drivers/s390/char/tape_core.c

   1 /*
   2  *  drivers/s390/char/tape_core.c
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright IBM Corp. 2001,2006
   7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Michael Holzheu <holzheu@de.ibm.com>
   9  *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
  10  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
  11  *               Stefan Bader <shbader@de.ibm.com>
  12  */
  13
  14 #define KMSG_COMPONENT "tape"
  15 #include <linux/module.h>
  16 #include <linux/init.h>      // for kernel parameters
  17 #include <linux/kmod.h>      // for requesting modules
  18 #include <linux/spinlock.h>  // for locks
  19 #include <linux/vmalloc.h>
  20 #include <linux/list.h>
  21
  22 #include <asm/types.h>       // for variable types
  23
  24 #define TAPE_DBF_AREA   tape_core_dbf
  25
  26 #include "tape.h"
  27 #include "tape_std.h"
  28
  29 #define LONG_BUSY_TIMEOUT 180 /* seconds */
  30
  31 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  32 static void tape_delayed_next_request(struct work_struct *);
  33 static void tape_long_busy_timeout(unsigned long data);
  34
  35 /*
  36  * One list to contain all tape devices of all disciplines, so
  37  * we can assign the devices to minor numbers of the same major
  38  * The list is protected by the rwlock
  39  */
  40 static LIST_HEAD(tape_device_list);
  41 static DEFINE_RWLOCK(tape_device_lock);
  42
  43 /*
  44  * Pointer to debug area.
  45  */
  46 debug_info_t *TAPE_DBF_AREA = NULL;
  47 EXPORT_SYMBOL(TAPE_DBF_AREA);
  48
  49 /*
  50  * Printable strings for tape enumerations.
  51  */
  52 const char *tape_state_verbose[TS_SIZE] =
  53 {
  54         [TS_UNUSED]   = "UNUSED",
  55         [TS_IN_USE]   = "IN_USE",
  56         [TS_BLKUSE]   = "BLKUSE",
  57         [TS_INIT]     = "INIT  ",
  58         [TS_NOT_OPER] = "NOT_OP"
  59 };
  60
  61 const char *tape_op_verbose[TO_SIZE] =
  62 {
  63         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  64         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  65         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  66         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  67         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  68         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  69         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  70         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  71         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  72         [TO_READ_ATTMSG] = "RAT",
  73         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  74         [TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
  75         [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
  76         [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
  77 };
  78
  79 static int devid_to_int(struct ccw_dev_id *dev_id)
  80 {
  81         return dev_id->devno + (dev_id->ssid << 16);
  82 }
  83
  84 /*
  85  * Some channel attached tape specific attributes.
  86  *
  87  * FIXME: In the future the first_minor and blocksize attribute should be
  88  *        replaced by a link to the cdev tree.
  89  */
  90 static ssize_t
  91 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
  92 {
  93         struct tape_device *tdev;
  94
  95         tdev = (struct tape_device *) dev->driver_data;
  96         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
  97 }
  98
  99 static
 100 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 101
 102 static ssize_t
 103 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 104 {
 105         struct tape_device *tdev;
 106
 107         tdev = (struct tape_device *) dev->driver_data;
 108         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 109 }
 110
 111 static
 112 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 113
 114 static ssize_t
 115 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 116 {
 117         struct tape_device *tdev;
 118
 119         tdev = (struct tape_device *) dev->driver_data;
 120         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 121                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 122 }
 123
 124 static
 125 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 126
 127 static ssize_t
 128 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 129 {
 130         struct tape_device *tdev;
 131         ssize_t rc;
 132
 133         tdev = (struct tape_device *) dev->driver_data;
 134         if (tdev->first_minor < 0)
 135                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 136
 137         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 138         if (list_empty(&tdev->req_queue))
 139                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 140         else {
 141                 struct tape_request *req;
 142
 143                 req = list_entry(tdev->req_queue.next, struct tape_request,
 144                         list);
 145                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 146         }
 147         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 148         return rc;
 149 }
 150
 151 static
 152 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 153
 154 static ssize_t
 155 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 156 {
 157         struct tape_device *tdev;
 158
 159         tdev = (struct tape_device *) dev->driver_data;
 160
 161         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 162 }
 163
 164 static
 165 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 166
 167 static struct attribute *tape_attrs[] = {
 168         &dev_attr_medium_state.attr,
 169         &dev_attr_first_minor.attr,
 170         &dev_attr_state.attr,
 171         &dev_attr_operation.attr,
 172         &dev_attr_blocksize.attr,
 173         NULL
 174 };
 175
 176 static struct attribute_group tape_attr_group = {
 177         .attrs = tape_attrs,
 178 };
 179
 180 /*
 181  * Tape state functions
 182  */
 183 void
 184 tape_state_set(struct tape_device *device, enum tape_state newstate)
 185 {
 186         const char *str;
 187
 188         if (device->tape_state == TS_NOT_OPER) {
 189                 DBF_EVENT(3, "ts_set err: not oper\n");
 190                 return;
 191         }
 192         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 193         DBF_EVENT(4, "old ts:\t\n");
