 224                         pr_info("%s: A tape cartridge has been mounted\n",
 225                                 dev_name(&device->cdev->dev));
 226                 break;
 227         default:
 228                 // print nothing
 229                 break;
 230         }
 231         device->medium_state = newstate;
 232         wake_up(&device->state_change_wq);
 233 }
 234
 235 /*
 236  * Stop running ccw. Has to be called with the device lock held.
 237  */
 238 static int
 239 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 240 {
 241         int retries;
 242         int rc;
 243
 244         /* Check if interrupt has already been processed */
 245         if (request->callback == NULL)
 246                 return 0;
 247
 248         rc = 0;
 249         for (retries = 0; retries < 5; retries++) {
 250                 rc = ccw_device_clear(device->cdev, (long) request);
 251
 252                 switch (rc) {
 253                         case 0:
 254                                 request->status = TAPE_REQUEST_DONE;
 255                                 return 0;
 256                         case -EBUSY:
 257                                 request->status = TAPE_REQUEST_CANCEL;
 258                                 schedule_delayed_work(&device->tape_dnr, 0);
 259                                 return 0;
 260                         case -ENODEV:
 261                                 DBF_EXCEPTION(2, "device gone, retry\n");
 262                                 break;
 263                         case -EIO:
 264                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 265                                 break;
 266                         default:
 267                                 BUG();
 268                 }
 269         }
 270
 271         return rc;
 272 }
 273
 274 /*
 275  * Add device into the sorted list, giving it the first
 276  * available minor number.
 277  */
 278 static int
 279 tape_assign_minor(struct tape_device *device)
 280 {
 281         struct tape_device *tmp;
 282         int minor;
 283
 284         minor = 0;
 285         write_lock(&tape_device_lock);
 286         list_for_each_entry(tmp, &tape_device_list, node) {
 287                 if (minor < tmp->first_minor)
 288                         break;
 289                 minor += TAPE_MINORS_PER_DEV;
 290         }
 291         if (minor >= 256) {
 292                 write_unlock(&tape_device_lock);
 293                 return -ENODEV;
 294         }
 295         device->first_minor = minor;
 296         list_add_tail(&device->node, &tmp->node);
 297         write_unlock(&tape_device_lock);
 298         return 0;
 299 }
 300
 301 /* remove device from the list */
 302 static void
 303 tape_remove_minor(struct tape_device *device)
 304 {
 305         write_lock(&tape_device_lock);
 306         list_del_init(&device->node);
 307         device->first_minor = -1;
 308         write_unlock(&tape_device_lock);
 309 }
 310
 311 /*
 312  * Set a device online.
 313  *
 314  * This function is called by the common I/O layer to move a device from the
 315  * detected but offline into the online state.
 316  * If we return an error (RC < 0) the device remains in the offline state. This
 317  * can happen if the device is assigned somewhere else, for example.
 318  */
 319 int
 320 tape_generic_online(struct tape_device *device,
 321                    struct tape_discipline *discipline)
 322 {
 323         int rc;
 324
 325         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 326
 327         if (device->tape_state != TS_INIT) {
 328                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 329                 return -EINVAL;
 330         }
 331
 332         init_timer(&device->lb_timeout);
 333         device->lb_timeout.function = tape_long_busy_timeout;
 334
 335         /* Let the discipline have a go at the device. */
 336         device->discipline = discipline;
 337         if (!try_module_get(discipline->owner)) {
 338                 return -EINVAL;
 339         }
 340
 341         rc = discipline->setup_device(device);
 342         if (rc)
 343                 goto out;
 344         rc = tape_assign_minor(device);
 345         if (rc)
 346                 goto out_discipline;
 347
 348         rc = tapechar_setup_device(device);
 349         if (rc)
 350                 goto out_minor;
 351         rc = tapeblock_setup_device(device);
 352         if (rc)
 353                 goto out_char;
 354
 355         tape_state_set(device, TS_UNUSED);
 356
 357         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 358
 359         return 0;
 360
 361 out_char:
 362         tapechar_cleanup_device(device);
 363 out_minor:
 364         tape_remove_minor(device);
 365 out_discipline:
 366         device->discipline->cleanup_device(device);
 367         device->discipline = NULL;
 368 out:
 369         module_put(discipline->owner);
 370         return rc;
 371 }
 372
 373 static void
 374 tape_cleanup_device(struct tape_device *device)
 375 {
 376         tapeblock_cleanup_device(device);
 377         tapechar_cleanup_device(device);
 378         device->discipline->cleanup_device(device);
 379         module_put(device->discipline->owner);
 380         tape_remove_minor(device);
 381         tape_med_state_set(device, MS_UNKNOWN);
 382 }
 383
 384 /*
 385  * Suspend device.
