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

   1 /*
   2  *  drivers/s390/char/tape_core.c
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright (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         if (device->tape_state < TO_SIZE && device->tape_state >= 0)
 214                 str = tape_state_verbose[device->tape_state];
 215         else
 216                 str = "UNKNOWN TS";
 217         DBF_EVENT(4, "old ts:   %s\n", str);
 218         if (device->tape_state < TO_SIZE && device->tape_state >=0 )
 219                 str = tape_state_verbose[device->tape_state];
 220         else
 221                 str = "UNKNOWN TS";
 222         DBF_EVENT(4, "%s\n", str);
 223         DBF_EVENT(4, "new ts:\t\n");
 224         if (newstate < TO_SIZE && newstate >= 0)
 225                 str = tape_state_verbose[newstate];
 226         else
 227                 str = "UNKNOWN TS";
 228         DBF_EVENT(4, "%s\n", str);
 229         device->tape_state = newstate;
 230         wake_up(&device->state_change_wq);
 231 }
 232
 233 void
 234 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 235 {
 236         if (device->medium_state == newstate)
 237                 return;
 238         switch(newstate){
 239         case MS_UNLOADED:
 240                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 241                 PRINT_INFO("(%s): Tape is unloaded\n",
 242                            device->cdev->dev.bus_id);
 243                 break;
 244         case MS_LOADED:
 245                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 246                 PRINT_INFO("(%s): Tape has been mounted\n",
 247                            device->cdev->dev.bus_id);
 248                 break;
 249         default:
 250                 // print nothing
 251                 break;
 252         }
 253         device->medium_state = newstate;
 254         wake_up(&device->state_change_wq);
 255 }
 256
 257 /*
 258  * Stop running ccw. Has to be called with the device lock held.
 259  */
 260 static inline int
 261 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 262 {
 263         int retries;
 264         int rc;
 265
 266         /* Check if interrupt has already been processed */
 267         if (request->callback == NULL)
 268                 return 0;
 269
 270         rc = 0;
 271         for (retries = 0; retries < 5; retries++) {
 272                 rc = ccw_device_clear(device->cdev, (long) request);
 273
 274                 switch (rc) {
 275                         case 0:
 276                                 request->status = TAPE_REQUEST_DONE;
 277                                 return 0;
 278                         case -EBUSY:
 279                                 request->status = TAPE_REQUEST_CANCEL;
 280                                 schedule_work(&device->tape_dnr);
 281                                 return 0;
 282                         case -ENODEV:
 283                                 DBF_EXCEPTION(2, "device gone, retry\n");
 284                                 break;
 285                         case -EIO:
 286                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 287                                 break;
 288                         default:
 289                                 BUG();
 290                 }
 291         }
 292
 293         return rc;
 294 }
 295
 296 /*
 297  * Add device into the sorted list, giving it the first
 298  * available minor number.
 299  */
 300 static int
 301 tape_assign_minor(struct tape_device *device)
 302 {
 303         struct tape_device *tmp;
 304         int minor;
 305
 306         minor = 0;
 307         write_lock(&tape_device_lock);
 308         list_for_each_entry(tmp, &tape_device_list, node) {
 309                 if (minor < tmp->first_minor)
 310                         break;
 311                 minor += TAPE_MINORS_PER_DEV;
 312         }
 313         if (minor >= 256) {
 314                 write_unlock(&tape_device_lock);
 315                 return -ENODEV;
 316         }
 317         device->first_minor = minor;
 318         list_add_tail(&device->node, &tmp->node);
 319         write_unlock(&tape_device_lock);
 320         return 0;
 321 }
 322
 323 /* remove device from the list */
 324 static void
 325 tape_remove_minor(struct tape_device *device)
 326 {
 327         write_lock(&tape_device_lock);
 328         list_del_init(&device->node);
 329         device->first_minor = -1;
 330         write_unlock(&tape_device_lock);
 331 }
 332
 333 /*
 334  * Set a device online.
 335  *
 336  * This function is called by the common I/O layer to move a device from the
 337  * detected but offline into the online state.
 338  * If we return an error (RC < 0) the device remains in the offline state. This
 339  * can happen if the device is assigned somewhere else, for example.
