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 = (struct tape_device *)
 457                 kmalloc(sizeof(struct tape_device), GFP_KERNEL);
 458         if (device == NULL) {
 459                 DBF_EXCEPTION(2, "ti:no mem\n");
 460                 PRINT_INFO ("can't allocate memory for "
 461                             "tape info structure\n");
 462                 return ERR_PTR(-ENOMEM);
 463         }
 464         memset(device, 0, sizeof(struct tape_device));
 465         device->modeset_byte = (char *) kmalloc(1, GFP_KERNEL | GFP_DMA);
 466         if (device->modeset_byte == NULL) {
 467                 DBF_EXCEPTION(2, "ti:no mem\n");
 468                 PRINT_INFO("can't allocate memory for modeset byte\n");
 469                 kfree(device);
 470                 return ERR_PTR(-ENOMEM);
 471         }
 472         INIT_LIST_HEAD(&device->req_queue);
 473         INIT_LIST_HEAD(&device->node);
 474         init_waitqueue_head(&device->state_change_wq);
 475         device->tape_state = TS_INIT;
 476         device->medium_state = MS_UNKNOWN;
 477         *device->modeset_byte = 0;
 478         device->first_minor = -1;
 479         atomic_set(&device->ref_count, 1);
 480         INIT_WORK(&device->tape_dnr, tape_delayed_next_request, device);
 481
 482         return device;
 483 }
 484
 485 /*
 486  * Get a reference to an existing device structure. This will automatically
 487  * increment the reference count.
 488  */
 489 struct tape_device *
 490 tape_get_device_reference(struct tape_device *device)
 491 {
 492         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 493                 atomic_inc_return(&device->ref_count));
 494
 495         return device;
 496 }
 497
 498 /*
 499  * Decrease the reference counter of a devices structure. If the
 500  * reference counter reaches zero free the device structure.
 501  * The function returns a NULL pointer to be used by the caller
 502  * for clearing reference pointers.
 503  */
 504 struct tape_device *
 505 tape_put_device(struct tape_device *device)
 506 {
 507         int remain;
 508
 509         remain = atomic_dec_return(&device->ref_count);
 510         if (remain > 0) {
 511                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 512         } else {
 513                 if (remain < 0) {
 514                         DBF_EVENT(4, "put device without reference\n");
 515                         PRINT_ERR("put device without reference\n");
 516                 } else {
 517                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 518                         kfree(device->modeset_byte);
 519                         kfree(device);
 520                 }
 521         }
 522
 523         return NULL;
 524 }
 525
 526 /*
 527  * Find tape device by a device index.
 528  */
 529 struct tape_device *
 530 tape_get_device(int devindex)
 531 {
 532         struct tape_device *device, *tmp;
 533
 534         device = ERR_PTR(-ENODEV);
 535         read_lock(&tape_device_lock);
 536         list_for_each_entry(tmp, &tape_device_list, node) {
 537                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 538                         device = tape_get_device_reference(tmp);
 539                         break;
 540                 }
 541         }
 542         read_unlock(&tape_device_lock);
 543         return device;
 544 }
 545
 546 /*
 547  * Driverfs tape probe function.
 548  */
 549 int
 550 tape_generic_probe(struct ccw_device *cdev)
 551 {
 552         struct tape_device *device;
 553
 554         device = tape_alloc_device();
 555         if (IS_ERR(device))
 556                 return -ENODEV;
 557         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 558         cdev->dev.driver_data = device;
 559         device->cdev = cdev;
 560         device->cdev_id = busid_to_int(cdev->dev.bus_id);
 561         cdev->handler = __tape_do_irq;
 562
 563         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 564         sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 565
 566         return 0;
 567 }
 568
 569 static inline void
 570 __tape_discard_requests(struct tape_device *device)
 571 {
 572         struct tape_request *   request;
 573         struct list_head *      l, *n;
 574
 575         list_for_each_safe(l, n, &device->req_queue) {
 576                 request = list_entry(l, struct tape_request, list);
 577                 if (request->status == TAPE_REQUEST_IN_IO)
 578                         request->status = TAPE_REQUEST_DONE;
 579                 list_del(&request->list);
 580
 581                 /* Decrease ref_count for removed request. */
 582                 request->device = tape_put_device(device);
 583                 request->rc = -EIO;
 584                 if (request->callback != NULL)
 585                         request->callback(request, request->callback_data);
 586         }
 587 }
 588
 589 /*
 590  * Driverfs tape remove function.
