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. 2001,2006
   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 #include <linux/module.h>
  15 #include <linux/init.h>      // for kernel parameters
  16 #include <linux/kmod.h>      // for requesting modules
  17 #include <linux/spinlock.h>  // for locks
  18 #include <linux/vmalloc.h>
  19 #include <linux/list.h>
  20
  21 #include <asm/types.h>       // for variable types
  22
  23 #define TAPE_DBF_AREA   tape_core_dbf
  24
  25 #include "tape.h"
  26 #include "tape_std.h"
  27
  28 #define PRINTK_HEADER "TAPE_CORE: "
  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 = (struct tape_device *) dev->driver_data;
  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 = (struct tape_device *) dev->driver_data;
 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 = (struct tape_device *) dev->driver_data;
 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 = (struct tape_device *) dev->driver_data;
 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 = (struct tape_device *) dev->driver_data;
 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                 PRINT_INFO("(%s): Tape is unloaded\n",
 218                            device->cdev->dev.bus_id);
 219                 break;
 220         case MS_LOADED:
 221                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 222                 PRINT_INFO("(%s): Tape has been mounted\n",
 223                            device->cdev->dev.bus_id);
 224                 break;
 225         default:
 226                 // print nothing
 227                 break;
 228         }
 229         device->medium_state = newstate;
 230         wake_up(&device->state_change_wq);
 231 }
 232
 233 /*
 234  * Stop running ccw. Has to be called with the device lock held.
 235  */
 236 static int
 237 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 238 {
 239         int retries;
 240         int rc;
 241
 242         /* Check if interrupt has already been processed */
 243         if (request->callback == NULL)
 244                 return 0;
 245
 246         rc = 0;
 247         for (retries = 0; retries < 5; retries++) {
 248                 rc = ccw_device_clear(device->cdev, (long) request);
 249
 250                 switch (rc) {
 251                         case 0:
 252                                 request->status = TAPE_REQUEST_DONE;
 253                                 return 0;
 254                         case -EBUSY:
 255                                 request->status = TAPE_REQUEST_CANCEL;
 256                                 schedule_delayed_work(&device->tape_dnr, 0);
 257                                 return 0;
 258                         case -ENODEV:
 259                                 DBF_EXCEPTION(2, "device gone, retry\n");
 260                                 break;
 261                         case -EIO:
 262                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 263                                 break;
 264                         default:
 265                                 BUG();
 266                 }
 267         }
 268
 269         return rc;
 270 }
 271
 272 /*
 273  * Add device into the sorted list, giving it the first
 274  * available minor number.
 275  */
 276 static int
 277 tape_assign_minor(struct tape_device *device)
 278 {
 279         struct tape_device *tmp;
 280         int minor;
 281
 282         minor = 0;
 283         write_lock(&tape_device_lock);
 284         list_for_each_entry(tmp, &tape_device_list, node) {
 285                 if (minor < tmp->first_minor)
 286                         break;
 287                 minor += TAPE_MINORS_PER_DEV;
 288         }
 289         if (minor >= 256) {
 290                 write_unlock(&tape_device_lock);
 291                 return -ENODEV;
 292         }
 293         device->first_minor = minor;
 294         list_add_tail(&device->node, &tmp->node);
 295         write_unlock(&tape_device_lock);
 296         return 0;
 297 }
 298
 299 /* remove device from the list */
 300 static void
 301 tape_remove_minor(struct tape_device *device)
 302 {
 303         write_lock(&tape_device_lock);
 304         list_del_init(&device->node);
 305         device->first_minor = -1;
 306         write_unlock(&tape_device_lock);
 307 }
 308
 309 /*
 310  * Set a device online.
 311  *
 312  * This function is called by the common I/O layer to move a device from the
 313  * detected but offline into the online state.
 314  * If we return an error (RC < 0) the device remains in the offline state. This
 315  * can happen if the device is assigned somewhere else, for example.