 340  */
 341 int
 342 tape_generic_online(struct tape_device *device,
 343                    struct tape_discipline *discipline)
 344 {
 345         int rc;
 346
 347         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 348
 349         if (device->tape_state != TS_INIT) {
 350                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 351                 return -EINVAL;
 352         }
 353
 354         /* Let the discipline have a go at the device. */
 355         device->discipline = discipline;
 356         if (!try_module_get(discipline->owner)) {
 357                 PRINT_ERR("Cannot get module. Module gone.\n");
 358                 return -EINVAL;
 359         }
 360
 361         rc = discipline->setup_device(device);
 362         if (rc)
 363                 goto out;
 364         rc = tape_assign_minor(device);
 365         if (rc)
 366                 goto out_discipline;
 367
 368         rc = tapechar_setup_device(device);
 369         if (rc)
 370                 goto out_minor;
 371         rc = tapeblock_setup_device(device);
 372         if (rc)
 373                 goto out_char;
 374
 375         tape_state_set(device, TS_UNUSED);
 376
 377         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 378
 379         return 0;
 380
 381 out_char:
 382         tapechar_cleanup_device(device);
 383 out_discipline:
 384         device->discipline->cleanup_device(device);
 385         device->discipline = NULL;
 386 out_minor:
 387         tape_remove_minor(device);
 388 out:
 389         module_put(discipline->owner);
 390         return rc;
 391 }
 392
 393 static inline void
 394 tape_cleanup_device(struct tape_device *device)
 395 {
 396         tapeblock_cleanup_device(device);
 397         tapechar_cleanup_device(device);
 398         device->discipline->cleanup_device(device);
 399         module_put(device->discipline->owner);
 400         tape_remove_minor(device);
 401         tape_med_state_set(device, MS_UNKNOWN);
 402 }
 403
 404 /*
 405  * Set device offline.
 406  *
 407  * Called by the common I/O layer if the drive should set offline on user
 408  * request. We may prevent this by returning an error.
 409  * Manual offline is only allowed while the drive is not in use.
 410  */
 411 int
 412 tape_generic_offline(struct tape_device *device)
 413 {
 414         if (!device) {
 415                 PRINT_ERR("tape_generic_offline: no such device\n");
 416                 return -ENODEV;
 417         }
 418
 419         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 420                 device->cdev_id, device);
 421
 422         spin_lock_irq(get_ccwdev_lock(device->cdev));
 423         switch (device->tape_state) {
 424                 case TS_INIT:
 425                 case TS_NOT_OPER:
 426                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 427                         break;
 428                 case TS_UNUSED:
 429                         tape_state_set(device, TS_INIT);
 430                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 431                         tape_cleanup_device(device);
 432                         break;
 433                 default:
 434                         DBF_EVENT(3, "(%08x): Set offline failed "
 435                                 "- drive in use.\n",
 436                                 device->cdev_id);
 437                         PRINT_WARN("(%s): Set offline failed "
 438                                 "- drive in use.\n",
 439                                 device->cdev->dev.bus_id);
 440                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 441                         return -EBUSY;
 442         }
 443
 444         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 445         return 0;
 446 }
 447
 448 /*
 449  * Allocate memory for a new device structure.
 450  */
 451 static struct tape_device *
 452 tape_alloc_device(void)
 453 {
 454         struct tape_device *device;
 455
 456         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 457         if (device == NULL) {
 458                 DBF_EXCEPTION(2, "ti:no mem\n");
 459                 PRINT_INFO ("can't allocate memory for "
 460                             "tape info structure\n");
 461                 return ERR_PTR(-ENOMEM);
 462         }
 463         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 464         if (device->modeset_byte == NULL) {
 465                 DBF_EXCEPTION(2, "ti:no mem\n");
 466                 PRINT_INFO("can't allocate memory for modeset byte\n");
 467                 kfree(device);
 468                 return ERR_PTR(-ENOMEM);
 469         }
 470         INIT_LIST_HEAD(&device->req_queue);
 471         INIT_LIST_HEAD(&device->node);
 472         init_waitqueue_head(&device->state_change_wq);
 473         device->tape_state = TS_INIT;
 474         device->medium_state = MS_UNKNOWN;
 475         *device->modeset_byte = 0;
 476         device->first_minor = -1;
 477         atomic_set(&device->ref_count, 1);
 478         INIT_WORK(&device->tape_dnr, tape_delayed_next_request, device);
 479
 480         return device;
 481 }
 482
 483 /*
 484  * Get a reference to an existing device structure. This will automatically
 485  * increment the reference count.
