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/module.h>
  15 #include <linux/init.h>      // for kernel parameters
  16 #include <linux/kmod.h>      // for requesting modules
  17 #include <linux/spinlock.h>  // for locks
  18 #include <linux/vmalloc.h>
  19 #include <linux/list.h>
  20
  21 #include <asm/types.h>       // for variable types
  22
  23 #define TAPE_DBF_AREA   tape_core_dbf
  24
  25 #include "tape.h"
  26 #include "tape_std.h"
  27
  28 #define PRINTK_HEADER "TAPE_CORE: "
  29
  30 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  31 static void tape_delayed_next_request(void * data);
  32
  33 /*
  34  * One list to contain all tape devices of all disciplines, so
  35  * we can assign the devices to minor numbers of the same major
  36  * The list is protected by the rwlock
  37  */
  38 static struct list_head tape_device_list = LIST_HEAD_INIT(tape_device_list);
  39 static DEFINE_RWLOCK(tape_device_lock);
  40
  41 /*
  42  * Pointer to debug area.
  43  */
  44 debug_info_t *TAPE_DBF_AREA = NULL;
  45 EXPORT_SYMBOL(TAPE_DBF_AREA);
  46
  47 /*
  48  * Printable strings for tape enumerations.
  49  */
  50 const char *tape_state_verbose[TS_SIZE] =
  51 {
  52         [TS_UNUSED]   = "UNUSED",
  53         [TS_IN_USE]   = "IN_USE",
  54         [TS_BLKUSE]   = "BLKUSE",
  55         [TS_INIT]     = "INIT  ",
  56         [TS_NOT_OPER] = "NOT_OP"
  57 };
  58
  59 const char *tape_op_verbose[TO_SIZE] =
  60 {
  61         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  62         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  63         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  64         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  65         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  66         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  67         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  68         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  69         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  70         [TO_READ_ATTMSG] = "RAT",
  71         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  72         [TO_UNASSIGN] = "UAS"
  73 };
  74
  75 static inline int
  76 busid_to_int(char *bus_id)
  77 {
  78         int     dec;
  79         int     d;
  80         char *  s;
  81
  82         for(s = bus_id, d = 0; *s != '\0' && *s != '.'; s++)
  83                 d = (d * 10) + (*s - '0');
  84         dec = d;
  85         for(s++, d = 0; *s != '\0' && *s != '.'; s++)
  86                 d = (d * 10) + (*s - '0');
  87         dec = (dec << 8) + d;
  88
  89         for(s++; *s != '\0'; s++) {
  90                 if (*s >= '0' && *s <= '9') {
  91                         d = *s - '0';
  92                 } else if (*s >= 'a' && *s <= 'f') {
  93                         d = *s - 'a' + 10;
  94                 } else {
  95                         d = *s - 'A' + 10;
  96                 }
  97                 dec = (dec << 4) + d;
  98         }
  99
 100         return dec;
 101 }
 102
 103 /*
 104  * Some channel attached tape specific attributes.
 105  *
 106  * FIXME: In the future the first_minor and blocksize attribute should be
 107  *        replaced by a link to the cdev tree.
 108  */
 109 static ssize_t
 110 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 111 {
 112         struct tape_device *tdev;
 113
 114         tdev = (struct tape_device *) dev->driver_data;
 115         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 116 }
 117
 118 static
 119 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 120
 121 static ssize_t
 122 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 123 {
 124         struct tape_device *tdev;
 125
 126         tdev = (struct tape_device *) dev->driver_data;
 127         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 128 }
 129
 130 static
 131 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 132
 133 static ssize_t
 134 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 135 {
 136         struct tape_device *tdev;
 137
 138         tdev = (struct tape_device *) dev->driver_data;
 139         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 140                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 141 }
 142
 143 static
 144 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 145
 146 static ssize_t
 147 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 148 {
 149         struct tape_device *tdev;
 150         ssize_t rc;
 151
 152         tdev = (struct tape_device *) dev->driver_data;
 153         if (tdev->first_minor < 0)
 154                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 155
 156         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 157         if (list_empty(&tdev->req_queue))
 158                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 159         else {
 160                 struct tape_request *req;
 161
 162                 req = list_entry(tdev->req_queue.next, struct tape_request,
 163                         list);
 164                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 165         }
 166         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 167         return rc;
 168 }
 169
 170 static
 171 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 172
 173 static ssize_t
 174 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 175 {
 176         struct tape_device *tdev;
