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 (C) 2001,2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Michael Holzheu <holzheu@de.ibm.com>
   9  *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
  10  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
  11  *               Stefan Bader <shbader@de.ibm.com>
  12  */
  13
  14 #include <linux/config.h>
  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 PRINTK_HEADER "TAPE_CORE: "
  30
  31 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  32 static void tape_delayed_next_request(void * data);
  33
  34 /*
  35  * One list to contain all tape devices of all disciplines, so
  36  * we can assign the devices to minor numbers of the same major
  37  * The list is protected by the rwlock
  38  */
  39 static struct list_head tape_device_list = LIST_HEAD_INIT(tape_device_list);
  40 static DEFINE_RWLOCK(tape_device_lock);
  41
  42 /*
  43  * Pointer to debug area.
  44  */
  45 debug_info_t *TAPE_DBF_AREA = NULL;
  46 EXPORT_SYMBOL(TAPE_DBF_AREA);
  47
  48 /*
  49  * Printable strings for tape enumerations.
  50  */
  51 const char *tape_state_verbose[TS_SIZE] =
  52 {
  53         [TS_UNUSED]   = "UNUSED",
  54         [TS_IN_USE]   = "IN_USE",
  55         [TS_BLKUSE]   = "BLKUSE",
  56         [TS_INIT]     = "INIT  ",
  57         [TS_NOT_OPER] = "NOT_OP"
  58 };
  59
  60 const char *tape_op_verbose[TO_SIZE] =
  61 {
  62         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  63         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  64         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  65         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  66         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  67         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  68         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  69         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  70         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  71         [TO_READ_ATTMSG] = "RAT",
  72         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  73         [TO_UNASSIGN] = "UAS"
  74 };
  75
  76 static inline int
  77 busid_to_int(char *bus_id)
  78 {
  79         int     dec;
  80         int     d;
  81         char *  s;
  82
  83         for(s = bus_id, d = 0; *s != '\0' && *s != '.'; s++)
  84                 d = (d * 10) + (*s - '0');
  85         dec = d;
  86         for(s++, d = 0; *s != '\0' && *s != '.'; s++)
  87                 d = (d * 10) + (*s - '0');
  88         dec = (dec << 8) + d;
  89
  90         for(s++; *s != '\0'; s++) {
  91                 if (*s >= '0' && *s <= '9') {
  92                         d = *s - '0';
  93                 } else if (*s >= 'a' && *s <= 'f') {
  94                         d = *s - 'a' + 10;
  95                 } else {
  96                         d = *s - 'A' + 10;
  97                 }
  98                 dec = (dec << 4) + d;
  99         }
 100
 101         return dec;
 102 }
 103
 104 /*
 105  * Some channel attached tape specific attributes.
 106  *
 107  * FIXME: In the future the first_minor and blocksize attribute should be
 108  *        replaced by a link to the cdev tree.
 109  */
 110 static ssize_t
 111 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 112 {
 113         struct tape_device *tdev;
 114
 115         tdev = (struct tape_device *) dev->driver_data;
 116         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 117 }
 118
 119 static
 120 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 121
 122 static ssize_t
 123 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 124 {
 125         struct tape_device *tdev;
 126
 127         tdev = (struct tape_device *) dev->driver_data;
 128         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 129 }
 130
 131 static
 132 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 133
 134 static ssize_t
 135 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 136 {
 137         struct tape_device *tdev;
 138
 139         tdev = (struct tape_device *) dev->driver_data;
 140         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 141                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 142 }
 143
 144 static
 145 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 146
 147 static ssize_t
 148 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 149 {
 150         struct tape_device *tdev;
 151         ssize_t rc;
 152
 153         tdev = (struct tape_device *) dev->driver_data;
 154         if (tdev->first_minor < 0)
 155                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 156
 157         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 158         if (list_empty(&tdev->req_queue))
 159                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 160         else {
 161                 struct tape_request *req;
 162
 163                 req = list_entry(tdev->req_queue.next, struct tape_request,
 164                         list);
 165                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 166         }
 167         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 168         return rc;
 169 }
 170
 171 static
 172 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 173
 174 static ssize_t
 175 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 176 {
 177         struct tape_device *tdev;
 178