 486  */
 487 struct tape_device *
 488 tape_get_device_reference(struct tape_device *device)
 489 {
 490         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 491                 atomic_inc_return(&device->ref_count));
 492
 493         return device;
 494 }
 495
 496 /*
 497  * Decrease the reference counter of a devices structure. If the
 498  * reference counter reaches zero free the device structure.
 499  * The function returns a NULL pointer to be used by the caller
 500  * for clearing reference pointers.
 501  */
 502 struct tape_device *
 503 tape_put_device(struct tape_device *device)
 504 {
 505         int remain;
 506
 507         remain = atomic_dec_return(&device->ref_count);
 508         if (remain > 0) {
 509                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 510         } else {
 511                 if (remain < 0) {
 512                         DBF_EVENT(4, "put device without reference\n");
 513                         PRINT_ERR("put device without reference\n");
 514                 } else {
 515                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 516                         kfree(device->modeset_byte);
 517                         kfree(device);
 518                 }
 519         }
 520
 521         return NULL;
 522 }
 523
 524 /*
 525  * Find tape device by a device index.
 526  */
 527 struct tape_device *
 528 tape_get_device(int devindex)
 529 {
 530         struct tape_device *device, *tmp;
 531
 532         device = ERR_PTR(-ENODEV);
 533         read_lock(&tape_device_lock);
 534         list_for_each_entry(tmp, &tape_device_list, node) {
 535                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 536                         device = tape_get_device_reference(tmp);
 537                         break;
 538                 }
 539         }
 540         read_unlock(&tape_device_lock);
 541         return device;
 542 }
 543
 544 /*
 545  * Driverfs tape probe function.
 546  */
 547 int
 548 tape_generic_probe(struct ccw_device *cdev)
 549 {
 550         struct tape_device *device;
 551
 552         device = tape_alloc_device();
 553         if (IS_ERR(device))
 554                 return -ENODEV;
 555         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 556         cdev->dev.driver_data = device;
 557         device->cdev = cdev;
 558         device->cdev_id = busid_to_int(cdev->dev.bus_id);
 559         cdev->handler = __tape_do_irq;
 560
 561         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 562         sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 563
 564         return 0;
 565 }
 566
 567 static inline void
 568 __tape_discard_requests(struct tape_device *device)
 569 {
 570         struct tape_request *   request;
 571         struct list_head *      l, *n;
 572
 573         list_for_each_safe(l, n, &device->req_queue) {
 574                 request = list_entry(l, struct tape_request, list);
 575                 if (request->status == TAPE_REQUEST_IN_IO)
 576                         request->status = TAPE_REQUEST_DONE;
 577                 list_del(&request->list);
 578
 579                 /* Decrease ref_count for removed request. */
 580                 request->device = tape_put_device(device);
 581                 request->rc = -EIO;
 582                 if (request->callback != NULL)
 583                         request->callback(request, request->callback_data);
 584         }
 585 }
 586
 587 /*
 588  * Driverfs tape remove function.
 589  *
 590  * This function is called whenever the common I/O layer detects the device
 591  * gone. This can happen at any time and we cannot refuse.
 592  */
 593 void
 594 tape_generic_remove(struct ccw_device *cdev)
 595 {
 596         struct tape_device *    device;
 597
 598         device = cdev->dev.driver_data;
 599         if (!device) {
 600                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 601                 return;
 602         }
 603         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 604
 605         spin_lock_irq(get_ccwdev_lock(device->cdev));
 606         switch (device->tape_state) {
 607                 case TS_INIT:
 608                         tape_state_set(device, TS_NOT_OPER);
 609                 case TS_NOT_OPER:
 610                         /*
 611                          * Nothing to do.
 612                          */
 613                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 614                         break;
 615                 case TS_UNUSED:
 616                         /*
 617                          * Need only to release the device.
 618                          */
 619                         tape_state_set(device, TS_NOT_OPER);
 620                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 621                         tape_cleanup_device(device);
 622                         break;
 623                 default:
 624                         /*
 625                          * There may be requests on the queue. We will not get
 626                          * an interrupt for a request that was running. So we
 627                          * just post them all as I/O errors.