 194         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 195                 str = tape_state_verbose[device->tape_state];
 196         else
 197                 str = "UNKNOWN TS";
 198         DBF_EVENT(4, "%s\n", str);
 199         DBF_EVENT(4, "new ts:\t\n");
 200         if (newstate < TS_SIZE && newstate >= 0)
 201                 str = tape_state_verbose[newstate];
 202         else
 203                 str = "UNKNOWN TS";
 204         DBF_EVENT(4, "%s\n", str);
 205         device->tape_state = newstate;
 206         wake_up(&device->state_change_wq);
 207 }
 208
 209 void
 210 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 211 {
 212         if (device->medium_state == newstate)
 213                 return;
 214         switch(newstate){
 215         case MS_UNLOADED:
 216                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 217                 dev_info(&device->cdev->dev, "The tape cartridge has been "
 218                         "successfully unloaded\n");
 219                 break;
 220         case MS_LOADED:
 221                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 222                 dev_info(&device->cdev->dev, "A tape cartridge has been "
 223                         "mounted\n");
 224                 break;
 225         default:
 226                 // print nothing
 227                 break;
 228         }
 229         device->medium_state = newstate;
 230         wake_up(&device->state_change_wq);
 231 }
 232
 233 /*
 234  * Stop running ccw. Has to be called with the device lock held.
 235  */
 236 static int
 237 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 238 {
 239         int retries;
 240         int rc;
 241
 242         /* Check if interrupt has already been processed */
 243         if (request->callback == NULL)
 244                 return 0;
 245
 246         rc = 0;
 247         for (retries = 0; retries < 5; retries++) {
 248                 rc = ccw_device_clear(device->cdev, (long) request);
 249
 250                 switch (rc) {
 251                         case 0:
 252                                 request->status = TAPE_REQUEST_DONE;
 253                                 return 0;
 254                         case -EBUSY:
 255                                 request->status = TAPE_REQUEST_CANCEL;
 256                                 schedule_delayed_work(&device->tape_dnr, 0);
 257                                 return 0;
 258                         case -ENODEV:
 259                                 DBF_EXCEPTION(2, "device gone, retry\n");
 260                                 break;
 261                         case -EIO:
 262                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 263                                 break;
 264                         default:
 265                                 BUG();
 266                 }
 267         }
 268
 269         return rc;
 270 }
 271
 272 /*
 273  * Add device into the sorted list, giving it the first
 274  * available minor number.
 275  */
 276 static int
 277 tape_assign_minor(struct tape_device *device)
 278 {
 279         struct tape_device *tmp;
 280         int minor;
 281
 282         minor = 0;
 283         write_lock(&tape_device_lock);
 284         list_for_each_entry(tmp, &tape_device_list, node) {
 285                 if (minor < tmp->first_minor)
 286                         break;
 287                 minor += TAPE_MINORS_PER_DEV;
 288         }
 289         if (minor >= 256) {
 290                 write_unlock(&tape_device_lock);
 291                 return -ENODEV;
 292         }
 293         device->first_minor = minor;
 294         list_add_tail(&device->node, &tmp->node);
 295         write_unlock(&tape_device_lock);
 296         return 0;
 297 }
 298
 299 /* remove device from the list */
 300 static void
 301 tape_remove_minor(struct tape_device *device)
 302 {
 303         write_lock(&tape_device_lock);
 304         list_del_init(&device->node);
 305         device->first_minor = -1;
 306         write_unlock(&tape_device_lock);
 307 }
 308
 309 /*
 310  * Set a device online.
 311  *
 312  * This function is called by the common I/O layer to move a device from the
 313  * detected but offline into the online state.
 314  * If we return an error (RC < 0) the device remains in the offline state. This
 315  * can happen if the device is assigned somewhere else, for example.
 316  */
 317 int
 318 tape_generic_online(struct tape_device *device,
 319                    struct tape_discipline *discipline)
 320 {
 321         int rc;
 322
 323         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 324
 325         if (device->tape_state != TS_INIT) {
 326                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 327                 return -EINVAL;
 328         }
 329
 330         init_timer(&device->lb_timeout);
 331         device->lb_timeout.function = tape_long_busy_timeout;
 332
 333         /* Let the discipline have a go at the device. */
 334         device->discipline = discipline;
 335         if (!try_module_get(discipline->owner)) {
 336                 return -EINVAL;
 337         }
 338
 339         rc = discipline->setup_device(device);
 340         if (rc)
 341                 goto out;
 342         rc = tape_assign_minor(device);
 343         if (rc)
 344                 goto out_discipline;
 345
 346         rc = tapechar_setup_device(device);
 347         if (rc)
 348                 goto out_minor;
 349         rc = tapeblock_setup_device(device);
 350         if (rc)
 351                 goto out_char;
 352
 353         tape_state_set(device, TS_UNUSED);
 354
 355         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 356
 357         return 0;
 358
 359 out_char:
 360         tapechar_cleanup_device(device);
 361 out_discipline:
 362         device->discipline->cleanup_device(device);
 363         device->discipline = NULL;
 364 out_minor:
 365         tape_remove_minor(device);
 366 out:
 367         module_put(discipline->owner);
 368         return rc;
 369 }
 370
 371 static void
 372 tape_cleanup_device(struct tape_device *device)
 373 {
 374         tapeblock_cleanup_device(device);
 375         tapechar_cleanup_device(device);
 376         device->discipline->cleanup_device(device);
 377         module_put(device->discipline->owner);
 378         tape_remove_minor(device);
 379         tape_med_state_set(device, MS_UNKNOWN);
 380 }
 381
 382 /*
 383  * Set device offline.
