drivers/s390/char/tape

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This source file includes following definitions.
devid_to_int
tape_medium_state_show
tape_first_minor_show
tape_state_show
tape_operation_show
tape_blocksize_show
tape_state_set
tape_med_state_work_handler
tape_med_state_work
tape_med_state_set
__tape_cancel_io
tape_assign_minor
tape_remove_minor
tape_generic_online
tape_cleanup_device
tape_generic_pm_suspend
tape_generic_offline
tape_alloc_device
tape_get_device
tape_put_device
tape_find_device
tape_generic_probe
__tape_discard_requests
tape_generic_remove
tape_alloc_request
tape_free_request
__tape_start_io
__tape_start_next_request
tape_delayed_next_request
tape_long_busy_timeout
__tape_end_request
tape_dump_sense_dbf
__tape_start_request
tape_do_io_async
__tape_wake_up
tape_do_io
__tape_wake_up_interruptible
tape_do_io_interruptible
tape_cancel_io
__tape_do_irq
tape_open
tape_release
tape_mtop
tape_init
tape_exit
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   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/module.h>
  18 #include <linux/init.h>      // for kernel parameters
  19 #include <linux/kmod.h>      // for requesting modules
  20 #include <linux/spinlock.h>  // for locks
  21 #include <linux/vmalloc.h>
  22 #include <linux/list.h>
  23 #include <linux/slab.h>
  24 
  25 #include <asm/types.h>       // for variable types
  26 
  27 #define TAPE_DBF_AREA   tape_core_dbf
  28 
  29 #include "tape.h"
  30 #include "tape_std.h"
  31 
  32 #define LONG_BUSY_TIMEOUT 180 /* seconds */
  33 
  34 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  35 static void tape_delayed_next_request(struct work_struct *);
  36 static void tape_long_busy_timeout(struct timer_list *t);
  37 
  38 /*
  39  * One list to contain all tape devices of all disciplines, so
  40  * we can assign the devices to minor numbers of the same major
  41  * The list is protected by the rwlock
  42  */
  43 static LIST_HEAD(tape_device_list);
  44 static DEFINE_RWLOCK(tape_device_lock);
  45 
  46 /*
  47  * Pointer to debug area.
  48  */
  49 debug_info_t *TAPE_DBF_AREA = NULL;
  50 EXPORT_SYMBOL(TAPE_DBF_AREA);
  51 
  52 /*
  53  * Printable strings for tape enumerations.
  54  */
  55 const char *tape_state_verbose[TS_SIZE] =
  56 {
  57         [TS_UNUSED]   = "UNUSED",
  58         [TS_IN_USE]   = "IN_USE",
  59         [TS_BLKUSE]   = "BLKUSE",
  60         [TS_INIT]     = "INIT  ",
  61         [TS_NOT_OPER] = "NOT_OP"
  62 };
  63 
  64 const char *tape_op_verbose[TO_SIZE] =
  65 {
  66         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  67         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  68         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  69         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  70         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  71         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  72         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  73         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  74         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  75         [TO_READ_ATTMSG] = "RAT",
  76         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  77         [TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
  78         [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
  79         [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
  80 };
  81 
  82 static int devid_to_int(struct ccw_dev_id *dev_id)
  83 {
  84         return dev_id->devno + (dev_id->ssid << 16);
  85 }
  86 
  87 /*
  88  * Some channel attached tape specific attributes.
  89  *
  90  * FIXME: In the future the first_minor and blocksize attribute should be
  91  *        replaced by a link to the cdev tree.
  92  */
  93 static ssize_t
  94 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
  95 {
  96         struct tape_device *tdev;
  97 
  98         tdev = dev_get_drvdata(dev);
  99         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 100 }
 101 
 102 static
 103 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 104 
 105 static ssize_t
 106 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 107 {
 108         struct tape_device *tdev;
 109 
 110         tdev = dev_get_drvdata(dev);
 111         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 112 }
 113 
 114 static
 115 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 116 
 117 static ssize_t
 118 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 119 {
 120         struct tape_device *tdev;
 121 
 122         tdev = dev_get_drvdata(dev);
 123         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 124                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 125 }
 126 
 127 static
 128 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 129 
 130 static ssize_t
 131 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 132 {
 133         struct tape_device *tdev;
 134         ssize_t rc;
 135 
 136         tdev = dev_get_drvdata(dev);
 137         if (tdev->first_minor < 0)
 138                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 139 
 140         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 141         if (list_empty(&tdev->req_queue))
 142                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 143         else {
 144                 struct tape_request *req;
 145 
 146                 req = list_entry(tdev->req_queue.next, struct tape_request,
 147                         list);
 148                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 149         }
 150         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 151         return rc;
 152 }
 153 
 154 static
 155 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 156 
 157 static ssize_t
 158 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 159 {
 160         struct tape_device *tdev;
 161 
 162         tdev = dev_get_drvdata(dev);
 163 
 164         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 165 }
 166 
 167 static
 168 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 169 
 170 static struct attribute *tape_attrs[] = {
 171         &dev_attr_medium_state.attr,
 172         &dev_attr_first_minor.attr,
 173         &dev_attr_state.attr,
 174         &dev_attr_operation.attr,
 175         &dev_attr_blocksize.attr,
 176         NULL
 177 };
 178 
 179 static const struct attribute_group tape_attr_group = {
 180         .attrs = tape_attrs,