 386  *
 387  * Called by the common I/O layer if the drive should be suspended on user
 388  * request. We refuse to suspend if the device is loaded or in use for the
 389  * following reason:
 390  * While the Linux guest is suspended, it might be logged off which causes
 391  * devices to be detached. Tape devices are automatically rewound and unloaded
 392  * during DETACH processing (unless the tape device was attached with the
 393  * NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
 394  * resume the original state of the tape device, since we would need to
 395  * manually re-load the cartridge which was active at suspend time.
 396  */
 397 int tape_generic_pm_suspend(struct ccw_device *cdev)
 398 {
 399         struct tape_device *device;
 400
 401         device = dev_get_drvdata(&cdev->dev);
 402         if (!device) {
 403                 return -ENODEV;
 404         }
 405
 406         DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
 407                 device->cdev_id, device);
 408
 409         if (device->medium_state != MS_UNLOADED) {
 410                 pr_err("A cartridge is loaded in tape device %s, "
 411                        "refusing to suspend\n", dev_name(&cdev->dev));
 412                 return -EBUSY;
 413         }
 414
 415         spin_lock_irq(get_ccwdev_lock(device->cdev));
 416         switch (device->tape_state) {
 417                 case TS_INIT:
 418                 case TS_NOT_OPER:
 419                 case TS_UNUSED:
 420                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 421                         break;
 422                 default:
 423                         pr_err("Tape device %s is busy, refusing to "
 424                                "suspend\n", dev_name(&cdev->dev));
 425                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 426                         return -EBUSY;
 427         }
 428
 429         DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
 430         return 0;
 431 }
 432
 433 /*
 434  * Set device offline.
 435  *
 436  * Called by the common I/O layer if the drive should set offline on user
 437  * request. We may prevent this by returning an error.
 438  * Manual offline is only allowed while the drive is not in use.
 439  */
 440 int
 441 tape_generic_offline(struct ccw_device *cdev)
 442 {
 443         struct tape_device *device;
 444
 445         device = dev_get_drvdata(&cdev->dev);
 446         if (!device) {
 447                 return -ENODEV;
 448         }
 449
 450         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 451                 device->cdev_id, device);
 452
 453         spin_lock_irq(get_ccwdev_lock(device->cdev));
 454         switch (device->tape_state) {
 455                 case TS_INIT:
 456                 case TS_NOT_OPER:
 457                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 458                         break;
 459                 case TS_UNUSED:
 460                         tape_state_set(device, TS_INIT);
 461                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 462                         tape_cleanup_device(device);
 463                         break;
 464                 default:
 465                         DBF_EVENT(3, "(%08x): Set offline failed "
 466                                 "- drive in use.\n",
 467                                 device->cdev_id);
 468                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 469                         return -EBUSY;
 470         }
 471
 472         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 473         return 0;
 474 }
 475
 476 /*
 477  * Allocate memory for a new device structure.
 478  */
 479 static struct tape_device *
 480 tape_alloc_device(void)
 481 {
 482         struct tape_device *device;
 483
 484         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 485         if (device == NULL) {
 486                 DBF_EXCEPTION(2, "ti:no mem\n");
 487                 return ERR_PTR(-ENOMEM);
 488         }
 489         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 490         if (device->modeset_byte == NULL) {
 491                 DBF_EXCEPTION(2, "ti:no mem\n");
 492                 kfree(device);
 493                 return ERR_PTR(-ENOMEM);
 494         }
 495         mutex_init(&device->mutex);
 496         INIT_LIST_HEAD(&device->req_queue);
 497         INIT_LIST_HEAD(&device->node);
 498         init_waitqueue_head(&device->state_change_wq);
 499         init_waitqueue_head(&device->wait_queue);
 500         device->tape_state = TS_INIT;
 501         device->medium_state = MS_UNKNOWN;
 502         *device->modeset_byte = 0;
 503         device->first_minor = -1;
 504         atomic_set(&device->ref_count, 1);
 505         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 506
 507         return device;
 508 }
 509
 510 /*
 511  * Get a reference to an existing device structure. This will automatically
 512  * increment the reference count.