 316  */
 317 int
 318 tape_generic_online(struct tape_device *device,
 319                    struct tape_discipline *discipline)
 320 {
 321         int rc;
 322
 323         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 324
 325         if (device->tape_state != TS_INIT) {
 326                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 327                 return -EINVAL;
 328         }
 329
 330         init_timer(&device->lb_timeout);
 331         device->lb_timeout.function = tape_long_busy_timeout;
 332
 333         /* Let the discipline have a go at the device. */
 334         device->discipline = discipline;
 335         if (!try_module_get(discipline->owner)) {
 336                 PRINT_ERR("Cannot get module. Module gone.\n");
 337                 return -EINVAL;
 338         }
 339
 340         rc = discipline->setup_device(device);
 341         if (rc)
 342                 goto out;
 343         rc = tape_assign_minor(device);
 344         if (rc)
 345                 goto out_discipline;
 346
 347         rc = tapechar_setup_device(device);
 348         if (rc)
 349                 goto out_minor;
 350         rc = tapeblock_setup_device(device);
 351         if (rc)
 352                 goto out_char;
 353
 354         tape_state_set(device, TS_UNUSED);
 355
 356         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 357
 358         return 0;
 359
 360 out_char:
 361         tapechar_cleanup_device(device);
 362 out_discipline:
 363         device->discipline->cleanup_device(device);
 364         device->discipline = NULL;
 365 out_minor:
 366         tape_remove_minor(device);
 367 out:
 368         module_put(discipline->owner);
 369         return rc;
 370 }
 371
 372 static void
 373 tape_cleanup_device(struct tape_device *device)
 374 {
 375         tapeblock_cleanup_device(device);
 376         tapechar_cleanup_device(device);
 377         device->discipline->cleanup_device(device);
 378         module_put(device->discipline->owner);
 379         tape_remove_minor(device);
 380         tape_med_state_set(device, MS_UNKNOWN);
 381 }
 382
 383 /*
 384  * Set device offline.
 385  *
 386  * Called by the common I/O layer if the drive should set offline on user
 387  * request. We may prevent this by returning an error.
 388  * Manual offline is only allowed while the drive is not in use.
 389  */
 390 int
 391 tape_generic_offline(struct tape_device *device)
 392 {
 393         if (!device) {
 394                 PRINT_ERR("tape_generic_offline: no such device\n");
 395                 return -ENODEV;
 396         }
 397
 398         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 399                 device->cdev_id, device);
 400
 401         spin_lock_irq(get_ccwdev_lock(device->cdev));
 402         switch (device->tape_state) {
 403                 case TS_INIT:
 404                 case TS_NOT_OPER:
 405                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 406                         break;
 407                 case TS_UNUSED:
 408                         tape_state_set(device, TS_INIT);
 409                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 410                         tape_cleanup_device(device);
 411                         break;
 412                 default:
 413                         DBF_EVENT(3, "(%08x): Set offline failed "
 414                                 "- drive in use.\n",
 415                                 device->cdev_id);
 416                         PRINT_WARN("(%s): Set offline failed "
 417                                 "- drive in use.\n",
 418                                 device->cdev->dev.bus_id);
 419                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 420                         return -EBUSY;
 421         }
 422
 423         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 424         return 0;
 425 }
 426
 427 /*
 428  * Allocate memory for a new device structure.
 429  */
 430 static struct tape_device *
 431 tape_alloc_device(void)
 432 {
 433         struct tape_device *device;
 434
 435         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 436         if (device == NULL) {
 437                 DBF_EXCEPTION(2, "ti:no mem\n");
 438                 PRINT_INFO ("can't allocate memory for "
 439                             "tape info structure\n");
 440                 return ERR_PTR(-ENOMEM);
 441         }
 442         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 443         if (device->modeset_byte == NULL) {
 444                 DBF_EXCEPTION(2, "ti:no mem\n");
 445                 PRINT_INFO("can't allocate memory for modeset byte\n");
 446                 kfree(device);
 447                 return ERR_PTR(-ENOMEM);
 448         }
 449         INIT_LIST_HEAD(&device->req_queue);
 450         INIT_LIST_HEAD(&device->node);
 451         init_waitqueue_head(&device->state_change_wq);
 452         device->tape_state = TS_INIT;
 453         device->medium_state = MS_UNKNOWN;
 454         *device->modeset_byte = 0;
 455         device->first_minor = -1;
 456         atomic_set(&device->ref_count, 1);
 457         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 458
 459         return device;
 460 }
 461
 462 /*
 463  * Get a reference to an existing device structure. This will automatically
 464  * increment the reference count.
 465  */
 466 struct tape_device *
 467 tape_get_device_reference(struct tape_device *device)
 468 {
 469         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 470                 atomic_inc_return(&device->ref_count));
 471
 472         return device;
 473 }
 474
 475 /*
 476  * Decrease the reference counter of a devices structure. If the
 477  * reference counter reaches zero free the device structure.
 478  * The function returns a NULL pointer to be used by the caller
 479  * for clearing reference pointers.