 181 };
 182 
 183 /*
 184  * Tape state functions
 185  */
 186 void
 187 tape_state_set(struct tape_device *device, enum tape_state newstate)
 188 {
 189         const char *str;
 190 
 191         if (device->tape_state == TS_NOT_OPER) {
 192                 DBF_EVENT(3, "ts_set err: not oper\n");
 193                 return;
 194         }
 195         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 196         DBF_EVENT(4, "old ts:\t\n");
 197         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 198                 str = tape_state_verbose[device->tape_state];
 199         else
 200                 str = "UNKNOWN TS";
 201         DBF_EVENT(4, "%s\n", str);
 202         DBF_EVENT(4, "new ts:\t\n");
 203         if (newstate < TS_SIZE && newstate >= 0)
 204                 str = tape_state_verbose[newstate];
 205         else
 206                 str = "UNKNOWN TS";
 207         DBF_EVENT(4, "%s\n", str);
 208         device->tape_state = newstate;
 209         wake_up(&device->state_change_wq);
 210 }
 211 
 212 struct tape_med_state_work_data {
 213         struct tape_device *device;
 214         enum tape_medium_state state;
 215         struct work_struct  work;
 216 };
 217 
 218 static void
 219 tape_med_state_work_handler(struct work_struct *work)
 220 {
 221         static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
 222         static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
 223         struct tape_med_state_work_data *p =
 224                 container_of(work, struct tape_med_state_work_data, work);
 225         struct tape_device *device = p->device;
 226         char *envp[] = { NULL, NULL };
 227 
 228         switch (p->state) {
 229         case MS_UNLOADED:
 230                 pr_info("%s: The tape cartridge has been successfully "
 231                         "unloaded\n", dev_name(&device->cdev->dev));
 232                 envp[0] = env_state_unloaded;
 233                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 234                 break;
 235         case MS_LOADED:
 236                 pr_info("%s: A tape cartridge has been mounted\n",
 237                         dev_name(&device->cdev->dev));
 238                 envp[0] = env_state_loaded;
 239                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 240                 break;
 241         default:
 242                 break;
 243         }
 244         tape_put_device(device);
 245         kfree(p);
 246 }
 247 
 248 static void
 249 tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
 250 {
 251         struct tape_med_state_work_data *p;
 252 
 253         p = kzalloc(sizeof(*p), GFP_ATOMIC);
 254         if (p) {
 255                 INIT_WORK(&p->work, tape_med_state_work_handler);
 256                 p->device = tape_get_device(device);
 257                 p->state = state;
 258                 schedule_work(&p->work);
 259         }
 260 }
 261 
 262 void
 263 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 264 {
 265         enum tape_medium_state oldstate;
 266 
 267         oldstate = device->medium_state;
 268         if (oldstate == newstate)
 269                 return;
 270         device->medium_state = newstate;
 271         switch(newstate){
 272         case MS_UNLOADED:
 273                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 274                 if (oldstate == MS_LOADED)
 275                         tape_med_state_work(device, MS_UNLOADED);
 276                 break;
 277         case MS_LOADED:
 278                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 279                 if (oldstate == MS_UNLOADED)
 280                         tape_med_state_work(device, MS_LOADED);
 281                 break;
 282         default:
 283                 break;
 284         }
 285         wake_up(&device->state_change_wq);
 286 }
 287 
 288 /*
 289  * Stop running ccw. Has to be called with the device lock held.
 290  */
 291 static int
 292 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 293 {
 294         int retries;
 295         int rc;
 296 
 297         /* Check if interrupt has already been processed */
 298         if (request->callback == NULL)
 299                 return 0;
 300 
 301         rc = 0;
 302         for (retries = 0; retries < 5; retries++) {
 303                 rc = ccw_device_clear(device->cdev, (long) request);
 304 
 305                 switch (rc) {
 306                         case 0:
 307                                 request->status = TAPE_REQUEST_DONE;
 308                                 return 0;
 309                         case -EBUSY:
 310                                 request->status = TAPE_REQUEST_CANCEL;
 311                                 schedule_delayed_work(&device->tape_dnr, 0);
 312                                 return 0;
 313                         case -ENODEV:
 314                                 DBF_EXCEPTION(2, "device gone, retry\n");
 315                                 break;
 316                         case -EIO:
 317                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 318                                 break;
 319                         default:
 320                                 BUG();
 321                 }
 322         }
 323 
 324         return rc;
 325 }
 326 
 327 /*
 328  * Add device into the sorted list, giving it the first
 329  * available minor number.
 330  */
 331 static int
 332 tape_assign_minor(struct tape_device *device)
 333 {
 334         struct tape_device *tmp;
 335         int minor;
 336 
 337         minor = 0;
 338         write_lock(&tape_device_lock);
 339         list_for_each_entry(tmp, &tape_device_list, node) {
 340                 if (minor < tmp->first_minor)
 341                         break;
 342                 minor += TAPE_MINORS_PER_DEV;
 343         }
 344         if (minor >= 256) {
 345                 write_unlock(&tape_device_lock);
 346                 return -ENODEV;
 347         }
 348         device->first_minor = minor;
 349         list_add_tail(&device->node, &tmp->node);
 350         write_unlock(&tape_device_lock);
 351         return 0;
 352 }
 353 
 354 /* remove device from the list */
 355 static void
 356 tape_remove_minor(struct tape_device *device)
 357 {
 358         write_lock(&tape_device_lock);
 359         list_del_init(&device->node);
 360         device->first_minor = -1;
 361         write_unlock(&tape_device_lock);
 362 }
 363 
 364 /*
 365  * Set a device online.
