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 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  16
  17 #include <linux/kernel_stat.h>
  18 #include <linux/module.h>
  19 #include <linux/init.h>      // for kernel parameters
  20 #include <linux/kmod.h>      // for requesting modules
  21 #include <linux/spinlock.h>  // for locks
  22 #include <linux/vmalloc.h>
  23 #include <linux/list.h>
  24 #include <linux/slab.h>
  25
  26 #include <asm/types.h>       // for variable types
  27
  28 #define TAPE_DBF_AREA   tape_core_dbf
  29
  30 #include "tape.h"
  31 #include "tape_std.h"
  32
  33 #define LONG_BUSY_TIMEOUT 180 /* seconds */
  34
  35 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  36 static void tape_delayed_next_request(struct work_struct *);
  37 static void tape_long_busy_timeout(unsigned long data);
  38
  39 /*
  40  * One list to contain all tape devices of all disciplines, so
  41  * we can assign the devices to minor numbers of the same major
  42  * The list is protected by the rwlock
  43  */
  44 static LIST_HEAD(tape_device_list);
  45 static DEFINE_RWLOCK(tape_device_lock);
  46
  47 /*
  48  * Pointer to debug area.
  49  */
  50 debug_info_t *TAPE_DBF_AREA = NULL;
  51 EXPORT_SYMBOL(TAPE_DBF_AREA);
  52
  53 /*
  54  * Printable strings for tape enumerations.
  55  */
  56 const char *tape_state_verbose[TS_SIZE] =
  57 {
  58         [TS_UNUSED]   = "UNUSED",
  59         [TS_IN_USE]   = "IN_USE",
  60         [TS_BLKUSE]   = "BLKUSE",
  61         [TS_INIT]     = "INIT  ",
  62         [TS_NOT_OPER] = "NOT_OP"
  63 };
  64
  65 const char *tape_op_verbose[TO_SIZE] =
  66 {
  67         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  68         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  69         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  70         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  71         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  72         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  73         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  74         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  75         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  76         [TO_READ_ATTMSG] = "RAT",
  77         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  78         [TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
  79         [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
  80         [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
  81 };
  82
  83 static int devid_to_int(struct ccw_dev_id *dev_id)
  84 {
  85         return dev_id->devno + (dev_id->ssid << 16);
  86 }
  87
  88 /*
  89  * Some channel attached tape specific attributes.
  90  *
  91  * FIXME: In the future the first_minor and blocksize attribute should be
  92  *        replaced by a link to the cdev tree.
  93  */
  94 static ssize_t
  95 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
  96 {
  97         struct tape_device *tdev;
  98
  99         tdev = dev_get_drvdata(dev);
 100         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 101 }
 102
 103 static
 104 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 105
 106 static ssize_t
 107 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 108 {
 109         struct tape_device *tdev;
 110
 111         tdev = dev_get_drvdata(dev);
 112         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 113 }
 114
 115 static
 116 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 117
 118 static ssize_t
 119 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 120 {
 121         struct tape_device *tdev;
 122
 123         tdev = dev_get_drvdata(dev);
 124         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 125                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 126 }
 127
 128 static
 129 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 130
 131 static ssize_t
 132 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 133 {
 134         struct tape_device *tdev;
 135         ssize_t rc;
 136
 137         tdev = dev_get_drvdata(dev);
 138         if (tdev->first_minor < 0)
 139                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 140
 141         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 142         if (list_empty(&tdev->req_queue))
 143                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 144         else {
 145                 struct tape_request *req;
 146
 147                 req = list_entry(tdev->req_queue.next, struct tape_request,
 148                         list);
 149                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 150         }
 151         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 152         return rc;
 153 }
 154
 155 static
 156 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 157
 158 static ssize_t
 159 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 160 {
 161         struct tape_device *tdev;
 162
 163         tdev = dev_get_drvdata(dev);
 164
 165         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 166 }
 167
 168 static
 169 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 170
 171 static struct attribute *tape_attrs[] = {
 172         &dev_attr_medium_state.attr,
 173         &dev_attr_first_minor.attr,
 174         &dev_attr_state.attr,
 175         &dev_attr_operation.attr,
 176         &dev_attr_blocksize.attr,
 177         NULL
 178 };
 179
 180 static struct attribute_group tape_attr_group = {
 181         .attrs = tape_attrs,
 182 };
 183
 184 /*
 185  * Tape state functions
 186  */
 187 void
 188 tape_state_set(struct tape_device *device, enum tape_state newstate)
 189 {
 190         const char *str;
 191
 192         if (device->tape_state == TS_NOT_OPER) {
 193                 DBF_EVENT(3, "ts_set err: not oper\n");
 194                 return;
 195         }
 196         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 197         DBF_EVENT(4, "old ts:\t\n");
 198         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 199                 str = tape_state_verbose[device->tape_state];
 200         else