 480  */
 481 struct tape_device *
 482 tape_put_device(struct tape_device *device)
 483 {
 484         int remain;
 485
 486         remain = atomic_dec_return(&device->ref_count);
 487         if (remain > 0) {
 488                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 489         } else {
 490                 if (remain < 0) {
 491                         DBF_EVENT(4, "put device without reference\n");
 492                         PRINT_ERR("put device without reference\n");
 493                 } else {
 494                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 495                         kfree(device->modeset_byte);
 496                         kfree(device);
 497                 }
 498         }
 499
 500         return NULL;
 501 }
 502
 503 /*
 504  * Find tape device by a device index.
 505  */
 506 struct tape_device *
 507 tape_get_device(int devindex)
 508 {
 509         struct tape_device *device, *tmp;
 510
 511         device = ERR_PTR(-ENODEV);
 512         read_lock(&tape_device_lock);
 513         list_for_each_entry(tmp, &tape_device_list, node) {
 514                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 515                         device = tape_get_device_reference(tmp);
 516                         break;
 517                 }
 518         }
 519         read_unlock(&tape_device_lock);
 520         return device;
 521 }
 522
 523 /*
 524  * Driverfs tape probe function.
 525  */
 526 int
 527 tape_generic_probe(struct ccw_device *cdev)
 528 {
 529         struct tape_device *device;
 530         int ret;
 531         struct ccw_dev_id dev_id;
 532
 533         device = tape_alloc_device();
 534         if (IS_ERR(device))
 535                 return -ENODEV;
 536         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 537         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 538         if (ret) {
 539                 tape_put_device(device);
 540                 PRINT_ERR("probe failed for tape device %s\n", cdev->dev.bus_id);
 541                 return ret;
 542         }
 543         cdev->dev.driver_data = device;
 544         cdev->handler = __tape_do_irq;
 545         device->cdev = cdev;
 546         ccw_device_get_id(cdev, &dev_id);
 547         device->cdev_id = devid_to_int(&dev_id);
 548         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 549         return ret;
 550 }
 551
 552 static void
 553 __tape_discard_requests(struct tape_device *device)
 554 {
 555         struct tape_request *   request;
 556         struct list_head *      l, *n;
 557
 558         list_for_each_safe(l, n, &device->req_queue) {
 559                 request = list_entry(l, struct tape_request, list);
 560                 if (request->status == TAPE_REQUEST_IN_IO)
 561                         request->status = TAPE_REQUEST_DONE;
 562                 list_del(&request->list);
 563
 564                 /* Decrease ref_count for removed request. */
 565                 request->device = tape_put_device(device);
 566                 request->rc = -EIO;
 567                 if (request->callback != NULL)
 568                         request->callback(request, request->callback_data);
 569         }
 570 }
 571
 572 /*
 573  * Driverfs tape remove function.
 574  *
 575  * This function is called whenever the common I/O layer detects the device
 576  * gone. This can happen at any time and we cannot refuse.
 577  */
 578 void
 579 tape_generic_remove(struct ccw_device *cdev)
 580 {
 581         struct tape_device *    device;
 582
 583         device = cdev->dev.driver_data;
 584         if (!device) {
 585                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 586                 return;
 587         }
 588         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 589
 590         spin_lock_irq(get_ccwdev_lock(device->cdev));
 591         switch (device->tape_state) {
 592                 case TS_INIT:
 593                         tape_state_set(device, TS_NOT_OPER);
 594                 case TS_NOT_OPER:
 595                         /*
 596                          * Nothing to do.
 597                          */
 598                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 599                         break;
 600                 case TS_UNUSED:
 601                         /*
 602                          * Need only to release the device.
 603                          */
 604                         tape_state_set(device, TS_NOT_OPER);
 605                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 606                         tape_cleanup_device(device);
 607                         break;
 608                 default:
 609                         /*
 610                          * There may be requests on the queue. We will not get
 611                          * an interrupt for a request that was running. So we
 612                          * just post them all as I/O errors.