 384  *
 385  * Called by the common I/O layer if the drive should set offline on user
 386  * request. We may prevent this by returning an error.
 387  * Manual offline is only allowed while the drive is not in use.
 388  */
 389 int
 390 tape_generic_offline(struct ccw_device *cdev)
 391 {
 392         struct tape_device *device;
 393
 394         device = cdev->dev.driver_data;
 395         if (!device) {
 396                 return -ENODEV;
 397         }
 398
 399         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 400                 device->cdev_id, device);
 401
 402         spin_lock_irq(get_ccwdev_lock(device->cdev));
 403         switch (device->tape_state) {
 404                 case TS_INIT:
 405                 case TS_NOT_OPER:
 406                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 407                         break;
 408                 case TS_UNUSED:
 409                         tape_state_set(device, TS_INIT);
 410                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 411                         tape_cleanup_device(device);
 412                         break;
 413                 default:
 414                         DBF_EVENT(3, "(%08x): Set offline failed "
 415                                 "- drive in use.\n",
 416                                 device->cdev_id);
 417                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 418                         return -EBUSY;
 419         }
 420
 421         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 422         return 0;
 423 }
 424
 425 /*
 426  * Allocate memory for a new device structure.
 427  */
 428 static struct tape_device *
 429 tape_alloc_device(void)
 430 {
 431         struct tape_device *device;
 432
 433         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 434         if (device == NULL) {
 435                 DBF_EXCEPTION(2, "ti:no mem\n");
 436                 return ERR_PTR(-ENOMEM);
 437         }
 438         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 439         if (device->modeset_byte == NULL) {
 440                 DBF_EXCEPTION(2, "ti:no mem\n");
 441                 kfree(device);
 442                 return ERR_PTR(-ENOMEM);
 443         }
 444         INIT_LIST_HEAD(&device->req_queue);
 445         INIT_LIST_HEAD(&device->node);
 446         init_waitqueue_head(&device->state_change_wq);
 447         init_waitqueue_head(&device->wait_queue);
 448         device->tape_state = TS_INIT;
 449         device->medium_state = MS_UNKNOWN;
 450         *device->modeset_byte = 0;
 451         device->first_minor = -1;
 452         atomic_set(&device->ref_count, 1);
 453         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 454
 455         return device;
 456 }
 457
 458 /*
 459  * Get a reference to an existing device structure. This will automatically
 460  * increment the reference count.
 461  */
 462 struct tape_device *
 463 tape_get_device_reference(struct tape_device *device)
 464 {
 465         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 466                 atomic_inc_return(&device->ref_count));
 467
 468         return device;
 469 }
 470
 471 /*
 472  * Decrease the reference counter of a devices structure. If the
 473  * reference counter reaches zero free the device structure.
 474  * The function returns a NULL pointer to be used by the caller
 475  * for clearing reference pointers.
 476  */
 477 struct tape_device *
 478 tape_put_device(struct tape_device *device)
 479 {
 480         int remain;
 481
 482         remain = atomic_dec_return(&device->ref_count);
 483         if (remain > 0) {
 484                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 485         } else {
 486                 if (remain < 0) {
 487                         DBF_EVENT(4, "put device without reference\n");
 488                 } else {
 489                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 490                         kfree(device->modeset_byte);
 491                         kfree(device);
 492                 }
 493         }
 494
 495         return NULL;
 496 }
 497
 498 /*
 499  * Find tape device by a device index.
 500  */
 501 struct tape_device *
 502 tape_get_device(int devindex)
 503 {
 504         struct tape_device *device, *tmp;
 505
 506         device = ERR_PTR(-ENODEV);
 507         read_lock(&tape_device_lock);
 508         list_for_each_entry(tmp, &tape_device_list, node) {
 509                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 510                         device = tape_get_device_reference(tmp);
 511                         break;
 512                 }
 513         }
 514         read_unlock(&tape_device_lock);
 515         return device;
 516 }
 517
 518 /*
 519  * Driverfs tape probe function.