 177
 178         tdev = (struct tape_device *) dev->driver_data;
 179
 180         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 181 }
 182
 183 static
 184 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 185
 186 static struct attribute *tape_attrs[] = {
 187         &dev_attr_medium_state.attr,
 188         &dev_attr_first_minor.attr,
 189         &dev_attr_state.attr,
 190         &dev_attr_operation.attr,
 191         &dev_attr_blocksize.attr,
 192         NULL
 193 };
 194
 195 static struct attribute_group tape_attr_group = {
 196         .attrs = tape_attrs,
 197 };
 198
 199 /*
 200  * Tape state functions
 201  */
 202 void
 203 tape_state_set(struct tape_device *device, enum tape_state newstate)
 204 {
 205         const char *str;
 206
 207         if (device->tape_state == TS_NOT_OPER) {
 208                 DBF_EVENT(3, "ts_set err: not oper\n");
 209                 return;
 210         }
 211         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 212         DBF_EVENT(4, "old ts:\t\n");
 213         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 214                 str = tape_state_verbose[device->tape_state];
 215         else
 216                 str = "UNKNOWN TS";
 217         DBF_EVENT(4, "%s\n", str);
 218         DBF_EVENT(4, "new ts:\t\n");
 219         if (newstate < TS_SIZE && newstate >= 0)
 220                 str = tape_state_verbose[newstate];
 221         else
 222                 str = "UNKNOWN TS";
 223         DBF_EVENT(4, "%s\n", str);
 224         device->tape_state = newstate;
 225         wake_up(&device->state_change_wq);
 226 }
 227
 228 void
 229 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 230 {
 231         if (device->medium_state == newstate)
 232                 return;
 233         switch(newstate){
 234         case MS_UNLOADED:
 235                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 236                 PRINT_INFO("(%s): Tape is unloaded\n",
 237                            device->cdev->dev.bus_id);
 238                 break;
 239         case MS_LOADED:
 240                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 241                 PRINT_INFO("(%s): Tape has been mounted\n",
 242                            device->cdev->dev.bus_id);
 243                 break;
 244         default:
 245                 // print nothing
 246                 break;
 247         }
 248         device->medium_state = newstate;
 249         wake_up(&device->state_change_wq);
 250 }
 251
 252 /*
 253  * Stop running ccw. Has to be called with the device lock held.
 254  */
 255 static inline int
 256 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 257 {
 258         int retries;
 259         int rc;
 260
 261         /* Check if interrupt has already been processed */
 262         if (request->callback == NULL)
 263                 return 0;
 264
 265         rc = 0;
 266         for (retries = 0; retries < 5; retries++) {
 267                 rc = ccw_device_clear(device->cdev, (long) request);
 268
 269                 switch (rc) {
 270                         case 0:
 271                                 request->status = TAPE_REQUEST_DONE;
 272                                 return 0;
 273                         case -EBUSY:
 274                                 request->status = TAPE_REQUEST_CANCEL;
 275                                 schedule_work(&device->tape_dnr);
 276                                 return 0;
 277                         case -ENODEV:
 278                                 DBF_EXCEPTION(2, "device gone, retry\n");
 279                                 break;
 280                         case -EIO:
 281                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 282                                 break;
 283                         default:
 284                                 BUG();
 285                 }
 286         }
 287
 288         return rc;
 289 }
 290
 291 /*
 292  * Add device into the sorted list, giving it the first
 293  * available minor number.
 294  */
 295 static int
 296 tape_assign_minor(struct tape_device *device)
 297 {
 298         struct tape_device *tmp;
 299         int minor;
 300
 301         minor = 0;
 302         write_lock(&tape_device_lock);
 303         list_for_each_entry(tmp, &tape_device_list, node) {
 304                 if (minor < tmp->first_minor)
 305                         break;
 306                 minor += TAPE_MINORS_PER_DEV;
 307         }
 308         if (minor >= 256) {
 309                 write_unlock(&tape_device_lock);
 310                 return -ENODEV;
 311         }
 312         device->first_minor = minor;
 313         list_add_tail(&device->node, &tmp->node);
 314         write_unlock(&tape_device_lock);
 315         return 0;
 316 }
 317
 318 /* remove device from the list */
 319 static void
 320 tape_remove_minor(struct tape_device *device)
 321 {
 322         write_lock(&tape_device_lock);
 323         list_del_init(&device->node);
 324         device->first_minor = -1;
 325         write_unlock(&tape_device_lock);
 326 }
 327
 328 /*
 329  * Set a device online.
 330  *
 331  * This function is called by the common I/O layer to move a device from the
 332  * detected but offline into the online state.
 333  * If we return an error (RC < 0) the device remains in the offline state. This
 334  * can happen if the device is assigned somewhere else, for example.