 201                 str = "UNKNOWN TS";
 202         DBF_EVENT(4, "%s\n", str);
 203         DBF_EVENT(4, "new ts:\t\n");
 204         if (newstate < TS_SIZE && newstate >= 0)
 205                 str = tape_state_verbose[newstate];
 206         else
 207                 str = "UNKNOWN TS";
 208         DBF_EVENT(4, "%s\n", str);
 209         device->tape_state = newstate;
 210         wake_up(&device->state_change_wq);
 211 }
 212
 213 struct tape_med_state_work_data {
 214         struct tape_device *device;
 215         enum tape_medium_state state;
 216         struct work_struct  work;
 217 };
 218
 219 static void
 220 tape_med_state_work_handler(struct work_struct *work)
 221 {
 222         static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
 223         static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
 224         struct tape_med_state_work_data *p =
 225                 container_of(work, struct tape_med_state_work_data, work);
 226         struct tape_device *device = p->device;
 227         char *envp[] = { NULL, NULL };
 228
 229         switch (p->state) {
 230         case MS_UNLOADED:
 231                 pr_info("%s: The tape cartridge has been successfully "
 232                         "unloaded\n", dev_name(&device->cdev->dev));
 233                 envp[0] = env_state_unloaded;
 234                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 235                 break;
 236         case MS_LOADED:
 237                 pr_info("%s: A tape cartridge has been mounted\n",
 238                         dev_name(&device->cdev->dev));
 239                 envp[0] = env_state_loaded;
 240                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 241                 break;
 242         default:
 243                 break;
 244         }
 245         tape_put_device(device);
 246         kfree(p);
 247 }
 248
 249 static void
 250 tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
 251 {
 252         struct tape_med_state_work_data *p;
 253
 254         p = kzalloc(sizeof(*p), GFP_ATOMIC);
 255         if (p) {
 256                 INIT_WORK(&p->work, tape_med_state_work_handler);
 257                 p->device = tape_get_device(device);
 258                 p->state = state;
 259                 schedule_work(&p->work);
 260         }
 261 }
 262
 263 void
 264 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 265 {
 266         enum tape_medium_state oldstate;
 267
 268         oldstate = device->medium_state;
 269         if (oldstate == newstate)
 270                 return;
 271         device->medium_state = newstate;
 272         switch(newstate){
 273         case MS_UNLOADED:
 274                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 275                 if (oldstate == MS_LOADED)
 276                         tape_med_state_work(device, MS_UNLOADED);
 277                 break;
 278         case MS_LOADED:
 279                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 280                 if (oldstate == MS_UNLOADED)
 281                         tape_med_state_work(device, MS_LOADED);
 282                 break;
 283         default:
 284                 break;
 285         }
 286         wake_up(&device->state_change_wq);
 287 }
 288
 289 /*
 290  * Stop running ccw. Has to be called with the device lock held.
 291  */
 292 static int
 293 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 294 {
 295         int retries;
 296         int rc;
 297
 298         /* Check if interrupt has already been processed */
 299         if (request->callback == NULL)
 300                 return 0;
 301
 302         rc = 0;
 303         for (retries = 0; retries < 5; retries++) {
 304                 rc = ccw_device_clear(device->cdev, (long) request);
 305
 306                 switch (rc) {
 307                         case 0:
 308                                 request->status = TAPE_REQUEST_DONE;
 309                                 return 0;
 310                         case -EBUSY:
 311                                 request->status = TAPE_REQUEST_CANCEL;
 312                                 schedule_delayed_work(&device->tape_dnr, 0);
 313                                 return 0;
 314                         case -ENODEV:
 315                                 DBF_EXCEPTION(2, "device gone, retry\n");
 316                                 break;
 317                         case -EIO:
 318                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 319                                 break;
 320                         default:
 321                                 BUG();
 322                 }
 323         }
 324
 325         return rc;
 326 }
 327
 328 /*
 329  * Add device into the sorted list, giving it the first
 330  * available minor number.
 331  */
 332 static int
 333 tape_assign_minor(struct tape_device *device)
 334 {
 335         struct tape_device *tmp;
 336         int minor;
 337
 338         minor = 0;
 339         write_lock(&tape_device_lock);
 340         list_for_each_entry(tmp, &tape_device_list, node) {
 341                 if (minor < tmp->first_minor)
 342                         break;
 343                 minor += TAPE_MINORS_PER_DEV;
 344         }
 345         if (minor >= 256) {
 346                 write_unlock(&tape_device_lock);
 347                 return -ENODEV;
 348         }
 349         device->first_minor = minor;
 350         list_add_tail(&device->node, &tmp->node);
 351         write_unlock(&tape_device_lock);
 352         return 0;
 353 }
 354
 355 /* remove device from the list */
 356 static void
 357 tape_remove_minor(struct tape_device *device)
 358 {
 359         write_lock(&tape_device_lock);
 360         list_del_init(&device->node);
 361         device->first_minor = -1;
 362         write_unlock(&tape_device_lock);
 363 }
 364
 365 /*
 366  * Set a device online.
 367  *
 368  * This function is called by the common I/O layer to move a device from the
 369  * detected but offline into the online state.
 370  * If we return an error (RC < 0) the device remains in the offline state. This
 371  * can happen if the device is assigned somewhere else, for example.
