git.oblomov.eu Git - linux-2.6/blob - drivers/s390/char/tape_core.c

   1 /*
   2  *  drivers/s390/char/tape_core.c
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright IBM Corp. 2001,2006
   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 tape_device *device)
 391 {
 392         if (!device) {
 393                 return -ENODEV;
 394         }
 395
 396         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 397                 device->cdev_id, device);
 398
 399         spin_lock_irq(get_ccwdev_lock(device->cdev));
 400         switch (device->tape_state) {
 401                 case TS_INIT:
 402                 case TS_NOT_OPER:
 403                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 404                         break;
 405                 case TS_UNUSED:
 406                         tape_state_set(device, TS_INIT);
 407                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 408                         tape_cleanup_device(device);
 409                         break;
 410                 default:
 411                         DBF_EVENT(3, "(%08x): Set offline failed "
 412                                 "- drive in use.\n",
 413                                 device->cdev_id);
 414                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 415                         return -EBUSY;
 416         }
 417
 418         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 419         return 0;
 420 }
 421
 422 /*
 423  * Allocate memory for a new device structure.
 424  */
 425 static struct tape_device *
 426 tape_alloc_device(void)
 427 {
 428         struct tape_device *device;
 429
 430         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 431         if (device == NULL) {
 432                 DBF_EXCEPTION(2, "ti:no mem\n");
 433                 return ERR_PTR(-ENOMEM);
 434         }
 435         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 436         if (device->modeset_byte == NULL) {
 437                 DBF_EXCEPTION(2, "ti:no mem\n");
 438                 kfree(device);
 439                 return ERR_PTR(-ENOMEM);
 440         }
 441         INIT_LIST_HEAD(&device->req_queue);
 442         INIT_LIST_HEAD(&device->node);
 443         init_waitqueue_head(&device->state_change_wq);
 444         init_waitqueue_head(&device->wait_queue);
 445         device->tape_state = TS_INIT;
 446         device->medium_state = MS_UNKNOWN;
 447         *device->modeset_byte = 0;
 448         device->first_minor = -1;
 449         atomic_set(&device->ref_count, 1);
 450         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 451
 452         return device;
 453 }
 454
 455 /*
 456  * Get a reference to an existing device structure. This will automatically
 457  * increment the reference count.
 458  */
 459 struct tape_device *
 460 tape_get_device_reference(struct tape_device *device)
 461 {
 462         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 463                 atomic_inc_return(&device->ref_count));
 464
 465         return device;
 466 }
 467
 468 /*
 469  * Decrease the reference counter of a devices structure. If the
 470  * reference counter reaches zero free the device structure.
 471  * The function returns a NULL pointer to be used by the caller
 472  * for clearing reference pointers.
 473  */
 474 struct tape_device *
 475 tape_put_device(struct tape_device *device)
 476 {
 477         int remain;
 478
 479         remain = atomic_dec_return(&device->ref_count);
 480         if (remain > 0) {
 481                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 482         } else {
 483                 if (remain < 0) {
 484                         DBF_EVENT(4, "put device without reference\n");
 485                 } else {
 486                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 487                         kfree(device->modeset_byte);
 488                         kfree(device);
 489                 }
 490         }
 491
 492         return NULL;
 493 }
 494
 495 /*
 496  * Find tape device by a device index.
 497  */
 498 struct tape_device *
 499 tape_get_device(int devindex)
 500 {
 501         struct tape_device *device, *tmp;
 502
 503         device = ERR_PTR(-ENODEV);
 504         read_lock(&tape_device_lock);
 505         list_for_each_entry(tmp, &tape_device_list, node) {
 506                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 507                         device = tape_get_device_reference(tmp);
 508                         break;
 509                 }
 510         }
 511         read_unlock(&tape_device_lock);
 512         return device;
 513 }
 514
 515 /*
 516  * Driverfs tape probe function.