 335  */
 336 int
 337 tape_generic_online(struct tape_device *device,
 338                    struct tape_discipline *discipline)
 339 {
 340         int rc;
 341
 342         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 343
 344         if (device->tape_state != TS_INIT) {
 345                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 346                 return -EINVAL;
 347         }
 348
 349         /* Let the discipline have a go at the device. */
 350         device->discipline = discipline;
 351         if (!try_module_get(discipline->owner)) {
 352                 PRINT_ERR("Cannot get module. Module gone.\n");
 353                 return -EINVAL;
 354         }
 355
 356         rc = discipline->setup_device(device);
 357         if (rc)
 358                 goto out;
 359         rc = tape_assign_minor(device);
 360         if (rc)
 361                 goto out_discipline;
 362
 363         rc = tapechar_setup_device(device);
 364         if (rc)
 365                 goto out_minor;
 366         rc = tapeblock_setup_device(device);
 367         if (rc)
 368                 goto out_char;
 369
 370         tape_state_set(device, TS_UNUSED);
 371
 372         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 373
 374         return 0;
 375
 376 out_char:
 377         tapechar_cleanup_device(device);
 378 out_discipline:
 379         device->discipline->cleanup_device(device);
 380         device->discipline = NULL;
 381 out_minor:
 382         tape_remove_minor(device);
 383 out:
 384         module_put(discipline->owner);
 385         return rc;
 386 }
 387
 388 static inline void
 389 tape_cleanup_device(struct tape_device *device)
 390 {
 391         tapeblock_cleanup_device(device);
 392         tapechar_cleanup_device(device);
 393         device->discipline->cleanup_device(device);
 394         module_put(device->discipline->owner);
 395         tape_remove_minor(device);
 396         tape_med_state_set(device, MS_UNKNOWN);
 397 }
 398
 399 /*
 400  * Set device offline.
 401  *
 402  * Called by the common I/O layer if the drive should set offline on user
 403  * request. We may prevent this by returning an error.
 404  * Manual offline is only allowed while the drive is not in use.
 405  */
 406 int
 407 tape_generic_offline(struct tape_device *device)
 408 {
 409         if (!device) {
 410                 PRINT_ERR("tape_generic_offline: no such device\n");
 411                 return -ENODEV;
 412         }
 413
 414         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 415                 device->cdev_id, device);
 416
 417         spin_lock_irq(get_ccwdev_lock(device->cdev));
 418         switch (device->tape_state) {
 419                 case TS_INIT:
 420                 case TS_NOT_OPER:
 421                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 422                         break;
 423                 case TS_UNUSED:
 424                         tape_state_set(device, TS_INIT);
 425                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 426                         tape_cleanup_device(device);
 427                         break;
 428                 default:
 429                         DBF_EVENT(3, "(%08x): Set offline failed "
 430                                 "- drive in use.\n",
 431                                 device->cdev_id);
 432                         PRINT_WARN("(%s): Set offline failed "
 433                                 "- drive in use.\n",
 434                                 device->cdev->dev.bus_id);
 435                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 436                         return -EBUSY;
 437         }
 438
 439         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 440         return 0;
 441 }
 442
 443 /*
 444  * Allocate memory for a new device structure.
 445  */
 446 static struct tape_device *
 447 tape_alloc_device(void)
 448 {
 449         struct tape_device *device;
 450
 451         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 452         if (device == NULL) {
 453                 DBF_EXCEPTION(2, "ti:no mem\n");
 454                 PRINT_INFO ("can't allocate memory for "
 455                             "tape info structure\n");
 456                 return ERR_PTR(-ENOMEM);
 457         }
 458         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 459         if (device->modeset_byte == NULL) {
 460                 DBF_EXCEPTION(2, "ti:no mem\n");
 461                 PRINT_INFO("can't allocate memory for modeset byte\n");
 462                 kfree(device);
 463                 return ERR_PTR(-ENOMEM);
 464         }
 465         INIT_LIST_HEAD(&device->req_queue);
 466         INIT_LIST_HEAD(&device->node);
 467         init_waitqueue_head(&device->state_change_wq);
 468         device->tape_state = TS_INIT;
 469         device->medium_state = MS_UNKNOWN;
 470         *device->modeset_byte = 0;
 471         device->first_minor = -1;
 472         atomic_set(&device->ref_count, 1);
 473         INIT_WORK(&device->tape_dnr, tape_delayed_next_request, device);
 474
 475         return device;
 476 }
 477
 478 /*
 479  * Get a reference to an existing device structure. This will automatically
 480  * increment the reference count.
 481  */
 482 struct tape_device *
 483 tape_get_device_reference(struct tape_device *device)
 484 {
 485         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 486                 atomic_inc_return(&device->ref_count));
 487
 488         return device;
 489 }
 490
 491 /*
 492  * Decrease the reference counter of a devices structure. If the
 493  * reference counter reaches zero free the device structure.
 494  * The function returns a NULL pointer to be used by the caller
 495  * for clearing reference pointers.
 496  */
 497 struct tape_device *
 498 tape_put_device(struct tape_device *device)
 499 {
 500         int remain;
 501
 502         remain = atomic_dec_return(&device->ref_count);
 503         if (remain > 0) {
 504                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 505         } else {
 506                 if (remain < 0) {
 507                         DBF_EVENT(4, "put device without reference\n");
 508                         PRINT_ERR("put device without reference\n");
 509                 } else {
 510                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 511                         kfree(device->modeset_byte);
 512                         kfree(device);
 513                 }
 514         }
 515
 516         return NULL;
 517 }
 518
 519 /*
 520  * Find tape device by a device index.