 179         tdev = (struct tape_device *) dev->driver_data;
 180
 181         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 182 }
 183
 184 static
 185 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 186
 187 static struct attribute *tape_attrs[] = {
 188         &dev_attr_medium_state.attr,
 189         &dev_attr_first_minor.attr,
 190         &dev_attr_state.attr,
 191         &dev_attr_operation.attr,
 192         &dev_attr_blocksize.attr,
 193         NULL
 194 };
 195
 196 static struct attribute_group tape_attr_group = {
 197         .attrs = tape_attrs,
 198 };
 199
 200 /*
 201  * Tape state functions
 202  */
 203 void
 204 tape_state_set(struct tape_device *device, enum tape_state newstate)
 205 {
 206         const char *str;
 207
 208         if (device->tape_state == TS_NOT_OPER) {
 209                 DBF_EVENT(3, "ts_set err: not oper\n");
 210                 return;
 211         }
 212         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 213         DBF_EVENT(4, "old ts:\t\n");
 214         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 215                 str = tape_state_verbose[device->tape_state];
 216         else
 217                 str = "UNKNOWN TS";
 218         DBF_EVENT(4, "%s\n", str);
 219         DBF_EVENT(4, "new ts:\t\n");
 220         if (newstate < TS_SIZE && newstate >= 0)
 221                 str = tape_state_verbose[newstate];
 222         else
 223                 str = "UNKNOWN TS";
 224         DBF_EVENT(4, "%s\n", str);
 225         device->tape_state = newstate;
 226         wake_up(&device->state_change_wq);
 227 }
 228
 229 void
 230 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 231 {
 232         if (device->medium_state == newstate)
 233                 return;
 234         switch(newstate){
 235         case MS_UNLOADED:
 236                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 237                 PRINT_INFO("(%s): Tape is unloaded\n",
 238                            device->cdev->dev.bus_id);
 239                 break;
 240         case MS_LOADED:
 241                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 242                 PRINT_INFO("(%s): Tape has been mounted\n",
 243                            device->cdev->dev.bus_id);
 244                 break;
 245         default:
 246                 // print nothing
 247                 break;
 248         }
 249         device->medium_state = newstate;
 250         wake_up(&device->state_change_wq);
 251 }
 252
 253 /*
 254  * Stop running ccw. Has to be called with the device lock held.
 255  */
 256 static inline int
 257 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 258 {
 259         int retries;
 260         int rc;
 261
 262         /* Check if interrupt has already been processed */
 263         if (request->callback == NULL)
 264                 return 0;
 265
 266         rc = 0;
 267         for (retries = 0; retries < 5; retries++) {
 268                 rc = ccw_device_clear(device->cdev, (long) request);
 269
 270                 switch (rc) {
 271                         case 0:
 272                                 request->status = TAPE_REQUEST_DONE;
 273                                 return 0;
 274                         case -EBUSY:
 275                                 request->status = TAPE_REQUEST_CANCEL;
 276                                 schedule_work(&device->tape_dnr);
 277                                 return 0;
 278                         case -ENODEV:
 279                                 DBF_EXCEPTION(2, "device gone, retry\n");
 280                                 break;
 281                         case -EIO:
 282                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 283                                 break;
 284                         default:
 285                                 BUG();
 286                 }
 287         }
 288
 289         return rc;
 290 }
 291
 292 /*
 293  * Add device into the sorted list, giving it the first
 294  * available minor number.
 295  */
 296 static int
 297 tape_assign_minor(struct tape_device *device)
 298 {
 299         struct tape_device *tmp;
 300         int minor;
 301
 302         minor = 0;
 303         write_lock(&tape_device_lock);
 304         list_for_each_entry(tmp, &tape_device_list, node) {
 305                 if (minor < tmp->first_minor)
 306                         break;
 307                 minor += TAPE_MINORS_PER_DEV;
 308         }
 309         if (minor >= 256) {
 310                 write_unlock(&tape_device_lock);
 311                 return -ENODEV;
 312         }
 313         device->first_minor = minor;
 314         list_add_tail(&device->node, &tmp->node);
 315         write_unlock(&tape_device_lock);
 316         return 0;
 317 }
 318
 319 /* remove device from the list */
 320 static void
 321 tape_remove_minor(struct tape_device *device)
 322 {
 323         write_lock(&tape_device_lock);
 324         list_del_init(&device->node);
 325         device->first_minor = -1;
 326         write_unlock(&tape_device_lock);
 327 }
 328
 329 /*
 330  * Set a device online.
 331  *
 332  * This function is called by the common I/O layer to move a device from the
 333  * detected but offline into the online state.
 334  * If we return an error (RC < 0) the device remains in the offline state. This
 335  * can happen if the device is assigned somewhere else, for example.