 517  */
 518 int
 519 tape_generic_probe(struct ccw_device *cdev)
 520 {
 521         struct tape_device *device;
 522         int ret;
 523         struct ccw_dev_id dev_id;
 524
 525         device = tape_alloc_device();
 526         if (IS_ERR(device))
 527                 return -ENODEV;
 528         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 529         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 530         if (ret) {
 531                 tape_put_device(device);
 532                 return ret;
 533         }
 534         cdev->dev.driver_data = device;
 535         cdev->handler = __tape_do_irq;
 536         device->cdev = cdev;
 537         ccw_device_get_id(cdev, &dev_id);
 538         device->cdev_id = devid_to_int(&dev_id);
 539         return ret;
 540 }
 541
 542 static void
 543 __tape_discard_requests(struct tape_device *device)
 544 {
 545         struct tape_request *   request;
 546         struct list_head *      l, *n;
 547
 548         list_for_each_safe(l, n, &device->req_queue) {
 549                 request = list_entry(l, struct tape_request, list);
 550                 if (request->status == TAPE_REQUEST_IN_IO)
 551                         request->status = TAPE_REQUEST_DONE;
 552                 list_del(&request->list);
 553
 554                 /* Decrease ref_count for removed request. */
 555                 request->device = tape_put_device(device);
 556                 request->rc = -EIO;
 557                 if (request->callback != NULL)
 558                         request->callback(request, request->callback_data);
 559         }
 560 }
 561
 562 /*
 563  * Driverfs tape remove function.
 564  *
 565  * This function is called whenever the common I/O layer detects the device
 566  * gone. This can happen at any time and we cannot refuse.
 567  */
 568 void
 569 tape_generic_remove(struct ccw_device *cdev)
 570 {
 571         struct tape_device *    device;
 572
 573         device = cdev->dev.driver_data;
 574         if (!device) {
 575                 return;
 576         }
 577         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 578
 579         spin_lock_irq(get_ccwdev_lock(device->cdev));
 580         switch (device->tape_state) {
 581                 case TS_INIT:
 582                         tape_state_set(device, TS_NOT_OPER);
 583                 case TS_NOT_OPER:
 584                         /*
 585                          * Nothing to do.
 586                          */
 587                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 588                         break;
 589                 case TS_UNUSED:
 590                         /*
 591                          * Need only to release the device.
 592                          */
 593                         tape_state_set(device, TS_NOT_OPER);
 594                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 595                         tape_cleanup_device(device);
 596                         break;
 597                 default:
 598                         /*
 599                          * There may be requests on the queue. We will not get
 600                          * an interrupt for a request that was running. So we
 601                          * just post them all as I/O errors.
 602                          */
 603                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 604                                 device->cdev_id);
 605                         dev_warn(&device->cdev->dev, "A tape unit was detached"
 606                                 " while in use\n");
 607                         tape_state_set(device, TS_NOT_OPER);
 608                         __tape_discard_requests(device);
 609                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 610                         tape_cleanup_device(device);
 611         }
 612
 613         if (cdev->dev.driver_data != NULL) {
 614                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 615                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 616         }
 617 }
 618
 619 /*
 620  * Allocate a new tape ccw request
 621  */
 622 struct tape_request *
 623 tape_alloc_request(int cplength, int datasize)
 624 {
 625         struct tape_request *request;
 626
 627         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 628
 629         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 630
 631         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 632         if (request == NULL) {
 633                 DBF_EXCEPTION(1, "cqra nomem\n");
 634                 return ERR_PTR(-ENOMEM);
 635         }
 636         /* allocate channel program */
 637         if (cplength > 0) {
 638                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 639                                           GFP_ATOMIC | GFP_DMA);
 640                 if (request->cpaddr == NULL) {
 641                         DBF_EXCEPTION(1, "cqra nomem\n");
 642                         kfree(request);
 643                         return ERR_PTR(-ENOMEM);
 644                 }
 645         }
 646         /* alloc small kernel buffer */
 647         if (datasize > 0) {
 648                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 649                 if (request->cpdata == NULL) {
 650                         DBF_EXCEPTION(1, "cqra nomem\n");
 651                         kfree(request->cpaddr);