 372  */
 373 int
 374 tape_generic_online(struct tape_device *device,
 375                    struct tape_discipline *discipline)
 376 {
 377         int rc;
 378
 379         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 380
 381         if (device->tape_state != TS_INIT) {
 382                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 383                 return -EINVAL;
 384         }
 385
 386         init_timer(&device->lb_timeout);
 387         device->lb_timeout.function = tape_long_busy_timeout;
 388
 389         /* Let the discipline have a go at the device. */
 390         device->discipline = discipline;
 391         if (!try_module_get(discipline->owner)) {
 392                 return -EINVAL;
 393         }
 394
 395         rc = discipline->setup_device(device);
 396         if (rc)
 397                 goto out;
 398         rc = tape_assign_minor(device);
 399         if (rc)
 400                 goto out_discipline;
 401
 402         rc = tapechar_setup_device(device);
 403         if (rc)
 404                 goto out_minor;
 405         rc = tapeblock_setup_device(device);
 406         if (rc)
 407                 goto out_char;
 408
 409         tape_state_set(device, TS_UNUSED);
 410
 411         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 412
 413         return 0;
 414
 415 out_char:
 416         tapechar_cleanup_device(device);
 417 out_minor:
 418         tape_remove_minor(device);
 419 out_discipline:
 420         device->discipline->cleanup_device(device);
 421         device->discipline = NULL;
 422 out:
 423         module_put(discipline->owner);
 424         return rc;
 425 }
 426
 427 static void
 428 tape_cleanup_device(struct tape_device *device)
 429 {
 430         tapeblock_cleanup_device(device);
 431         tapechar_cleanup_device(device);
 432         device->discipline->cleanup_device(device);
 433         module_put(device->discipline->owner);
 434         tape_remove_minor(device);
 435         tape_med_state_set(device, MS_UNKNOWN);
 436 }
 437
 438 /*
 439  * Suspend device.
 440  *
 441  * Called by the common I/O layer if the drive should be suspended on user
 442  * request. We refuse to suspend if the device is loaded or in use for the
 443  * following reason:
 444  * While the Linux guest is suspended, it might be logged off which causes
 445  * devices to be detached. Tape devices are automatically rewound and unloaded
 446  * during DETACH processing (unless the tape device was attached with the
 447  * NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
 448  * resume the original state of the tape device, since we would need to
 449  * manually re-load the cartridge which was active at suspend time.
 450  */
 451 int tape_generic_pm_suspend(struct ccw_device *cdev)
 452 {
 453         struct tape_device *device;
 454
 455         device = dev_get_drvdata(&cdev->dev);
 456         if (!device) {
 457                 return -ENODEV;
 458         }
 459
 460         DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
 461                 device->cdev_id, device);
 462
 463         if (device->medium_state != MS_UNLOADED) {
 464                 pr_err("A cartridge is loaded in tape device %s, "
 465                        "refusing to suspend\n", dev_name(&cdev->dev));
 466                 return -EBUSY;
 467         }
 468
 469         spin_lock_irq(get_ccwdev_lock(device->cdev));
 470         switch (device->tape_state) {
 471                 case TS_INIT:
 472                 case TS_NOT_OPER:
 473                 case TS_UNUSED:
 474                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 475                         break;
 476                 default:
 477                         pr_err("Tape device %s is busy, refusing to "
 478                                "suspend\n", dev_name(&cdev->dev));
 479                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 480                         return -EBUSY;
 481         }
 482
 483         DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
 484         return 0;
 485 }
 486
 487 /*
 488  * Set device offline.
 489  *
 490  * Called by the common I/O layer if the drive should set offline on user
 491  * request. We may prevent this by returning an error.
 492  * Manual offline is only allowed while the drive is not in use.
 493  */
 494 int
 495 tape_generic_offline(struct ccw_device *cdev)
 496 {
 497         struct tape_device *device;
 498
 499         device = dev_get_drvdata(&cdev->dev);
 500         if (!device) {
 501                 return -ENODEV;
 502         }
 503
 504         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 505                 device->cdev_id, device);
 506
 507         spin_lock_irq(get_ccwdev_lock(device->cdev));
 508         switch (device->tape_state) {
 509                 case TS_INIT:
 510                 case TS_NOT_OPER:
 511                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 512                         break;
 513                 case TS_UNUSED:
 514                         tape_state_set(device, TS_INIT);
 515                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 516                         tape_cleanup_device(device);
 517                         break;
 518                 default:
 519                         DBF_EVENT(3, "(%08x): Set offline failed "
 520                                 "- drive in use.\n",
 521                                 device->cdev_id);
 522                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 523                         return -EBUSY;
 524         }
 525
 526         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 527         return 0;
 528 }
 529
 530 /*
 531  * Allocate memory for a new device structure.
 532  */
 533 static struct tape_device *
 534 tape_alloc_device(void)
 535 {
 536         struct tape_device *device;
 537
 538         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 539         if (device == NULL) {
 540                 DBF_EXCEPTION(2, "ti:no mem\n");
 541                 return ERR_PTR(-ENOMEM);
 542         }
 543         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 544         if (device->modeset_byte == NULL) {
 545                 DBF_EXCEPTION(2, "ti:no mem\n");
 546                 kfree(device);
 547                 return ERR_PTR(-ENOMEM);
 548         }
 549         mutex_init(&device->mutex);
 550         INIT_LIST_HEAD(&device->req_queue);
 551         INIT_LIST_HEAD(&device->node);
 552         init_waitqueue_head(&device->state_change_wq);
 553         init_waitqueue_head(&device->wait_queue);
 554         device->tape_state = TS_INIT;
 555         device->medium_state = MS_UNKNOWN;
 556         *device->modeset_byte = 0;
 557         device->first_minor = -1;
 558         atomic_set(&device->ref_count, 1);
 559         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 560
 561         return device;
 562 }
 563
 564 /*
 565  * Get a reference to an existing device structure. This will automatically
 566  * increment the reference count.