 613                          */
 614                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 615                                 device->cdev_id);
 616                         PRINT_WARN("(%s): Drive in use vanished - "
 617                                 "expect trouble!\n",
 618                                 device->cdev->dev.bus_id);
 619                         PRINT_WARN("State was %i\n", device->tape_state);
 620                         tape_state_set(device, TS_NOT_OPER);
 621                         __tape_discard_requests(device);
 622                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 623                         tape_cleanup_device(device);
 624         }
 625
 626         if (cdev->dev.driver_data != NULL) {
 627                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 628                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 629         }
 630 }
 631
 632 /*
 633  * Allocate a new tape ccw request
 634  */
 635 struct tape_request *
 636 tape_alloc_request(int cplength, int datasize)
 637 {
 638         struct tape_request *request;
 639
 640         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 641                 BUG();
 642
 643         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 644
 645         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 646         if (request == NULL) {
 647                 DBF_EXCEPTION(1, "cqra nomem\n");
 648                 return ERR_PTR(-ENOMEM);
 649         }
 650         /* allocate channel program */
 651         if (cplength > 0) {
 652                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 653                                           GFP_ATOMIC | GFP_DMA);
 654                 if (request->cpaddr == NULL) {
 655                         DBF_EXCEPTION(1, "cqra nomem\n");
 656                         kfree(request);
 657                         return ERR_PTR(-ENOMEM);
 658                 }
 659         }
 660         /* alloc small kernel buffer */
 661         if (datasize > 0) {
 662                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 663                 if (request->cpdata == NULL) {
 664                         DBF_EXCEPTION(1, "cqra nomem\n");
 665                         kfree(request->cpaddr);
 666                         kfree(request);
 667                         return ERR_PTR(-ENOMEM);
 668                 }
 669         }
 670         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 671                 request->cpdata);
 672
 673         return request;
 674 }
 675
 676 /*
 677  * Free tape ccw request
 678  */
 679 void
 680 tape_free_request (struct tape_request * request)
 681 {
 682         DBF_LH(6, "Free request %p\n", request);
 683
 684         if (request->device != NULL) {
 685                 request->device = tape_put_device(request->device);
 686         }
 687         kfree(request->cpdata);
 688         kfree(request->cpaddr);
 689         kfree(request);
 690 }
 691
 692 static int
 693 __tape_start_io(struct tape_device *device, struct tape_request *request)
 694 {
 695         int rc;
 696
 697 #ifdef CONFIG_S390_TAPE_BLOCK
 698         if (request->op == TO_BLOCK)
 699                 device->discipline->check_locate(device, request);
 700 #endif
 701         rc = ccw_device_start(
 702                 device->cdev,
 703                 request->cpaddr,
 704                 (unsigned long) request,
 705                 0x00,
 706                 request->options
 707         );
 708         if (rc == 0) {
 709                 request->status = TAPE_REQUEST_IN_IO;
 710         } else if (rc == -EBUSY) {
 711                 /* The common I/O subsystem is currently busy. Retry later. */
 712                 request->status = TAPE_REQUEST_QUEUED;
 713                 schedule_delayed_work(&device->tape_dnr, 0);
 714                 rc = 0;
 715         } else {
 716                 /* Start failed. Remove request and indicate failure. */
 717                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 718         }
 719         return rc;
 720 }
 721
 722 static void
 723 __tape_start_next_request(struct tape_device *device)
 724 {
 725         struct list_head *l, *n;
 726         struct tape_request *request;
 727         int rc;
 728
 729         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 730         /*
 731          * Try to start each request on request queue until one is
 732          * started successful.
 733          */
 734         list_for_each_safe(l, n, &device->req_queue) {
 735                 request = list_entry(l, struct tape_request, list);
 736
 737                 /*
 738                  * Avoid race condition if bottom-half was triggered more than
 739                  * once.
 740                  */
 741                 if (request->status == TAPE_REQUEST_IN_IO)
 742                         return;
 743                 /*
 744                  * Request has already been stopped. We have to wait until
 745                  * the request is removed from the queue in the interrupt
 746                  * handling.
 747                  */
 748                 if (request->status == TAPE_REQUEST_DONE)
 749                         return;
 750
 751                 /*
 752                  * We wanted to cancel the request but the common I/O layer
 753                  * was busy at that time. This can only happen if this
 754                  * function is called by delayed_next_request.
 755                  * Otherwise we start the next request on the queue.