 336  */
 337 int
 338 tape_generic_online(struct tape_device *device,
 339                    struct tape_discipline *discipline)
 340 {
 341         int rc;
 342
 343         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 344
 345         if (device->tape_state != TS_INIT) {
 346                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 347                 return -EINVAL;
 348         }
 349
 350         /* Let the discipline have a go at the device. */
 351         device->discipline = discipline;
 352         if (!try_module_get(discipline->owner)) {
 353                 PRINT_ERR("Cannot get module. Module gone.\n");
 354                 return -EINVAL;
 355         }
 356
 357         rc = discipline->setup_device(device);
 358         if (rc)
 359                 goto out;
 360         rc = tape_assign_minor(device);
 361         if (rc)
 362                 goto out_discipline;
 363
 364         rc = tapechar_setup_device(device);
 365         if (rc)
 366                 goto out_minor;
 367         rc = tapeblock_setup_device(device);
 368         if (rc)
 369                 goto out_char;
 370
 371         tape_state_set(device, TS_UNUSED);
 372
 373         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 374
 375         return 0;
 376
 377 out_char:
 378         tapechar_cleanup_device(device);
 379 out_discipline:
 380         device->discipline->cleanup_device(device);
 381         device->discipline = NULL;
 382 out_minor:
 383         tape_remove_minor(device);
 384 out:
 385         module_put(discipline->owner);
 386         return rc;
 387 }
 388
 389 static inline void
 390 tape_cleanup_device(struct tape_device *device)
 391 {
 392         tapeblock_cleanup_device(device);
 393         tapechar_cleanup_device(device);
 394         device->discipline->cleanup_device(device);
 395         module_put(device->discipline->owner);
 396         tape_remove_minor(device);
 397         tape_med_state_set(device, MS_UNKNOWN);
 398 }
 399
 400 /*
 401  * Set device offline.
 402  *
 403  * Called by the common I/O layer if the drive should set offline on user
 404  * request. We may prevent this by returning an error.
 405  * Manual offline is only allowed while the drive is not in use.
 406  */
 407 int
 408 tape_generic_offline(struct tape_device *device)
 409 {
 410         if (!device) {
 411                 PRINT_ERR("tape_generic_offline: no such device\n");
 412                 return -ENODEV;
 413         }
 414
 415         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 416                 device->cdev_id, device);
 417
 418         spin_lock_irq(get_ccwdev_lock(device->cdev));
 419         switch (device->tape_state) {
 420                 case TS_INIT:
 421                 case TS_NOT_OPER:
 422                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 423                         break;
 424                 case TS_UNUSED:
 425                         tape_state_set(device, TS_INIT);
 426                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 427                         tape_cleanup_device(device);
 428                         break;
 429                 default:
 430                         DBF_EVENT(3, "(%08x): Set offline failed "
 431                                 "- drive in use.\n",
 432                                 device->cdev_id);
 433                         PRINT_WARN("(%s): Set offline failed "
 434                                 "- drive in use.\n",
 435                                 device->cdev->dev.bus_id);
 436                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 437                         return -EBUSY;
 438         }
 439
 440         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 441         return 0;
 442 }
 443
 444 /*
 445  * Allocate memory for a new device structure.
 446  */
 447 static struct tape_device *
 448 tape_alloc_device(void)
 449 {
 450         struct tape_device *device;
 451
 452         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 453         if (device == NULL) {
 454                 DBF_EXCEPTION(2, "ti:no mem\n");
 455                 PRINT_INFO ("can't allocate memory for "
 456                             "tape info structure\n");
 457                 return ERR_PTR(-ENOMEM);
 458         }
 459         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 460         if (device->modeset_byte == NULL) {
 461                 DBF_EXCEPTION(2, "ti:no mem\n");
 462                 PRINT_INFO("can't allocate memory for modeset byte\n");
 463                 kfree(device);
 464                 return ERR_PTR(-ENOMEM);
 465         }
 466         INIT_LIST_HEAD(&device->req_queue);
 467         INIT_LIST_HEAD(&device->node);
 468         init_waitqueue_head(&device->state_change_wq);
 469         device->tape_state = TS_INIT;
 470         device->medium_state = MS_UNKNOWN;
 471         *device->modeset_byte = 0;
 472         device->first_minor = -1;
 473         atomic_set(&device->ref_count, 1);
 474         INIT_WORK(&device->tape_dnr, tape_delayed_next_request, device);
 475
 476         return device;
 477 }
 478
 479 /*
 480  * Get a reference to an existing device structure. This will automatically
 481  * increment the reference count.
 482  */
 483 struct tape_device *
 484 tape_get_device_reference(struct tape_device *device)
 485 {
 486         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 487                 atomic_inc_return(&device->ref_count));
 488
 489         return device;
 490 }
 491
 492 /*
 493  * Decrease the reference counter of a devices structure. If the
 494  * reference counter reaches zero free the device structure.
 495  * The function returns a NULL pointer to be used by the caller
 496  * for clearing reference pointers.
 497  */
 498 struct tape_device *
 499 tape_put_device(struct tape_device *device)
 500 {
 501         int remain;
 502
 503         remain = atomic_dec_return(&device->ref_count);
 504         if (remain > 0) {
 505                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 506         } else {
 507                 if (remain < 0) {
 508                         DBF_EVENT(4, "put device without reference\n");
 509                         PRINT_ERR("put device without reference\n");
 510                 } else {
 511                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 512                         kfree(device->modeset_byte);
 513                         kfree(device);
 514                 }
 515         }
 516
 517         return NULL;
 518 }
 519
 520 /*
 521  * Find tape device by a device index.