 567  */
 568 struct tape_device *
 569 tape_get_device(struct tape_device *device)
 570 {
 571         int count;
 572
 573         count = atomic_inc_return(&device->ref_count);
 574         DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
 575         return device;
 576 }
 577
 578 /*
 579  * Decrease the reference counter of a devices structure. If the
 580  * reference counter reaches zero free the device structure.
 581  * The function returns a NULL pointer to be used by the caller
 582  * for clearing reference pointers.
 583  */
 584 void
 585 tape_put_device(struct tape_device *device)
 586 {
 587         int count;
 588
 589         count = atomic_dec_return(&device->ref_count);
 590         DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
 591         BUG_ON(count < 0);
 592         if (count == 0) {
 593                 kfree(device->modeset_byte);
 594                 kfree(device);
 595         }
 596 }
 597
 598 /*
 599  * Find tape device by a device index.
 600  */
 601 struct tape_device *
 602 tape_find_device(int devindex)
 603 {
 604         struct tape_device *device, *tmp;
 605
 606         device = ERR_PTR(-ENODEV);
 607         read_lock(&tape_device_lock);
 608         list_for_each_entry(tmp, &tape_device_list, node) {
 609                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 610                         device = tape_get_device(tmp);
 611                         break;
 612                 }
 613         }
 614         read_unlock(&tape_device_lock);
 615         return device;
 616 }
 617
 618 /*
 619  * Driverfs tape probe function.
 620  */
 621 int
 622 tape_generic_probe(struct ccw_device *cdev)
 623 {
 624         struct tape_device *device;
 625         int ret;
 626         struct ccw_dev_id dev_id;
 627
 628         device = tape_alloc_device();
 629         if (IS_ERR(device))
 630                 return -ENODEV;
 631         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
 632                                      CCWDEV_DO_MULTIPATH);
 633         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 634         if (ret) {
 635                 tape_put_device(device);
 636                 return ret;
 637         }
 638         dev_set_drvdata(&cdev->dev, device);
 639         cdev->handler = __tape_do_irq;
 640         device->cdev = cdev;
 641         ccw_device_get_id(cdev, &dev_id);
 642         device->cdev_id = devid_to_int(&dev_id);
 643         return ret;
 644 }
 645
 646 static void
 647 __tape_discard_requests(struct tape_device *device)
 648 {
 649         struct tape_request *   request;
 650         struct list_head *      l, *n;
 651
 652         list_for_each_safe(l, n, &device->req_queue) {
 653                 request = list_entry(l, struct tape_request, list);
 654                 if (request->status == TAPE_REQUEST_IN_IO)
 655                         request->status = TAPE_REQUEST_DONE;
 656                 list_del(&request->list);
 657
 658                 /* Decrease ref_count for removed request. */
 659                 request->device = NULL;
 660                 tape_put_device(device);
 661                 request->rc = -EIO;
 662                 if (request->callback != NULL)
 663                         request->callback(request, request->callback_data);
 664         }
 665 }
 666
 667 /*
 668  * Driverfs tape remove function.
 669  *
 670  * This function is called whenever the common I/O layer detects the device
 671  * gone. This can happen at any time and we cannot refuse.
 672  */
 673 void
 674 tape_generic_remove(struct ccw_device *cdev)
 675 {
 676         struct tape_device *    device;
 677
 678         device = dev_get_drvdata(&cdev->dev);
 679         if (!device) {
 680                 return;
 681         }
 682         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 683
 684         spin_lock_irq(get_ccwdev_lock(device->cdev));
 685         switch (device->tape_state) {
 686                 case TS_INIT:
 687                         tape_state_set(device, TS_NOT_OPER);
 688                 case TS_NOT_OPER:
 689                         /*
 690                          * Nothing to do.
 691                          */
 692                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 693                         break;
 694                 case TS_UNUSED:
 695                         /*
 696                          * Need only to release the device.
 697                          */
 698                         tape_state_set(device, TS_NOT_OPER);
 699                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 700                         tape_cleanup_device(device);
 701                         break;
 702                 default:
 703                         /*
 704                          * There may be requests on the queue. We will not get
 705                          * an interrupt for a request that was running. So we
 706                          * just post them all as I/O errors.