 520  */
 521 int
 522 tape_generic_probe(struct ccw_device *cdev)
 523 {
 524         struct tape_device *device;
 525         int ret;
 526         struct ccw_dev_id dev_id;
 527
 528         device = tape_alloc_device();
 529         if (IS_ERR(device))
 530                 return -ENODEV;
 531         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 532         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 533         if (ret) {
 534                 tape_put_device(device);
 535                 return ret;
 536         }
 537         cdev->dev.driver_data = device;
 538         cdev->handler = __tape_do_irq;
 539         device->cdev = cdev;
 540         ccw_device_get_id(cdev, &dev_id);
 541         device->cdev_id = devid_to_int(&dev_id);
 542         return ret;
 543 }
 544
 545 static void
 546 __tape_discard_requests(struct tape_device *device)
 547 {
 548         struct tape_request *   request;
 549         struct list_head *      l, *n;
 550
 551         list_for_each_safe(l, n, &device->req_queue) {
 552                 request = list_entry(l, struct tape_request, list);
 553                 if (request->status == TAPE_REQUEST_IN_IO)
 554                         request->status = TAPE_REQUEST_DONE;
 555                 list_del(&request->list);
 556
 557                 /* Decrease ref_count for removed request. */
 558                 request->device = tape_put_device(device);
 559                 request->rc = -EIO;
 560                 if (request->callback != NULL)
 561                         request->callback(request, request->callback_data);
 562         }
 563 }
 564
 565 /*
 566  * Driverfs tape remove function.
 567  *
 568  * This function is called whenever the common I/O layer detects the device
 569  * gone. This can happen at any time and we cannot refuse.
 570  */
 571 void
 572 tape_generic_remove(struct ccw_device *cdev)
 573 {
 574         struct tape_device *    device;
 575
 576         device = cdev->dev.driver_data;
 577         if (!device) {
 578                 return;
 579         }
 580         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 581
 582         spin_lock_irq(get_ccwdev_lock(device->cdev));
 583         switch (device->tape_state) {
 584                 case TS_INIT:
 585                         tape_state_set(device, TS_NOT_OPER);
 586                 case TS_NOT_OPER:
 587                         /*
 588                          * Nothing to do.
 589                          */
 590                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 591                         break;
 592                 case TS_UNUSED:
 593                         /*
 594                          * Need only to release the device.
 595                          */
 596                         tape_state_set(device, TS_NOT_OPER);
 597                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 598                         tape_cleanup_device(device);
 599                         break;
 600                 default:
 601                         /*
 602                          * There may be requests on the queue. We will not get
 603                          * an interrupt for a request that was running. So we
 604                          * just post them all as I/O errors.
 605                          */
 606                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 607                                 device->cdev_id);
 608                         dev_warn(&device->cdev->dev, "A tape unit was detached"
 609                                 " while in use\n");
 610                         tape_state_set(device, TS_NOT_OPER);
 611                         __tape_discard_requests(device);
 612                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 613                         tape_cleanup_device(device);
 614         }
 615
 616         if (cdev->dev.driver_data != NULL) {
 617                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 618                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 619         }
 620 }
 621
 622 /*
 623  * Allocate a new tape ccw request
 624  */
 625 struct tape_request *
 626 tape_alloc_request(int cplength, int datasize)
 627 {
 628         struct tape_request *request;
 629
 630         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 631
 632         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 633
 634         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 635         if (request == NULL) {
 636                 DBF_EXCEPTION(1, "cqra nomem\n");
 637                 return ERR_PTR(-ENOMEM);
 638         }
 639         /* allocate channel program */
 640         if (cplength > 0) {
 641                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 642                                           GFP_ATOMIC | GFP_DMA);
 643                 if (request->cpaddr == NULL) {
 644                         DBF_EXCEPTION(1, "cqra nomem\n");
 645                         kfree(request);
 646                         return ERR_PTR(-ENOMEM);
 647                 }
 648         }
 649         /* alloc small kernel buffer */
 650         if (datasize > 0) {
 651                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 652                 if (request->cpdata == NULL) {
 653                         DBF_EXCEPTION(1, "cqra nomem\n");
 654                         kfree(request->cpaddr);
 655                         kfree(request);
 656                         return ERR_PTR(-ENOMEM);
 657                 }
 658         }
 659         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 660                 request->cpdata);
 661
 662         return request;
 663 }
 664
 665 /*
 666  * Free tape ccw request
 667  */
 668 void
 669 tape_free_request (struct tape_request * request)
 670 {
 671         DBF_LH(6, "Free request %p\n", request);
 672
 673         if (request->device != NULL) {
 674                 request->device = tape_put_device(request->device);
 675         }
 676         kfree(request->cpdata);
 677         kfree(request->cpaddr);
 678         kfree(request);
 679 }
 680
 681 static int
 682 __tape_start_io(struct tape_device *device, struct tape_request *request)
 683 {
 684         int rc;
 685
 686 #ifdef CONFIG_S390_TAPE_BLOCK
 687         if (request->op == TO_BLOCK)
 688                 device->discipline->check_locate(device, request);
 689 #endif
 690         rc = ccw_device_start(
 691                 device->cdev,
 692                 request->cpaddr,
 693                 (unsigned long) request,
 694                 0x00,
 695                 request->options
 696         );
 697         if (rc == 0) {
 698                 request->status = TAPE_REQUEST_IN_IO;
 699         } else if (rc == -EBUSY) {
 700                 /* The common I/O subsystem is currently busy. Retry later. */
 701                 request->status = TAPE_REQUEST_QUEUED;
 702                 schedule_delayed_work(&device->tape_dnr, 0);
 703                 rc = 0;
 704         } else {
 705                 /* Start failed. Remove request and indicate failure. */
 706                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 707         }
 708         return rc;
 709 }
 710
 711 static void
 712 __tape_start_next_request(struct tape_device *device)
 713 {
 714         struct list_head *l, *n;
 715         struct tape_request *request;
 716         int rc;
 717
 718         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 719         /*
 720          * Try to start each request on request queue until one is
 721          * started successful.