 652                         kfree(request);
 653                         return ERR_PTR(-ENOMEM);
 654                 }
 655         }
 656         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 657                 request->cpdata);
 658
 659         return request;
 660 }
 661
 662 /*
 663  * Free tape ccw request
 664  */
 665 void
 666 tape_free_request (struct tape_request * request)
 667 {
 668         DBF_LH(6, "Free request %p\n", request);
 669
 670         if (request->device != NULL) {
 671                 request->device = tape_put_device(request->device);
 672         }
 673         kfree(request->cpdata);
 674         kfree(request->cpaddr);
 675         kfree(request);
 676 }
 677
 678 static int
 679 __tape_start_io(struct tape_device *device, struct tape_request *request)
 680 {
 681         int rc;
 682
 683 #ifdef CONFIG_S390_TAPE_BLOCK
 684         if (request->op == TO_BLOCK)
 685                 device->discipline->check_locate(device, request);
 686 #endif
 687         rc = ccw_device_start(
 688                 device->cdev,
 689                 request->cpaddr,
 690                 (unsigned long) request,
 691                 0x00,
 692                 request->options
 693         );
 694         if (rc == 0) {
 695                 request->status = TAPE_REQUEST_IN_IO;
 696         } else if (rc == -EBUSY) {
 697                 /* The common I/O subsystem is currently busy. Retry later. */
 698                 request->status = TAPE_REQUEST_QUEUED;
 699                 schedule_delayed_work(&device->tape_dnr, 0);
 700                 rc = 0;
 701         } else {
 702                 /* Start failed. Remove request and indicate failure. */
 703                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 704         }
 705         return rc;
 706 }
 707
 708 static void
 709 __tape_start_next_request(struct tape_device *device)
 710 {
 711         struct list_head *l, *n;
 712         struct tape_request *request;
 713         int rc;
 714
 715         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 716         /*
 717          * Try to start each request on request queue until one is
 718          * started successful.
 719          */
 720         list_for_each_safe(l, n, &device->req_queue) {
 721                 request = list_entry(l, struct tape_request, list);
 722
 723                 /*
 724                  * Avoid race condition if bottom-half was triggered more than
 725                  * once.
 726                  */
 727                 if (request->status == TAPE_REQUEST_IN_IO)
 728                         return;
 729                 /*
 730                  * Request has already been stopped. We have to wait until
 731                  * the request is removed from the queue in the interrupt
 732                  * handling.
 733                  */
 734                 if (request->status == TAPE_REQUEST_DONE)
 735                         return;
 736
 737                 /*
 738                  * We wanted to cancel the request but the common I/O layer
 739                  * was busy at that time. This can only happen if this
 740                  * function is called by delayed_next_request.
 741                  * Otherwise we start the next request on the queue.
 742                  */
 743                 if (request->status == TAPE_REQUEST_CANCEL) {
 744                         rc = __tape_cancel_io(device, request);
 745                 } else {
 746                         rc = __tape_start_io(device, request);
 747                 }
 748                 if (rc == 0)
 749                         return;
 750
 751                 /* Set ending status. */
 752                 request->rc = rc;
 753                 request->status = TAPE_REQUEST_DONE;
 754
 755                 /* Remove from request queue. */
 756                 list_del(&request->list);
 757
 758                 /* Do callback. */
 759                 if (request->callback != NULL)
 760                         request->callback(request, request->callback_data);
 761         }
 762 }
 763
 764 static void
 765 tape_delayed_next_request(struct work_struct *work)
 766 {
 767         struct tape_device *device =
 768                 container_of(work, struct tape_device, tape_dnr.work);
 769
 770         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 771         spin_lock_irq(get_ccwdev_lock(device->cdev));
 772         __tape_start_next_request(device);
 773         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 774 }
 775
 776 static void tape_long_busy_timeout(unsigned long data)
 777 {
 778         struct tape_request *request;
 779         struct tape_device *device;
 780
 781         device = (struct tape_device *) data;
 782         spin_lock_irq(get_ccwdev_lock(device->cdev));
 783         request = list_entry(device->req_queue.next, struct tape_request, list);
 784         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 785         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 786         __tape_start_next_request(device);
 787         device->lb_timeout.data = (unsigned long) tape_put_device(device);
 788         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 789 }
 790
 791 static void
 792 __tape_end_request(
 793         struct tape_device *    device,
 794         struct tape_request *   request,