 591  *
 592  * This function is called whenever the common I/O layer detects the device
 593  * gone. This can happen at any time and we cannot refuse.
 594  */
 595 void
 596 tape_generic_remove(struct ccw_device *cdev)
 597 {
 598         struct tape_device *    device;
 599
 600         device = cdev->dev.driver_data;
 601         if (!device) {
 602                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 603                 return;
 604         }
 605         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 606
 607         spin_lock_irq(get_ccwdev_lock(device->cdev));
 608         switch (device->tape_state) {
 609                 case TS_INIT:
 610                         tape_state_set(device, TS_NOT_OPER);
 611                 case TS_NOT_OPER:
 612                         /*
 613                          * Nothing to do.
 614                          */
 615                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 616                         break;
 617                 case TS_UNUSED:
 618                         /*
 619                          * Need only to release the device.
 620                          */
 621                         tape_state_set(device, TS_NOT_OPER);
 622                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 623                         tape_cleanup_device(device);
 624                         break;
 625                 default:
 626                         /*
 627                          * There may be requests on the queue. We will not get
 628                          * an interrupt for a request that was running. So we
 629                          * just post them all as I/O errors.
 630                          */
 631                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 632                                 device->cdev_id);
 633                         PRINT_WARN("(%s): Drive in use vanished - "
 634                                 "expect trouble!\n",
 635                                 device->cdev->dev.bus_id);
 636                         PRINT_WARN("State was %i\n", device->tape_state);
 637                         tape_state_set(device, TS_NOT_OPER);
 638                         __tape_discard_requests(device);
 639                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 640                         tape_cleanup_device(device);
 641         }
 642
 643         if (cdev->dev.driver_data != NULL) {
 644                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 645                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 646         }
 647 }
 648
 649 /*
 650  * Allocate a new tape ccw request
 651  */
 652 struct tape_request *
 653 tape_alloc_request(int cplength, int datasize)
 654 {
 655         struct tape_request *request;
 656
 657         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 658                 BUG();
 659
 660         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 661
 662         request = (struct tape_request *) kmalloc(sizeof(struct tape_request),
 663                                                   GFP_KERNEL);
 664         if (request == NULL) {
 665                 DBF_EXCEPTION(1, "cqra nomem\n");
 666                 return ERR_PTR(-ENOMEM);
 667         }
 668         memset(request, 0, sizeof(struct tape_request));
 669         /* allocate channel program */
 670         if (cplength > 0) {
 671                 request->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
 672                                           GFP_ATOMIC | GFP_DMA);
 673                 if (request->cpaddr == NULL) {
 674                         DBF_EXCEPTION(1, "cqra nomem\n");
 675                         kfree(request);
 676                         return ERR_PTR(-ENOMEM);
 677                 }
 678                 memset(request->cpaddr, 0, cplength*sizeof(struct ccw1));
 679         }
 680         /* alloc small kernel buffer */
 681         if (datasize > 0) {
 682                 request->cpdata = kmalloc(datasize, GFP_KERNEL | GFP_DMA);
 683                 if (request->cpdata == NULL) {
 684                         DBF_EXCEPTION(1, "cqra nomem\n");
 685                         if (request->cpaddr != NULL)
 686                                 kfree(request->cpaddr);
 687                         kfree(request);
 688                         return ERR_PTR(-ENOMEM);
 689                 }
 690                 memset(request->cpdata, 0, datasize);
 691         }
 692         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 693                 request->cpdata);
 694
 695         return request;
 696 }
 697
 698 /*