 722          */
 723         list_for_each_safe(l, n, &device->req_queue) {
 724                 request = list_entry(l, struct tape_request, list);
 725
 726                 /*
 727                  * Avoid race condition if bottom-half was triggered more than
 728                  * once.
 729                  */
 730                 if (request->status == TAPE_REQUEST_IN_IO)
 731                         return;
 732                 /*
 733                  * Request has already been stopped. We have to wait until
 734                  * the request is removed from the queue in the interrupt
 735                  * handling.
 736                  */
 737                 if (request->status == TAPE_REQUEST_DONE)
 738                         return;
 739
 740                 /*
 741                  * We wanted to cancel the request but the common I/O layer
 742                  * was busy at that time. This can only happen if this
 743                  * function is called by delayed_next_request.
 744                  * Otherwise we start the next request on the queue.
 745                  */
 746                 if (request->status == TAPE_REQUEST_CANCEL) {
 747                         rc = __tape_cancel_io(device, request);
 748                 } else {
 749                         rc = __tape_start_io(device, request);
 750                 }
 751                 if (rc == 0)
 752                         return;
 753
 754                 /* Set ending status. */
 755                 request->rc = rc;
 756                 request->status = TAPE_REQUEST_DONE;
 757
 758                 /* Remove from request queue. */
 759                 list_del(&request->list);
 760
 761                 /* Do callback. */
 762                 if (request->callback != NULL)
 763                         request->callback(request, request->callback_data);
 764         }
 765 }
 766
 767 static void
 768 tape_delayed_next_request(struct work_struct *work)
 769 {
 770         struct tape_device *device =
 771                 container_of(work, struct tape_device, tape_dnr.work);
 772
 773         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 774         spin_lock_irq(get_ccwdev_lock(device->cdev));
 775         __tape_start_next_request(device);
 776         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 777 }
 778
 779 static void tape_long_busy_timeout(unsigned long data)
 780 {
 781         struct tape_request *request;
 782         struct tape_device *device;
 783
 784         device = (struct tape_device *) data;
 785         spin_lock_irq(get_ccwdev_lock(device->cdev));
 786         request = list_entry(device->req_queue.next, struct tape_request, list);
 787         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 788         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 789         __tape_start_next_request(device);
 790         device->lb_timeout.data = (unsigned long) tape_put_device(device);
 791         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 792 }
 793
 794 static void
 795 __tape_end_request(
 796         struct tape_device *    device,
 797         struct tape_request *   request,
 798         int                     rc)
 799 {
 800         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 801         if (request) {
 802                 request->rc = rc;
 803                 request->status = TAPE_REQUEST_DONE;
 804
 805                 /* Remove from request queue. */
 806                 list_del(&request->list);
 807
 808                 /* Do callback. */
 809                 if (request->callback != NULL)
 810                         request->callback(request, request->callback_data);
 811         }
 812
 813         /* Start next request. */
 814         if (!list_empty(&device->req_queue))
 815                 __tape_start_next_request(device);
 816 }
 817
 818 /*
 819  * Write sense data to dbf
 820  */
 821 void
 822 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 823                     struct irb *irb)
 824 {
 825         unsigned int *sptr;
 826         const char* op;
 827
 828         if (request != NULL)
 829                 op = tape_op_verbose[request->op];
 830         else
 831                 op = "---";
 832         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 833                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 834         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 835         sptr = (unsigned int *) irb->ecw;
 836         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 837         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 838         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 839         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 840 }
 841
 842 /*
 843  * I/O helper function. Adds the request to the request queue
 844  * and starts it if the tape is idle. Has to be called with
 845  * the device lock held.