 795         int                     rc)
 796 {
 797         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 798         if (request) {
 799                 request->rc = rc;
 800                 request->status = TAPE_REQUEST_DONE;
 801
 802                 /* Remove from request queue. */
 803                 list_del(&request->list);
 804
 805                 /* Do callback. */
 806                 if (request->callback != NULL)
 807                         request->callback(request, request->callback_data);
 808         }
 809
 810         /* Start next request. */
 811         if (!list_empty(&device->req_queue))
 812                 __tape_start_next_request(device);
 813 }
 814
 815 /*
 816  * Write sense data to dbf
 817  */
 818 void
 819 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 820                     struct irb *irb)
 821 {
 822         unsigned int *sptr;
 823         const char* op;
 824
 825         if (request != NULL)
 826                 op = tape_op_verbose[request->op];
 827         else
 828                 op = "---";
 829         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 830                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 831         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 832         sptr = (unsigned int *) irb->ecw;
 833         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 834         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 835         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 836         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 837 }
 838
 839 /*
 840  * I/O helper function. Adds the request to the request queue
 841  * and starts it if the tape is idle. Has to be called with
 842  * the device lock held.
 843  */
 844 static int
 845 __tape_start_request(struct tape_device *device, struct tape_request *request)
 846 {
 847         int rc;
 848
 849         switch (request->op) {
 850                 case TO_MSEN:
 851                 case TO_ASSIGN:
 852                 case TO_UNASSIGN:
 853                 case TO_READ_ATTMSG:
 854                 case TO_RDC:
 855                         if (device->tape_state == TS_INIT)
 856                                 break;
 857                         if (device->tape_state == TS_UNUSED)
 858                                 break;
 859                 default:
 860                         if (device->tape_state == TS_BLKUSE)
 861                                 break;
 862                         if (device->tape_state != TS_IN_USE)
 863                                 return -ENODEV;
 864         }
 865
 866         /* Increase use count of device for the added request. */
 867         request->device = tape_get_device_reference(device);
 868
 869         if (list_empty(&device->req_queue)) {
 870                 /* No other requests are on the queue. Start this one. */
 871                 rc = __tape_start_io(device, request);
 872                 if (rc)
 873                         return rc;
 874
 875                 DBF_LH(5, "Request %p added for execution.\n", request);
 876                 list_add(&request->list, &device->req_queue);
 877         } else {
 878                 DBF_LH(5, "Request %p add to queue.\n", request);
 879                 request->status = TAPE_REQUEST_QUEUED;
 880                 list_add_tail(&request->list, &device->req_queue);
 881         }
 882         return 0;
 883 }
 884
 885 /*
 886  * Add the request to the request queue, try to start it if the
 887  * tape is idle. Return without waiting for end of i/o.
 888  */
 889 int
 890 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 891 {
 892         int rc;
 893
 894         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 895
 896         spin_lock_irq(get_ccwdev_lock(device->cdev));
 897         /* Add request to request queue and try to start it. */
 898         rc = __tape_start_request(device, request);
 899         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 900         return rc;
 901 }
 902
 903 /*
 904  * tape_do_io/__tape_wake_up
 905  * Add the request to the request queue, try to start it if the
 906  * tape is idle and wait uninterruptible for its completion.
 907  */
 908 static void
 909 __tape_wake_up(struct tape_request *request, void *data)
 910 {
 911         request->callback = NULL;
 912         wake_up((wait_queue_head_t *) data);
 913 }
 914
 915 int
 916 tape_do_io(struct tape_device *device, struct tape_request *request)
 917 {
 918         int rc;
 919
 920         spin_lock_irq(get_ccwdev_lock(device->cdev));
 921         /* Setup callback */
 922         request->callback = __tape_wake_up;
 923         request->callback_data = &device->wait_queue;
 924         /* Add request to request queue and try to start it. */
 925         rc = __tape_start_request(device, request);
 926         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 927         if (rc)
 928                 return rc;
 929         /* Request added to the queue. Wait for its completion. */
 930         wait_event(device->wait_queue, (request->callback == NULL));
 931         /* Get rc from request */
 932         return request->rc;
 933 }
 934
 935 /*
 936  * tape_do_io_interruptible/__tape_wake_up_interruptible
 937  * Add the request to the request queue, try to start it if the
 938  * tape is idle and wait uninterruptible for its completion.