 628                          */
 629                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 630                                 device->cdev_id);
 631                         PRINT_WARN("(%s): Drive in use vanished - "
 632                                 "expect trouble!\n",
 633                                 device->cdev->dev.bus_id);
 634                         PRINT_WARN("State was %i\n", device->tape_state);
 635                         tape_state_set(device, TS_NOT_OPER);
 636                         __tape_discard_requests(device);
 637                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 638                         tape_cleanup_device(device);
 639         }
 640
 641         if (cdev->dev.driver_data != NULL) {
 642                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 643                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 644         }
 645 }
 646
 647 /*
 648  * Allocate a new tape ccw request
 649  */
 650 struct tape_request *
 651 tape_alloc_request(int cplength, int datasize)
 652 {
 653         struct tape_request *request;
 654
 655         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 656                 BUG();
 657
 658         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 659
 660         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 661         if (request == NULL) {
 662                 DBF_EXCEPTION(1, "cqra nomem\n");
 663                 return ERR_PTR(-ENOMEM);
 664         }
 665         /* allocate channel program */
 666         if (cplength > 0) {
 667                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 668                                           GFP_ATOMIC | GFP_DMA);
 669                 if (request->cpaddr == NULL) {
 670                         DBF_EXCEPTION(1, "cqra nomem\n");
 671                         kfree(request);
 672                         return ERR_PTR(-ENOMEM);
 673                 }
 674         }
 675         /* alloc small kernel buffer */
 676         if (datasize > 0) {
 677                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 678                 if (request->cpdata == NULL) {
 679                         DBF_EXCEPTION(1, "cqra nomem\n");
 680                         kfree(request->cpaddr);
 681                         kfree(request);
 682                         return ERR_PTR(-ENOMEM);
 683                 }
 684         }
 685         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 686                 request->cpdata);
 687
 688         return request;
 689 }
 690
 691 /*
 692  * Free tape ccw request
 693  */
 694 void
 695 tape_free_request (struct tape_request * request)
 696 {
 697         DBF_LH(6, "Free request %p\n", request);
 698
 699         if (request->device != NULL) {
 700                 request->device = tape_put_device(request->device);
 701         }
 702         kfree(request->cpdata);
 703         kfree(request->cpaddr);
 704         kfree(request);
 705 }
 706
 707 static inline int
 708 __tape_start_io(struct tape_device *device, struct tape_request *request)
 709 {
 710         int rc;
 711
 712 #ifdef CONFIG_S390_TAPE_BLOCK
 713         if (request->op == TO_BLOCK)
 714                 device->discipline->check_locate(device, request);
 715 #endif
 716         rc = ccw_device_start(
 717                 device->cdev,
 718                 request->cpaddr,
 719                 (unsigned long) request,
 720                 0x00,
 721                 request->options
 722         );
 723         if (rc == 0) {
 724                 request->status = TAPE_REQUEST_IN_IO;
 725         } else if (rc == -EBUSY) {
 726                 /* The common I/O subsystem is currently busy. Retry later. */
 727                 request->status = TAPE_REQUEST_QUEUED;
 728                 schedule_work(&device->tape_dnr);
 729                 rc = 0;
 730         } else {
 731                 /* Start failed. Remove request and indicate failure. */
 732                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 733         }
 734         return rc;
 735 }
 736
 737 static inline void
 738 __tape_start_next_request(struct tape_device *device)
 739 {
 740         struct list_head *l, *n;
 741         struct tape_request *request;
 742         int rc;
 743
 744         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 745         /*
 746          * Try to start each request on request queue until one is
 747          * started successful.
 748          */
 749         list_for_each_safe(l, n, &device->req_queue) {
 750                 request = list_entry(l, struct tape_request, list);
 751
 752                 /*
 753                  * Avoid race condition if bottom-half was triggered more than
 754                  * once.
 755                  */
 756                 if (request->status == TAPE_REQUEST_IN_IO)
 757                         return;
 758                 /*
 759                  * Request has already been stopped. We have to wait until
 760                  * the request is removed from the queue in the interrupt
 761                  * handling.
 762                  */
 763                 if (request->status == TAPE_REQUEST_DONE)
 764                         return;
 765
 766                 /*
 767                  * We wanted to cancel the request but the common I/O layer
 768                  * was busy at that time. This can only happen if this
 769                  * function is called by delayed_next_request.
 770                  * Otherwise we start the next request on the queue.