 521  */
 522 struct tape_device *
 523 tape_get_device(int devindex)
 524 {
 525         struct tape_device *device, *tmp;
 526
 527         device = ERR_PTR(-ENODEV);
 528         read_lock(&tape_device_lock);
 529         list_for_each_entry(tmp, &tape_device_list, node) {
 530                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 531                         device = tape_get_device_reference(tmp);
 532                         break;
 533                 }
 534         }
 535         read_unlock(&tape_device_lock);
 536         return device;
 537 }
 538
 539 /*
 540  * Driverfs tape probe function.
 541  */
 542 int
 543 tape_generic_probe(struct ccw_device *cdev)
 544 {
 545         struct tape_device *device;
 546         int ret;
 547
 548         device = tape_alloc_device();
 549         if (IS_ERR(device))
 550                 return -ENODEV;
 551         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 552         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 553         if (ret) {
 554                 tape_put_device(device);
 555                 PRINT_ERR("probe failed for tape device %s\n", cdev->dev.bus_id);
 556                 return ret;
 557         }
 558         cdev->dev.driver_data = device;
 559         cdev->handler = __tape_do_irq;
 560         device->cdev = cdev;
 561         device->cdev_id = busid_to_int(cdev->dev.bus_id);
 562         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 563         return ret;
 564 }
 565
 566 static inline void
 567 __tape_discard_requests(struct tape_device *device)
 568 {
 569         struct tape_request *   request;
 570         struct list_head *      l, *n;
 571
 572         list_for_each_safe(l, n, &device->req_queue) {
 573                 request = list_entry(l, struct tape_request, list);
 574                 if (request->status == TAPE_REQUEST_IN_IO)
 575                         request->status = TAPE_REQUEST_DONE;
 576                 list_del(&request->list);
 577
 578                 /* Decrease ref_count for removed request. */
 579                 request->device = tape_put_device(device);
 580                 request->rc = -EIO;
 581                 if (request->callback != NULL)
 582                         request->callback(request, request->callback_data);
 583         }
 584 }
 585
 586 /*
 587  * Driverfs tape remove function.
 588  *
 589  * This function is called whenever the common I/O layer detects the device
 590  * gone. This can happen at any time and we cannot refuse.
 591  */
 592 void
 593 tape_generic_remove(struct ccw_device *cdev)
 594 {
 595         struct tape_device *    device;
 596
 597         device = cdev->dev.driver_data;
 598         if (!device) {
 599                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 600                 return;
 601         }
 602         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 603
 604         spin_lock_irq(get_ccwdev_lock(device->cdev));
 605         switch (device->tape_state) {
 606                 case TS_INIT:
 607                         tape_state_set(device, TS_NOT_OPER);
 608                 case TS_NOT_OPER:
 609                         /*
 610                          * Nothing to do.
 611                          */
 612                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 613                         break;
 614                 case TS_UNUSED:
 615                         /*
 616                          * Need only to release the device.
 617                          */
 618                         tape_state_set(device, TS_NOT_OPER);
 619                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 620                         tape_cleanup_device(device);
 621                         break;
 622                 default:
 623                         /*
 624                          * There may be requests on the queue. We will not get
 625                          * an interrupt for a request that was running. So we
 626                          * just post them all as I/O errors.
 627                          */
 628                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 629                                 device->cdev_id);
 630                         PRINT_WARN("(%s): Drive in use vanished - "
 631                                 "expect trouble!\n",
 632                                 device->cdev->dev.bus_id);
 633                         PRINT_WARN("State was %i\n", device->tape_state);
 634                         tape_state_set(device, TS_NOT_OPER);
 635                         __tape_discard_requests(device);
 636                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 637                         tape_cleanup_device(device);
 638         }
 639
 640         if (cdev->dev.driver_data != NULL) {
 641                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 642                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 643         }
 644 }
 645
 646 /*
 647  * Allocate a new tape ccw request
 648  */
 649 struct tape_request *
 650 tape_alloc_request(int cplength, int datasize)
 651 {
 652         struct tape_request *request;
 653
 654         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 655                 BUG();
 656
 657         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 658
 659         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 660         if (request == NULL) {
 661                 DBF_EXCEPTION(1, "cqra nomem\n");
 662                 return ERR_PTR(-ENOMEM);
 663         }
 664         /* allocate channel program */
 665         if (cplength > 0) {
 666                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 667                                           GFP_ATOMIC | GFP_DMA);
 668                 if (request->cpaddr == NULL) {
 669                         DBF_EXCEPTION(1, "cqra nomem\n");
 670                         kfree(request);
 671                         return ERR_PTR(-ENOMEM);
 672                 }
 673         }
 674         /* alloc small kernel buffer */
 675         if (datasize > 0) {
 676                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 677                 if (request->cpdata == NULL) {
 678                         DBF_EXCEPTION(1, "cqra nomem\n");
 679                         kfree(request->cpaddr);
 680                         kfree(request);
 681                         return ERR_PTR(-ENOMEM);
 682                 }
 683         }
 684         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 685                 request->cpdata);
 686
 687         return request;
 688 }
 689
 690 /*
 691  * Free tape ccw request
 692  */
 693 void
 694 tape_free_request (struct tape_request * request)
 695 {
 696         DBF_LH(6, "Free request %p\n", request);
 697
 698         if (request->device != NULL) {