 699  * Free tape ccw request
 700  */
 701 void
 702 tape_free_request (struct tape_request * request)
 703 {
 704         DBF_LH(6, "Free request %p\n", request);
 705
 706         if (request->device != NULL) {
 707                 request->device = tape_put_device(request->device);
 708         }
 709         if (request->cpdata != NULL)
 710                 kfree(request->cpdata);
 711         if (request->cpaddr != NULL)
 712                 kfree(request->cpaddr);
 713         kfree(request);
 714 }
 715
 716 static inline int
 717 __tape_start_io(struct tape_device *device, struct tape_request *request)
 718 {
 719         int rc;
 720
 721 #ifdef CONFIG_S390_TAPE_BLOCK
 722         if (request->op == TO_BLOCK)
 723                 device->discipline->check_locate(device, request);
 724 #endif
 725         rc = ccw_device_start(
 726                 device->cdev,
 727                 request->cpaddr,
 728                 (unsigned long) request,
 729                 0x00,
 730                 request->options
 731         );
 732         if (rc == 0) {
 733                 request->status = TAPE_REQUEST_IN_IO;
 734         } else if (rc == -EBUSY) {
 735                 /* The common I/O subsystem is currently busy. Retry later. */
 736                 request->status = TAPE_REQUEST_QUEUED;
 737                 schedule_work(&device->tape_dnr);
 738                 rc = 0;
 739         } else {
 740                 /* Start failed. Remove request and indicate failure. */
 741                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 742         }
 743         return rc;
 744 }
 745
 746 static inline void
 747 __tape_start_next_request(struct tape_device *device)
 748 {
 749         struct list_head *l, *n;
 750         struct tape_request *request;
 751         int rc;
 752
 753         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 754         /*
 755          * Try to start each request on request queue until one is
 756          * started successful.
 757          */
 758         list_for_each_safe(l, n, &device->req_queue) {
 759                 request = list_entry(l, struct tape_request, list);
 760
 761                 /*
 762                  * Avoid race condition if bottom-half was triggered more than
 763                  * once.
 764                  */
 765                 if (request->status == TAPE_REQUEST_IN_IO)
 766                         return;
 767
 768                 /*
 769                  * We wanted to cancel the request but the common I/O layer
 770                  * was busy at that time. This can only happen if this
 771                  * function is called by delayed_next_request.
 772                  * Otherwise we start the next request on the queue.
 773                  */
 774                 if (request->status == TAPE_REQUEST_CANCEL) {
 775                         rc = __tape_cancel_io(device, request);
 776                 } else {
 777                         rc = __tape_start_io(device, request);
 778                 }
 779                 if (rc == 0)
 780                         return;
 781
 782                 /* Set ending status. */
 783                 request->rc = rc;
 784                 request->status = TAPE_REQUEST_DONE;
 785
 786                 /* Remove from request queue. */
 787                 list_del(&request->list);
 788
 789                 /* Do callback. */
 790                 if (request->callback != NULL)
 791                         request->callback(request, request->callback_data);
 792         }
 793 }
 794
 795 static void
 796 tape_delayed_next_request(void *data)
 797 {
 798         struct tape_device *    device;
 799
 800         device = (struct tape_device *) data;
 801         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 802         spin_lock_irq(get_ccwdev_lock(device->cdev));
 803         __tape_start_next_request(device);
 804         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 805 }
 806
 807 static inline void
 808 __tape_end_request(
 809         struct tape_device *    device,
 810         struct tape_request *   request,
 811         int                     rc)
 812 {
 813         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 814         if (request) {
 815                 request->rc = rc;
 816                 request->status = TAPE_REQUEST_DONE;
 817
 818                 /* Remove from request queue. */
 819                 list_del(&request->list);
 820
 821                 /* Do callback. */
 822                 if (request->callback != NULL)
 823                         request->callback(request, request->callback_data);
 824         }