 939  */
 940 static void
 941 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 942 {
 943         request->callback = NULL;
 944         wake_up_interruptible((wait_queue_head_t *) data);
 945 }
 946
 947 int
 948 tape_do_io_interruptible(struct tape_device *device,
 949                          struct tape_request *request)
 950 {
 951         int rc;
 952
 953         spin_lock_irq(get_ccwdev_lock(device->cdev));
 954         /* Setup callback */
 955         request->callback = __tape_wake_up_interruptible;
 956         request->callback_data = &device->wait_queue;
 957         rc = __tape_start_request(device, request);
 958         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 959         if (rc)
 960                 return rc;
 961         /* Request added to the queue. Wait for its completion. */
 962         rc = wait_event_interruptible(device->wait_queue,
 963                                       (request->callback == NULL));
 964         if (rc != -ERESTARTSYS)
 965                 /* Request finished normally. */
 966                 return request->rc;
 967
 968         /* Interrupted by a signal. We have to stop the current request. */
 969         spin_lock_irq(get_ccwdev_lock(device->cdev));
 970         rc = __tape_cancel_io(device, request);
 971         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 972         if (rc == 0) {
 973                 /* Wait for the interrupt that acknowledges the halt. */
 974                 do {
 975                         rc = wait_event_interruptible(
 976                                 device->wait_queue,
 977                                 (request->callback == NULL)
 978                         );
 979                 } while (rc == -ERESTARTSYS);
 980
 981                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
 982                 rc = -ERESTARTSYS;
 983         }
 984         return rc;
 985 }
 986
 987 /*
 988  * Stop running ccw.
 989  */
 990 int
 991 tape_cancel_io(struct tape_device *device, struct tape_request *request)
 992 {
 993         int rc;
 994
 995         spin_lock_irq(get_ccwdev_lock(device->cdev));
 996         rc = __tape_cancel_io(device, request);
 997         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 998         return rc;
 999 }
1000
1001 /*
1002  * Tape interrupt routine, called from the ccw_device layer
1003  */
1004 static void
1005 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1006 {
1007         struct tape_device *device;
1008         struct tape_request *request;
1009         int rc;
1010
1011         device = (struct tape_device *) cdev->dev.driver_data;
1012         if (device == NULL) {
1013                 return;
1014         }
1015         request = (struct tape_request *) intparm;
1016
1017         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1018
1019         /* On special conditions irb is an error pointer */
1020         if (IS_ERR(irb)) {
1021                 /* FIXME: What to do with the request? */
1022                 switch (PTR_ERR(irb)) {
1023                         case -ETIMEDOUT:
1024                                 DBF_LH(1, "(%s): Request timed out\n",
1025                                         dev_name(&cdev->dev));
1026                         case -EIO:
1027                                 __tape_end_request(device, request, -EIO);
1028                                 break;
1029                         default:
1030                                 DBF_LH(1, "(%s): Unexpected i/o error %li\n",
1031                                         dev_name(&cdev->dev),
1032                                         PTR_ERR(irb));
1033                 }
1034                 return;
1035         }
1036
1037         /*
1038          * If the condition code is not zero and the start function bit is
1039          * still set, this is an deferred error and the last start I/O did
1040          * not succeed. At this point the condition that caused the deferred
1041          * error might still apply. So we just schedule the request to be
1042          * started later.