 522  */
 523 struct tape_device *
 524 tape_get_device(int devindex)
 525 {
 526         struct tape_device *device, *tmp;
 527
 528         device = ERR_PTR(-ENODEV);
 529         read_lock(&tape_device_lock);
 530         list_for_each_entry(tmp, &tape_device_list, node) {
 531                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 532                         device = tape_get_device_reference(tmp);
 533                         break;
 534                 }
 535         }
 536         read_unlock(&tape_device_lock);
 537         return device;
 538 }
 539
 540 /*
 541  * Driverfs tape probe function.
 542  */
 543 int
 544 tape_generic_probe(struct ccw_device *cdev)
 545 {
 546         struct tape_device *device;
 547
 548         device = tape_alloc_device();
 549         if (IS_ERR(device))
 550                 return -ENODEV;
 551         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 552         cdev->dev.driver_data = device;
 553         device->cdev = cdev;
 554         device->cdev_id = busid_to_int(cdev->dev.bus_id);
 555         cdev->handler = __tape_do_irq;
 556
 557         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 558         sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 559
 560         return 0;
 561 }
 562
 563 static inline void
 564 __tape_discard_requests(struct tape_device *device)
 565 {
 566         struct tape_request *   request;
 567         struct list_head *      l, *n;
 568
 569         list_for_each_safe(l, n, &device->req_queue) {
 570                 request = list_entry(l, struct tape_request, list);
 571                 if (request->status == TAPE_REQUEST_IN_IO)
 572                         request->status = TAPE_REQUEST_DONE;
 573                 list_del(&request->list);
 574
 575                 /* Decrease ref_count for removed request. */
 576                 request->device = tape_put_device(device);
 577                 request->rc = -EIO;
 578                 if (request->callback != NULL)
 579                         request->callback(request, request->callback_data);
 580         }
 581 }
 582
 583 /*
 584  * Driverfs tape remove function.
 585  *
 586  * This function is called whenever the common I/O layer detects the device
 587  * gone. This can happen at any time and we cannot refuse.
 588  */
 589 void
 590 tape_generic_remove(struct ccw_device *cdev)
 591 {
 592         struct tape_device *    device;
 593
 594         device = cdev->dev.driver_data;
 595         if (!device) {
 596                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 597                 return;
 598         }
 599         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 600
 601         spin_lock_irq(get_ccwdev_lock(device->cdev));
 602         switch (device->tape_state) {
 603                 case TS_INIT:
 604                         tape_state_set(device, TS_NOT_OPER);
 605                 case TS_NOT_OPER:
 606                         /*
 607                          * Nothing to do.
 608                          */
 609                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 610                         break;
 611                 case TS_UNUSED:
 612                         /*
 613                          * Need only to release the device.
 614                          */
 615                         tape_state_set(device, TS_NOT_OPER);
 616                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 617                         tape_cleanup_device(device);
 618                         break;
 619                 default:
 620                         /*
 621                          * There may be requests on the queue. We will not get
 622                          * an interrupt for a request that was running. So we
 623                          * just post them all as I/O errors.
 624                          */
 625                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 626                                 device->cdev_id);
 627                         PRINT_WARN("(%s): Drive in use vanished - "
 628                                 "expect trouble!\n",
 629                                 device->cdev->dev.bus_id);
 630                         PRINT_WARN("State was %i\n", device->tape_state);
 631                         tape_state_set(device, TS_NOT_OPER);
 632                         __tape_discard_requests(device);
 633                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 634                         tape_cleanup_device(device);
 635         }
 636
 637         if (cdev->dev.driver_data != NULL) {
 638                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 639                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 640         }
 641 }
 642
 643 /*
 644  * Allocate a new tape ccw request
 645  */
 646 struct tape_request *
 647 tape_alloc_request(int cplength, int datasize)
 648 {
 649         struct tape_request *request;
 650
 651         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 652                 BUG();
 653
 654         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 655
 656         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 657         if (request == NULL) {
 658                 DBF_EXCEPTION(1, "cqra nomem\n");
 659                 return ERR_PTR(-ENOMEM);
 660         }
 661         /* allocate channel program */
 662         if (cplength > 0) {
 663                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 664                                           GFP_ATOMIC | GFP_DMA);
 665                 if (request->cpaddr == NULL) {
 666                         DBF_EXCEPTION(1, "cqra nomem\n");
 667                         kfree(request);
 668                         return ERR_PTR(-ENOMEM);
 669                 }
 670         }
 671         /* alloc small kernel buffer */
 672         if (datasize > 0) {
 673                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 674                 if (request->cpdata == NULL) {
 675                         DBF_EXCEPTION(1, "cqra nomem\n");
 676                         kfree(request->cpaddr);
 677                         kfree(request);
 678                         return ERR_PTR(-ENOMEM);
 679                 }
 680         }
 681         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 682                 request->cpdata);
 683
 684         return request;
 685 }
 686
 687 /*
 688  * Free tape ccw request
 689  */
 690 void
 691 tape_free_request (struct tape_request * request)
 692 {
 693         DBF_LH(6, "Free request %p\n", request);
 694
 695         if (request->device != NULL) {
 696                 request->device = tape_put_device(request->device);
 697         }
 698         kfree(request->cpdata);