 825
 826         /* Start next request. */
 827         if (!list_empty(&device->req_queue))
 828                 __tape_start_next_request(device);
 829 }
 830
 831 /*
 832  * Write sense data to console/dbf
 833  */
 834 void
 835 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 836                 struct irb *irb)
 837 {
 838         unsigned int *sptr;
 839
 840         PRINT_INFO("-------------------------------------------------\n");
 841         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 842                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 843         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 844         if (request != NULL)
 845                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 846
 847         sptr = (unsigned int *) irb->ecw;
 848         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 849                    sptr[0], sptr[1], sptr[2], sptr[3]);
 850         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 851                    sptr[4], sptr[5], sptr[6], sptr[7]);
 852         PRINT_INFO("--------------------------------------------------\n");
 853 }
 854
 855 /*
 856  * Write sense data to dbf
 857  */
 858 void
 859 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 860                     struct irb *irb)
 861 {
 862         unsigned int *sptr;
 863         const char* op;
 864
 865         if (request != NULL)
 866                 op = tape_op_verbose[request->op];
 867         else
 868                 op = "---";
 869         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 870                   irb->scsw.dstat,irb->scsw.cstat);
 871         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 872         sptr = (unsigned int *) irb->ecw;
 873         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 874         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 875         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 876         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 877 }
 878
 879 /*
 880  * I/O helper function. Adds the request to the request queue
 881  * and starts it if the tape is idle. Has to be called with
 882  * the device lock held.
 883  */
 884 static inline int
 885 __tape_start_request(struct tape_device *device, struct tape_request *request)
 886 {
 887         int rc;
 888
 889         switch (request->op) {
 890                 case TO_MSEN:
 891                 case TO_ASSIGN:
 892                 case TO_UNASSIGN:
 893                 case TO_READ_ATTMSG:
 894                         if (device->tape_state == TS_INIT)
 895                                 break;
 896                         if (device->tape_state == TS_UNUSED)
 897                                 break;
 898                 default:
 899                         if (device->tape_state == TS_BLKUSE)
 900                                 break;
 901                         if (device->tape_state != TS_IN_USE)
 902                                 return -ENODEV;
 903         }
 904
 905         /* Increase use count of device for the added request. */
 906         request->device = tape_get_device_reference(device);
 907
 908         if (list_empty(&device->req_queue)) {
 909                 /* No other requests are on the queue. Start this one. */
 910                 rc = __tape_start_io(device, request);
 911                 if (rc)
 912                         return rc;
 913
 914                 DBF_LH(5, "Request %p added for execution.\n", request);
 915                 list_add(&request->list, &device->req_queue);
 916         } else {
 917                 DBF_LH(5, "Request %p add to queue.\n", request);
 918                 request->status = TAPE_REQUEST_QUEUED;
 919                 list_add_tail(&request->list, &device->req_queue);
 920         }
 921         return 0;
 922 }
 923
 924 /*
 925  * Add the request to the request queue, try to start it if the
 926  * tape is idle. Return without waiting for end of i/o.
 927  */
 928 int
 929 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 930 {
 931         int rc;
 932
 933         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 934
 935         spin_lock_irq(get_ccwdev_lock(device->cdev));
 936         /* Add request to request queue and try to start it. */
 937         rc = __tape_start_request(device, request);
 938         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 939         return rc;
 940 }
 941
 942 /*
 943  * tape_do_io/__tape_wake_up
 944  * Add the request to the request queue, try to start it if the
 945  * tape is idle and wait uninterruptible for its completion.