 771                  */
 772                 if (request->status == TAPE_REQUEST_CANCEL) {
 773                         rc = __tape_cancel_io(device, request);
 774                 } else {
 775                         rc = __tape_start_io(device, request);
 776                 }
 777                 if (rc == 0)
 778                         return;
 779
 780                 /* Set ending status. */
 781                 request->rc = rc;
 782                 request->status = TAPE_REQUEST_DONE;
 783
 784                 /* Remove from request queue. */
 785                 list_del(&request->list);
 786
 787                 /* Do callback. */
 788                 if (request->callback != NULL)
 789                         request->callback(request, request->callback_data);
 790         }
 791 }
 792
 793 static void
 794 tape_delayed_next_request(void *data)
 795 {
 796         struct tape_device *    device;
 797
 798         device = (struct tape_device *) data;
 799         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 800         spin_lock_irq(get_ccwdev_lock(device->cdev));
 801         __tape_start_next_request(device);
 802         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 803 }
 804
 805 static inline void
 806 __tape_end_request(
 807         struct tape_device *    device,
 808         struct tape_request *   request,
 809         int                     rc)
 810 {
 811         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 812         if (request) {
 813                 request->rc = rc;
 814                 request->status = TAPE_REQUEST_DONE;
 815
 816                 /* Remove from request queue. */
 817                 list_del(&request->list);
 818
 819                 /* Do callback. */
 820                 if (request->callback != NULL)
 821                         request->callback(request, request->callback_data);
 822         }
 823
 824         /* Start next request. */
 825         if (!list_empty(&device->req_queue))
 826                 __tape_start_next_request(device);
 827 }
 828
 829 /*
 830  * Write sense data to console/dbf
 831  */
 832 void
 833 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 834                 struct irb *irb)
 835 {
 836         unsigned int *sptr;
 837
 838         PRINT_INFO("-------------------------------------------------\n");
 839         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 840                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 841         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 842         if (request != NULL)
 843                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 844
 845         sptr = (unsigned int *) irb->ecw;
 846         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 847                    sptr[0], sptr[1], sptr[2], sptr[3]);
 848         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 849                    sptr[4], sptr[5], sptr[6], sptr[7]);
 850         PRINT_INFO("--------------------------------------------------\n");
 851 }
 852
 853 /*
 854  * Write sense data to dbf
 855  */
 856 void
 857 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 858                     struct irb *irb)
 859 {
 860         unsigned int *sptr;
 861         const char* op;
 862
 863         if (request != NULL)
 864                 op = tape_op_verbose[request->op];
 865         else
 866                 op = "---";
 867         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 868                   irb->scsw.dstat,irb->scsw.cstat);
 869         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 870         sptr = (unsigned int *) irb->ecw;
 871         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 872         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 873         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 874         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 875 }
 876
 877 /*
 878  * I/O helper function. Adds the request to the request queue
 879  * and starts it if the tape is idle. Has to be called with
 880  * the device lock held.
 881  */
 882 static inline int
 883 __tape_start_request(struct tape_device *device, struct tape_request *request)
 884 {
 885         int rc;
 886
 887         switch (request->op) {
 888                 case TO_MSEN:
 889                 case TO_ASSIGN:
 890                 case TO_UNASSIGN:
 891                 case TO_READ_ATTMSG:
 892                         if (device->tape_state == TS_INIT)
 893                                 break;
 894                         if (device->tape_state == TS_UNUSED)
 895                                 break;
 896                 default:
 897                         if (device->tape_state == TS_BLKUSE)
 898                                 break;
 899                         if (device->tape_state != TS_IN_USE)
 900                                 return -ENODEV;
 901         }
 902
 903         /* Increase use count of device for the added request. */
 904         request->device = tape_get_device_reference(device);
 905
 906         if (list_empty(&device->req_queue)) {
 907                 /* No other requests are on the queue. Start this one. */
 908                 rc = __tape_start_io(device, request);
 909                 if (rc)
 910                         return rc;
 911
 912                 DBF_LH(5, "Request %p added for execution.\n", request);
 913                 list_add(&request->list, &device->req_queue);
 914         } else {
 915                 DBF_LH(5, "Request %p add to queue.\n", request);
 916                 request->status = TAPE_REQUEST_QUEUED;
 917                 list_add_tail(&request->list, &device->req_queue);
 918         }
 919         return 0;
 920 }
 921
 922 /*
 923  * Add the request to the request queue, try to start it if the
 924  * tape is idle. Return without waiting for end of i/o.