 366  *
 367  * This function is called by the common I/O layer to move a device from the
 368  * detected but offline into the online state.
 369  * If we return an error (RC < 0) the device remains in the offline state. This
 370  * can happen if the device is assigned somewhere else, for example.
 371  */
 372 int
 373 tape_generic_online(struct tape_device *device,
 374                    struct tape_discipline *discipline)
 375 {
 376         int rc;
 377 
 378         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 379 
 380         if (device->tape_state != TS_INIT) {
 381                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 382                 return -EINVAL;
 383         }
 384 
 385         timer_setup(&device->lb_timeout, tape_long_busy_timeout, 0);
 386 
 387         /* Let the discipline have a go at the device. */
 388         device->discipline = discipline;
 389         if (!try_module_get(discipline->owner)) {
 390                 return -EINVAL;
 391         }
 392 
 393         rc = discipline->setup_device(device);
 394         if (rc)
 395                 goto out;
 396         rc = tape_assign_minor(device);
 397         if (rc)
 398                 goto out_discipline;
 399 
 400         rc = tapechar_setup_device(device);
 401         if (rc)
 402                 goto out_minor;
 403 
 404         tape_state_set(device, TS_UNUSED);
 405 
 406         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 407 
 408         return 0;
 409 
 410 out_minor:
 411         tape_remove_minor(device);
 412 out_discipline:
 413         device->discipline->cleanup_device(device);
 414         device->discipline = NULL;
 415 out:
 416         module_put(discipline->owner);
 417         return rc;
 418 }
 419 
 420 static void
 421 tape_cleanup_device(struct tape_device *device)
 422 {
 423         tapechar_cleanup_device(device);
 424         device->discipline->cleanup_device(device);
 425         module_put(device->discipline->owner);
 426         tape_remove_minor(device);
 427         tape_med_state_set(device, MS_UNKNOWN);
 428 }
 429 
 430 /*
 431  * Suspend device.
 432  *
 433  * Called by the common I/O layer if the drive should be suspended on user
 434  * request. We refuse to suspend if the device is loaded or in use for the
 435  * following reason:
 436  * While the Linux guest is suspended, it might be logged off which causes
 437  * devices to be detached. Tape devices are automatically rewound and unloaded
 438  * during DETACH processing (unless the tape device was attached with the
 439  * NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
 440  * resume the original state of the tape device, since we would need to
 441  * manually re-load the cartridge which was active at suspend time.
 442  */
 443 int tape_generic_pm_suspend(struct ccw_device *cdev)
 444 {
 445         struct tape_device *device;
 446 
 447         device = dev_get_drvdata(&cdev->dev);
 448         if (!device) {
 449                 return -ENODEV;
 450         }
 451 
 452         DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
 453                 device->cdev_id, device);
 454 
 455         if (device->medium_state != MS_UNLOADED) {
 456                 pr_err("A cartridge is loaded in tape device %s, "
 457                        "refusing to suspend\n", dev_name(&cdev->dev));
 458                 return -EBUSY;
 459         }
 460 
 461         spin_lock_irq(get_ccwdev_lock(device->cdev));
 462         switch (device->tape_state) {
 463                 case TS_INIT:
 464                 case TS_NOT_OPER:
 465                 case TS_UNUSED:
 466                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 467                         break;
 468                 default:
 469                         pr_err("Tape device %s is busy, refusing to "
 470                                "suspend\n", dev_name(&cdev->dev));
 471                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 472                         return -EBUSY;
 473         }
 474 
 475         DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
 476         return 0;
 477 }
 478 
 479 /*
 480  * Set device offline.
 481  *
 482  * Called by the common I/O layer if the drive should set offline on user
 483  * request. We may prevent this by returning an error.
 484  * Manual offline is only allowed while the drive is not in use.
 485  */
 486 int
 487 tape_generic_offline(struct ccw_device *cdev)
 488 {
 489         struct tape_device *device;
 490 
 491         device = dev_get_drvdata(&cdev->dev);
 492         if (!device) {
 493                 return -ENODEV;
 494         }
 495 
 496         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 497                 device->cdev_id, device);
 498 
 499         spin_lock_irq(get_ccwdev_lock(device->cdev));
 500         switch (device->tape_state) {
 501                 case TS_INIT:
 502                 case TS_NOT_OPER:
 503                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 504                         break;
 505                 case TS_UNUSED:
 506                         tape_state_set(device, TS_INIT);
 507                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 508                         tape_cleanup_device(device);
 509                         break;
 510                 default:
 511                         DBF_EVENT(3, "(%08x): Set offline failed "
 512                                 "- drive in use.\n",
 513                                 device->cdev_id);
 514                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 515                         return -EBUSY;
 516         }
 517 
 518         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 519         return 0;
 520 }
 521 
 522 /*
 523  * Allocate memory for a new device structure.