 699                 request->device = tape_put_device(request->device);
 700         }
 701         kfree(request->cpdata);
 702         kfree(request->cpaddr);
 703         kfree(request);
 704 }
 705
 706 static inline int
 707 __tape_start_io(struct tape_device *device, struct tape_request *request)
 708 {
 709         int rc;
 710
 711 #ifdef CONFIG_S390_TAPE_BLOCK
 712         if (request->op == TO_BLOCK)
 713                 device->discipline->check_locate(device, request);
 714 #endif
 715         rc = ccw_device_start(
 716                 device->cdev,
 717                 request->cpaddr,
 718                 (unsigned long) request,
 719                 0x00,
 720                 request->options
 721         );
 722         if (rc == 0) {
 723                 request->status = TAPE_REQUEST_IN_IO;
 724         } else if (rc == -EBUSY) {
 725                 /* The common I/O subsystem is currently busy. Retry later. */
 726                 request->status = TAPE_REQUEST_QUEUED;
 727                 schedule_work(&device->tape_dnr);
 728                 rc = 0;
 729         } else {
 730                 /* Start failed. Remove request and indicate failure. */
 731                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 732         }
 733         return rc;
 734 }
 735
 736 static inline void
 737 __tape_start_next_request(struct tape_device *device)
 738 {
 739         struct list_head *l, *n;
 740         struct tape_request *request;
 741         int rc;
 742
 743         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 744         /*
 745          * Try to start each request on request queue until one is
 746          * started successful.
 747          */
 748         list_for_each_safe(l, n, &device->req_queue) {
 749                 request = list_entry(l, struct tape_request, list);
 750
 751                 /*
 752                  * Avoid race condition if bottom-half was triggered more than
 753                  * once.
 754                  */
 755                 if (request->status == TAPE_REQUEST_IN_IO)
 756                         return;
 757                 /*
 758                  * Request has already been stopped. We have to wait until
 759                  * the request is removed from the queue in the interrupt
 760                  * handling.
 761                  */
 762                 if (request->status == TAPE_REQUEST_DONE)
 763                         return;
 764
 765                 /*
 766                  * We wanted to cancel the request but the common I/O layer
 767                  * was busy at that time. This can only happen if this
 768                  * function is called by delayed_next_request.
 769                  * Otherwise we start the next request on the queue.
 770                  */
 771                 if (request->status == TAPE_REQUEST_CANCEL) {
 772                         rc = __tape_cancel_io(device, request);
 773                 } else {
 774                         rc = __tape_start_io(device, request);
 775                 }
 776                 if (rc == 0)
 777                         return;
 778
 779                 /* Set ending status. */
 780                 request->rc = rc;
 781                 request->status = TAPE_REQUEST_DONE;
 782
 783                 /* Remove from request queue. */
 784                 list_del(&request->list);
 785
 786                 /* Do callback. */
 787                 if (request->callback != NULL)
 788                         request->callback(request, request->callback_data);
 789         }
 790 }
 791
 792 static void
 793 tape_delayed_next_request(void *data)
 794 {
 795         struct tape_device *    device;
 796
 797         device = (struct tape_device *) data;
 798         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 799         spin_lock_irq(get_ccwdev_lock(device->cdev));
 800         __tape_start_next_request(device);
 801         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 802 }
 803
 804 static inline void
 805 __tape_end_request(
 806         struct tape_device *    device,
 807         struct tape_request *   request,
 808         int                     rc)
 809 {
 810         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 811         if (request) {
 812                 request->rc = rc;
 813                 request->status = TAPE_REQUEST_DONE;
 814
 815                 /* Remove from request queue. */
 816                 list_del(&request->list);
 817
 818                 /* Do callback. */
 819                 if (request->callback != NULL)
 820                         request->callback(request, request->callback_data);
 821         }
 822
 823         /* Start next request. */
 824         if (!list_empty(&device->req_queue))
 825                 __tape_start_next_request(device);
 826 }
 827
 828 /*
 829  * Write sense data to console/dbf
 830  */
 831 void
 832 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 833                 struct irb *irb)
 834 {
 835         unsigned int *sptr;
 836
 837         PRINT_INFO("-------------------------------------------------\n");
 838         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 839                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 840         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 841         if (request != NULL)
 842                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 843
 844         sptr = (unsigned int *) irb->ecw;
 845         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 846                    sptr[0], sptr[1], sptr[2], sptr[3]);
 847         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 848                    sptr[4], sptr[5], sptr[6], sptr[7]);
 849         PRINT_INFO("--------------------------------------------------\n");
 850 }
 851
 852 /*
 853  * Write sense data to dbf
 854  */
 855 void
 856 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 857                     struct irb *irb)
 858 {
 859         unsigned int *sptr;
 860         const char* op;
 861
 862         if (request != NULL)
 863                 op = tape_op_verbose[request->op];
 864         else
 865                 op = "---";
 866         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 867                   irb->scsw.dstat,irb->scsw.cstat);
 868         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 869         sptr = (unsigned int *) irb->ecw;
 870         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 871         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 872         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 873         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 874 }
 875
 876 /*
 877  * I/O helper function. Adds the request to the request queue
 878  * and starts it if the tape is idle. Has to be called with
 879  * the device lock held.