1043          */
1044         if (irb->scsw.cmd.cc != 0 &&
1045             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1046             (request->status == TAPE_REQUEST_IN_IO)) {
1047                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1048                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1049                 request->status = TAPE_REQUEST_QUEUED;
1050                 schedule_delayed_work(&device->tape_dnr, HZ);
1051                 return;
1052         }
1053
1054         /* May be an unsolicited irq */
1055         if(request != NULL)
1056                 request->rescnt = irb->scsw.cmd.count;
1057         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1058                  !list_empty(&device->req_queue)) {
1059                 /* Not Ready to Ready after long busy ? */
1060                 struct tape_request *req;
1061                 req = list_entry(device->req_queue.next,
1062                                  struct tape_request, list);
1063                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1064                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1065                         if (del_timer(&device->lb_timeout)) {
1066                                 device->lb_timeout.data = (unsigned long)
1067                                         tape_put_device(device);
1068                                 __tape_start_next_request(device);
1069                         }
1070                         return;
1071                 }
1072         }
1073         if (irb->scsw.cmd.dstat != 0x0c) {
1074                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1075                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1076                         device->tape_generic_status |= GMT_ONLINE(~0);
1077                 else
1078                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1079
1080                 /*
1081                  * Any request that does not come back with channel end
1082                  * and device end is unusual. Log the sense data.
1083                  */
1084                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1085                 tape_dump_sense_dbf(device, request, irb);
1086         } else {
1087                 /* Upon normal completion the device _is_ online */
1088                 device->tape_generic_status |= GMT_ONLINE(~0);
1089         }
1090         if (device->tape_state == TS_NOT_OPER) {
1091                 DBF_EVENT(6, "tape:device is not operational\n");
1092                 return;
1093         }
1094
1095         /*
1096          * Request that were canceled still come back with an interrupt.
1097          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1098          */
1099         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1100                 __tape_end_request(device, request, -EIO);
1101                 return;
1102         }
1103
1104         rc = device->discipline->irq(device, request, irb);
1105         /*
1106          * rc < 0 : request finished unsuccessfully.
1107          * rc == TAPE_IO_SUCCESS: request finished successfully.
1108          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1109          * rc == TAPE_IO_RETRY: request finished but needs another go.
1110          * rc == TAPE_IO_STOP: request needs to get terminated.
1111          */
1112         switch (rc) {
1113                 case TAPE_IO_SUCCESS:
1114                         /* Upon normal completion the device _is_ online */
1115                         device->tape_generic_status |= GMT_ONLINE(~0);
1116                         __tape_end_request(device, request, rc);
1117                         break;
1118                 case TAPE_IO_PENDING:
1119                         break;
1120                 case TAPE_IO_LONG_BUSY:
1121                         device->lb_timeout.data =
1122                                 (unsigned long)tape_get_device_reference(device);
1123                         device->lb_timeout.expires = jiffies +
1124                                 LONG_BUSY_TIMEOUT * HZ;
1125                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1126                         add_timer(&device->lb_timeout);
1127                         request->status = TAPE_REQUEST_LONG_BUSY;
1128                         break;
1129                 case TAPE_IO_RETRY:
1130                         rc = __tape_start_io(device, request);
1131                         if (rc)
1132                                 __tape_end_request(device, request, rc);
1133                         break;
1134                 case TAPE_IO_STOP:
1135                         rc = __tape_cancel_io(device, request);
1136                         if (rc)
1137                                 __tape_end_request(device, request, rc);
1138                         break;
1139                 default:
1140                         if (rc > 0) {
1141                                 DBF_EVENT(6, "xunknownrc\n");
1142                                 __tape_end_request(device, request, -EIO);
1143                         } else {
1144                                 __tape_end_request(device, request, rc);
1145                         }
1146                         break;
1147         }
1148 }
1149
1150 /*
1151  * Tape device open function used by tape_char & tape_block frontends.