 513  */
 514 struct tape_device *
 515 tape_get_device(struct tape_device *device)
 516 {
 517         int count;
 518
 519         count = atomic_inc_return(&device->ref_count);
 520         DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
 521         return device;
 522 }
 523
 524 /*
 525  * Decrease the reference counter of a devices structure. If the
 526  * reference counter reaches zero free the device structure.
 527  * The function returns a NULL pointer to be used by the caller
 528  * for clearing reference pointers.
 529  */
 530 void
 531 tape_put_device(struct tape_device *device)
 532 {
 533         int count;
 534
 535         count = atomic_dec_return(&device->ref_count);
 536         DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
 537         BUG_ON(count < 0);
 538         if (count == 0) {
 539                 kfree(device->modeset_byte);
 540                 kfree(device);
 541         }
 542 }
 543
 544 /*
 545  * Find tape device by a device index.
 546  */
 547 struct tape_device *
 548 tape_find_device(int devindex)
 549 {
 550         struct tape_device *device, *tmp;
 551
 552         device = ERR_PTR(-ENODEV);
 553         read_lock(&tape_device_lock);
 554         list_for_each_entry(tmp, &tape_device_list, node) {
 555                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 556                         device = tape_get_device(tmp);
 557                         break;
 558                 }
 559         }
 560         read_unlock(&tape_device_lock);
 561         return device;
 562 }
 563
 564 /*
 565  * Driverfs tape probe function.
 566  */
 567 int
 568 tape_generic_probe(struct ccw_device *cdev)
 569 {
 570         struct tape_device *device;
 571         int ret;
 572         struct ccw_dev_id dev_id;
 573
 574         device = tape_alloc_device();
 575         if (IS_ERR(device))
 576                 return -ENODEV;
 577         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
 578                                      CCWDEV_DO_MULTIPATH);
 579         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 580         if (ret) {
 581                 tape_put_device(device);
 582                 return ret;
 583         }
 584         dev_set_drvdata(&cdev->dev, device);
 585         cdev->handler = __tape_do_irq;
 586         device->cdev = cdev;
 587         ccw_device_get_id(cdev, &dev_id);
 588         device->cdev_id = devid_to_int(&dev_id);
 589         return ret;
 590 }
 591
 592 static void
 593 __tape_discard_requests(struct tape_device *device)
 594 {
 595         struct tape_request *   request;
 596         struct list_head *      l, *n;
 597
 598         list_for_each_safe(l, n, &device->req_queue) {
 599                 request = list_entry(l, struct tape_request, list);
 600                 if (request->status == TAPE_REQUEST_IN_IO)
 601                         request->status = TAPE_REQUEST_DONE;
 602                 list_del(&request->list);
 603
 604                 /* Decrease ref_count for removed request. */
 605                 request->device = NULL;
 606                 tape_put_device(device);
 607                 request->rc = -EIO;
 608                 if (request->callback != NULL)
 609                         request->callback(request, request->callback_data);
 610         }
 611 }
 612
 613 /*
 614  * Driverfs tape remove function.
 615  *
 616  * This function is called whenever the common I/O layer detects the device
 617  * gone. This can happen at any time and we cannot refuse.
 618  */
 619 void
 620 tape_generic_remove(struct ccw_device *cdev)
 621 {
 622         struct tape_device *    device;
 623
 624         device = dev_get_drvdata(&cdev->dev);
 625         if (!device) {
 626                 return;
 627         }
 628         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 629
 630         spin_lock_irq(get_ccwdev_lock(device->cdev));
 631         switch (device->tape_state) {
 632                 case TS_INIT:
 633                         tape_state_set(device, TS_NOT_OPER);
 634                 case TS_NOT_OPER:
 635                         /*
 636                          * Nothing to do.
 637                          */
 638                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 639                         break;
 640                 case TS_UNUSED:
 641                         /*
 642                          * Need only to release the device.
 643                          */
 644                         tape_state_set(device, TS_NOT_OPER);
 645                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 646                         tape_cleanup_device(device);
 647                         break;
 648                 default:
 649                         /*
 650                          * There may be requests on the queue. We will not get
 651                          * an interrupt for a request that was running. So we
 652                          * just post them all as I/O errors.