 756                  */
 757                 if (request->status == TAPE_REQUEST_CANCEL) {
 758                         rc = __tape_cancel_io(device, request);
 759                 } else {
 760                         rc = __tape_start_io(device, request);
 761                 }
 762                 if (rc == 0)
 763                         return;
 764
 765                 /* Set ending status. */
 766                 request->rc = rc;
 767                 request->status = TAPE_REQUEST_DONE;
 768
 769                 /* Remove from request queue. */
 770                 list_del(&request->list);
 771
 772                 /* Do callback. */
 773                 if (request->callback != NULL)
 774                         request->callback(request, request->callback_data);
 775         }
 776 }
 777
 778 static void
 779 tape_delayed_next_request(struct work_struct *work)
 780 {
 781         struct tape_device *device =
 782                 container_of(work, struct tape_device, tape_dnr.work);
 783
 784         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 785         spin_lock_irq(get_ccwdev_lock(device->cdev));
 786         __tape_start_next_request(device);
 787         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 788 }
 789
 790 static void tape_long_busy_timeout(unsigned long data)
 791 {
 792         struct tape_request *request;
 793         struct tape_device *device;
 794
 795         device = (struct tape_device *) data;
 796         spin_lock_irq(get_ccwdev_lock(device->cdev));
 797         request = list_entry(device->req_queue.next, struct tape_request, list);
 798         if (request->status != TAPE_REQUEST_LONG_BUSY)
 799                 BUG();
 800         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 801         __tape_start_next_request(device);
 802         device->lb_timeout.data = (unsigned long) tape_put_device(device);
 803         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 804 }
 805
 806 static void
 807 __tape_end_request(
 808         struct tape_device *    device,
 809         struct tape_request *   request,
 810         int                     rc)
 811 {
 812         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 813         if (request) {
 814                 request->rc = rc;
 815                 request->status = TAPE_REQUEST_DONE;
 816
 817                 /* Remove from request queue. */
 818                 list_del(&request->list);
 819
 820                 /* Do callback. */
 821                 if (request->callback != NULL)
 822                         request->callback(request, request->callback_data);
 823         }
 824
 825         /* Start next request. */
 826         if (!list_empty(&device->req_queue))
 827                 __tape_start_next_request(device);
 828 }
 829
 830 /*
 831  * Write sense data to console/dbf
 832  */
 833 void
 834 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 835                 struct irb *irb)
 836 {
 837         unsigned int *sptr;
 838
 839         PRINT_INFO("-------------------------------------------------\n");
 840         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 841                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 842         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 843         if (request != NULL)
 844                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 845
 846         sptr = (unsigned int *) irb->ecw;
 847         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 848                    sptr[0], sptr[1], sptr[2], sptr[3]);
 849         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 850                    sptr[4], sptr[5], sptr[6], sptr[7]);
 851         PRINT_INFO("--------------------------------------------------\n");
 852 }
 853
 854 /*
 855  * Write sense data to dbf
 856  */
 857 void
 858 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 859                     struct irb *irb)
 860 {
 861         unsigned int *sptr;
 862         const char* op;
 863
 864         if (request != NULL)
 865                 op = tape_op_verbose[request->op];
 866         else
 867                 op = "---";
 868         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 869                   irb->scsw.dstat,irb->scsw.cstat);
 870         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 871         sptr = (unsigned int *) irb->ecw;
 872         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 873         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 874         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 875         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 876 }
 877
 878 /*
 879  * I/O helper function. Adds the request to the request queue
 880  * and starts it if the tape is idle. Has to be called with
 881  * the device lock held.
 882  */
 883 static int
 884 __tape_start_request(struct tape_device *device, struct tape_request *request)
 885 {
 886         int rc;
 887
 888         switch (request->op) {
 889                 case TO_MSEN:
 890                 case TO_ASSIGN:
 891                 case TO_UNASSIGN:
 892                 case TO_READ_ATTMSG:
 893                 case TO_RDC:
 894                         if (device->tape_state == TS_INIT)
 895                                 break;
 896                         if (device->tape_state == TS_UNUSED)
 897                                 break;
 898                 default:
 899                         if (device->tape_state == TS_BLKUSE)
 900                                 break;
 901                         if (device->tape_state != TS_IN_USE)
 902                                 return -ENODEV;
 903         }
 904
 905         /* Increase use count of device for the added request. */
 906         request->device = tape_get_device_reference(device);
 907
 908         if (list_empty(&device->req_queue)) {
 909                 /* No other requests are on the queue. Start this one. */
 910                 rc = __tape_start_io(device, request);
 911                 if (rc)
 912                         return rc;
 913
 914                 DBF_LH(5, "Request %p added for execution.\n", request);
 915                 list_add(&request->list, &device->req_queue);
 916         } else {
 917                 DBF_LH(5, "Request %p add to queue.\n", request);
 918                 request->status = TAPE_REQUEST_QUEUED;
 919                 list_add_tail(&request->list, &device->req_queue);
 920         }
 921         return 0;
 922 }
 923
 924 /*
 925  * Add the request to the request queue, try to start it if the
 926  * tape is idle. Return without waiting for end of i/o.