1152  */
1153 int
1154 tape_open(struct tape_device *device)
1155 {
1156         int rc;
1157
1158         spin_lock_irq(get_ccwdev_lock(device->cdev));
1159         if (device->tape_state == TS_NOT_OPER) {
1160                 DBF_EVENT(6, "TAPE:nodev\n");
1161                 rc = -ENODEV;
1162         } else if (device->tape_state == TS_IN_USE) {
1163                 DBF_EVENT(6, "TAPE:dbusy\n");
1164                 rc = -EBUSY;
1165         } else if (device->tape_state == TS_BLKUSE) {
1166                 DBF_EVENT(6, "TAPE:dbusy\n");
1167                 rc = -EBUSY;
1168         } else if (device->discipline != NULL &&
1169                    !try_module_get(device->discipline->owner)) {
1170                 DBF_EVENT(6, "TAPE:nodisc\n");
1171                 rc = -ENODEV;
1172         } else {
1173                 tape_state_set(device, TS_IN_USE);
1174                 rc = 0;
1175         }
1176         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1177         return rc;
1178 }
1179
1180 /*
1181  * Tape device release function used by tape_char & tape_block frontends.
1182  */
1183 int
1184 tape_release(struct tape_device *device)
1185 {
1186         spin_lock_irq(get_ccwdev_lock(device->cdev));
1187         if (device->tape_state == TS_IN_USE)
1188                 tape_state_set(device, TS_UNUSED);
1189         module_put(device->discipline->owner);
1190         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1191         return 0;
1192 }
1193
1194 /*
1195  * Execute a magnetic tape command a number of times.
1196  */
1197 int
1198 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1199 {
1200         tape_mtop_fn fn;
1201         int rc;
1202
1203         DBF_EVENT(6, "TAPE:mtio\n");
1204         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1205         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1206
1207         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1208                 return -EINVAL;
1209         fn = device->discipline->mtop_array[mt_op];
1210         if (fn == NULL)
1211                 return -EINVAL;
1212
1213         /* We assume that the backends can handle count up to 500. */
1214         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1215             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1216                 rc = 0;
1217                 for (; mt_count > 500; mt_count -= 500)
1218                         if ((rc = fn(device, 500)) != 0)
1219                                 break;
1220                 if (rc == 0)
1221                         rc = fn(device, mt_count);
1222         } else
1223                 rc = fn(device, mt_count);
1224         return rc;
1225
1226 }
1227
1228 /*
1229  * Tape init function.
1230  */
1231 static int
1232 tape_init (void)
1233 {
1234         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1235         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1236 #ifdef DBF_LIKE_HELL
1237         debug_set_level(TAPE_DBF_AREA, 6);
1238 #endif
1239         DBF_EVENT(3, "tape init\n");
1240         tape_proc_init();
1241         tapechar_init ();
1242         tapeblock_init ();
1243         return 0;
1244 }
1245
1246 /*
1247  * Tape exit function.
1248  */
1249 static void
1250 tape_exit(void)
1251 {
1252         DBF_EVENT(6, "tape exit\n");
1253
1254         /* Get rid of the frontends */
1255         tapechar_exit();
1256         tapeblock_exit();
1257         tape_proc_cleanup();
1258         debug_unregister (TAPE_DBF_AREA);
1259 }
1260
1261 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1262               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1263 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1264 MODULE_LICENSE("GPL");
1265
1266 module_init(tape_init);
1267 module_exit(tape_exit);
1268
1269 EXPORT_SYMBOL(tape_generic_remove);
1270 EXPORT_SYMBOL(tape_generic_probe);
1271 EXPORT_SYMBOL(tape_generic_online);
1272 EXPORT_SYMBOL(tape_generic_offline);
1273 EXPORT_SYMBOL(tape_put_device);
1274 EXPORT_SYMBOL(tape_get_device_reference);
1275 EXPORT_SYMBOL(tape_state_verbose);
1276 EXPORT_SYMBOL(tape_op_verbose);
1277 EXPORT_SYMBOL(tape_state_set);
1278 EXPORT_SYMBOL(tape_med_state_set);
1279 EXPORT_SYMBOL(tape_alloc_request);
1280 EXPORT_SYMBOL(tape_free_request);
1281 EXPORT_SYMBOL(tape_dump_sense_dbf);
1282 EXPORT_SYMBOL(tape_do_io);
1283 EXPORT_SYMBOL(tape_do_io_async);
1284 EXPORT_SYMBOL(tape_do_io_interruptible);
1285 EXPORT_SYMBOL(tape_cancel_io);
1286 EXPORT_SYMBOL(tape_mtop);