 880  */
 881 static inline int
 882 __tape_start_request(struct tape_device *device, struct tape_request *request)
 883 {
 884         int rc;
 885
 886         switch (request->op) {
 887                 case TO_MSEN:
 888                 case TO_ASSIGN:
 889                 case TO_UNASSIGN:
 890                 case TO_READ_ATTMSG:
 891                         if (device->tape_state == TS_INIT)
 892                                 break;
 893                         if (device->tape_state == TS_UNUSED)
 894                                 break;
 895                 default:
 896                         if (device->tape_state == TS_BLKUSE)
 897                                 break;
 898                         if (device->tape_state != TS_IN_USE)
 899                                 return -ENODEV;
 900         }
 901
 902         /* Increase use count of device for the added request. */
 903         request->device = tape_get_device_reference(device);
 904
 905         if (list_empty(&device->req_queue)) {
 906                 /* No other requests are on the queue. Start this one. */
 907                 rc = __tape_start_io(device, request);
 908                 if (rc)
 909                         return rc;
 910
 911                 DBF_LH(5, "Request %p added for execution.\n", request);
 912                 list_add(&request->list, &device->req_queue);
 913         } else {
 914                 DBF_LH(5, "Request %p add to queue.\n", request);
 915                 request->status = TAPE_REQUEST_QUEUED;
 916                 list_add_tail(&request->list, &device->req_queue);
 917         }
 918         return 0;
 919 }
 920
 921 /*
 922  * Add the request to the request queue, try to start it if the
 923  * tape is idle. Return without waiting for end of i/o.
 924  */
 925 int
 926 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 927 {
 928         int rc;
 929
 930         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 931
 932         spin_lock_irq(get_ccwdev_lock(device->cdev));
 933         /* Add request to request queue and try to start it. */
 934         rc = __tape_start_request(device, request);
 935         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 936         return rc;
 937 }
 938
 939 /*
 940  * tape_do_io/__tape_wake_up
 941  * Add the request to the request queue, try to start it if the
 942  * tape is idle and wait uninterruptible for its completion.
 943  */
 944 static void
 945 __tape_wake_up(struct tape_request *request, void *data)
 946 {
 947         request->callback = NULL;
 948         wake_up((wait_queue_head_t *) data);
 949 }
 950
 951 int
 952 tape_do_io(struct tape_device *device, struct tape_request *request)
 953 {
 954         wait_queue_head_t wq;
 955         int rc;
 956
 957         init_waitqueue_head(&wq);
 958         spin_lock_irq(get_ccwdev_lock(device->cdev));
 959         /* Setup callback */
 960         request->callback = __tape_wake_up;
 961         request->callback_data = &wq;
 962         /* Add request to request queue and try to start it. */
 963         rc = __tape_start_request(device, request);
 964         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 965         if (rc)
 966                 return rc;
 967         /* Request added to the queue. Wait for its completion. */
 968         wait_event(wq, (request->callback == NULL));
 969         /* Get rc from request */
 970         return request->rc;
 971 }
 972
 973 /*
 974  * tape_do_io_interruptible/__tape_wake_up_interruptible
 975  * Add the request to the request queue, try to start it if the
 976  * tape is idle and wait uninterruptible for its completion.
 977  */
 978 static void
 979 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 980 {
 981         request->callback = NULL;
 982         wake_up_interruptible((wait_queue_head_t *) data);
 983 }
 984
 985 int
 986 tape_do_io_interruptible(struct tape_device *device,
 987                          struct tape_request *request)
 988 {
 989         wait_queue_head_t wq;
 990         int rc;
 991
 992         init_waitqueue_head(&wq);
 993         spin_lock_irq(get_ccwdev_lock(device->cdev));
 994         /* Setup callback */
 995         request->callback = __tape_wake_up_interruptible;
 996         request->callback_data = &wq;
 997         rc = __tape_start_request(device, request);
 998         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 999         if (rc)
1000                 return rc;
1001         /* Request added to the queue. Wait for its completion. */
1002         rc = wait_event_interruptible(wq, (request->callback == NULL));
1003         if (rc != -ERESTARTSYS)
1004                 /* Request finished normally. */
1005                 return request->rc;
1006
1007         /* Interrupted by a signal. We have to stop the current request. */
1008         spin_lock_irq(get_ccwdev_lock(device->cdev));
1009         rc = __tape_cancel_io(device, request);
1010         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1011         if (rc == 0) {
1012                 /* Wait for the interrupt that acknowledges the halt. */
1013                 do {
1014                         rc = wait_event_interruptible(
1015                                 wq,
1016                                 (request->callback == NULL)
1017                         );
1018                 } while (rc == -ERESTARTSYS);
1019
1020                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1021                 rc = -ERESTARTSYS;
1022         }
1023         return rc;
1024 }
1025
1026 /*
1027  * Stop running ccw.
