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                         kfree(request->cpaddr);
 686                         kfree(request);
 687                         return ERR_PTR(-ENOMEM);
 688                 }
 689                 memset(request->cpdata, 0, datasize);
 690         }
 691         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 692                 request->cpdata);
 693
 694         return request;
 695 }
 696
 697 /*
 698  * Free tape ccw request
 699  */
 700 void
 701 tape_free_request (struct tape_request * request)
 702 {
 703         DBF_LH(6, "Free request %p\n", request);
 704
 705         if (request->device != NULL) {
 706                 request->device = tape_put_device(request->device);
 707         }
 708         kfree(request->cpdata);
 709         kfree(request->cpaddr);
 710         kfree(request);
 711 }
 712
 713 static inline int
 714 __tape_start_io(struct tape_device *device, struct tape_request *request)
 715 {
 716         int rc;
 717
 718 #ifdef CONFIG_S390_TAPE_BLOCK
 719         if (request->op == TO_BLOCK)
 720                 device->discipline->check_locate(device, request);
 721 #endif
 722         rc = ccw_device_start(
 723                 device->cdev,
 724                 request->cpaddr,
 725                 (unsigned long) request,
 726                 0x00,
 727                 request->options
 728         );
 729         if (rc == 0) {
 730                 request->status = TAPE_REQUEST_IN_IO;
 731         } else if (rc == -EBUSY) {
 732                 /* The common I/O subsystem is currently busy. Retry later. */
 733                 request->status = TAPE_REQUEST_QUEUED;
 734                 schedule_work(&device->tape_dnr);
 735                 rc = 0;
 736         } else {
 737                 /* Start failed. Remove request and indicate failure. */
 738                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 739         }
 740         return rc;
 741 }
 742
 743 static inline void
 744 __tape_start_next_request(struct tape_device *device)
 745 {
 746         struct list_head *l, *n;
 747         struct tape_request *request;
 748         int rc;
 749
 750         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 751         /*
 752          * Try to start each request on request queue until one is
 753          * started successful.
 754          */
 755         list_for_each_safe(l, n, &device->req_queue) {
 756                 request = list_entry(l, struct tape_request, list);
 757
 758                 /*
 759                  * Avoid race condition if bottom-half was triggered more than
 760                  * once.
 761                  */
 762                 if (request->status == TAPE_REQUEST_IN_IO)
 763                         return;
 764
 765                 /*
 766                  * We wanted to cancel the request but the common I/O layer
 767                  * was busy at that time. This can only happen if this
 768                  * function is called by delayed_next_request.
 769                  * Otherwise we start the next request on the queue.
 770                  */
 771                 if (request->status == TAPE_REQUEST_CANCEL) {
 772                         rc = __tape_cancel_io(device, request);
 773                 } else {
 774                         rc = __tape_start_io(device, request);
 775                 }
 776                 if (rc == 0)
 777                         return;
 778
 779                 /* Set ending status. */
 780                 request->rc = rc;
 781                 request->status = TAPE_REQUEST_DONE;
 782
 783                 /* Remove from request queue. */
 784                 list_del(&request->list);
 785
 786                 /* Do callback. */
 787                 if (request->callback != NULL)
 788                         request->callback(request, request->callback_data);
 789         }
 790 }
 791
 792 static void
 793 tape_delayed_next_request(void *data)
 794 {
 795         struct tape_device *    device;
 796
 797         device = (struct tape_device *) data;
 798         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 799         spin_lock_irq(get_ccwdev_lock(device->cdev));
 800         __tape_start_next_request(device);
 801         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 802 }
 803
 804 static inline void
 805 __tape_end_request(
 806         struct tape_device *    device,
 807         struct tape_request *   request,
 808         int                     rc)
 809 {
 810         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 811         if (request) {
 812                 request->rc = rc;
 813                 request->status = TAPE_REQUEST_DONE;
 814
 815                 /* Remove from request queue. */
 816                 list_del(&request->list);
 817
 818                 /* Do callback. */
 819                 if (request->callback != NULL)
 820                         request->callback(request, request->callback_data);
 821         }
 822
 823         /* Start next request. */
 824         if (!list_empty(&device->req_queue))
 825                 __tape_start_next_request(device);
 826 }
 827
 828 /*
 829  * Write sense data to console/dbf
 830  */
 831 void
 832 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 833                 struct irb *irb)
 834 {
 835         unsigned int *sptr;
 836
 837         PRINT_INFO("-------------------------------------------------\n");
 838         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 839                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 840         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 841         if (request != NULL)
 842                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 843
 844         sptr = (unsigned int *) irb->ecw;
 845         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 846                    sptr[0], sptr[1], sptr[2], sptr[3]);
 847         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 848                    sptr[4], sptr[5], sptr[6], sptr[7]);
 849         PRINT_INFO("--------------------------------------------------\n");
 850 }
 851
 852 /*
 853  * Write sense data to dbf
 854  */
 855 void
 856 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 857                     struct irb *irb)
 858 {
 859         unsigned int *sptr;
 860         const char* op;
 861
 862         if (request != NULL)
 863                 op = tape_op_verbose[request->op];
 864         else
 865                 op = "---";
 866         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 867                   irb->scsw.dstat,irb->scsw.cstat);
 868         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 869         sptr = (unsigned int *) irb->ecw;
 870         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 871         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 872         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 873         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 874 }
 875
 876 /*
 877  * I/O helper function. Adds the request to the request queue
 878  * and starts it if the tape is idle. Has to be called with
 879  * the device lock held.