 707                          */
 708                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 709                                 device->cdev_id);
 710                         pr_warning("%s: A tape unit was detached while in "
 711                                    "use\n", dev_name(&device->cdev->dev));
 712                         tape_state_set(device, TS_NOT_OPER);
 713                         __tape_discard_requests(device);
 714                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 715                         tape_cleanup_device(device);
 716         }
 717
 718         device = dev_get_drvdata(&cdev->dev);
 719         if (device) {
 720                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 721                 dev_set_drvdata(&cdev->dev, NULL);
 722                 tape_put_device(device);
 723         }
 724 }
 725
 726 /*
 727  * Allocate a new tape ccw request
 728  */
 729 struct tape_request *
 730 tape_alloc_request(int cplength, int datasize)
 731 {
 732         struct tape_request *request;
 733
 734         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 735
 736         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 737
 738         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 739         if (request == NULL) {
 740                 DBF_EXCEPTION(1, "cqra nomem\n");
 741                 return ERR_PTR(-ENOMEM);
 742         }
 743         /* allocate channel program */
 744         if (cplength > 0) {
 745                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 746                                           GFP_ATOMIC | GFP_DMA);
 747                 if (request->cpaddr == NULL) {
 748                         DBF_EXCEPTION(1, "cqra nomem\n");
 749                         kfree(request);
 750                         return ERR_PTR(-ENOMEM);
 751                 }
 752         }
 753         /* alloc small kernel buffer */
 754         if (datasize > 0) {
 755                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 756                 if (request->cpdata == NULL) {
 757                         DBF_EXCEPTION(1, "cqra nomem\n");
 758                         kfree(request->cpaddr);
 759                         kfree(request);
 760                         return ERR_PTR(-ENOMEM);
 761                 }
 762         }
 763         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 764                 request->cpdata);
 765
 766         return request;
 767 }
 768
 769 /*
 770  * Free tape ccw request
 771  */
 772 void
 773 tape_free_request (struct tape_request * request)
 774 {
 775         DBF_LH(6, "Free request %p\n", request);
 776
 777         if (request->device)
 778                 tape_put_device(request->device);
 779         kfree(request->cpdata);
 780         kfree(request->cpaddr);
 781         kfree(request);
 782 }
 783
 784 static int
 785 __tape_start_io(struct tape_device *device, struct tape_request *request)
 786 {
 787         int rc;
 788
 789 #ifdef CONFIG_S390_TAPE_BLOCK
 790         if (request->op == TO_BLOCK)
 791                 device->discipline->check_locate(device, request);
 792 #endif
 793         rc = ccw_device_start(
 794                 device->cdev,
 795                 request->cpaddr,
 796                 (unsigned long) request,
 797                 0x00,
 798                 request->options
 799         );
 800         if (rc == 0) {
 801                 request->status = TAPE_REQUEST_IN_IO;
 802         } else if (rc == -EBUSY) {
 803                 /* The common I/O subsystem is currently busy. Retry later. */
 804                 request->status = TAPE_REQUEST_QUEUED;
 805                 schedule_delayed_work(&device->tape_dnr, 0);
 806                 rc = 0;
 807         } else {
 808                 /* Start failed. Remove request and indicate failure. */
 809                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 810         }
 811         return rc;
 812 }
 813
 814 static void
 815 __tape_start_next_request(struct tape_device *device)
 816 {
 817         struct list_head *l, *n;
 818         struct tape_request *request;
 819         int rc;
 820
 821         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 822         /*
 823          * Try to start each request on request queue until one is
 824          * started successful.
 825          */
 826         list_for_each_safe(l, n, &device->req_queue) {
 827                 request = list_entry(l, struct tape_request, list);
 828
 829                 /*
 830                  * Avoid race condition if bottom-half was triggered more than
 831                  * once.
 832                  */
 833                 if (request->status == TAPE_REQUEST_IN_IO)
 834                         return;
 835                 /*
 836                  * Request has already been stopped. We have to wait until
 837                  * the request is removed from the queue in the interrupt
 838                  * handling.
 839                  */
 840                 if (request->status == TAPE_REQUEST_DONE)
 841                         return;
 842
 843                 /*
 844                  * We wanted to cancel the request but the common I/O layer
 845                  * was busy at that time. This can only happen if this
 846                  * function is called by delayed_next_request.
 847                  * Otherwise we start the next request on the queue.
 848                  */
 849                 if (request->status == TAPE_REQUEST_CANCEL) {
 850                         rc = __tape_cancel_io(device, request);
 851                 } else {
 852                         rc = __tape_start_io(device, request);
 853                 }
 854                 if (rc == 0)
 855                         return;
 856
 857                 /* Set ending status. */
 858                 request->rc = rc;
 859                 request->status = TAPE_REQUEST_DONE;
 860
 861                 /* Remove from request queue. */
 862                 list_del(&request->list);
 863
 864                 /* Do callback. */
 865                 if (request->callback != NULL)
 866                         request->callback(request, request->callback_data);
 867         }
 868 }
 869
 870 static void
 871 tape_delayed_next_request(struct work_struct *work)
 872 {
 873         struct tape_device *device =
 874                 container_of(work, struct tape_device, tape_dnr.work);
 875
 876         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 877         spin_lock_irq(get_ccwdev_lock(device->cdev));
 878         __tape_start_next_request(device);
 879         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 880 }
 881
 882 static void tape_long_busy_timeout(unsigned long data)
 883 {
 884         struct tape_request *request;
 885         struct tape_device *device;
 886
 887         device = (struct tape_device *) data;
 888         spin_lock_irq(get_ccwdev_lock(device->cdev));
 889         request = list_entry(device->req_queue.next, struct tape_request, list);
 890         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 891         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 892         __tape_start_next_request(device);
 893         device->lb_timeout.data = 0UL;
 894         tape_put_device(device);
 895         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 896 }
 897
 898 static void
 899 __tape_end_request(
 900         struct tape_device *    device,
 901         struct tape_request *   request,
 902         int                     rc)
 903 {
 904         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 905         if (request) {
 906                 request->rc = rc;
 907                 request->status = TAPE_REQUEST_DONE;
 908
 909                 /* Remove from request queue. */
 910                 list_del(&request->list);
 911
 912                 /* Do callback. */
 913                 if (request->callback != NULL)
 914                         request->callback(request, request->callback_data);
 915         }
 916
 917         /* Start next request. */
 918         if (!list_empty(&device->req_queue))
 919                 __tape_start_next_request(device);
 920 }
 921
 922 /*
 923  * Write sense data to dbf
 924  */
 925 void
 926 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 927                     struct irb *irb)
 928 {
 929         unsigned int *sptr;
 930         const char* op;
 931
 932         if (request != NULL)
 933                 op = tape_op_verbose[request->op];
 934         else
 935                 op = "---";
 936         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 937                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 938         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 939         sptr = (unsigned int *) irb->ecw;
 940         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 941         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 942         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 943         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 944 }
 945
 946 /*
 947  * I/O helper function. Adds the request to the request queue
 948  * and starts it if the tape is idle. Has to be called with
 949  * the device lock held.