 524  */
 525 static struct tape_device *
 526 tape_alloc_device(void)
 527 {
 528         struct tape_device *device;
 529 
 530         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 531         if (device == NULL) {
 532                 DBF_EXCEPTION(2, "ti:no mem\n");
 533                 return ERR_PTR(-ENOMEM);
 534         }
 535         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 536         if (device->modeset_byte == NULL) {
 537                 DBF_EXCEPTION(2, "ti:no mem\n");
 538                 kfree(device);
 539                 return ERR_PTR(-ENOMEM);
 540         }
 541         mutex_init(&device->mutex);
 542         INIT_LIST_HEAD(&device->req_queue);
 543         INIT_LIST_HEAD(&device->node);
 544         init_waitqueue_head(&device->state_change_wq);
 545         init_waitqueue_head(&device->wait_queue);
 546         device->tape_state = TS_INIT;
 547         device->medium_state = MS_UNKNOWN;
 548         *device->modeset_byte = 0;
 549         device->first_minor = -1;
 550         atomic_set(&device->ref_count, 1);
 551         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 552 
 553         return device;
 554 }
 555 
 556 /*
 557  * Get a reference to an existing device structure. This will automatically
 558  * increment the reference count.
 559  */
 560 struct tape_device *
 561 tape_get_device(struct tape_device *device)
 562 {
 563         int count;
 564 
 565         count = atomic_inc_return(&device->ref_count);
 566         DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
 567         return device;
 568 }
 569 
 570 /*
 571  * Decrease the reference counter of a devices structure. If the
 572  * reference counter reaches zero free the device structure.
 573  * The function returns a NULL pointer to be used by the caller
 574  * for clearing reference pointers.
 575  */
 576 void
 577 tape_put_device(struct tape_device *device)
 578 {
 579         int count;
 580 
 581         count = atomic_dec_return(&device->ref_count);
 582         DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
 583         BUG_ON(count < 0);
 584         if (count == 0) {
 585                 kfree(device->modeset_byte);
 586                 kfree(device);
 587         }
 588 }
 589 
 590 /*
 591  * Find tape device by a device index.
 592  */
 593 struct tape_device *
 594 tape_find_device(int devindex)
 595 {
 596         struct tape_device *device, *tmp;
 597 
 598         device = ERR_PTR(-ENODEV);
 599         read_lock(&tape_device_lock);
 600         list_for_each_entry(tmp, &tape_device_list, node) {
 601                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 602                         device = tape_get_device(tmp);
 603                         break;
 604                 }
 605         }
 606         read_unlock(&tape_device_lock);
 607         return device;
 608 }
 609 
 610 /*
 611  * Driverfs tape probe function.
 612  */
 613 int
 614 tape_generic_probe(struct ccw_device *cdev)
 615 {
 616         struct tape_device *device;
 617         int ret;
 618         struct ccw_dev_id dev_id;
 619 
 620         device = tape_alloc_device();
 621         if (IS_ERR(device))
 622                 return -ENODEV;
 623         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
 624                                      CCWDEV_DO_MULTIPATH);
 625         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 626         if (ret) {
 627                 tape_put_device(device);
 628                 return ret;
 629         }
 630         dev_set_drvdata(&cdev->dev, device);
 631         cdev->handler = __tape_do_irq;
 632         device->cdev = cdev;
 633         ccw_device_get_id(cdev, &dev_id);
 634         device->cdev_id = devid_to_int(&dev_id);
 635         return ret;
 636 }
 637 
 638 static void
 639 __tape_discard_requests(struct tape_device *device)
 640 {
 641         struct tape_request *   request;
 642         struct list_head *      l, *n;
 643 
 644         list_for_each_safe(l, n, &device->req_queue) {
 645                 request = list_entry(l, struct tape_request, list);
 646                 if (request->status == TAPE_REQUEST_IN_IO)
 647                         request->status = TAPE_REQUEST_DONE;
 648                 list_del(&request->list);
 649 
 650                 /* Decrease ref_count for removed request. */
 651                 request->device = NULL;
 652                 tape_put_device(device);
 653                 request->rc = -EIO;
 654                 if (request->callback != NULL)
 655                         request->callback(request, request->callback_data);
 656         }
 657 }
 658 
 659 /*
 660  * Driverfs tape remove function.
 661  *
 662  * This function is called whenever the common I/O layer detects the device
 663  * gone. This can happen at any time and we cannot refuse.
 664  */
 665 void
 666 tape_generic_remove(struct ccw_device *cdev)
 667 {
 668         struct tape_device *    device;
 669 
 670         device = dev_get_drvdata(&cdev->dev);
 671         if (!device) {
 672                 return;
 673         }
 674         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 675 
 676         spin_lock_irq(get_ccwdev_lock(device->cdev));
 677         switch (device->tape_state) {
 678                 case TS_INIT:
 679                         tape_state_set(device, TS_NOT_OPER);
 680                         /* fallthrough */
 681                 case TS_NOT_OPER:
 682                         /*
 683                          * Nothing to do.
 684                          */
 685                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 686                         break;
 687                 case TS_UNUSED:
 688                         /*
 689                          * Need only to release the device.
 690                          */
 691                         tape_state_set(device, TS_NOT_OPER);
 692                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 693                         tape_cleanup_device(device);
 694                         break;
 695                 default:
 696                         /*
 697                          * There may be requests on the queue. We will not get
 698                          * an interrupt for a request that was running. So we
 699                          * just post them all as I/O errors.