 653                          */
 654                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 655                                 device->cdev_id);
 656                         pr_warning("%s: A tape unit was detached while in "
 657                                    "use\n", dev_name(&device->cdev->dev));
 658                         tape_state_set(device, TS_NOT_OPER);
 659                         __tape_discard_requests(device);
 660                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 661                         tape_cleanup_device(device);
 662         }
 663
 664         device = dev_get_drvdata(&cdev->dev);
 665         if (device) {
 666                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 667                 dev_set_drvdata(&cdev->dev, NULL);
 668                 tape_put_device(device);
 669         }
 670 }
 671
 672 /*
 673  * Allocate a new tape ccw request
 674  */
 675 struct tape_request *
 676 tape_alloc_request(int cplength, int datasize)
 677 {
 678         struct tape_request *request;
 679
 680         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 681
 682         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 683
 684         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 685         if (request == NULL) {
 686                 DBF_EXCEPTION(1, "cqra nomem\n");
 687                 return ERR_PTR(-ENOMEM);
 688         }
 689         /* allocate channel program */
 690         if (cplength > 0) {
 691                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 692                                           GFP_ATOMIC | GFP_DMA);
 693                 if (request->cpaddr == NULL) {
 694                         DBF_EXCEPTION(1, "cqra nomem\n");
 695                         kfree(request);
 696                         return ERR_PTR(-ENOMEM);
 697                 }
 698         }
 699         /* alloc small kernel buffer */
 700         if (datasize > 0) {
 701                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 702                 if (request->cpdata == NULL) {
 703                         DBF_EXCEPTION(1, "cqra nomem\n");
 704                         kfree(request->cpaddr);
 705                         kfree(request);
 706                         return ERR_PTR(-ENOMEM);
 707                 }
 708         }
 709         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 710                 request->cpdata);
 711
 712         return request;
 713 }
 714
 715 /*
 716  * Free tape ccw request
 717  */
 718 void
 719 tape_free_request (struct tape_request * request)
 720 {
 721         DBF_LH(6, "Free request %p\n", request);
 722
 723         if (request->device)
 724                 tape_put_device(request->device);
 725         kfree(request->cpdata);
 726         kfree(request->cpaddr);
 727         kfree(request);
 728 }
 729
 730 static int
 731 __tape_start_io(struct tape_device *device, struct tape_request *request)
 732 {
 733         int rc;
 734
 735 #ifdef CONFIG_S390_TAPE_BLOCK
 736         if (request->op == TO_BLOCK)
 737                 device->discipline->check_locate(device, request);
 738 #endif
 739         rc = ccw_device_start(
 740                 device->cdev,
 741                 request->cpaddr,
 742                 (unsigned long) request,
 743                 0x00,
 744                 request->options
 745         );
 746         if (rc == 0) {
 747                 request->status = TAPE_REQUEST_IN_IO;
 748         } else if (rc == -EBUSY) {
 749                 /* The common I/O subsystem is currently busy. Retry later. */
 750                 request->status = TAPE_REQUEST_QUEUED;
 751                 schedule_delayed_work(&device->tape_dnr, 0);
 752                 rc = 0;
 753         } else {
 754                 /* Start failed. Remove request and indicate failure. */
 755                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 756         }
 757         return rc;
 758 }
 759
 760 static void
 761 __tape_start_next_request(struct tape_device *device)
 762 {
 763         struct list_head *l, *n;
 764         struct tape_request *request;
 765         int rc;
 766
 767         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 768         /*
 769          * Try to start each request on request queue until one is
 770          * started successful.
 771          */
 772         list_for_each_safe(l, n, &device->req_queue) {
 773                 request = list_entry(l, struct tape_request, list);
 774
 775                 /*
 776                  * Avoid race condition if bottom-half was triggered more than
 777                  * once.
 778                  */
 779                 if (request->status == TAPE_REQUEST_IN_IO)
 780                         return;
 781                 /*
 782                  * Request has already been stopped. We have to wait until
 783                  * the request is removed from the queue in the interrupt
 784                  * handling.
 785                  */
 786                 if (request->status == TAPE_REQUEST_DONE)
 787                         return;
 788
 789                 /*
 790                  * We wanted to cancel the request but the common I/O layer
 791                  * was busy at that time. This can only happen if this
 792                  * function is called by delayed_next_request.
 793                  * Otherwise we start the next request on the queue.