 950  */
 951 static int
 952 __tape_start_request(struct tape_device *device, struct tape_request *request)
 953 {
 954         int rc;
 955
 956         switch (request->op) {
 957                 case TO_MSEN:
 958                 case TO_ASSIGN:
 959                 case TO_UNASSIGN:
 960                 case TO_READ_ATTMSG:
 961                 case TO_RDC:
 962                         if (device->tape_state == TS_INIT)
 963                                 break;
 964                         if (device->tape_state == TS_UNUSED)
 965                                 break;
 966                 default:
 967                         if (device->tape_state == TS_BLKUSE)
 968                                 break;
 969                         if (device->tape_state != TS_IN_USE)
 970                                 return -ENODEV;
 971         }
 972
 973         /* Increase use count of device for the added request. */
 974         request->device = tape_get_device(device);
 975
 976         if (list_empty(&device->req_queue)) {
 977                 /* No other requests are on the queue. Start this one. */
 978                 rc = __tape_start_io(device, request);
 979                 if (rc)
 980                         return rc;
 981
 982                 DBF_LH(5, "Request %p added for execution.\n", request);
 983                 list_add(&request->list, &device->req_queue);
 984         } else {
 985                 DBF_LH(5, "Request %p add to queue.\n", request);
 986                 request->status = TAPE_REQUEST_QUEUED;
 987                 list_add_tail(&request->list, &device->req_queue);
 988         }
 989         return 0;
 990 }
 991
 992 /*
 993  * Add the request to the request queue, try to start it if the
 994  * tape is idle. Return without waiting for end of i/o.
 995  */
 996 int
 997 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 998 {
 999         int rc;
1000
1001         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
1002
1003         spin_lock_irq(get_ccwdev_lock(device->cdev));
1004         /* Add request to request queue and try to start it. */
1005         rc = __tape_start_request(device, request);
1006         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1007         return rc;
1008 }
1009
1010 /*
1011  * tape_do_io/__tape_wake_up
1012  * Add the request to the request queue, try to start it if the
1013  * tape is idle and wait uninterruptible for its completion.
1014  */
1015 static void
1016 __tape_wake_up(struct tape_request *request, void *data)
1017 {
1018         request->callback = NULL;
1019         wake_up((wait_queue_head_t *) data);
1020 }
1021
1022 int
1023 tape_do_io(struct tape_device *device, struct tape_request *request)
1024 {
1025         int rc;
1026
1027         spin_lock_irq(get_ccwdev_lock(device->cdev));
1028         /* Setup callback */
1029         request->callback = __tape_wake_up;
1030         request->callback_data = &device->wait_queue;
1031         /* Add request to request queue and try to start it. */
1032         rc = __tape_start_request(device, request);
1033         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1034         if (rc)
1035                 return rc;
1036         /* Request added to the queue. Wait for its completion. */
1037         wait_event(device->wait_queue, (request->callback == NULL));
1038         /* Get rc from request */
1039         return request->rc;
1040 }
1041
1042 /*
1043  * tape_do_io_interruptible/__tape_wake_up_interruptible
1044  * Add the request to the request queue, try to start it if the
1045  * tape is idle and wait uninterruptible for its completion.
1046  */
1047 static void
1048 __tape_wake_up_interruptible(struct tape_request *request, void *data)
1049 {
1050         request->callback = NULL;
1051         wake_up_interruptible((wait_queue_head_t *) data);
1052 }
1053
1054 int
1055 tape_do_io_interruptible(struct tape_device *device,
1056                          struct tape_request *request)
1057 {
1058         int rc;
1059
1060         spin_lock_irq(get_ccwdev_lock(device->cdev));
1061         /* Setup callback */
1062         request->callback = __tape_wake_up_interruptible;
1063         request->callback_data = &device->wait_queue;
1064         rc = __tape_start_request(device, request);
1065         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1066         if (rc)
1067                 return rc;
1068         /* Request added to the queue. Wait for its completion. */
1069         rc = wait_event_interruptible(device->wait_queue,
1070                                       (request->callback == NULL));
1071         if (rc != -ERESTARTSYS)
1072                 /* Request finished normally. */
1073                 return request->rc;
1074
1075         /* Interrupted by a signal. We have to stop the current request. */
1076         spin_lock_irq(get_ccwdev_lock(device->cdev));
1077         rc = __tape_cancel_io(device, request);
1078         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1079         if (rc == 0) {
1080                 /* Wait for the interrupt that acknowledges the halt. */
1081                 do {
1082                         rc = wait_event_interruptible(
1083                                 device->wait_queue,
1084                                 (request->callback == NULL)
1085                         );
1086                 } while (rc == -ERESTARTSYS);
1087
1088                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1089                 rc = -ERESTARTSYS;
1090         }
1091         return rc;
1092 }
1093
1094 /*
1095  * Stop running ccw.