 927  */
 928 int
 929 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 930 {
 931         int rc;
 932
 933         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 934
 935         spin_lock_irq(get_ccwdev_lock(device->cdev));
 936         /* Add request to request queue and try to start it. */
 937         rc = __tape_start_request(device, request);
 938         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 939         return rc;
 940 }
 941
 942 /*
 943  * tape_do_io/__tape_wake_up
 944  * Add the request to the request queue, try to start it if the
 945  * tape is idle and wait uninterruptible for its completion.
 946  */
 947 static void
 948 __tape_wake_up(struct tape_request *request, void *data)
 949 {
 950         request->callback = NULL;
 951         wake_up((wait_queue_head_t *) data);
 952 }
 953
 954 int
 955 tape_do_io(struct tape_device *device, struct tape_request *request)
 956 {
 957         wait_queue_head_t wq;
 958         int rc;
 959
 960         init_waitqueue_head(&wq);
 961         spin_lock_irq(get_ccwdev_lock(device->cdev));
 962         /* Setup callback */
 963         request->callback = __tape_wake_up;
 964         request->callback_data = &wq;
 965         /* Add request to request queue and try to start it. */
 966         rc = __tape_start_request(device, request);
 967         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 968         if (rc)
 969                 return rc;
 970         /* Request added to the queue. Wait for its completion. */
 971         wait_event(wq, (request->callback == NULL));
 972         /* Get rc from request */
 973         return request->rc;
 974 }
 975
 976 /*
 977  * tape_do_io_interruptible/__tape_wake_up_interruptible
 978  * Add the request to the request queue, try to start it if the
 979  * tape is idle and wait uninterruptible for its completion.
 980  */
 981 static void
 982 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 983 {
 984         request->callback = NULL;
 985         wake_up_interruptible((wait_queue_head_t *) data);
 986 }
 987
 988 int
 989 tape_do_io_interruptible(struct tape_device *device,
 990                          struct tape_request *request)
 991 {
 992         wait_queue_head_t wq;
 993         int rc;
 994
 995         init_waitqueue_head(&wq);
 996         spin_lock_irq(get_ccwdev_lock(device->cdev));
 997         /* Setup callback */
 998         request->callback = __tape_wake_up_interruptible;
 999         request->callback_data = &wq;
1000         rc = __tape_start_request(device, request);
1001         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1002         if (rc)
1003                 return rc;
1004         /* Request added to the queue. Wait for its completion. */
1005         rc = wait_event_interruptible(wq, (request->callback == NULL));
1006         if (rc != -ERESTARTSYS)
1007                 /* Request finished normally. */
1008                 return request->rc;
1009
1010         /* Interrupted by a signal. We have to stop the current request. */
1011         spin_lock_irq(get_ccwdev_lock(device->cdev));
1012         rc = __tape_cancel_io(device, request);
1013         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1014         if (rc == 0) {
1015                 /* Wait for the interrupt that acknowledges the halt. */
1016                 do {
1017                         rc = wait_event_interruptible(
1018                                 wq,
1019                                 (request->callback == NULL)
1020                         );
1021                 } while (rc == -ERESTARTSYS);
1022
1023                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1024                 rc = -ERESTARTSYS;
1025         }
1026         return rc;
1027 }
1028
1029 /*
1030  * Stop running ccw.
1031  */
1032 int
1033 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1034 {
1035         int rc;
1036
1037         spin_lock_irq(get_ccwdev_lock(device->cdev));
1038         rc = __tape_cancel_io(device, request);
1039         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1040         return rc;
1041 }
1042
1043 /*
1044  * Tape interrupt routine, called from the ccw_device layer
1045  */
1046 static void
1047 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1048 {
1049         struct tape_device *device;
1050         struct tape_request *request;
1051         int rc;
1052
1053         device = (struct tape_device *) cdev->dev.driver_data;
1054         if (device == NULL) {
1055                 PRINT_ERR("could not get device structure for %s "
1056                           "in interrupt\n", cdev->dev.bus_id);
1057                 return;
1058         }
1059         request = (struct tape_request *) intparm;
1060
1061         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1062
1063         /* On special conditions irb is an error pointer */
1064         if (IS_ERR(irb)) {
1065                 /* FIXME: What to do with the request? */
1066                 switch (PTR_ERR(irb)) {
1067                         case -ETIMEDOUT:
1068                                 PRINT_WARN("(%s): Request timed out\n",
1069                                         cdev->dev.bus_id);
1070                         case -EIO:
1071                                 __tape_end_request(device, request, -EIO);
1072                                 break;
1073                         default:
1074                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1075                                         cdev->dev.bus_id,
1076                                         PTR_ERR(irb));
1077                 }
1078                 return;
1079         }
1080
1081         /*
1082          * If the condition code is not zero and the start function bit is
1083          * still set, this is an deferred error and the last start I/O did
1084          * not succeed. At this point the condition that caused the deferred
1085          * error might still apply. So we just schedule the request to be
1086          * started later.