 880  */
 881 static inline int
 882 __tape_start_request(struct tape_device *device, struct tape_request *request)
 883 {
 884         int rc;
 885
 886         switch (request->op) {
 887                 case TO_MSEN:
 888                 case TO_ASSIGN:
 889                 case TO_UNASSIGN:
 890                 case TO_READ_ATTMSG:
 891                         if (device->tape_state == TS_INIT)
 892                                 break;
 893                         if (device->tape_state == TS_UNUSED)
 894                                 break;
 895                 default:
 896                         if (device->tape_state == TS_BLKUSE)
 897                                 break;
 898                         if (device->tape_state != TS_IN_USE)
 899                                 return -ENODEV;
 900         }
 901
 902         /* Increase use count of device for the added request. */
 903         request->device = tape_get_device_reference(device);
 904
 905         if (list_empty(&device->req_queue)) {
 906                 /* No other requests are on the queue. Start this one. */
 907                 rc = __tape_start_io(device, request);
 908                 if (rc)
 909                         return rc;
 910
 911                 DBF_LH(5, "Request %p added for execution.\n", request);
 912                 list_add(&request->list, &device->req_queue);
 913         } else {
 914                 DBF_LH(5, "Request %p add to queue.\n", request);
 915                 request->status = TAPE_REQUEST_QUEUED;
 916                 list_add_tail(&request->list, &device->req_queue);
 917         }
 918         return 0;
 919 }
 920
 921 /*
 922  * Add the request to the request queue, try to start it if the
 923  * tape is idle. Return without waiting for end of i/o.
 924  */
 925 int
 926 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 927 {
 928         int rc;
 929
 930         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 931
 932         spin_lock_irq(get_ccwdev_lock(device->cdev));
 933         /* Add request to request queue and try to start it. */
 934         rc = __tape_start_request(device, request);
 935         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 936         return rc;
 937 }
 938
 939 /*
 940  * tape_do_io/__tape_wake_up
 941  * Add the request to the request queue, try to start it if the
 942  * tape is idle and wait uninterruptible for its completion.
 943  */
 944 static void
 945 __tape_wake_up(struct tape_request *request, void *data)
 946 {
 947         request->callback = NULL;
 948         wake_up((wait_queue_head_t *) data);
 949 }
 950
 951 int
 952 tape_do_io(struct tape_device *device, struct tape_request *request)
 953 {
 954         wait_queue_head_t wq;
 955         int rc;
 956
 957         init_waitqueue_head(&wq);
 958         spin_lock_irq(get_ccwdev_lock(device->cdev));
 959         /* Setup callback */
 960         request->callback = __tape_wake_up;
 961         request->callback_data = &wq;
 962         /* Add request to request queue and try to start it. */
 963         rc = __tape_start_request(device, request);
 964         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 965         if (rc)
 966                 return rc;
 967         /* Request added to the queue. Wait for its completion. */
 968         wait_event(wq, (request->callback == NULL));
 969         /* Get rc from request */
 970         return request->rc;
 971 }
 972
 973 /*
 974  * tape_do_io_interruptible/__tape_wake_up_interruptible
 975  * Add the request to the request queue, try to start it if the
 976  * tape is idle and wait uninterruptible for its completion.