 699         kfree(request->cpaddr);
 700         kfree(request);
 701 }
 702
 703 static inline int
 704 __tape_start_io(struct tape_device *device, struct tape_request *request)
 705 {
 706         int rc;
 707
 708 #ifdef CONFIG_S390_TAPE_BLOCK
 709         if (request->op == TO_BLOCK)
 710                 device->discipline->check_locate(device, request);
 711 #endif
 712         rc = ccw_device_start(
 713                 device->cdev,
 714                 request->cpaddr,
 715                 (unsigned long) request,
 716                 0x00,
 717                 request->options
 718         );
 719         if (rc == 0) {
 720                 request->status = TAPE_REQUEST_IN_IO;
 721         } else if (rc == -EBUSY) {
 722                 /* The common I/O subsystem is currently busy. Retry later. */
 723                 request->status = TAPE_REQUEST_QUEUED;
 724                 schedule_work(&device->tape_dnr);
 725                 rc = 0;
 726         } else {
 727                 /* Start failed. Remove request and indicate failure. */
 728                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 729         }
 730         return rc;
 731 }
 732
 733 static inline void
 734 __tape_start_next_request(struct tape_device *device)
 735 {
 736         struct list_head *l, *n;
 737         struct tape_request *request;
 738         int rc;
 739
 740         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 741         /*
 742          * Try to start each request on request queue until one is
 743          * started successful.
 744          */
 745         list_for_each_safe(l, n, &device->req_queue) {
 746                 request = list_entry(l, struct tape_request, list);
 747
 748                 /*
 749                  * Avoid race condition if bottom-half was triggered more than
 750                  * once.
 751                  */
 752                 if (request->status == TAPE_REQUEST_IN_IO)
 753                         return;
 754                 /*
 755                  * Request has already been stopped. We have to wait until
 756                  * the request is removed from the queue in the interrupt
 757                  * handling.
 758                  */
 759                 if (request->status == TAPE_REQUEST_DONE)
 760                         return;
 761
 762                 /*
 763                  * We wanted to cancel the request but the common I/O layer
 764                  * was busy at that time. This can only happen if this
 765                  * function is called by delayed_next_request.
 766                  * Otherwise we start the next request on the queue.
 767                  */
 768                 if (request->status == TAPE_REQUEST_CANCEL) {
 769                         rc = __tape_cancel_io(device, request);
 770                 } else {
 771                         rc = __tape_start_io(device, request);
 772                 }
 773                 if (rc == 0)
 774                         return;
 775
 776                 /* Set ending status. */
 777                 request->rc = rc;
 778                 request->status = TAPE_REQUEST_DONE;
 779
 780                 /* Remove from request queue. */
 781                 list_del(&request->list);
 782
 783                 /* Do callback. */
 784                 if (request->callback != NULL)
 785                         request->callback(request, request->callback_data);
 786         }
 787 }
 788
 789 static void
 790 tape_delayed_next_request(void *data)
 791 {
 792         struct tape_device *    device;
 793
 794         device = (struct tape_device *) data;
 795         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 796         spin_lock_irq(get_ccwdev_lock(device->cdev));
 797         __tape_start_next_request(device);
 798         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 799 }
 800
 801 static inline void
 802 __tape_end_request(
 803         struct tape_device *    device,
 804         struct tape_request *   request,
 805         int                     rc)
 806 {
 807         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 808         if (request) {
 809                 request->rc = rc;
 810                 request->status = TAPE_REQUEST_DONE;
 811
 812                 /* Remove from request queue. */
 813                 list_del(&request->list);
 814
 815                 /* Do callback. */
 816                 if (request->callback != NULL)
 817                         request->callback(request, request->callback_data);
 818         }
 819
 820         /* Start next request. */
 821         if (!list_empty(&device->req_queue))
 822                 __tape_start_next_request(device);
 823 }
 824
 825 /*
 826  * Write sense data to console/dbf
 827  */
 828 void
 829 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 830                 struct irb *irb)
 831 {
 832         unsigned int *sptr;
 833
 834         PRINT_INFO("-------------------------------------------------\n");
 835         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 836                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 837         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 838         if (request != NULL)
 839                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 840
 841         sptr = (unsigned int *) irb->ecw;
 842         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 843                    sptr[0], sptr[1], sptr[2], sptr[3]);
 844         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 845                    sptr[4], sptr[5], sptr[6], sptr[7]);
 846         PRINT_INFO("--------------------------------------------------\n");
 847 }
 848
 849 /*
 850  * Write sense data to dbf
 851  */
 852 void
 853 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 854                     struct irb *irb)
 855 {
 856         unsigned int *sptr;
 857         const char* op;
 858
 859         if (request != NULL)
 860                 op = tape_op_verbose[request->op];
 861         else
 862                 op = "---";
 863         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 864                   irb->scsw.dstat,irb->scsw.cstat);
 865         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 866         sptr = (unsigned int *) irb->ecw;
 867         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 868         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 869         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 870         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 871 }
 872
 873 /*
 874  * I/O helper function. Adds the request to the request queue
 875  * and starts it if the tape is idle. Has to be called with
 876  * the device lock held.