 700                          */
 701                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 702                                 device->cdev_id);
 703                         pr_warn("%s: A tape unit was detached while in use\n",
 704                                 dev_name(&device->cdev->dev));
 705                         tape_state_set(device, TS_NOT_OPER);
 706                         __tape_discard_requests(device);
 707                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 708                         tape_cleanup_device(device);
 709         }
 710 
 711         device = dev_get_drvdata(&cdev->dev);
 712         if (device) {
 713                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 714                 dev_set_drvdata(&cdev->dev, NULL);
 715                 tape_put_device(device);
 716         }
 717 }
 718 
 719 /*
 720  * Allocate a new tape ccw request
 721  */
 722 struct tape_request *
 723 tape_alloc_request(int cplength, int datasize)
 724 {
 725         struct tape_request *request;
 726 
 727         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 728 
 729         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 730 
 731         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 732         if (request == NULL) {
 733                 DBF_EXCEPTION(1, "cqra nomem\n");
 734                 return ERR_PTR(-ENOMEM);
 735         }
 736         /* allocate channel program */
 737         if (cplength > 0) {
 738                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 739                                           GFP_ATOMIC | GFP_DMA);
 740                 if (request->cpaddr == NULL) {
 741                         DBF_EXCEPTION(1, "cqra nomem\n");
 742                         kfree(request);
 743                         return ERR_PTR(-ENOMEM);
 744                 }
 745         }
 746         /* alloc small kernel buffer */
 747         if (datasize > 0) {
 748                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 749                 if (request->cpdata == NULL) {
 750                         DBF_EXCEPTION(1, "cqra nomem\n");
 751                         kfree(request->cpaddr);
 752                         kfree(request);
 753                         return ERR_PTR(-ENOMEM);
 754                 }
 755         }
 756         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 757                 request->cpdata);
 758 
 759         return request;
 760 }
 761 
 762 /*
 763  * Free tape ccw request
 764  */
 765 void
 766 tape_free_request (struct tape_request * request)
 767 {
 768         DBF_LH(6, "Free request %p\n", request);
 769 
 770         if (request->device)
 771                 tape_put_device(request->device);
 772         kfree(request->cpdata);
 773         kfree(request->cpaddr);
 774         kfree(request);
 775 }
 776 
 777 static int
 778 __tape_start_io(struct tape_device *device, struct tape_request *request)
 779 {
 780         int rc;
 781 
 782         rc = ccw_device_start(
 783                 device->cdev,
 784                 request->cpaddr,
 785                 (unsigned long) request,
 786                 0x00,
 787                 request->options
 788         );
 789         if (rc == 0) {
 790                 request->status = TAPE_REQUEST_IN_IO;
 791         } else if (rc == -EBUSY) {
 792                 /* The common I/O subsystem is currently busy. Retry later. */
 793                 request->status = TAPE_REQUEST_QUEUED;
 794                 schedule_delayed_work(&device->tape_dnr, 0);
 795                 rc = 0;
 796         } else {
 797                 /* Start failed. Remove request and indicate failure. */
 798                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 799         }
 800         return rc;
 801 }
 802 
 803 static void
 804 __tape_start_next_request(struct tape_device *device)
 805 {
 806         struct list_head *l, *n;
 807         struct tape_request *request;
 808         int rc;
 809 
 810         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 811         /*
 812          * Try to start each request on request queue until one is
 813          * started successful.
 814          */
 815         list_for_each_safe(l, n, &device->req_queue) {
 816                 request = list_entry(l, struct tape_request, list);
 817 
 818                 /*
 819                  * Avoid race condition if bottom-half was triggered more than
 820                  * once.
 821                  */
 822                 if (request->status == TAPE_REQUEST_IN_IO)
 823                         return;
 824                 /*
 825                  * Request has already been stopped. We have to wait until
 826                  * the request is removed from the queue in the interrupt
 827                  * handling.
 828                  */
 829                 if (request->status == TAPE_REQUEST_DONE)
 830                         return;
 831 
 832                 /*
 833                  * We wanted to cancel the request but the common I/O layer
 834                  * was busy at that time. This can only happen if this
 835                  * function is called by delayed_next_request.
 836                  * Otherwise we start the next request on the queue.
 837                  */
 838                 if (request->status == TAPE_REQUEST_CANCEL) {
 839                         rc = __tape_cancel_io(device, request);
 840                 } else {
 841                         rc = __tape_start_io(device, request);
 842                 }
 843                 if (rc == 0)
 844                         return;
 845 
 846                 /* Set ending status. */
 847                 request->rc = rc;
 848                 request->status = TAPE_REQUEST_DONE;
 849 
 850                 /* Remove from request queue. */
 851                 list_del(&request->list);
 852 
 853                 /* Do callback. */
 854                 if (request->callback != NULL)
 855                         request->callback(request, request->callback_data);
 856         }
 857 }
 858 
 859 static void
 860 tape_delayed_next_request(struct work_struct *work)
 861 {
 862         struct tape_device *device =
 863                 container_of(work, struct tape_device, tape_dnr.work);
 864 
 865         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 866         spin_lock_irq(get_ccwdev_lock(device->cdev));
 867         __tape_start_next_request(device);
 868         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 869 }
 870 
 871 static void tape_long_busy_timeout(struct timer_list *t)
 872 {
 873         struct tape_device *device = from_timer(device, t, lb_timeout);
 874         struct tape_request *request;
 875 
 876         spin_lock_irq(get_ccwdev_lock(device->cdev));
 877         request = list_entry(device->req_queue.next, struct tape_request, list);
 878         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 879         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 880         __tape_start_next_request(device);
 881         tape_put_device(device);
 882         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 883 }
 884 
 885 static void
 886 __tape_end_request(
 887         struct tape_device *    device,
 888         struct tape_request *   request,
 889         int                     rc)
 890 {
 891         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 892         if (request) {
 893                 request->rc = rc;
 894                 request->status = TAPE_REQUEST_DONE;
 895 
 896                 /* Remove from request queue. */
 897                 list_del(&request->list);
 898 
 899                 /* Do callback. */
 900                 if (request->callback != NULL)
 901                         request->callback(request, request->callback_data);
 902         }
 903 
 904         /* Start next request. */
 905         if (!list_empty(&device->req_queue))
 906                 __tape_start_next_request(device);
 907 }
 908 
 909 /*
 910  * Write sense data to dbf
 911  */
 912 void
 913 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 914                     struct irb *irb)
 915 {
 916         unsigned int *sptr;
 917         const char* op;
 918 
 919         if (request != NULL)
 920                 op = tape_op_verbose[request->op];
 921         else
 922                 op = "---";
 923         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 924                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 925         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 926         sptr = (unsigned int *) irb->ecw;
 927         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 928         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 929         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 930         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 931 }
 932 
 933 /*
 934  * I/O helper function. Adds the request to the request queue
 935  * and starts it if the tape is idle. Has to be called with
 936  * the device lock held.