1096  */
1097 int
1098 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1099 {
1100         int rc;
1101
1102         spin_lock_irq(get_ccwdev_lock(device->cdev));
1103         rc = __tape_cancel_io(device, request);
1104         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1105         return rc;
1106 }
1107
1108 /*
1109  * Tape interrupt routine, called from the ccw_device layer
1110  */
1111 static void
1112 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1113 {
1114         struct tape_device *device;
1115         struct tape_request *request;
1116         int rc;
1117
1118         kstat_cpu(smp_processor_id()).irqs[IOINT_TAP]++;
1119         device = dev_get_drvdata(&cdev->dev);
1120         if (device == NULL) {
1121                 return;
1122         }
1123         request = (struct tape_request *) intparm;
1124
1125         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1126
1127         /* On special conditions irb is an error pointer */
1128         if (IS_ERR(irb)) {
1129                 /* FIXME: What to do with the request? */
1130                 switch (PTR_ERR(irb)) {
1131                         case -ETIMEDOUT:
1132                                 DBF_LH(1, "(%08x): Request timed out\n",
1133                                        device->cdev_id);
1134                         case -EIO:
1135                                 __tape_end_request(device, request, -EIO);
1136                                 break;
1137                         default:
1138                                 DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
1139                                        device->cdev_id, PTR_ERR(irb));
1140                 }
1141                 return;
1142         }
1143
1144         /*
1145          * If the condition code is not zero and the start function bit is
1146          * still set, this is an deferred error and the last start I/O did
1147          * not succeed. At this point the condition that caused the deferred
1148          * error might still apply. So we just schedule the request to be
1149          * started later.
1150          */
1151         if (irb->scsw.cmd.cc != 0 &&
1152             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1153             (request->status == TAPE_REQUEST_IN_IO)) {
1154                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1155                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1156                 request->status = TAPE_REQUEST_QUEUED;
1157                 schedule_delayed_work(&device->tape_dnr, HZ);
1158                 return;
1159         }
1160
1161         /* May be an unsolicited irq */
1162         if(request != NULL)
1163                 request->rescnt = irb->scsw.cmd.count;
1164         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1165                  !list_empty(&device->req_queue)) {
1166                 /* Not Ready to Ready after long busy ? */
1167                 struct tape_request *req;
1168                 req = list_entry(device->req_queue.next,
1169                                  struct tape_request, list);
1170                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1171                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1172                         if (del_timer(&device->lb_timeout)) {
1173                                 device->lb_timeout.data = 0UL;
1174                                 tape_put_device(device);
1175                                 __tape_start_next_request(device);
1176                         }
1177                         return;
1178                 }
1179         }
1180         if (irb->scsw.cmd.dstat != 0x0c) {
1181                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1182                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1183                         device->tape_generic_status |= GMT_ONLINE(~0);
1184                 else
1185                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1186
1187                 /*
1188                  * Any request that does not come back with channel end
1189                  * and device end is unusual. Log the sense data.
1190                  */
1191                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1192                 tape_dump_sense_dbf(device, request, irb);
1193         } else {
1194                 /* Upon normal completion the device _is_ online */
1195                 device->tape_generic_status |= GMT_ONLINE(~0);
1196         }
1197         if (device->tape_state == TS_NOT_OPER) {
1198                 DBF_EVENT(6, "tape:device is not operational\n");
1199                 return;
1200         }
1201
1202         /*
1203          * Request that were canceled still come back with an interrupt.
1204          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1205          */
1206         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1207                 __tape_end_request(device, request, -EIO);
1208                 return;
1209         }
1210
1211         rc = device->discipline->irq(device, request, irb);
1212         /*
1213          * rc < 0 : request finished unsuccessfully.
1214          * rc == TAPE_IO_SUCCESS: request finished successfully.
1215          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1216          * rc == TAPE_IO_RETRY: request finished but needs another go.
1217          * rc == TAPE_IO_STOP: request needs to get terminated.
1218          */
1219         switch (rc) {
1220                 case TAPE_IO_SUCCESS:
1221                         /* Upon normal completion the device _is_ online */
1222                         device->tape_generic_status |= GMT_ONLINE(~0);
1223                         __tape_end_request(device, request, rc);
1224                         break;
1225                 case TAPE_IO_PENDING:
1226                         break;
1227                 case TAPE_IO_LONG_BUSY:
1228                         device->lb_timeout.data =
1229                                 (unsigned long) tape_get_device(device);
1230                         device->lb_timeout.expires = jiffies +
1231                                 LONG_BUSY_TIMEOUT * HZ;
1232                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1233                         add_timer(&device->lb_timeout);
1234                         request->status = TAPE_REQUEST_LONG_BUSY;
1235                         break;
1236                 case TAPE_IO_RETRY:
1237                         rc = __tape_start_io(device, request);
1238                         if (rc)
1239                                 __tape_end_request(device, request, rc);
1240                         break;
1241                 case TAPE_IO_STOP:
1242                         rc = __tape_cancel_io(device, request);
1243                         if (rc)
1244                                 __tape_end_request(device, request, rc);
1245                         break;
1246                 default:
1247                         if (rc > 0) {
1248                                 DBF_EVENT(6, "xunknownrc\n");
1249                                 __tape_end_request(device, request, -EIO);
1250                         } else {
1251                                 __tape_end_request(device, request, rc);
1252                         }
1253                         break;
1254         }
1255 }
1256
1257 /*
1258  * Tape device open function used by tape_char & tape_block frontends.