 794                  */
 795                 if (request->status == TAPE_REQUEST_CANCEL) {
 796                         rc = __tape_cancel_io(device, request);
 797                 } else {
 798                         rc = __tape_start_io(device, request);
 799                 }
 800                 if (rc == 0)
 801                         return;
 802
 803                 /* Set ending status. */
 804                 request->rc = rc;
 805                 request->status = TAPE_REQUEST_DONE;
 806
 807                 /* Remove from request queue. */
 808                 list_del(&request->list);
 809
 810                 /* Do callback. */
 811                 if (request->callback != NULL)
 812                         request->callback(request, request->callback_data);
 813         }
 814 }
 815
 816 static void
 817 tape_delayed_next_request(struct work_struct *work)
 818 {
 819         struct tape_device *device =
 820                 container_of(work, struct tape_device, tape_dnr.work);
 821
 822         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 823         spin_lock_irq(get_ccwdev_lock(device->cdev));
 824         __tape_start_next_request(device);
 825         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 826 }
 827
 828 static void tape_long_busy_timeout(unsigned long data)
 829 {
 830         struct tape_request *request;
 831         struct tape_device *device;
 832
 833         device = (struct tape_device *) data;
 834         spin_lock_irq(get_ccwdev_lock(device->cdev));
 835         request = list_entry(device->req_queue.next, struct tape_request, list);
 836         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 837         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 838         __tape_start_next_request(device);
 839         device->lb_timeout.data = 0UL;
 840         tape_put_device(device);
 841         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 842 }
 843
 844 static void
 845 __tape_end_request(
 846         struct tape_device *    device,
 847         struct tape_request *   request,
 848         int                     rc)
 849 {
 850         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 851         if (request) {
 852                 request->rc = rc;
 853                 request->status = TAPE_REQUEST_DONE;
 854
 855                 /* Remove from request queue. */
 856                 list_del(&request->list);
 857
 858                 /* Do callback. */
 859                 if (request->callback != NULL)
 860                         request->callback(request, request->callback_data);
 861         }
 862
 863         /* Start next request. */
 864         if (!list_empty(&device->req_queue))
 865                 __tape_start_next_request(device);
 866 }
 867
 868 /*
 869  * Write sense data to dbf
 870  */
 871 void
 872 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 873                     struct irb *irb)
 874 {
 875         unsigned int *sptr;
 876         const char* op;
 877
 878         if (request != NULL)
 879                 op = tape_op_verbose[request->op];
 880         else
 881                 op = "---";
 882         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 883                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 884         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 885         sptr = (unsigned int *) irb->ecw;
 886         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 887         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 888         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 889         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 890 }
 891
 892 /*
 893  * I/O helper function. Adds the request to the request queue
 894  * and starts it if the tape is idle. Has to be called with
 895  * the device lock held.
 896  */
 897 static int
 898 __tape_start_request(struct tape_device *device, struct tape_request *request)
 899 {
 900         int rc;
 901
 902         switch (request->op) {
 903                 case TO_MSEN:
 904                 case TO_ASSIGN:
 905                 case TO_UNASSIGN:
 906                 case TO_READ_ATTMSG:
 907                 case TO_RDC:
 908                         if (device->tape_state == TS_INIT)
 909                                 break;
 910                         if (device->tape_state == TS_UNUSED)
 911                                 break;
 912                 default:
 913                         if (device->tape_state == TS_BLKUSE)
 914                                 break;
 915                         if (device->tape_state != TS_IN_USE)
 916                                 return -ENODEV;
 917         }
 918
 919         /* Increase use count of device for the added request. */
 920         request->device = tape_get_device(device);
 921
 922         if (list_empty(&device->req_queue)) {
 923                 /* No other requests are on the queue. Start this one. */
 924                 rc = __tape_start_io(device, request);
 925                 if (rc)
 926                         return rc;
 927
 928                 DBF_LH(5, "Request %p added for execution.\n", request);
 929                 list_add(&request->list, &device->req_queue);
 930         } else {
 931                 DBF_LH(5, "Request %p add to queue.\n", request);
 932                 request->status = TAPE_REQUEST_QUEUED;
 933                 list_add_tail(&request->list, &device->req_queue);
 934         }
 935         return 0;
 936 }
 937
 938 /*
 939  * Add the request to the request queue, try to start it if the
 940  * tape is idle. Return without waiting for end of i/o.