 946  */
 947 static void
 948 __tape_wake_up(struct tape_request *request, void *data)
 949 {
 950         request->callback = NULL;
 951         wake_up((wait_queue_head_t *) data);
 952 }
 953
 954 int
 955 tape_do_io(struct tape_device *device, struct tape_request *request)
 956 {
 957         wait_queue_head_t wq;
 958         int rc;
 959
 960         init_waitqueue_head(&wq);
 961         spin_lock_irq(get_ccwdev_lock(device->cdev));
 962         /* Setup callback */
 963         request->callback = __tape_wake_up;
 964         request->callback_data = &wq;
 965         /* Add request to request queue and try to start it. */
 966         rc = __tape_start_request(device, request);
 967         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 968         if (rc)
 969                 return rc;
 970         /* Request added to the queue. Wait for its completion. */
 971         wait_event(wq, (request->callback == NULL));
 972         /* Get rc from request */
 973         return request->rc;
 974 }
 975
 976 /*
 977  * tape_do_io_interruptible/__tape_wake_up_interruptible
 978  * Add the request to the request queue, try to start it if the
 979  * tape is idle and wait uninterruptible for its completion.
 980  */
 981 static void
 982 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 983 {
 984         request->callback = NULL;
 985         wake_up_interruptible((wait_queue_head_t *) data);
 986 }
 987
 988 int
 989 tape_do_io_interruptible(struct tape_device *device,
 990                          struct tape_request *request)
 991 {
 992         wait_queue_head_t wq;
 993         int rc;
 994
 995         init_waitqueue_head(&wq);
 996         spin_lock_irq(get_ccwdev_lock(device->cdev));
 997         /* Setup callback */
 998         request->callback = __tape_wake_up_interruptible;
 999         request->callback_data = &wq;
1000         rc = __tape_start_request(device, request);
1001         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1002         if (rc)
1003                 return rc;
1004         /* Request added to the queue. Wait for its completion. */
1005         rc = wait_event_interruptible(wq, (request->callback == NULL));
1006         if (rc != -ERESTARTSYS)
1007                 /* Request finished normally. */
1008                 return request->rc;
1009
1010         /* Interrupted by a signal. We have to stop the current request. */
1011         spin_lock_irq(get_ccwdev_lock(device->cdev));
1012         rc = __tape_cancel_io(device, request);
1013         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1014         if (rc == 0) {
1015                 /* Wait for the interrupt that acknowledges the halt. */
1016                 do {
1017                         rc = wait_event_interruptible(
1018                                 wq,
1019                                 (request->callback == NULL)
1020                         );
1021                 } while (rc != -ERESTARTSYS);
1022
1023                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1024                 rc = -ERESTARTSYS;
1025         }
1026         return rc;
1027 }
1028
1029 /*
1030  * Tape interrupt routine, called from the ccw_device layer
1031  */
1032 static void
1033 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1034 {
1035         struct tape_device *device;
1036         struct tape_request *request;
1037         int rc;
1038
1039         device = (struct tape_device *) cdev->dev.driver_data;
1040         if (device == NULL) {
1041                 PRINT_ERR("could not get device structure for %s "
1042                           "in interrupt\n", cdev->dev.bus_id);
1043                 return;
1044         }
1045         request = (struct tape_request *) intparm;
1046
1047         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1048
1049         /* On special conditions irb is an error pointer */
1050         if (IS_ERR(irb)) {
1051                 /* FIXME: What to do with the request? */
1052                 switch (PTR_ERR(irb)) {
1053                         case -ETIMEDOUT:
1054                                 PRINT_WARN("(%s): Request timed out\n",
1055                                         cdev->dev.bus_id);
1056                         case -EIO:
1057                                 __tape_end_request(device, request, -EIO);
1058                                 break;
1059                         default:
1060                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1061                                         cdev->dev.bus_id,
1062                                         PTR_ERR(irb));
1063                 }
1064                 return;
1065         }
1066
1067         /*
1068          * If the condition code is not zero and the start function bit is
1069          * still set, this is an deferred error and the last start I/O did
1070          * not succeed. Restart the request now.