 937  */
 938 static int
 939 __tape_start_request(struct tape_device *device, struct tape_request *request)
 940 {
 941         int rc;
 942 
 943         switch (request->op) {
 944                 case TO_MSEN:
 945                 case TO_ASSIGN:
 946                 case TO_UNASSIGN:
 947                 case TO_READ_ATTMSG:
 948                 case TO_RDC:
 949                         if (device->tape_state == TS_INIT)
 950                                 break;
 951                         if (device->tape_state == TS_UNUSED)
 952                                 break;
 953                         /* fallthrough */
 954                 default:
 955                         if (device->tape_state == TS_BLKUSE)
 956                                 break;
 957                         if (device->tape_state != TS_IN_USE)
 958                                 return -ENODEV;
 959         }
 960 
 961         /* Increase use count of device for the added request. */
 962         request->device = tape_get_device(device);
 963 
 964         if (list_empty(&device->req_queue)) {
 965                 /* No other requests are on the queue. Start this one. */
 966                 rc = __tape_start_io(device, request);
 967                 if (rc)
 968                         return rc;
 969 
 970                 DBF_LH(5, "Request %p added for execution.\n", request);
 971                 list_add(&request->list, &device->req_queue);
 972         } else {
 973                 DBF_LH(5, "Request %p add to queue.\n", request);
 974                 request->status = TAPE_REQUEST_QUEUED;
 975                 list_add_tail(&request->list, &device->req_queue);
 976         }
 977         return 0;
 978 }
 979 
 980 /*
 981  * Add the request to the request queue, try to start it if the
 982  * tape is idle. Return without waiting for end of i/o.
 983  */
 984 int
 985 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 986 {
 987         int rc;
 988 
 989         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 990 
 991         spin_lock_irq(get_ccwdev_lock(device->cdev));
 992         /* Add request to request queue and try to start it. */
 993         rc = __tape_start_request(device, request);
 994         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 995         return rc;
 996 }
 997 
 998 /*
 999  * tape_do_io/__tape_wake_up
1000  * Add the request to the request queue, try to start it if the
1001  * tape is idle and wait uninterruptible for its completion.
1002  */
1003 static void
1004 __tape_wake_up(struct tape_request *request, void *data)
1005 {
1006         request->callback = NULL;
1007         wake_up((wait_queue_head_t *) data);
1008 }
1009 
1010 int
1011 tape_do_io(struct tape_device *device, struct tape_request *request)
1012 {
1013         int rc;
1014 
1015         spin_lock_irq(get_ccwdev_lock(device->cdev));
1016         /* Setup callback */
1017         request->callback = __tape_wake_up;
1018         request->callback_data = &device->wait_queue;
1019         /* Add request to request queue and try to start it. */
1020         rc = __tape_start_request(device, request);
1021         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1022         if (rc)
1023                 return rc;
1024         /* Request added to the queue. Wait for its completion. */
1025         wait_event(device->wait_queue, (request->callback == NULL));
1026         /* Get rc from request */
1027         return request->rc;
1028 }
1029 
1030 /*
1031  * tape_do_io_interruptible/__tape_wake_up_interruptible
1032  * Add the request to the request queue, try to start it if the
1033  * tape is idle and wait uninterruptible for its completion.
1034  */
1035 static void
1036 __tape_wake_up_interruptible(struct tape_request *request, void *data)
1037 {
1038         request->callback = NULL;
1039         wake_up_interruptible((wait_queue_head_t *) data);
1040 }
1041 
1042 int
1043 tape_do_io_interruptible(struct tape_device *device,
1044                          struct tape_request *request)
1045 {
1046         int rc;
1047 
1048         spin_lock_irq(get_ccwdev_lock(device->cdev));
1049         /* Setup callback */
1050         request->callback = __tape_wake_up_interruptible;
1051         request->callback_data = &device->wait_queue;
1052         rc = __tape_start_request(device, request);
1053         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1054         if (rc)
1055                 return rc;
1056         /* Request added to the queue. Wait for its completion. */
1057         rc = wait_event_interruptible(device->wait_queue,
1058                                       (request->callback == NULL));
1059         if (rc != -ERESTARTSYS)
1060                 /* Request finished normally. */
1061                 return request->rc;
1062 
1063         /* Interrupted by a signal. We have to stop the current request. */
1064         spin_lock_irq(get_ccwdev_lock(device->cdev));
1065         rc = __tape_cancel_io(device, request);
1066         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1067         if (rc == 0) {
1068                 /* Wait for the interrupt that acknowledges the halt. */
1069                 do {
1070                         rc = wait_event_interruptible(
1071                                 device->wait_queue,
1072                                 (request->callback == NULL)
1073                         );
1074                 } while (rc == -ERESTARTSYS);
1075 
1076                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1077                 rc = -ERESTARTSYS;
1078         }
1079         return rc;
1080 }
1081 
1082 /*
1083  * Stop running ccw.