 941  */
 942 int
 943 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 944 {
 945         int rc;
 946
 947         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 948
 949         spin_lock_irq(get_ccwdev_lock(device->cdev));
 950         /* Add request to request queue and try to start it. */
 951         rc = __tape_start_request(device, request);
 952         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 953         return rc;
 954 }
 955
 956 /*
 957  * tape_do_io/__tape_wake_up
 958  * Add the request to the request queue, try to start it if the
 959  * tape is idle and wait uninterruptible for its completion.
 960  */
 961 static void
 962 __tape_wake_up(struct tape_request *request, void *data)
 963 {
 964         request->callback = NULL;
 965         wake_up((wait_queue_head_t *) data);
 966 }
 967
 968 int
 969 tape_do_io(struct tape_device *device, struct tape_request *request)
 970 {
 971         int rc;
 972
 973         spin_lock_irq(get_ccwdev_lock(device->cdev));
 974         /* Setup callback */
 975         request->callback = __tape_wake_up;
 976         request->callback_data = &device->wait_queue;
 977         /* Add request to request queue and try to start it. */
 978         rc = __tape_start_request(device, request);
 979         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 980         if (rc)
 981                 return rc;
 982         /* Request added to the queue. Wait for its completion. */
 983         wait_event(device->wait_queue, (request->callback == NULL));
 984         /* Get rc from request */
 985         return request->rc;
 986 }
 987
 988 /*
 989  * tape_do_io_interruptible/__tape_wake_up_interruptible
 990  * Add the request to the request queue, try to start it if the
 991  * tape is idle and wait uninterruptible for its completion.
 992  */
 993 static void
 994 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 995 {
 996         request->callback = NULL;
 997         wake_up_interruptible((wait_queue_head_t *) data);
 998 }
 999
1000 int
1001 tape_do_io_interruptible(struct tape_device *device,
1002                          struct tape_request *request)
1003 {
1004         int rc;
1005
1006         spin_lock_irq(get_ccwdev_lock(device->cdev));
1007         /* Setup callback */
1008         request->callback = __tape_wake_up_interruptible;
1009         request->callback_data = &device->wait_queue;
1010         rc = __tape_start_request(device, request);
1011         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1012         if (rc)
1013                 return rc;
1014         /* Request added to the queue. Wait for its completion. */
1015         rc = wait_event_interruptible(device->wait_queue,
1016                                       (request->callback == NULL));
1017         if (rc != -ERESTARTSYS)
1018                 /* Request finished normally. */
1019                 return request->rc;
1020
1021         /* Interrupted by a signal. We have to stop the current request. */
1022         spin_lock_irq(get_ccwdev_lock(device->cdev));
1023         rc = __tape_cancel_io(device, request);
1024         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1025         if (rc == 0) {
1026                 /* Wait for the interrupt that acknowledges the halt. */
1027                 do {
1028                         rc = wait_event_interruptible(
1029                                 device->wait_queue,
1030                                 (request->callback == NULL)
1031                         );
1032                 } while (rc == -ERESTARTSYS);
1033
1034                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1035                 rc = -ERESTARTSYS;
1036         }
1037         return rc;
1038 }
1039
1040 /*
1041  * Stop running ccw.
1042  */
1043 int
1044 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1045 {
1046         int rc;
1047
1048         spin_lock_irq(get_ccwdev_lock(device->cdev));
1049         rc = __tape_cancel_io(device, request);
1050         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1051         return rc;
1052 }
1053
1054 /*
1055  * Tape interrupt routine, called from the ccw_device layer
1056  */
1057 static void
1058 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1059 {
1060         struct tape_device *device;
1061         struct tape_request *request;
1062         int rc;
1063
1064         device = dev_get_drvdata(&cdev->dev);
1065         if (device == NULL) {
1066                 return;
1067         }
1068         request = (struct tape_request *) intparm;
1069
1070         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1071
1072         /* On special conditions irb is an error pointer */
1073         if (IS_ERR(irb)) {
1074                 /* FIXME: What to do with the request? */
1075                 switch (PTR_ERR(irb)) {
1076                         case -ETIMEDOUT:
1077                                 DBF_LH(1, "(%s): Request timed out\n",
1078                                         dev_name(&cdev->dev));
1079                         case -EIO:
1080                                 __tape_end_request(device, request, -EIO);
1081                                 break;
1082                         default:
1083                                 DBF_LH(1, "(%s): Unexpected i/o error %li\n",
1084                                         dev_name(&cdev->dev),
1085                                         PTR_ERR(irb));
1086                 }
1087                 return;
1088         }
1089
1090         /*
1091          * If the condition code is not zero and the start function bit is
1092          * still set, this is an deferred error and the last start I/O did
1093          * not succeed. At this point the condition that caused the deferred
1094          * error might still apply. So we just schedule the request to be
1095          * started later.