1071          */
1072         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC)) {
1073                 PRINT_WARN("(%s): deferred cc=%i. restaring\n",
1074                         cdev->dev.bus_id,
1075                         irb->scsw.cc);
1076                 rc = __tape_start_io(device, request);
1077                 if (rc)
1078                         __tape_end_request(device, request, rc);
1079                 return;
1080         }
1081
1082         /* May be an unsolicited irq */
1083         if(request != NULL)
1084                 request->rescnt = irb->scsw.count;
1085
1086         if (irb->scsw.dstat != 0x0c) {
1087                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1088                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1089                         device->tape_generic_status |= GMT_ONLINE(~0);
1090                 else
1091                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1092
1093                 /*
1094                  * Any request that does not come back with channel end
1095                  * and device end is unusual. Log the sense data.
1096                  */
1097                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1098                 tape_dump_sense_dbf(device, request, irb);
1099         } else {
1100                 /* Upon normal completion the device _is_ online */
1101                 device->tape_generic_status |= GMT_ONLINE(~0);
1102         }
1103         if (device->tape_state == TS_NOT_OPER) {
1104                 DBF_EVENT(6, "tape:device is not operational\n");
1105                 return;
1106         }
1107
1108         /*
1109          * Request that were canceled still come back with an interrupt.
1110          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1111          */
1112         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1113                 __tape_end_request(device, request, -EIO);
1114                 return;
1115         }
1116
1117         rc = device->discipline->irq(device, request, irb);
1118         /*
1119          * rc < 0 : request finished unsuccessfully.
1120          * rc == TAPE_IO_SUCCESS: request finished successfully.
1121          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1122          * rc == TAPE_IO_RETRY: request finished but needs another go.
1123          * rc == TAPE_IO_STOP: request needs to get terminated.
1124          */
1125         switch (rc) {
1126                 case TAPE_IO_SUCCESS:
1127                         /* Upon normal completion the device _is_ online */
1128                         device->tape_generic_status |= GMT_ONLINE(~0);
1129                         __tape_end_request(device, request, rc);
1130                         break;
1131                 case TAPE_IO_PENDING:
1132                         break;
1133                 case TAPE_IO_RETRY:
1134                         rc = __tape_start_io(device, request);
1135                         if (rc)
1136                                 __tape_end_request(device, request, rc);
1137                         break;
1138                 case TAPE_IO_STOP:
1139                         rc = __tape_cancel_io(device, request);
1140                         if (rc)
1141                                 __tape_end_request(device, request, rc);
1142                         break;
1143                 default:
1144                         if (rc > 0) {
1145                                 DBF_EVENT(6, "xunknownrc\n");
1146                                 PRINT_ERR("Invalid return code from discipline "
1147                                         "interrupt function.\n");
1148                                 __tape_end_request(device, request, -EIO);
1149                         } else {
1150                                 __tape_end_request(device, request, rc);
1151                         }
1152                         break;
1153         }
1154 }
1155
1156 /*
1157  * Tape device open function used by tape_char & tape_block frontends.
1158  */
1159 int
1160 tape_open(struct tape_device *device)
1161 {
1162         int rc;
1163
1164         spin_lock(get_ccwdev_lock(device->cdev));
1165         if (device->tape_state == TS_NOT_OPER) {
1166                 DBF_EVENT(6, "TAPE:nodev\n");
1167                 rc = -ENODEV;
1168         } else if (device->tape_state == TS_IN_USE) {
1169                 DBF_EVENT(6, "TAPE:dbusy\n");
1170                 rc = -EBUSY;
1171         } else if (device->tape_state == TS_BLKUSE) {
1172                 DBF_EVENT(6, "TAPE:dbusy\n");
1173                 rc = -EBUSY;
1174         } else if (device->discipline != NULL &&
1175                    !try_module_get(device->discipline->owner)) {
1176                 DBF_EVENT(6, "TAPE:nodisc\n");
1177                 rc = -ENODEV;
1178         } else {
1179                 tape_state_set(device, TS_IN_USE);
1180                 rc = 0;
1181         }
1182         spin_unlock(get_ccwdev_lock(device->cdev));
1183         return rc;
1184 }
1185
1186 /*
1187  * Tape device release function used by tape_char & tape_block frontends.