 846  */
 847 static int
 848 __tape_start_request(struct tape_device *device, struct tape_request *request)
 849 {
 850         int rc;
 851
 852         switch (request->op) {
 853                 case TO_MSEN:
 854                 case TO_ASSIGN:
 855                 case TO_UNASSIGN:
 856                 case TO_READ_ATTMSG:
 857                 case TO_RDC:
 858                         if (device->tape_state == TS_INIT)
 859                                 break;
 860                         if (device->tape_state == TS_UNUSED)
 861                                 break;
 862                 default:
 863                         if (device->tape_state == TS_BLKUSE)
 864                                 break;
 865                         if (device->tape_state != TS_IN_USE)
 866                                 return -ENODEV;
 867         }
 868
 869         /* Increase use count of device for the added request. */
 870         request->device = tape_get_device_reference(device);
 871
 872         if (list_empty(&device->req_queue)) {
 873                 /* No other requests are on the queue. Start this one. */
 874                 rc = __tape_start_io(device, request);
 875                 if (rc)
 876                         return rc;
 877
 878                 DBF_LH(5, "Request %p added for execution.\n", request);
 879                 list_add(&request->list, &device->req_queue);
 880         } else {
 881                 DBF_LH(5, "Request %p add to queue.\n", request);
 882                 request->status = TAPE_REQUEST_QUEUED;
 883                 list_add_tail(&request->list, &device->req_queue);
 884         }
 885         return 0;
 886 }
 887
 888 /*
 889  * Add the request to the request queue, try to start it if the
 890  * tape is idle. Return without waiting for end of i/o.
 891  */
 892 int
 893 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 894 {
 895         int rc;
 896
 897         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 898
 899         spin_lock_irq(get_ccwdev_lock(device->cdev));
 900         /* Add request to request queue and try to start it. */
 901         rc = __tape_start_request(device, request);
 902         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 903         return rc;
 904 }
 905
 906 /*
 907  * tape_do_io/__tape_wake_up
 908  * Add the request to the request queue, try to start it if the
 909  * tape is idle and wait uninterruptible for its completion.
 910  */
 911 static void
 912 __tape_wake_up(struct tape_request *request, void *data)
 913 {
 914         request->callback = NULL;
 915         wake_up((wait_queue_head_t *) data);
 916 }
 917
 918 int
 919 tape_do_io(struct tape_device *device, struct tape_request *request)
 920 {
 921         int rc;
 922
 923         spin_lock_irq(get_ccwdev_lock(device->cdev));
 924         /* Setup callback */
 925         request->callback = __tape_wake_up;
 926         request->callback_data = &device->wait_queue;
 927         /* Add request to request queue and try to start it. */
 928         rc = __tape_start_request(device, request);
 929         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 930         if (rc)
 931                 return rc;
 932         /* Request added to the queue. Wait for its completion. */
 933         wait_event(device->wait_queue, (request->callback == NULL));
 934         /* Get rc from request */
 935         return request->rc;
 936 }
 937
 938 /*
 939  * tape_do_io_interruptible/__tape_wake_up_interruptible
 940  * Add the request to the request queue, try to start it if the
 941  * tape is idle and wait uninterruptible for its completion.
 942  */
 943 static void
 944 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 945 {
 946         request->callback = NULL;
 947         wake_up_interruptible((wait_queue_head_t *) data);
 948 }
 949
 950 int
 951 tape_do_io_interruptible(struct tape_device *device,
 952                          struct tape_request *request)
 953 {
 954         int rc;
 955
 956         spin_lock_irq(get_ccwdev_lock(device->cdev));
 957         /* Setup callback */
 958         request->callback = __tape_wake_up_interruptible;
 959         request->callback_data = &device->wait_queue;
 960         rc = __tape_start_request(device, request);
 961         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 962         if (rc)
 963                 return rc;
 964         /* Request added to the queue. Wait for its completion. */
 965         rc = wait_event_interruptible(device->wait_queue,
 966                                       (request->callback == NULL));
 967         if (rc != -ERESTARTSYS)
 968                 /* Request finished normally. */
 969                 return request->rc;
 970
 971         /* Interrupted by a signal. We have to stop the current request. */
 972         spin_lock_irq(get_ccwdev_lock(device->cdev));
 973         rc = __tape_cancel_io(device, request);
 974         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 975         if (rc == 0) {
 976                 /* Wait for the interrupt that acknowledges the halt. */
 977                 do {
 978                         rc = wait_event_interruptible(
 979                                 device->wait_queue,
 980                                 (request->callback == NULL)
 981                         );
 982                 } while (rc == -ERESTARTSYS);
 983
 984                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
 985                 rc = -ERESTARTSYS;
 986         }
 987         return rc;
 988 }
 989
 990 /*
 991  * Stop running ccw.