1096          */
1097         if (irb->scsw.cmd.cc != 0 &&
1098             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1099             (request->status == TAPE_REQUEST_IN_IO)) {
1100                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1101                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1102                 request->status = TAPE_REQUEST_QUEUED;
1103                 schedule_delayed_work(&device->tape_dnr, HZ);
1104                 return;
1105         }
1106
1107         /* May be an unsolicited irq */
1108         if(request != NULL)
1109                 request->rescnt = irb->scsw.cmd.count;
1110         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1111                  !list_empty(&device->req_queue)) {
1112                 /* Not Ready to Ready after long busy ? */
1113                 struct tape_request *req;
1114                 req = list_entry(device->req_queue.next,
1115                                  struct tape_request, list);
1116                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1117                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1118                         if (del_timer(&device->lb_timeout)) {
1119                                 device->lb_timeout.data = 0UL;
1120                                 tape_put_device(device);
1121                                 __tape_start_next_request(device);
1122                         }
1123                         return;
1124                 }
1125         }
1126         if (irb->scsw.cmd.dstat != 0x0c) {
1127                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1128                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1129                         device->tape_generic_status |= GMT_ONLINE(~0);
1130                 else
1131                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1132
1133                 /*
1134                  * Any request that does not come back with channel end
1135                  * and device end is unusual. Log the sense data.
1136                  */
1137                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1138                 tape_dump_sense_dbf(device, request, irb);
1139         } else {
1140                 /* Upon normal completion the device _is_ online */
1141                 device->tape_generic_status |= GMT_ONLINE(~0);
1142         }
1143         if (device->tape_state == TS_NOT_OPER) {
1144                 DBF_EVENT(6, "tape:device is not operational\n");
1145                 return;
1146         }
1147
1148         /*
1149          * Request that were canceled still come back with an interrupt.
1150          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1151          */
1152         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1153                 __tape_end_request(device, request, -EIO);
1154                 return;
1155         }
1156
1157         rc = device->discipline->irq(device, request, irb);
1158         /*
1159          * rc < 0 : request finished unsuccessfully.
1160          * rc == TAPE_IO_SUCCESS: request finished successfully.
1161          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1162          * rc == TAPE_IO_RETRY: request finished but needs another go.
1163          * rc == TAPE_IO_STOP: request needs to get terminated.
1164          */
1165         switch (rc) {
1166                 case TAPE_IO_SUCCESS:
1167                         /* Upon normal completion the device _is_ online */
1168                         device->tape_generic_status |= GMT_ONLINE(~0);
1169                         __tape_end_request(device, request, rc);
1170                         break;
1171                 case TAPE_IO_PENDING:
1172                         break;
1173                 case TAPE_IO_LONG_BUSY:
1174                         device->lb_timeout.data =
1175                                 (unsigned long) tape_get_device(device);
1176                         device->lb_timeout.expires = jiffies +
1177                                 LONG_BUSY_TIMEOUT * HZ;
1178                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1179                         add_timer(&device->lb_timeout);
1180                         request->status = TAPE_REQUEST_LONG_BUSY;
1181                         break;
1182                 case TAPE_IO_RETRY:
1183                         rc = __tape_start_io(device, request);
1184                         if (rc)
1185                                 __tape_end_request(device, request, rc);
1186                         break;
1187                 case TAPE_IO_STOP:
1188                         rc = __tape_cancel_io(device, request);
1189                         if (rc)
1190                                 __tape_end_request(device, request, rc);
1191                         break;
1192                 default:
1193                         if (rc > 0) {
1194                                 DBF_EVENT(6, "xunknownrc\n");
1195                                 __tape_end_request(device, request, -EIO);
1196                         } else {
1197                                 __tape_end_request(device, request, rc);
1198                         }
1199                         break;
1200         }
1201 }
1202
1203 /*
1204  * Tape device open function used by tape_char & tape_block frontends.