1259  */
1260 int
1261 tape_open(struct tape_device *device)
1262 {
1263         int rc;
1264
1265         spin_lock_irq(get_ccwdev_lock(device->cdev));
1266         if (device->tape_state == TS_NOT_OPER) {
1267                 DBF_EVENT(6, "TAPE:nodev\n");
1268                 rc = -ENODEV;
1269         } else if (device->tape_state == TS_IN_USE) {
1270                 DBF_EVENT(6, "TAPE:dbusy\n");
1271                 rc = -EBUSY;
1272         } else if (device->tape_state == TS_BLKUSE) {
1273                 DBF_EVENT(6, "TAPE:dbusy\n");
1274                 rc = -EBUSY;
1275         } else if (device->discipline != NULL &&
1276                    !try_module_get(device->discipline->owner)) {
1277                 DBF_EVENT(6, "TAPE:nodisc\n");
1278                 rc = -ENODEV;
1279         } else {
1280                 tape_state_set(device, TS_IN_USE);
1281                 rc = 0;
1282         }
1283         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1284         return rc;
1285 }
1286
1287 /*
1288  * Tape device release function used by tape_char & tape_block frontends.
1289  */
1290 int
1291 tape_release(struct tape_device *device)
1292 {
1293         spin_lock_irq(get_ccwdev_lock(device->cdev));
1294         if (device->tape_state == TS_IN_USE)
1295                 tape_state_set(device, TS_UNUSED);
1296         module_put(device->discipline->owner);
1297         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1298         return 0;
1299 }
1300
1301 /*
1302  * Execute a magnetic tape command a number of times.
1303  */
1304 int
1305 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1306 {
1307         tape_mtop_fn fn;
1308         int rc;
1309
1310         DBF_EVENT(6, "TAPE:mtio\n");
1311         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1312         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1313
1314         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1315                 return -EINVAL;
1316         fn = device->discipline->mtop_array[mt_op];
1317         if (fn == NULL)
1318                 return -EINVAL;
1319
1320         /* We assume that the backends can handle count up to 500. */
1321         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1322             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1323                 rc = 0;
1324                 for (; mt_count > 500; mt_count -= 500)
1325                         if ((rc = fn(device, 500)) != 0)
1326                                 break;
1327                 if (rc == 0)
1328                         rc = fn(device, mt_count);
1329         } else
1330                 rc = fn(device, mt_count);
1331         return rc;
1332
1333 }
1334
1335 /*
1336  * Tape init function.
1337  */
1338 static int
1339 tape_init (void)
1340 {
1341         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1342         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1343 #ifdef DBF_LIKE_HELL
1344         debug_set_level(TAPE_DBF_AREA, 6);
1345 #endif
1346         DBF_EVENT(3, "tape init\n");
1347         tape_proc_init();
1348         tapechar_init ();
1349         tapeblock_init ();
1350         return 0;
1351 }
1352
1353 /*
1354  * Tape exit function.
1355  */
1356 static void
1357 tape_exit(void)
1358 {
1359         DBF_EVENT(6, "tape exit\n");
1360
1361         /* Get rid of the frontends */
1362         tapechar_exit();
1363         tapeblock_exit();
1364         tape_proc_cleanup();
1365         debug_unregister (TAPE_DBF_AREA);
1366 }
1367
1368 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1369               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1370 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1371 MODULE_LICENSE("GPL");
1372
1373 module_init(tape_init);
1374 module_exit(tape_exit);
1375
1376 EXPORT_SYMBOL(tape_generic_remove);
1377 EXPORT_SYMBOL(tape_generic_probe);
1378 EXPORT_SYMBOL(tape_generic_online);
1379 EXPORT_SYMBOL(tape_generic_offline);
1380 EXPORT_SYMBOL(tape_generic_pm_suspend);
1381 EXPORT_SYMBOL(tape_put_device);
1382 EXPORT_SYMBOL(tape_get_device);
1383 EXPORT_SYMBOL(tape_state_verbose);
1384 EXPORT_SYMBOL(tape_op_verbose);
1385 EXPORT_SYMBOL(tape_state_set);
1386 EXPORT_SYMBOL(tape_med_state_set);
1387 EXPORT_SYMBOL(tape_alloc_request);
1388 EXPORT_SYMBOL(tape_free_request);
1389 EXPORT_SYMBOL(tape_dump_sense_dbf);
1390 EXPORT_SYMBOL(tape_do_io);
1391 EXPORT_SYMBOL(tape_do_io_async);
1392 EXPORT_SYMBOL(tape_do_io_interruptible);
1393 EXPORT_SYMBOL(tape_cancel_io);
1394 EXPORT_SYMBOL(tape_mtop);