 992  */
 993 int
 994 tape_cancel_io(struct tape_device *device, struct tape_request *request)
 995 {
 996         int rc;
 997
 998         spin_lock_irq(get_ccwdev_lock(device->cdev));
 999         rc = __tape_cancel_io(device, request);
1000         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1001         return rc;
1002 }
1003
1004 /*
1005  * Tape interrupt routine, called from the ccw_device layer
1006  */
1007 static void
1008 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1009 {
1010         struct tape_device *device;
1011         struct tape_request *request;
1012         int rc;
1013
1014         device = (struct tape_device *) cdev->dev.driver_data;
1015         if (device == NULL) {
1016                 return;
1017         }
1018         request = (struct tape_request *) intparm;
1019
1020         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1021
1022         /* On special conditions irb is an error pointer */
1023         if (IS_ERR(irb)) {
1024                 /* FIXME: What to do with the request? */
1025                 switch (PTR_ERR(irb)) {
1026                         case -ETIMEDOUT:
1027                                 DBF_LH(1, "(%s): Request timed out\n",
1028                                         dev_name(&cdev->dev));
1029                         case -EIO:
1030                                 __tape_end_request(device, request, -EIO);
1031                                 break;
1032                         default:
1033                                 DBF_LH(1, "(%s): Unexpected i/o error %li\n",
1034                                         dev_name(&cdev->dev),
1035                                         PTR_ERR(irb));
1036                 }
1037                 return;
1038         }
1039
1040         /*
1041          * If the condition code is not zero and the start function bit is
1042          * still set, this is an deferred error and the last start I/O did
1043          * not succeed. At this point the condition that caused the deferred
1044          * error might still apply. So we just schedule the request to be
1045          * started later.
1046          */
1047         if (irb->scsw.cmd.cc != 0 &&
1048             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1049             (request->status == TAPE_REQUEST_IN_IO)) {
1050                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1051                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1052                 request->status = TAPE_REQUEST_QUEUED;
1053                 schedule_delayed_work(&device->tape_dnr, HZ);
1054                 return;
1055         }
1056
1057         /* May be an unsolicited irq */
1058         if(request != NULL)
1059                 request->rescnt = irb->scsw.cmd.count;
1060         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1061                  !list_empty(&device->req_queue)) {
1062                 /* Not Ready to Ready after long busy ? */
1063                 struct tape_request *req;
1064                 req = list_entry(device->req_queue.next,
1065                                  struct tape_request, list);
1066                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1067                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1068                         if (del_timer(&device->lb_timeout)) {
1069                                 device->lb_timeout.data = (unsigned long)
1070                                         tape_put_device(device);
1071                                 __tape_start_next_request(device);
1072                         }
1073                         return;
1074                 }
1075         }
1076         if (irb->scsw.cmd.dstat != 0x0c) {
1077                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1078                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1079                         device->tape_generic_status |= GMT_ONLINE(~0);
1080                 else
1081                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1082
1083                 /*
1084                  * Any request that does not come back with channel end
1085                  * and device end is unusual. Log the sense data.
1086                  */
1087                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1088                 tape_dump_sense_dbf(device, request, irb);
1089         } else {
1090                 /* Upon normal completion the device _is_ online */
1091                 device->tape_generic_status |= GMT_ONLINE(~0);
1092         }
1093         if (device->tape_state == TS_NOT_OPER) {
1094                 DBF_EVENT(6, "tape:device is not operational\n");
1095                 return;
1096         }
1097
1098         /*
1099          * Request that were canceled still come back with an interrupt.
1100          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1101          */
1102         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1103                 __tape_end_request(device, request, -EIO);
1104                 return;
1105         }
1106
1107         rc = device->discipline->irq(device, request, irb);
1108         /*
1109          * rc < 0 : request finished unsuccessfully.
1110          * rc == TAPE_IO_SUCCESS: request finished successfully.
1111          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1112          * rc == TAPE_IO_RETRY: request finished but needs another go.
1113          * rc == TAPE_IO_STOP: request needs to get terminated.
1114          */
1115         switch (rc) {
1116                 case TAPE_IO_SUCCESS:
1117                         /* Upon normal completion the device _is_ online */
1118                         device->tape_generic_status |= GMT_ONLINE(~0);
1119                         __tape_end_request(device, request, rc);
1120                         break;
1121                 case TAPE_IO_PENDING:
1122                         break;
1123                 case TAPE_IO_LONG_BUSY:
1124                         device->lb_timeout.data =
1125                                 (unsigned long)tape_get_device_reference(device);
1126                         device->lb_timeout.expires = jiffies +
1127                                 LONG_BUSY_TIMEOUT * HZ;
1128                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1129                         add_timer(&device->lb_timeout);
1130                         request->status = TAPE_REQUEST_LONG_BUSY;
1131                         break;
1132                 case TAPE_IO_RETRY:
1133                         rc = __tape_start_io(device, request);
1134                         if (rc)
1135                                 __tape_end_request(device, request, rc);
1136                         break;
1137                 case TAPE_IO_STOP:
1138                         rc = __tape_cancel_io(device, request);
1139                         if (rc)
1140                                 __tape_end_request(device, request, rc);
1141                         break;
1142                 default:
1143                         if (rc > 0) {
1144                                 DBF_EVENT(6, "xunknownrc\n");
1145                                 __tape_end_request(device, request, -EIO);
1146                         } else {
1147                                 __tape_end_request(device, request, rc);
1148                         }
1149                         break;
1150         }
1151 }
1152
1153 /*
1154  * Tape device open function used by tape_char & tape_block frontends.