1205  */
1206 int
1207 tape_open(struct tape_device *device)
1208 {
1209         int rc;
1210
1211         spin_lock_irq(get_ccwdev_lock(device->cdev));
1212         if (device->tape_state == TS_NOT_OPER) {
1213                 DBF_EVENT(6, "TAPE:nodev\n");
1214                 rc = -ENODEV;
1215         } else if (device->tape_state == TS_IN_USE) {
1216                 DBF_EVENT(6, "TAPE:dbusy\n");
1217                 rc = -EBUSY;
1218         } else if (device->tape_state == TS_BLKUSE) {
1219                 DBF_EVENT(6, "TAPE:dbusy\n");
1220                 rc = -EBUSY;
1221         } else if (device->discipline != NULL &&
1222                    !try_module_get(device->discipline->owner)) {
1223                 DBF_EVENT(6, "TAPE:nodisc\n");
1224                 rc = -ENODEV;
1225         } else {
1226                 tape_state_set(device, TS_IN_USE);
1227                 rc = 0;
1228         }
1229         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1230         return rc;
1231 }
1232
1233 /*
1234  * Tape device release function used by tape_char & tape_block frontends.
1235  */
1236 int
1237 tape_release(struct tape_device *device)
1238 {
1239         spin_lock_irq(get_ccwdev_lock(device->cdev));
1240         if (device->tape_state == TS_IN_USE)
1241                 tape_state_set(device, TS_UNUSED);
1242         module_put(device->discipline->owner);
1243         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1244         return 0;
1245 }
1246
1247 /*
1248  * Execute a magnetic tape command a number of times.
1249  */
1250 int
1251 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1252 {
1253         tape_mtop_fn fn;
1254         int rc;
1255
1256         DBF_EVENT(6, "TAPE:mtio\n");
1257         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1258         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1259
1260         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1261                 return -EINVAL;
1262         fn = device->discipline->mtop_array[mt_op];
1263         if (fn == NULL)
1264                 return -EINVAL;
1265
1266         /* We assume that the backends can handle count up to 500. */
1267         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1268             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1269                 rc = 0;
1270                 for (; mt_count > 500; mt_count -= 500)
1271                         if ((rc = fn(device, 500)) != 0)
1272                                 break;
1273                 if (rc == 0)
1274                         rc = fn(device, mt_count);
1275         } else
1276                 rc = fn(device, mt_count);
1277         return rc;
1278
1279 }
1280
1281 /*
1282  * Tape init function.
1283  */
1284 static int
1285 tape_init (void)
1286 {
1287         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1288         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1289 #ifdef DBF_LIKE_HELL
1290         debug_set_level(TAPE_DBF_AREA, 6);
1291 #endif
1292         DBF_EVENT(3, "tape init\n");
1293         tape_proc_init();
1294         tapechar_init ();
1295         tapeblock_init ();
1296         return 0;
1297 }
1298
1299 /*
1300  * Tape exit function.
1301  */
1302 static void
1303 tape_exit(void)
1304 {
1305         DBF_EVENT(6, "tape exit\n");
1306
1307         /* Get rid of the frontends */
1308         tapechar_exit();
1309         tapeblock_exit();
1310         tape_proc_cleanup();
1311         debug_unregister (TAPE_DBF_AREA);
1312 }
1313
1314 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1315               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1316 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1317 MODULE_LICENSE("GPL");
1318
1319 module_init(tape_init);
1320 module_exit(tape_exit);
1321
1322 EXPORT_SYMBOL(tape_generic_remove);
1323 EXPORT_SYMBOL(tape_generic_probe);
1324 EXPORT_SYMBOL(tape_generic_online);
1325 EXPORT_SYMBOL(tape_generic_offline);
1326 EXPORT_SYMBOL(tape_generic_pm_suspend);
1327 EXPORT_SYMBOL(tape_put_device);
1328 EXPORT_SYMBOL(tape_get_device);
1329 EXPORT_SYMBOL(tape_state_verbose);
1330 EXPORT_SYMBOL(tape_op_verbose);
1331 EXPORT_SYMBOL(tape_state_set);
1332 EXPORT_SYMBOL(tape_med_state_set);
1333 EXPORT_SYMBOL(tape_alloc_request);
1334 EXPORT_SYMBOL(tape_free_request);
1335 EXPORT_SYMBOL(tape_dump_sense_dbf);
1336 EXPORT_SYMBOL(tape_do_io);
1337 EXPORT_SYMBOL(tape_do_io_async);
1338 EXPORT_SYMBOL(tape_do_io_interruptible);
1339 EXPORT_SYMBOL(tape_cancel_io);
1340 EXPORT_SYMBOL(tape_mtop);