1087          */
1088         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC) &&
1089             (request->status == TAPE_REQUEST_IN_IO)) {
1090                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1091                         device->cdev_id, irb->scsw.cc, irb->scsw.fctl);
1092                 request->status = TAPE_REQUEST_QUEUED;
1093                 schedule_delayed_work(&device->tape_dnr, HZ);
1094                 return;
1095         }
1096
1097         /* May be an unsolicited irq */
1098         if(request != NULL)
1099                 request->rescnt = irb->scsw.count;
1100         else if ((irb->scsw.dstat == 0x85 || irb->scsw.dstat == 0x80) &&
1101                  !list_empty(&device->req_queue)) {
1102                 /* Not Ready to Ready after long busy ? */
1103                 struct tape_request *req;
1104                 req = list_entry(device->req_queue.next,
1105                                  struct tape_request, list);
1106                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1107                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1108                         if (del_timer(&device->lb_timeout)) {
1109                                 device->lb_timeout.data = (unsigned long)
1110                                         tape_put_device(device);
1111                                 __tape_start_next_request(device);
1112                         }
1113                         return;
1114                 }
1115         }
1116         if (irb->scsw.dstat != 0x0c) {
1117                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1118                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1119                         device->tape_generic_status |= GMT_ONLINE(~0);
1120                 else
1121                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1122
1123                 /*
1124                  * Any request that does not come back with channel end
1125                  * and device end is unusual. Log the sense data.
1126                  */
1127                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1128                 tape_dump_sense_dbf(device, request, irb);
1129         } else {
1130                 /* Upon normal completion the device _is_ online */
1131                 device->tape_generic_status |= GMT_ONLINE(~0);
1132         }
1133         if (device->tape_state == TS_NOT_OPER) {
1134                 DBF_EVENT(6, "tape:device is not operational\n");
1135                 return;
1136         }
1137
1138         /*
1139          * Request that were canceled still come back with an interrupt.
1140          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1141          */
1142         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1143                 __tape_end_request(device, request, -EIO);
1144                 return;
1145         }
1146
1147         rc = device->discipline->irq(device, request, irb);
1148         /*
1149          * rc < 0 : request finished unsuccessfully.
1150          * rc == TAPE_IO_SUCCESS: request finished successfully.
1151          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1152          * rc == TAPE_IO_RETRY: request finished but needs another go.
1153          * rc == TAPE_IO_STOP: request needs to get terminated.
1154          */
1155         switch (rc) {
1156                 case TAPE_IO_SUCCESS:
1157                         /* Upon normal completion the device _is_ online */
1158                         device->tape_generic_status |= GMT_ONLINE(~0);
1159                         __tape_end_request(device, request, rc);
1160                         break;
1161                 case TAPE_IO_PENDING:
1162                         break;
1163                 case TAPE_IO_LONG_BUSY:
1164                         device->lb_timeout.data =
1165                                 (unsigned long)tape_get_device_reference(device);
1166                         device->lb_timeout.expires = jiffies +
1167                                 LONG_BUSY_TIMEOUT * HZ;
1168                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1169                         add_timer(&device->lb_timeout);
1170                         request->status = TAPE_REQUEST_LONG_BUSY;
1171                         break;
1172                 case TAPE_IO_RETRY:
1173                         rc = __tape_start_io(device, request);
1174                         if (rc)
1175                                 __tape_end_request(device, request, rc);
1176                         break;
1177                 case TAPE_IO_STOP:
1178                         rc = __tape_cancel_io(device, request);
1179                         if (rc)
1180                                 __tape_end_request(device, request, rc);
1181                         break;
1182                 default:
1183                         if (rc > 0) {
1184                                 DBF_EVENT(6, "xunknownrc\n");
1185                                 PRINT_ERR("Invalid return code from discipline "
1186                                         "interrupt function.\n");
1187                                 __tape_end_request(device, request, -EIO);
1188                         } else {
1189                                 __tape_end_request(device, request, rc);
1190                         }
1191                         break;
1192         }
1193 }
1194
1195 /*
1196  * Tape device open function used by tape_char & tape_block frontends.