1155  */
1156 int
1157 tape_open(struct tape_device *device)
1158 {
1159         int rc;
1160
1161         spin_lock_irq(get_ccwdev_lock(device->cdev));
1162         if (device->tape_state == TS_NOT_OPER) {
1163                 DBF_EVENT(6, "TAPE:nodev\n");
1164                 rc = -ENODEV;
1165         } else if (device->tape_state == TS_IN_USE) {
1166                 DBF_EVENT(6, "TAPE:dbusy\n");
1167                 rc = -EBUSY;
1168         } else if (device->tape_state == TS_BLKUSE) {
1169                 DBF_EVENT(6, "TAPE:dbusy\n");
1170                 rc = -EBUSY;
1171         } else if (device->discipline != NULL &&
1172                    !try_module_get(device->discipline->owner)) {
1173                 DBF_EVENT(6, "TAPE:nodisc\n");
1174                 rc = -ENODEV;
1175         } else {
1176                 tape_state_set(device, TS_IN_USE);
1177                 rc = 0;
1178         }
1179         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1180         return rc;
1181 }
1182
1183 /*
1184  * Tape device release function used by tape_char & tape_block frontends.
1185  */
1186 int
1187 tape_release(struct tape_device *device)
1188 {
1189         spin_lock_irq(get_ccwdev_lock(device->cdev));
1190         if (device->tape_state == TS_IN_USE)
1191                 tape_state_set(device, TS_UNUSED);
1192         module_put(device->discipline->owner);
1193         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1194         return 0;
1195 }
1196
1197 /*
1198  * Execute a magnetic tape command a number of times.
1199  */
1200 int
1201 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1202 {
1203         tape_mtop_fn fn;
1204         int rc;
1205
1206         DBF_EVENT(6, "TAPE:mtio\n");
1207         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1208         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1209
1210         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1211                 return -EINVAL;
1212         fn = device->discipline->mtop_array[mt_op];
1213         if (fn == NULL)
1214                 return -EINVAL;
1215
1216         /* We assume that the backends can handle count up to 500. */
1217         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1218             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1219                 rc = 0;
1220                 for (; mt_count > 500; mt_count -= 500)
1221                         if ((rc = fn(device, 500)) != 0)
1222                                 break;
1223                 if (rc == 0)
1224                         rc = fn(device, mt_count);
1225         } else
1226                 rc = fn(device, mt_count);
1227         return rc;
1228
1229 }
1230
1231 /*
1232  * Tape init function.
1233  */
1234 static int
1235 tape_init (void)
1236 {
1237         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1238         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1239 #ifdef DBF_LIKE_HELL
1240         debug_set_level(TAPE_DBF_AREA, 6);
1241 #endif
1242         DBF_EVENT(3, "tape init\n");
1243         tape_proc_init();
1244         tapechar_init ();
1245         tapeblock_init ();
1246         return 0;
1247 }
1248
1249 /*
1250  * Tape exit function.
1251  */
1252 static void
1253 tape_exit(void)
1254 {
1255         DBF_EVENT(6, "tape exit\n");
1256
1257         /* Get rid of the frontends */
1258         tapechar_exit();
1259         tapeblock_exit();
1260         tape_proc_cleanup();
1261         debug_unregister (TAPE_DBF_AREA);
1262 }
1263
1264 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1265               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1266 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1267 MODULE_LICENSE("GPL");
1268
1269 module_init(tape_init);
1270 module_exit(tape_exit);
1271
1272 EXPORT_SYMBOL(tape_generic_remove);
1273 EXPORT_SYMBOL(tape_generic_probe);
1274 EXPORT_SYMBOL(tape_generic_online);
1275 EXPORT_SYMBOL(tape_generic_offline);
1276 EXPORT_SYMBOL(tape_put_device);
1277 EXPORT_SYMBOL(tape_get_device_reference);
1278 EXPORT_SYMBOL(tape_state_verbose);
1279 EXPORT_SYMBOL(tape_op_verbose);
1280 EXPORT_SYMBOL(tape_state_set);
1281 EXPORT_SYMBOL(tape_med_state_set);
1282 EXPORT_SYMBOL(tape_alloc_request);
1283 EXPORT_SYMBOL(tape_free_request);
1284 EXPORT_SYMBOL(tape_dump_sense_dbf);
1285 EXPORT_SYMBOL(tape_do_io);
1286 EXPORT_SYMBOL(tape_do_io_async);
1287 EXPORT_SYMBOL(tape_do_io_interruptible);
1288 EXPORT_SYMBOL(tape_cancel_io);
1289 EXPORT_SYMBOL(tape_mtop);