 977  */
 978 static void
 979 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 980 {
 981         request->callback = NULL;
 982         wake_up_interruptible((wait_queue_head_t *) data);
 983 }
 984
 985 int
 986 tape_do_io_interruptible(struct tape_device *device,
 987                          struct tape_request *request)
 988 {
 989         wait_queue_head_t wq;
 990         int rc;
 991
 992         init_waitqueue_head(&wq);
 993         spin_lock_irq(get_ccwdev_lock(device->cdev));
 994         /* Setup callback */
 995         request->callback = __tape_wake_up_interruptible;
 996         request->callback_data = &wq;
 997         rc = __tape_start_request(device, request);
 998         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 999         if (rc)
1000                 return rc;
1001         /* Request added to the queue. Wait for its completion. */
1002         rc = wait_event_interruptible(wq, (request->callback == NULL));
1003         if (rc != -ERESTARTSYS)
1004                 /* Request finished normally. */
1005                 return request->rc;
1006
1007         /* Interrupted by a signal. We have to stop the current request. */
1008         spin_lock_irq(get_ccwdev_lock(device->cdev));
1009         rc = __tape_cancel_io(device, request);
1010         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1011         if (rc == 0) {
1012                 /* Wait for the interrupt that acknowledges the halt. */
1013                 do {
1014                         rc = wait_event_interruptible(
1015                                 wq,
1016                                 (request->callback == NULL)
1017                         );
1018                 } while (rc != -ERESTARTSYS);
1019
1020                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1021                 rc = -ERESTARTSYS;
1022         }
1023         return rc;
1024 }
1025
1026 /*
1027  * Tape interrupt routine, called from the ccw_device layer
1028  */
1029 static void
1030 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1031 {
1032         struct tape_device *device;
1033         struct tape_request *request;
1034         int rc;
1035
1036         device = (struct tape_device *) cdev->dev.driver_data;
1037         if (device == NULL) {
1038                 PRINT_ERR("could not get device structure for %s "
1039                           "in interrupt\n", cdev->dev.bus_id);
1040                 return;
1041         }
1042         request = (struct tape_request *) intparm;
1043
1044         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1045
1046         /* On special conditions irb is an error pointer */
1047         if (IS_ERR(irb)) {
1048                 /* FIXME: What to do with the request? */
1049                 switch (PTR_ERR(irb)) {
1050                         case -ETIMEDOUT:
1051                                 PRINT_WARN("(%s): Request timed out\n",
1052                                         cdev->dev.bus_id);
1053                         case -EIO:
1054                                 __tape_end_request(device, request, -EIO);
1055                                 break;
1056                         default:
1057                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1058                                         cdev->dev.bus_id,
1059                                         PTR_ERR(irb));
1060                 }
1061                 return;
1062         }
1063
1064         /*
1065          * If the condition code is not zero and the start function bit is
1066          * still set, this is an deferred error and the last start I/O did
1067          * not succeed. Restart the request now.
1068          */
1069         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC)) {
1070                 PRINT_WARN("(%s): deferred cc=%i. restaring\n",
1071                         cdev->dev.bus_id,
1072                         irb->scsw.cc);
1073                 rc = __tape_start_io(device, request);
1074                 if (rc)
1075                         __tape_end_request(device, request, rc);
1076                 return;
1077         }
1078
1079         /* May be an unsolicited irq */
1080         if(request != NULL)
1081                 request->rescnt = irb->scsw.count;
1082
1083         if (irb->scsw.dstat != 0x0c) {
1084                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1085                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1086                         device->tape_generic_status |= GMT_ONLINE(~0);
1087                 else
1088                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1089
1090                 /*
1091                  * Any request that does not come back with channel end
1092                  * and device end is unusual. Log the sense data.
1093                  */
1094                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1095                 tape_dump_sense_dbf(device, request, irb);
1096         } else {
1097                 /* Upon normal completion the device _is_ online */
1098                 device->tape_generic_status |= GMT_ONLINE(~0);
1099         }
1100         if (device->tape_state == TS_NOT_OPER) {
1101                 DBF_EVENT(6, "tape:device is not operational\n");
1102                 return;
1103         }
1104
1105         /*
1106          * Request that were canceled still come back with an interrupt.
1107          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1108          */
1109         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1110                 __tape_end_request(device, request, -EIO);
1111                 return;
1112         }
1113
1114         rc = device->discipline->irq(device, request, irb);
1115         /*
1116          * rc < 0 : request finished unsuccessfully.