 877  */
 878 static inline int
 879 __tape_start_request(struct tape_device *device, struct tape_request *request)
 880 {
 881         int rc;
 882
 883         switch (request->op) {
 884                 case TO_MSEN:
 885                 case TO_ASSIGN:
 886                 case TO_UNASSIGN:
 887                 case TO_READ_ATTMSG:
 888                         if (device->tape_state == TS_INIT)
 889                                 break;
 890                         if (device->tape_state == TS_UNUSED)
 891                                 break;
 892                 default:
 893                         if (device->tape_state == TS_BLKUSE)
 894                                 break;
 895                         if (device->tape_state != TS_IN_USE)
 896                                 return -ENODEV;
 897         }
 898
 899         /* Increase use count of device for the added request. */
 900         request->device = tape_get_device_reference(device);
 901
 902         if (list_empty(&device->req_queue)) {
 903                 /* No other requests are on the queue. Start this one. */
 904                 rc = __tape_start_io(device, request);
 905                 if (rc)
 906                         return rc;
 907
 908                 DBF_LH(5, "Request %p added for execution.\n", request);
 909                 list_add(&request->list, &device->req_queue);
 910         } else {
 911                 DBF_LH(5, "Request %p add to queue.\n", request);
 912                 request->status = TAPE_REQUEST_QUEUED;
 913                 list_add_tail(&request->list, &device->req_queue);
 914         }
 915         return 0;
 916 }
 917
 918 /*
 919  * Add the request to the request queue, try to start it if the
 920  * tape is idle. Return without waiting for end of i/o.
 921  */
 922 int
 923 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 924 {
 925         int rc;
 926
 927         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 928
 929         spin_lock_irq(get_ccwdev_lock(device->cdev));
 930         /* Add request to request queue and try to start it. */
 931         rc = __tape_start_request(device, request);
 932         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 933         return rc;
 934 }
 935
 936 /*
 937  * tape_do_io/__tape_wake_up
 938  * Add the request to the request queue, try to start it if the
 939  * tape is idle and wait uninterruptible for its completion.
 940  */
 941 static void
 942 __tape_wake_up(struct tape_request *request, void *data)
 943 {
 944         request->callback = NULL;
 945         wake_up((wait_queue_head_t *) data);
 946 }
 947
 948 int
 949 tape_do_io(struct tape_device *device, struct tape_request *request)
 950 {
 951         wait_queue_head_t wq;
 952         int rc;
 953
 954         init_waitqueue_head(&wq);
 955         spin_lock_irq(get_ccwdev_lock(device->cdev));
 956         /* Setup callback */
 957         request->callback = __tape_wake_up;
 958         request->callback_data = &wq;
 959         /* Add request to request queue and try to start it. */
 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         wait_event(wq, (request->callback == NULL));
 966         /* Get rc from request */
 967         return request->rc;
 968 }
 969
 970 /*
 971  * tape_do_io_interruptible/__tape_wake_up_interruptible
 972  * Add the request to the request queue, try to start it if the
 973  * tape is idle and wait uninterruptible for its completion.
 974  */
 975 static void
 976 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 977 {
 978         request->callback = NULL;
 979         wake_up_interruptible((wait_queue_head_t *) data);
 980 }
 981
 982 int
 983 tape_do_io_interruptible(struct tape_device *device,
 984                          struct tape_request *request)
 985 {
 986         wait_queue_head_t wq;
 987         int rc;
 988
 989         init_waitqueue_head(&wq);
 990         spin_lock_irq(get_ccwdev_lock(device->cdev));
 991         /* Setup callback */
 992         request->callback = __tape_wake_up_interruptible;
 993         request->callback_data = &wq;
 994         rc = __tape_start_request(device, request);
 995         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 996         if (rc)
 997                 return rc;
 998         /* Request added to the queue. Wait for its completion. */
 999         rc = wait_event_interruptible(wq, (request->callback == NULL));
1000         if (rc != -ERESTARTSYS)
1001                 /* Request finished normally. */
1002                 return request->rc;
1003
1004         /* Interrupted by a signal. We have to stop the current request. */
1005         spin_lock_irq(get_ccwdev_lock(device->cdev));
1006         rc = __tape_cancel_io(device, request);
1007         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1008         if (rc == 0) {
1009                 /* Wait for the interrupt that acknowledges the halt. */
1010                 do {
1011                         rc = wait_event_interruptible(
1012                                 wq,
1013                                 (request->callback == NULL)
1014                         );
1015                 } while (rc == -ERESTARTSYS);
1016
1017                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1018                 rc = -ERESTARTSYS;
1019         }
1020         return rc;
1021 }
1022
1023 /*
1024  * Stop running ccw.