1028  */
1029 int
1030 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1031 {
1032         int rc;
1033
1034         spin_lock_irq(get_ccwdev_lock(device->cdev));
1035         rc = __tape_cancel_io(device, request);
1036         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1037         return rc;
1038 }
1039
1040 /*
1041  * Tape interrupt routine, called from the ccw_device layer
1042  */
1043 static void
1044 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1045 {
1046         struct tape_device *device;
1047         struct tape_request *request;
1048         int rc;
1049
1050         device = (struct tape_device *) cdev->dev.driver_data;
1051         if (device == NULL) {
1052                 PRINT_ERR("could not get device structure for %s "
1053                           "in interrupt\n", cdev->dev.bus_id);
1054                 return;
1055         }
1056         request = (struct tape_request *) intparm;
1057
1058         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1059
1060         /* On special conditions irb is an error pointer */
1061         if (IS_ERR(irb)) {
1062                 /* FIXME: What to do with the request? */
1063                 switch (PTR_ERR(irb)) {
1064                         case -ETIMEDOUT:
1065                                 PRINT_WARN("(%s): Request timed out\n",
1066                                         cdev->dev.bus_id);
1067                         case -EIO:
1068                                 __tape_end_request(device, request, -EIO);
1069                                 break;
1070                         default:
1071                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1072                                         cdev->dev.bus_id,
1073                                         PTR_ERR(irb));
1074                 }
1075                 return;
1076         }
1077
1078         /*
1079          * If the condition code is not zero and the start function bit is
1080          * still set, this is an deferred error and the last start I/O did
1081          * not succeed. At this point the condition that caused the deferred
1082          * error might still apply. So we just schedule the request to be
1083          * started later.
1084          */
1085         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC) &&
1086             (request->status == TAPE_REQUEST_IN_IO)) {
1087                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1088                         device->cdev_id, irb->scsw.cc, irb->scsw.fctl);
1089                 request->status = TAPE_REQUEST_QUEUED;
1090                 schedule_delayed_work(&device->tape_dnr, HZ);
1091                 return;
1092         }
1093
1094         /* May be an unsolicited irq */
1095         if(request != NULL)
1096                 request->rescnt = irb->scsw.count;
1097
1098         if (irb->scsw.dstat != 0x0c) {
1099                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1100                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1101                         device->tape_generic_status |= GMT_ONLINE(~0);
1102                 else
1103                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1104
1105                 /*
1106                  * Any request that does not come back with channel end
1107                  * and device end is unusual. Log the sense data.
1108                  */
1109                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1110                 tape_dump_sense_dbf(device, request, irb);
1111         } else {
1112                 /* Upon normal completion the device _is_ online */
1113                 device->tape_generic_status |= GMT_ONLINE(~0);
1114         }
1115         if (device->tape_state == TS_NOT_OPER) {
1116                 DBF_EVENT(6, "tape:device is not operational\n");
1117                 return;
1118         }
1119
1120         /*
1121          * Request that were canceled still come back with an interrupt.
1122          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1123          */
1124         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1125                 __tape_end_request(device, request, -EIO);
1126                 return;
1127         }
1128
1129         rc = device->discipline->irq(device, request, irb);
1130         /*
1131          * rc < 0 : request finished unsuccessfully.
1132          * rc == TAPE_IO_SUCCESS: request finished successfully.
1133          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1134          * rc == TAPE_IO_RETRY: request finished but needs another go.
1135          * rc == TAPE_IO_STOP: request needs to get terminated.
1136          */
1137         switch (rc) {
1138                 case TAPE_IO_SUCCESS:
1139                         /* Upon normal completion the device _is_ online */
1140                         device->tape_generic_status |= GMT_ONLINE(~0);
1141                         __tape_end_request(device, request, rc);
1142                         break;
1143                 case TAPE_IO_PENDING:
1144                         break;
1145                 case TAPE_IO_RETRY:
1146                         rc = __tape_start_io(device, request);
1147                         if (rc)
1148                                 __tape_end_request(device, request, rc);
1149                         break;
1150                 case TAPE_IO_STOP:
1151                         rc = __tape_cancel_io(device, request);
1152                         if (rc)
1153                                 __tape_end_request(device, request, rc);
1154                         break;
1155                 default:
1156                         if (rc > 0) {
1157                                 DBF_EVENT(6, "xunknownrc\n");
1158                                 PRINT_ERR("Invalid return code from discipline "
1159                                         "interrupt function.\n");
1160                                 __tape_end_request(device, request, -EIO);
1161                         } else {
1162                                 __tape_end_request(device, request, rc);
1163                         }
1164                         break;
1165         }
1166 }
1167
1168 /*
1169  * Tape device open function used by tape_char & tape_block frontends.