1084  */
1085 int
1086 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1087 {
1088         int rc;
1089 
1090         spin_lock_irq(get_ccwdev_lock(device->cdev));
1091         rc = __tape_cancel_io(device, request);
1092         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1093         return rc;
1094 }
1095 
1096 /*
1097  * Tape interrupt routine, called from the ccw_device layer
1098  */
1099 static void
1100 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1101 {
1102         struct tape_device *device;
1103         struct tape_request *request;
1104         int rc;
1105 
1106         device = dev_get_drvdata(&cdev->dev);
1107         if (device == NULL) {
1108                 return;
1109         }
1110         request = (struct tape_request *) intparm;
1111 
1112         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1113 
1114         /* On special conditions irb is an error pointer */
1115         if (IS_ERR(irb)) {
1116                 /* FIXME: What to do with the request? */
1117                 switch (PTR_ERR(irb)) {
1118                         case -ETIMEDOUT:
1119                                 DBF_LH(1, "(%08x): Request timed out\n",
1120                                        device->cdev_id);
1121                                 /* fallthrough */
1122                         case -EIO:
1123                                 __tape_end_request(device, request, -EIO);
1124                                 break;
1125                         default:
1126                                 DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
1127                                        device->cdev_id, PTR_ERR(irb));
1128                 }
1129                 return;
1130         }
1131 
1132         /*
1133          * If the condition code is not zero and the start function bit is
1134          * still set, this is an deferred error and the last start I/O did
1135          * not succeed. At this point the condition that caused the deferred
1136          * error might still apply. So we just schedule the request to be
1137          * started later.
1138          */
1139         if (irb->scsw.cmd.cc != 0 &&
1140             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1141             (request->status == TAPE_REQUEST_IN_IO)) {
1142                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1143                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1144                 request->status = TAPE_REQUEST_QUEUED;
1145                 schedule_delayed_work(&device->tape_dnr, HZ);
1146                 return;
1147         }
1148 
1149         /* May be an unsolicited irq */
1150         if(request != NULL)
1151                 request->rescnt = irb->scsw.cmd.count;
1152         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1153                  !list_empty(&device->req_queue)) {
1154                 /* Not Ready to Ready after long busy ? */
1155                 struct tape_request *req;
1156                 req = list_entry(device->req_queue.next,
1157                                  struct tape_request, list);
1158                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1159                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1160                         if (del_timer(&device->lb_timeout)) {
1161                                 tape_put_device(device);
1162                                 __tape_start_next_request(device);
1163                         }
1164                         return;
1165                 }
1166         }
1167         if (irb->scsw.cmd.dstat != 0x0c) {
1168                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1169                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1170                         device->tape_generic_status |= GMT_ONLINE(~0);
1171                 else
1172                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1173 
1174                 /*
1175                  * Any request that does not come back with channel end
1176                  * and device end is unusual. Log the sense data.
1177                  */
1178                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1179                 tape_dump_sense_dbf(device, request, irb);
1180         } else {
1181                 /* Upon normal completion the device _is_ online */
1182                 device->tape_generic_status |= GMT_ONLINE(~0);
1183         }
1184         if (device->tape_state == TS_NOT_OPER) {
1185                 DBF_EVENT(6, "tape:device is not operational\n");
1186                 return;
1187         }
1188 
1189         /*
1190          * Request that were canceled still come back with an interrupt.
1191          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1192          */
1193         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1194                 __tape_end_request(device, request, -EIO);
1195                 return;
1196         }
1197 
1198         rc = device->discipline->irq(device, request, irb);
1199         /*
1200          * rc < 0 : request finished unsuccessfully.
1201          * rc == TAPE_IO_SUCCESS: request finished successfully.
1202          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1203          * rc == TAPE_IO_RETRY: request finished but needs another go.
1204          * rc == TAPE_IO_STOP: request needs to get terminated.
1205          */
1206         switch (rc) {
1207                 case TAPE_IO_SUCCESS:
1208                         /* Upon normal completion the device _is_ online */
1209                         device->tape_generic_status |= GMT_ONLINE(~0);
1210                         __tape_end_request(device, request, rc);
1211                         break;
1212                 case TAPE_IO_PENDING:
1213                         break;
1214                 case TAPE_IO_LONG_BUSY:
1215                         device->lb_timeout.expires = jiffies +
1216                                 LONG_BUSY_TIMEOUT * HZ;
1217                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1218                         add_timer(&device->lb_timeout);
1219                         request->status = TAPE_REQUEST_LONG_BUSY;
1220                         break;
1221                 case TAPE_IO_RETRY:
1222                         rc = __tape_start_io(device, request);
1223                         if (rc)
1224                                 __tape_end_request(device, request, rc);
1225                         break;
1226                 case TAPE_IO_STOP:
1227                         rc = __tape_cancel_io(device, request);
1228                         if (rc)
1229                                 __tape_end_request(device, request, rc);
1230                         break;
1231                 default:
1232                         if (rc > 0) {
1233                                 DBF_EVENT(6, "xunknownrc\n");
1234                                 __tape_end_request(device, request, -EIO);
1235                         } else {
1236                                 __tape_end_request(device, request, rc);
1237                         }
1238                         break;
1239         }
1240 }
1241 
1242 /*
1243  * Tape device open function used by tape_char frontend.