1025  */
1026 int
1027 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1028 {
1029         int rc;
1030
1031         spin_lock_irq(get_ccwdev_lock(device->cdev));
1032         rc = __tape_cancel_io(device, request);
1033         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1034         return rc;
1035 }
1036
1037 /*
1038  * Tape interrupt routine, called from the ccw_device layer
1039  */
1040 static void
1041 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1042 {
1043         struct tape_device *device;
1044         struct tape_request *request;
1045         int rc;
1046
1047         device = (struct tape_device *) cdev->dev.driver_data;
1048         if (device == NULL) {
1049                 PRINT_ERR("could not get device structure for %s "
1050                           "in interrupt\n", cdev->dev.bus_id);
1051                 return;
1052         }
1053         request = (struct tape_request *) intparm;
1054
1055         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1056
1057         /* On special conditions irb is an error pointer */
1058         if (IS_ERR(irb)) {
1059                 /* FIXME: What to do with the request? */
1060                 switch (PTR_ERR(irb)) {
1061                         case -ETIMEDOUT:
1062                                 PRINT_WARN("(%s): Request timed out\n",
1063                                         cdev->dev.bus_id);
1064                         case -EIO:
1065                                 __tape_end_request(device, request, -EIO);
1066                                 break;
1067                         default:
1068                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1069                                         cdev->dev.bus_id,
1070                                         PTR_ERR(irb));
1071                 }
1072                 return;
1073         }
1074
1075         /*
1076          * If the condition code is not zero and the start function bit is
1077          * still set, this is an deferred error and the last start I/O did
1078          * not succeed. At this point the condition that caused the deferred
1079          * error might still apply. So we just schedule the request to be
1080          * started later.
1081          */
1082         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC) &&
1083             (request->status == TAPE_REQUEST_IN_IO)) {
1084                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1085                         device->cdev_id, irb->scsw.cc, irb->scsw.fctl);
1086                 request->status = TAPE_REQUEST_QUEUED;
1087                 schedule_delayed_work(&device->tape_dnr, HZ);
1088                 return;
1089         }
1090
1091         /* May be an unsolicited irq */
1092         if(request != NULL)
1093                 request->rescnt = irb->scsw.count;
1094
1095         if (irb->scsw.dstat != 0x0c) {
1096                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1097                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1098                         device->tape_generic_status |= GMT_ONLINE(~0);
1099                 else
1100                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1101
1102                 /*
1103                  * Any request that does not come back with channel end
1104                  * and device end is unusual. Log the sense data.
1105                  */
1106                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1107                 tape_dump_sense_dbf(device, request, irb);
1108         } else {
1109                 /* Upon normal completion the device _is_ online */
1110                 device->tape_generic_status |= GMT_ONLINE(~0);
1111         }
1112         if (device->tape_state == TS_NOT_OPER) {
1113                 DBF_EVENT(6, "tape:device is not operational\n");
1114                 return;
1115         }
1116
1117         /*
1118          * Request that were canceled still come back with an interrupt.
1119          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1120          */
1121         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1122                 __tape_end_request(device, request, -EIO);
1123                 return;
1124         }
1125
1126         rc = device->discipline->irq(device, request, irb);
1127         /*
1128          * rc < 0 : request finished unsuccessfully.
1129          * rc == TAPE_IO_SUCCESS: request finished successfully.
1130          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1131          * rc == TAPE_IO_RETRY: request finished but needs another go.
1132          * rc == TAPE_IO_STOP: request needs to get terminated.
1133          */
1134         switch (rc) {
1135                 case TAPE_IO_SUCCESS:
1136                         /* Upon normal completion the device _is_ online */
1137                         device->tape_generic_status |= GMT_ONLINE(~0);
1138                         __tape_end_request(device, request, rc);
1139                         break;
1140                 case TAPE_IO_PENDING:
1141                         break;
1142                 case TAPE_IO_RETRY:
1143                         rc = __tape_start_io(device, request);
1144                         if (rc)
1145                                 __tape_end_request(device, request, rc);
1146                         break;
1147                 case TAPE_IO_STOP:
1148                         rc = __tape_cancel_io(device, request);
1149                         if (rc)
1150                                 __tape_end_request(device, request, rc);
1151                         break;
1152                 default:
1153                         if (rc > 0) {
1154                                 DBF_EVENT(6, "xunknownrc\n");
1155                                 PRINT_ERR("Invalid return code from discipline "
1156                                         "interrupt function.\n");
1157                                 __tape_end_request(device, request, -EIO);
1158                         } else {
1159                                 __tape_end_request(device, request, rc);
1160                         }
1161                         break;
1162         }
1163 }
1164
1165 /*
1166  * Tape device open function used by tape_char & tape_block frontends.