1188  */
1189 int
1190 tape_release(struct tape_device *device)
1191 {
1192         spin_lock(get_ccwdev_lock(device->cdev));
1193         if (device->tape_state == TS_IN_USE)
1194                 tape_state_set(device, TS_UNUSED);
1195         module_put(device->discipline->owner);
1196         spin_unlock(get_ccwdev_lock(device->cdev));
1197         return 0;
1198 }
1199
1200 /*
1201  * Execute a magnetic tape command a number of times.
1202  */
1203 int
1204 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1205 {
1206         tape_mtop_fn fn;
1207         int rc;
1208
1209         DBF_EVENT(6, "TAPE:mtio\n");
1210         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1211         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1212
1213         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1214                 return -EINVAL;
1215         fn = device->discipline->mtop_array[mt_op];
1216         if (fn == NULL)
1217                 return -EINVAL;
1218
1219         /* We assume that the backends can handle count up to 500. */
1220         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1221             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1222                 rc = 0;
1223                 for (; mt_count > 500; mt_count -= 500)
1224                         if ((rc = fn(device, 500)) != 0)
1225                                 break;
1226                 if (rc == 0)
1227                         rc = fn(device, mt_count);
1228         } else
1229                 rc = fn(device, mt_count);
1230         return rc;
1231
1232 }
1233
1234 /*
1235  * Tape init function.
1236  */
1237 static int
1238 tape_init (void)
1239 {
1240         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1241         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1242 #ifdef DBF_LIKE_HELL
1243         debug_set_level(TAPE_DBF_AREA, 6);
1244 #endif
1245         DBF_EVENT(3, "tape init: ($Revision: 1.54 $)\n");
1246         tape_proc_init();
1247         tapechar_init ();
1248         tapeblock_init ();
1249         return 0;
1250 }
1251
1252 /*
1253  * Tape exit function.
1254  */
1255 static void
1256 tape_exit(void)
1257 {
1258         DBF_EVENT(6, "tape exit\n");
1259
1260         /* Get rid of the frontends */
1261         tapechar_exit();
1262         tapeblock_exit();
1263         tape_proc_cleanup();
1264         debug_unregister (TAPE_DBF_AREA);
1265 }
1266
1267 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1268               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1269 MODULE_DESCRIPTION("Linux on zSeries channel attached "
1270                    "tape device driver ($Revision: 1.54 $)");
1271 MODULE_LICENSE("GPL");
1272
1273 module_init(tape_init);
1274 module_exit(tape_exit);
1275
1276 EXPORT_SYMBOL(tape_generic_remove);
1277 EXPORT_SYMBOL(tape_generic_probe);
1278 EXPORT_SYMBOL(tape_generic_online);
1279 EXPORT_SYMBOL(tape_generic_offline);
1280 EXPORT_SYMBOL(tape_put_device);
1281 EXPORT_SYMBOL(tape_get_device_reference);
1282 EXPORT_SYMBOL(tape_state_verbose);
1283 EXPORT_SYMBOL(tape_op_verbose);
1284 EXPORT_SYMBOL(tape_state_set);
1285 EXPORT_SYMBOL(tape_med_state_set);
1286 EXPORT_SYMBOL(tape_alloc_request);
1287 EXPORT_SYMBOL(tape_free_request);
1288 EXPORT_SYMBOL(tape_dump_sense);
1289 EXPORT_SYMBOL(tape_dump_sense_dbf);
1290 EXPORT_SYMBOL(tape_do_io);
1291 EXPORT_SYMBOL(tape_do_io_async);
1292 EXPORT_SYMBOL(tape_do_io_interruptible);
1293 EXPORT_SYMBOL(tape_mtop);