1197  */
1198 int
1199 tape_open(struct tape_device *device)
1200 {
1201         int rc;
1202
1203         spin_lock(get_ccwdev_lock(device->cdev));
1204         if (device->tape_state == TS_NOT_OPER) {
1205                 DBF_EVENT(6, "TAPE:nodev\n");
1206                 rc = -ENODEV;
1207         } else if (device->tape_state == TS_IN_USE) {
1208                 DBF_EVENT(6, "TAPE:dbusy\n");
1209                 rc = -EBUSY;
1210         } else if (device->tape_state == TS_BLKUSE) {
1211                 DBF_EVENT(6, "TAPE:dbusy\n");
1212                 rc = -EBUSY;
1213         } else if (device->discipline != NULL &&
1214                    !try_module_get(device->discipline->owner)) {
1215                 DBF_EVENT(6, "TAPE:nodisc\n");
1216                 rc = -ENODEV;
1217         } else {
1218                 tape_state_set(device, TS_IN_USE);
1219                 rc = 0;
1220         }
1221         spin_unlock(get_ccwdev_lock(device->cdev));
1222         return rc;
1223 }
1224
1225 /*
1226  * Tape device release function used by tape_char & tape_block frontends.
1227  */
1228 int
1229 tape_release(struct tape_device *device)
1230 {
1231         spin_lock(get_ccwdev_lock(device->cdev));
1232         if (device->tape_state == TS_IN_USE)
1233                 tape_state_set(device, TS_UNUSED);
1234         module_put(device->discipline->owner);
1235         spin_unlock(get_ccwdev_lock(device->cdev));
1236         return 0;
1237 }
1238
1239 /*
1240  * Execute a magnetic tape command a number of times.
1241  */
1242 int
1243 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1244 {
1245         tape_mtop_fn fn;
1246         int rc;
1247
1248         DBF_EVENT(6, "TAPE:mtio\n");
1249         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1250         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1251
1252         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1253                 return -EINVAL;
1254         fn = device->discipline->mtop_array[mt_op];
1255         if (fn == NULL)
1256                 return -EINVAL;
1257
1258         /* We assume that the backends can handle count up to 500. */
1259         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1260             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1261                 rc = 0;
1262                 for (; mt_count > 500; mt_count -= 500)
1263                         if ((rc = fn(device, 500)) != 0)
1264                                 break;
1265                 if (rc == 0)
1266                         rc = fn(device, mt_count);
1267         } else
1268                 rc = fn(device, mt_count);
1269         return rc;
1270
1271 }
1272
1273 /*
1274  * Tape init function.
1275  */
1276 static int
1277 tape_init (void)
1278 {
1279         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1280         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1281 #ifdef DBF_LIKE_HELL
1282         debug_set_level(TAPE_DBF_AREA, 6);
1283 #endif
1284         DBF_EVENT(3, "tape init\n");
1285         tape_proc_init();
1286         tapechar_init ();
1287         tapeblock_init ();
1288         return 0;
1289 }
1290
1291 /*
1292  * Tape exit function.
1293  */
1294 static void
1295 tape_exit(void)
1296 {
1297         DBF_EVENT(6, "tape exit\n");
1298
1299         /* Get rid of the frontends */
1300         tapechar_exit();
1301         tapeblock_exit();
1302         tape_proc_cleanup();
1303         debug_unregister (TAPE_DBF_AREA);
1304 }
1305
1306 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1307               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1308 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1309 MODULE_LICENSE("GPL");
1310
1311 module_init(tape_init);
1312 module_exit(tape_exit);
1313
1314 EXPORT_SYMBOL(tape_generic_remove);
1315 EXPORT_SYMBOL(tape_generic_probe);
1316 EXPORT_SYMBOL(tape_generic_online);
1317 EXPORT_SYMBOL(tape_generic_offline);
1318 EXPORT_SYMBOL(tape_put_device);
1319 EXPORT_SYMBOL(tape_get_device_reference);
1320 EXPORT_SYMBOL(tape_state_verbose);
1321 EXPORT_SYMBOL(tape_op_verbose);
1322 EXPORT_SYMBOL(tape_state_set);
1323 EXPORT_SYMBOL(tape_med_state_set);
1324 EXPORT_SYMBOL(tape_alloc_request);
1325 EXPORT_SYMBOL(tape_free_request);
1326 EXPORT_SYMBOL(tape_dump_sense);
1327 EXPORT_SYMBOL(tape_dump_sense_dbf);
1328 EXPORT_SYMBOL(tape_do_io);
1329 EXPORT_SYMBOL(tape_do_io_async);
1330 EXPORT_SYMBOL(tape_do_io_interruptible);
1331 EXPORT_SYMBOL(tape_cancel_io);
1332 EXPORT_SYMBOL(tape_mtop);