1167  */
1168 int
1169 tape_open(struct tape_device *device)
1170 {
1171         int rc;
1172
1173         spin_lock(get_ccwdev_lock(device->cdev));
1174         if (device->tape_state == TS_NOT_OPER) {
1175                 DBF_EVENT(6, "TAPE:nodev\n");
1176                 rc = -ENODEV;
1177         } else if (device->tape_state == TS_IN_USE) {
1178                 DBF_EVENT(6, "TAPE:dbusy\n");
1179                 rc = -EBUSY;
1180         } else if (device->tape_state == TS_BLKUSE) {
1181                 DBF_EVENT(6, "TAPE:dbusy\n");
1182                 rc = -EBUSY;
1183         } else if (device->discipline != NULL &&
1184                    !try_module_get(device->discipline->owner)) {
1185                 DBF_EVENT(6, "TAPE:nodisc\n");
1186                 rc = -ENODEV;
1187         } else {
1188                 tape_state_set(device, TS_IN_USE);
1189                 rc = 0;
1190         }
1191         spin_unlock(get_ccwdev_lock(device->cdev));
1192         return rc;
1193 }
1194
1195 /*
1196  * Tape device release function used by tape_char & tape_block frontends.
1197  */
1198 int
1199 tape_release(struct tape_device *device)
1200 {
1201         spin_lock(get_ccwdev_lock(device->cdev));
1202         if (device->tape_state == TS_IN_USE)
1203                 tape_state_set(device, TS_UNUSED);
1204         module_put(device->discipline->owner);
1205         spin_unlock(get_ccwdev_lock(device->cdev));
1206         return 0;
1207 }
1208
1209 /*
1210  * Execute a magnetic tape command a number of times.
1211  */
1212 int
1213 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1214 {
1215         tape_mtop_fn fn;
1216         int rc;
1217
1218         DBF_EVENT(6, "TAPE:mtio\n");
1219         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1220         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1221
1222         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1223                 return -EINVAL;
1224         fn = device->discipline->mtop_array[mt_op];
1225         if (fn == NULL)
1226                 return -EINVAL;
1227
1228         /* We assume that the backends can handle count up to 500. */
1229         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1230             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1231                 rc = 0;
1232                 for (; mt_count > 500; mt_count -= 500)
1233                         if ((rc = fn(device, 500)) != 0)
1234                                 break;
1235                 if (rc == 0)
1236                         rc = fn(device, mt_count);
1237         } else
1238                 rc = fn(device, mt_count);
1239         return rc;
1240
1241 }
1242
1243 /*
1244  * Tape init function.
1245  */
1246 static int
1247 tape_init (void)
1248 {
1249         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1250         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1251 #ifdef DBF_LIKE_HELL
1252         debug_set_level(TAPE_DBF_AREA, 6);
1253 #endif
1254         DBF_EVENT(3, "tape init\n");
1255         tape_proc_init();
1256         tapechar_init ();
1257         tapeblock_init ();
1258         return 0;
1259 }
1260
1261 /*
1262  * Tape exit function.
1263  */
1264 static void
1265 tape_exit(void)
1266 {
1267         DBF_EVENT(6, "tape exit\n");
1268
1269         /* Get rid of the frontends */
1270         tapechar_exit();
1271         tapeblock_exit();
1272         tape_proc_cleanup();
1273         debug_unregister (TAPE_DBF_AREA);
1274 }
1275
1276 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1277               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1278 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1279 MODULE_LICENSE("GPL");
1280
1281 module_init(tape_init);
1282 module_exit(tape_exit);
1283
1284 EXPORT_SYMBOL(tape_generic_remove);
1285 EXPORT_SYMBOL(tape_generic_probe);
1286 EXPORT_SYMBOL(tape_generic_online);
1287 EXPORT_SYMBOL(tape_generic_offline);
1288 EXPORT_SYMBOL(tape_put_device);
1289 EXPORT_SYMBOL(tape_get_device_reference);
1290 EXPORT_SYMBOL(tape_state_verbose);
1291 EXPORT_SYMBOL(tape_op_verbose);
1292 EXPORT_SYMBOL(tape_state_set);
1293 EXPORT_SYMBOL(tape_med_state_set);
1294 EXPORT_SYMBOL(tape_alloc_request);
1295 EXPORT_SYMBOL(tape_free_request);
1296 EXPORT_SYMBOL(tape_dump_sense);
1297 EXPORT_SYMBOL(tape_dump_sense_dbf);
1298 EXPORT_SYMBOL(tape_do_io);
1299 EXPORT_SYMBOL(tape_do_io_async);
1300 EXPORT_SYMBOL(tape_do_io_interruptible);
1301 EXPORT_SYMBOL(tape_cancel_io);
1302 EXPORT_SYMBOL(tape_mtop);