1170  */
1171 int
1172 tape_open(struct tape_device *device)
1173 {
1174         int rc;
1175
1176         spin_lock(get_ccwdev_lock(device->cdev));
1177         if (device->tape_state == TS_NOT_OPER) {
1178                 DBF_EVENT(6, "TAPE:nodev\n");
1179                 rc = -ENODEV;
1180         } else if (device->tape_state == TS_IN_USE) {
1181                 DBF_EVENT(6, "TAPE:dbusy\n");
1182                 rc = -EBUSY;
1183         } else if (device->tape_state == TS_BLKUSE) {
1184                 DBF_EVENT(6, "TAPE:dbusy\n");
1185                 rc = -EBUSY;
1186         } else if (device->discipline != NULL &&
1187                    !try_module_get(device->discipline->owner)) {
1188                 DBF_EVENT(6, "TAPE:nodisc\n");
1189                 rc = -ENODEV;
1190         } else {
1191                 tape_state_set(device, TS_IN_USE);
1192                 rc = 0;
1193         }
1194         spin_unlock(get_ccwdev_lock(device->cdev));
1195         return rc;
1196 }
1197
1198 /*
1199  * Tape device release function used by tape_char & tape_block frontends.
1200  */
1201 int
1202 tape_release(struct tape_device *device)
1203 {
1204         spin_lock(get_ccwdev_lock(device->cdev));
1205         if (device->tape_state == TS_IN_USE)
1206                 tape_state_set(device, TS_UNUSED);
1207         module_put(device->discipline->owner);
1208         spin_unlock(get_ccwdev_lock(device->cdev));
1209         return 0;
1210 }
1211
1212 /*
1213  * Execute a magnetic tape command a number of times.
1214  */
1215 int
1216 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1217 {
1218         tape_mtop_fn fn;
1219         int rc;
1220
1221         DBF_EVENT(6, "TAPE:mtio\n");
1222         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1223         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1224
1225         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1226                 return -EINVAL;
1227         fn = device->discipline->mtop_array[mt_op];
1228         if (fn == NULL)
1229                 return -EINVAL;
1230
1231         /* We assume that the backends can handle count up to 500. */
1232         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1233             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1234                 rc = 0;
1235                 for (; mt_count > 500; mt_count -= 500)
1236                         if ((rc = fn(device, 500)) != 0)
1237                                 break;
1238                 if (rc == 0)
1239                         rc = fn(device, mt_count);
1240         } else
1241                 rc = fn(device, mt_count);
1242         return rc;
1243
1244 }
1245
1246 /*
1247  * Tape init function.
1248  */
1249 static int
1250 tape_init (void)
1251 {
1252         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1253         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1254 #ifdef DBF_LIKE_HELL
1255         debug_set_level(TAPE_DBF_AREA, 6);
1256 #endif
1257         DBF_EVENT(3, "tape init\n");
1258         tape_proc_init();
1259         tapechar_init ();
1260         tapeblock_init ();
1261         return 0;
1262 }
1263
1264 /*
1265  * Tape exit function.
1266  */
1267 static void
1268 tape_exit(void)
1269 {
1270         DBF_EVENT(6, "tape exit\n");
1271
1272         /* Get rid of the frontends */
1273         tapechar_exit();
1274         tapeblock_exit();
1275         tape_proc_cleanup();
1276         debug_unregister (TAPE_DBF_AREA);
1277 }
1278
1279 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1280               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1281 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1282 MODULE_LICENSE("GPL");
1283
1284 module_init(tape_init);
1285 module_exit(tape_exit);
1286
1287 EXPORT_SYMBOL(tape_generic_remove);
1288 EXPORT_SYMBOL(tape_generic_probe);
1289 EXPORT_SYMBOL(tape_generic_online);
1290 EXPORT_SYMBOL(tape_generic_offline);
1291 EXPORT_SYMBOL(tape_put_device);
1292 EXPORT_SYMBOL(tape_get_device_reference);
1293 EXPORT_SYMBOL(tape_state_verbose);
1294 EXPORT_SYMBOL(tape_op_verbose);
1295 EXPORT_SYMBOL(tape_state_set);
1296 EXPORT_SYMBOL(tape_med_state_set);
1297 EXPORT_SYMBOL(tape_alloc_request);
1298 EXPORT_SYMBOL(tape_free_request);
1299 EXPORT_SYMBOL(tape_dump_sense);
1300 EXPORT_SYMBOL(tape_dump_sense_dbf);
1301 EXPORT_SYMBOL(tape_do_io);
1302 EXPORT_SYMBOL(tape_do_io_async);
1303 EXPORT_SYMBOL(tape_do_io_interruptible);
1304 EXPORT_SYMBOL(tape_cancel_io);
1305 EXPORT_SYMBOL(tape_mtop);