 925  */
 926 int
 927 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 928 {
 929         int rc;
 930
 931         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 932
 933         spin_lock_irq(get_ccwdev_lock(device->cdev));
 934         /* Add request to request queue and try to start it. */
 935         rc = __tape_start_request(device, request);
 936         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 937         return rc;
 938 }
 939
 940 /*
 941  * tape_do_io/__tape_wake_up
 942  * Add the request to the request queue, try to start it if the
 943  * tape is idle and wait uninterruptible for its completion.
 944  */
 945 static void
 946 __tape_wake_up(struct tape_request *request, void *data)
 947 {
 948         request->callback = NULL;
 949         wake_up((wait_queue_head_t *) data);
 950 }
 951
 952 int
 953 tape_do_io(struct tape_device *device, struct tape_request *request)
 954 {
 955         wait_queue_head_t wq;
 956         int rc;
 957
 958         init_waitqueue_head(&wq);
 959         spin_lock_irq(get_ccwdev_lock(device->cdev));
 960         /* Setup callback */
 961         request->callback = __tape_wake_up;
 962         request->callback_data = &wq;
 963         /* Add request to request queue and try to start it. */
 964         rc = __tape_start_request(device, request);
 965         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 966         if (rc)
 967                 return rc;
 968         /* Request added to the queue. Wait for its completion. */
 969         wait_event(wq, (request->callback == NULL));
 970         /* Get rc from request */
 971         return request->rc;
 972 }
 973
 974 /*
 975  * tape_do_io_interruptible/__tape_wake_up_interruptible
 976  * Add the request to the request queue, try to start it if the
 977  * tape is idle and wait uninterruptible for its completion.
 978  */
 979 static void
 980 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 981 {
 982         request->callback = NULL;
 983         wake_up_interruptible((wait_queue_head_t *) data);
 984 }
 985
 986 int
 987 tape_do_io_interruptible(struct tape_device *device,
 988                          struct tape_request *request)
 989 {
 990         wait_queue_head_t wq;
 991         int rc;
 992
 993         init_waitqueue_head(&wq);
 994         spin_lock_irq(get_ccwdev_lock(device->cdev));
 995         /* Setup callback */
 996         request->callback = __tape_wake_up_interruptible;
 997         request->callback_data = &wq;
 998         rc = __tape_start_request(device, request);
 999         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1000         if (rc)
1001                 return rc;
1002         /* Request added to the queue. Wait for its completion. */
1003         rc = wait_event_interruptible(wq, (request->callback == NULL));
1004         if (rc != -ERESTARTSYS)
1005                 /* Request finished normally. */
1006                 return request->rc;
1007
1008         /* Interrupted by a signal. We have to stop the current request. */
1009         spin_lock_irq(get_ccwdev_lock(device->cdev));
1010         rc = __tape_cancel_io(device, request);
1011         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1012         if (rc == 0) {
1013                 /* Wait for the interrupt that acknowledges the halt. */
1014                 do {
1015                         rc = wait_event_interruptible(
1016                                 wq,
1017                                 (request->callback == NULL)
1018                         );
1019                 } while (rc == -ERESTARTSYS);
1020
1021                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1022                 rc = -ERESTARTSYS;
1023         }
1024         return rc;
1025 }
1026
1027 /*
1028  * Stop running ccw.
1029  */
1030 int
1031 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1032 {
1033         int rc;
1034
1035         spin_lock_irq(get_ccwdev_lock(device->cdev));
1036         rc = __tape_cancel_io(device, request);
1037         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1038         return rc;
1039 }
1040
1041 /*
1042  * Tape interrupt routine, called from the ccw_device layer
1043  */
1044 static void
1045 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1046 {
1047         struct tape_device *device;
1048         struct tape_request *request;
1049         int rc;
1050
1051         device = (struct tape_device *) cdev->dev.driver_data;
1052         if (device == NULL) {
1053                 PRINT_ERR("could not get device structure for %s "
1054                           "in interrupt\n", cdev->dev.bus_id);
1055                 return;
1056         }
1057         request = (struct tape_request *) intparm;
1058
1059         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1060
1061         /* On special conditions irb is an error pointer */
1062         if (IS_ERR(irb)) {
1063                 /* FIXME: What to do with the request? */
1064                 switch (PTR_ERR(irb)) {
1065                         case -ETIMEDOUT:
1066                                 PRINT_WARN("(%s): Request timed out\n",
1067                                         cdev->dev.bus_id);
1068                         case -EIO:
1069                                 __tape_end_request(device, request, -EIO);
1070                                 break;
1071                         default:
1072                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1073                                         cdev->dev.bus_id,
1074                                         PTR_ERR(irb));
1075                 }
1076                 return;
1077         }
1078
1079         /*
1080          * If the condition code is not zero and the start function bit is
1081          * still set, this is an deferred error and the last start I/O did
1082          * not succeed. At this point the condition that caused the deferred
1083          * error might still apply. So we just schedule the request to be
1084          * started later.