1244  */
1245 int
1246 tape_open(struct tape_device *device)
1247 {
1248         int rc;
1249 
1250         spin_lock_irq(get_ccwdev_lock(device->cdev));
1251         if (device->tape_state == TS_NOT_OPER) {
1252                 DBF_EVENT(6, "TAPE:nodev\n");
1253                 rc = -ENODEV;
1254         } else if (device->tape_state == TS_IN_USE) {
1255                 DBF_EVENT(6, "TAPE:dbusy\n");
1256                 rc = -EBUSY;
1257         } else if (device->tape_state == TS_BLKUSE) {
1258                 DBF_EVENT(6, "TAPE:dbusy\n");
1259                 rc = -EBUSY;
1260         } else if (device->discipline != NULL &&
1261                    !try_module_get(device->discipline->owner)) {
1262                 DBF_EVENT(6, "TAPE:nodisc\n");
1263                 rc = -ENODEV;
1264         } else {
1265                 tape_state_set(device, TS_IN_USE);
1266                 rc = 0;
1267         }
1268         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1269         return rc;
1270 }
1271 
1272 /*
1273  * Tape device release function used by tape_char frontend.
1274  */
1275 int
1276 tape_release(struct tape_device *device)
1277 {
1278         spin_lock_irq(get_ccwdev_lock(device->cdev));
1279         if (device->tape_state == TS_IN_USE)
1280                 tape_state_set(device, TS_UNUSED);
1281         module_put(device->discipline->owner);
1282         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1283         return 0;
1284 }
1285 
1286 /*
1287  * Execute a magnetic tape command a number of times.
1288  */
1289 int
1290 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1291 {
1292         tape_mtop_fn fn;
1293         int rc;
1294 
1295         DBF_EVENT(6, "TAPE:mtio\n");
1296         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1297         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1298 
1299         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1300                 return -EINVAL;
1301         fn = device->discipline->mtop_array[mt_op];
1302         if (fn == NULL)
1303                 return -EINVAL;
1304 
1305         /* We assume that the backends can handle count up to 500. */
1306         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1307             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1308                 rc = 0;
1309                 for (; mt_count > 500; mt_count -= 500)
1310                         if ((rc = fn(device, 500)) != 0)
1311                                 break;
1312                 if (rc == 0)
1313                         rc = fn(device, mt_count);
1314         } else
1315                 rc = fn(device, mt_count);
1316         return rc;
1317 
1318 }
1319 
1320 /*
1321  * Tape init function.
1322  */
1323 static int
1324 tape_init (void)
1325 {
1326         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1327         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1328 #ifdef DBF_LIKE_HELL
1329         debug_set_level(TAPE_DBF_AREA, 6);
1330 #endif
1331         DBF_EVENT(3, "tape init\n");
1332         tape_proc_init();
1333         tapechar_init ();
1334         return 0;
1335 }
1336 
1337 /*
1338  * Tape exit function.
1339  */
1340 static void
1341 tape_exit(void)
1342 {
1343         DBF_EVENT(6, "tape exit\n");
1344 
1345         /* Get rid of the frontends */
1346         tapechar_exit();
1347         tape_proc_cleanup();
1348         debug_unregister (TAPE_DBF_AREA);
1349 }
1350 
1351 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1352               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1353 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1354 MODULE_LICENSE("GPL");
1355 
1356 module_init(tape_init);
1357 module_exit(tape_exit);
1358 
1359 EXPORT_SYMBOL(tape_generic_remove);
1360 EXPORT_SYMBOL(tape_generic_probe);
1361 EXPORT_SYMBOL(tape_generic_online);
1362 EXPORT_SYMBOL(tape_generic_offline);
1363 EXPORT_SYMBOL(tape_generic_pm_suspend);
1364 EXPORT_SYMBOL(tape_put_device);
1365 EXPORT_SYMBOL(tape_get_device);
1366 EXPORT_SYMBOL(tape_state_verbose);
1367 EXPORT_SYMBOL(tape_op_verbose);
1368 EXPORT_SYMBOL(tape_state_set);
1369 EXPORT_SYMBOL(tape_med_state_set);
1370 EXPORT_SYMBOL(tape_alloc_request);
1371 EXPORT_SYMBOL(tape_free_request);
1372 EXPORT_SYMBOL(tape_dump_sense_dbf);
1373 EXPORT_SYMBOL(tape_do_io);
1374 EXPORT_SYMBOL(tape_do_io_async);
1375 EXPORT_SYMBOL(tape_do_io_interruptible);
1376 EXPORT_SYMBOL(tape_cancel_io);
1377 EXPORT_SYMBOL(tape_mtop);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/s390/char/tape_core.c

DEFINITIONS