1085          */
1086         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC) &&
1087             (request->status == TAPE_REQUEST_IN_IO)) {
1088                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1089                         device->cdev_id, irb->scsw.cc, irb->scsw.fctl);
1090                 request->status = TAPE_REQUEST_QUEUED;
1091                 schedule_delayed_work(&device->tape_dnr, HZ);
1092                 return;
1093         }
1094
1095         /* May be an unsolicited irq */
1096         if(request != NULL)
1097                 request->rescnt = irb->scsw.count;
1098
1099         if (irb->scsw.dstat != 0x0c) {
1100                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1101                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1102                         device->tape_generic_status |= GMT_ONLINE(~0);
1103                 else
1104                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1105
1106                 /*
1107                  * Any request that does not come back with channel end
1108                  * and device end is unusual. Log the sense data.
1109                  */
1110                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1111                 tape_dump_sense_dbf(device, request, irb);
1112         } else {
1113                 /* Upon normal completion the device _is_ online */
1114                 device->tape_generic_status |= GMT_ONLINE(~0);
1115         }
1116         if (device->tape_state == TS_NOT_OPER) {
1117                 DBF_EVENT(6, "tape:device is not operational\n");
1118                 return;
1119         }
1120
1121         /*
1122          * Request that were canceled still come back with an interrupt.
1123          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1124          */
1125         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1126                 __tape_end_request(device, request, -EIO);
1127                 return;
1128         }
1129
1130         rc = device->discipline->irq(device, request, irb);
1131         /*
1132          * rc < 0 : request finished unsuccessfully.
1133          * rc == TAPE_IO_SUCCESS: request finished successfully.
1134          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1135          * rc == TAPE_IO_RETRY: request finished but needs another go.
1136          * rc == TAPE_IO_STOP: request needs to get terminated.
1137          */
1138         switch (rc) {
1139                 case TAPE_IO_SUCCESS:
1140                         /* Upon normal completion the device _is_ online */
1141                         device->tape_generic_status |= GMT_ONLINE(~0);
1142                         __tape_end_request(device, request, rc);
1143                         break;
1144                 case TAPE_IO_PENDING:
1145                         break;
1146                 case TAPE_IO_RETRY:
1147                         rc = __tape_start_io(device, request);
1148                         if (rc)
1149                                 __tape_end_request(device, request, rc);
1150                         break;
1151                 case TAPE_IO_STOP:
1152                         rc = __tape_cancel_io(device, request);
1153                         if (rc)
1154                                 __tape_end_request(device, request, rc);
1155                         break;
1156                 default:
1157                         if (rc > 0) {
1158                                 DBF_EVENT(6, "xunknownrc\n");
1159                                 PRINT_ERR("Invalid return code from discipline "
1160                                         "interrupt function.\n");
1161                                 __tape_end_request(device, request, -EIO);
1162                         } else {
1163                                 __tape_end_request(device, request, rc);
1164                         }
1165                         break;
1166         }
1167 }
1168
1169 /*
1170  * Tape device open function used by tape_char & tape_block frontends.
1171  */
1172 int
1173 tape_open(struct tape_device *device)
1174 {
1175         int rc;
1176
1177         spin_lock(get_ccwdev_lock(device->cdev));
1178         if (device->tape_state == TS_NOT_OPER) {
1179                 DBF_EVENT(6, "TAPE:nodev\n");
1180                 rc = -ENODEV;
1181         } else if (device->tape_state == TS_IN_USE) {
1182                 DBF_EVENT(6, "TAPE:dbusy\n");
1183                 rc = -EBUSY;
1184         } else if (device->tape_state == TS_BLKUSE) {
1185                 DBF_EVENT(6, "TAPE:dbusy\n");
1186                 rc = -EBUSY;
1187         } else if (device->discipline != NULL &&
1188                    !try_module_get(device->discipline->owner)) {
1189                 DBF_EVENT(6, "TAPE:nodisc\n");
1190                 rc = -ENODEV;
1191         } else {
1192                 tape_state_set(device, TS_IN_USE);
1193                 rc = 0;
1194         }
1195         spin_unlock(get_ccwdev_lock(device->cdev));
1196         return rc;
1197 }
1198
1199 /*
1200  * Tape device release function used by tape_char & tape_block frontends.
1201  */
1202 int
1203 tape_release(struct tape_device *device)
1204 {
1205         spin_lock(get_ccwdev_lock(device->cdev));
1206         if (device->tape_state == TS_IN_USE)
1207                 tape_state_set(device, TS_UNUSED);
1208         module_put(device->discipline->owner);
1209         spin_unlock(get_ccwdev_lock(device->cdev));
1210         return 0;
1211 }
1212
1213 /*
1214  * Execute a magnetic tape command a number of times.
1215  */
1216 int
1217 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1218 {
1219         tape_mtop_fn fn;
1220         int rc;
1221
1222         DBF_EVENT(6, "TAPE:mtio\n");
1223         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1224         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1225
1226         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1227                 return -EINVAL;
1228         fn = device->discipline->mtop_array[mt_op];
1229         if (fn == NULL)
1230                 return -EINVAL;
1231
1232         /* We assume that the backends can handle count up to 500. */
1233         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1234             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1235                 rc = 0;
1236                 for (; mt_count > 500; mt_count -= 500)
1237                         if ((rc = fn(device, 500)) != 0)
1238                                 break;
1239                 if (rc == 0)
1240                         rc = fn(device, mt_count);
1241         } else
1242                 rc = fn(device, mt_count);
1243         return rc;
1244
1245 }
1246
1247 /*
1248  * Tape init function.
1249  */
1250 static int
1251 tape_init (void)
1252 {
1253         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1254         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1255 #ifdef DBF_LIKE_HELL
1256         debug_set_level(TAPE_DBF_AREA, 6);
1257 #endif
1258         DBF_EVENT(3, "tape init\n");
1259         tape_proc_init();
1260         tapechar_init ();
1261         tapeblock_init ();
1262         return 0;
1263 }
1264
1265 /*
1266  * Tape exit function.
1267  */
1268 static void
1269 tape_exit(void)
1270 {
1271         DBF_EVENT(6, "tape exit\n");
1272
1273         /* Get rid of the frontends */
1274         tapechar_exit();
1275         tapeblock_exit();
1276         tape_proc_cleanup();
1277         debug_unregister (TAPE_DBF_AREA);
1278 }
1279
1280 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1281               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1282 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1283 MODULE_LICENSE("GPL");
1284
1285 module_init(tape_init);
1286 module_exit(tape_exit);
1287
1288 EXPORT_SYMBOL(tape_generic_remove);
1289 EXPORT_SYMBOL(tape_generic_probe);
1290 EXPORT_SYMBOL(tape_generic_online);
1291 EXPORT_SYMBOL(tape_generic_offline);
1292 EXPORT_SYMBOL(tape_put_device);
1293 EXPORT_SYMBOL(tape_get_device_reference);
1294 EXPORT_SYMBOL(tape_state_verbose);
1295 EXPORT_SYMBOL(tape_op_verbose);
1296 EXPORT_SYMBOL(tape_state_set);
1297 EXPORT_SYMBOL(tape_med_state_set);
1298 EXPORT_SYMBOL(tape_alloc_request);
1299 EXPORT_SYMBOL(tape_free_request);
1300 EXPORT_SYMBOL(tape_dump_sense);
1301 EXPORT_SYMBOL(tape_dump_sense_dbf);
1302 EXPORT_SYMBOL(tape_do_io);
1303 EXPORT_SYMBOL(tape_do_io_async);
1304 EXPORT_SYMBOL(tape_do_io_interruptible);
1305 EXPORT_SYMBOL(tape_cancel_io);
1306 EXPORT_SYMBOL(tape_mtop);