1117          * rc == TAPE_IO_SUCCESS: request finished successfully.
1118          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1119          * rc == TAPE_IO_RETRY: request finished but needs another go.
1120          * rc == TAPE_IO_STOP: request needs to get terminated.
1121          */
1122         switch (rc) {
1123                 case TAPE_IO_SUCCESS:
1124                         /* Upon normal completion the device _is_ online */
1125                         device->tape_generic_status |= GMT_ONLINE(~0);
1126                         __tape_end_request(device, request, rc);
1127                         break;
1128                 case TAPE_IO_PENDING:
1129                         break;
1130                 case TAPE_IO_RETRY:
1131                         rc = __tape_start_io(device, request);
1132                         if (rc)
1133                                 __tape_end_request(device, request, rc);
1134                         break;
1135                 case TAPE_IO_STOP:
1136                         rc = __tape_cancel_io(device, request);
1137                         if (rc)
1138                                 __tape_end_request(device, request, rc);
1139                         break;
1140                 default:
1141                         if (rc > 0) {
1142                                 DBF_EVENT(6, "xunknownrc\n");
1143                                 PRINT_ERR("Invalid return code from discipline "
1144                                         "interrupt function.\n");
1145                                 __tape_end_request(device, request, -EIO);
1146                         } else {
1147                                 __tape_end_request(device, request, rc);
1148                         }
1149                         break;
1150         }
1151 }
1152
1153 /*
1154  * Tape device open function used by tape_char & tape_block frontends.
1155  */
1156 int
1157 tape_open(struct tape_device *device)
1158 {
1159         int rc;
1160
1161         spin_lock(get_ccwdev_lock(device->cdev));
1162         if (device->tape_state == TS_NOT_OPER) {
1163                 DBF_EVENT(6, "TAPE:nodev\n");
1164                 rc = -ENODEV;
1165         } else if (device->tape_state == TS_IN_USE) {
1166                 DBF_EVENT(6, "TAPE:dbusy\n");
1167                 rc = -EBUSY;
1168         } else if (device->tape_state == TS_BLKUSE) {
1169                 DBF_EVENT(6, "TAPE:dbusy\n");
1170                 rc = -EBUSY;
1171         } else if (device->discipline != NULL &&
1172                    !try_module_get(device->discipline->owner)) {
1173                 DBF_EVENT(6, "TAPE:nodisc\n");
1174                 rc = -ENODEV;
1175         } else {
1176                 tape_state_set(device, TS_IN_USE);
1177                 rc = 0;
1178         }
1179         spin_unlock(get_ccwdev_lock(device->cdev));
1180         return rc;
1181 }
1182
1183 /*
1184  * Tape device release function used by tape_char & tape_block frontends.
1185  */
1186 int
1187 tape_release(struct tape_device *device)
1188 {
1189         spin_lock(get_ccwdev_lock(device->cdev));
1190         if (device->tape_state == TS_IN_USE)
1191                 tape_state_set(device, TS_UNUSED);
1192         module_put(device->discipline->owner);
1193         spin_unlock(get_ccwdev_lock(device->cdev));
1194         return 0;
1195 }
1196
1197 /*
1198  * Execute a magnetic tape command a number of times.
1199  */
1200 int
1201 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1202 {
1203         tape_mtop_fn fn;
1204         int rc;
1205
1206         DBF_EVENT(6, "TAPE:mtio\n");
1207         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1208         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1209
1210         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1211                 return -EINVAL;
1212         fn = device->discipline->mtop_array[mt_op];
1213         if (fn == NULL)
1214                 return -EINVAL;
1215
1216         /* We assume that the backends can handle count up to 500. */
1217         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1218             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1219                 rc = 0;
1220                 for (; mt_count > 500; mt_count -= 500)
1221                         if ((rc = fn(device, 500)) != 0)
1222                                 break;
1223                 if (rc == 0)
1224                         rc = fn(device, mt_count);
1225         } else
1226                 rc = fn(device, mt_count);
1227         return rc;
1228
1229 }
1230
1231 /*
1232  * Tape init function.
1233  */
1234 static int
1235 tape_init (void)
1236 {
1237         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1238         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1239 #ifdef DBF_LIKE_HELL
1240         debug_set_level(TAPE_DBF_AREA, 6);
1241 #endif
1242         DBF_EVENT(3, "tape init\n");
1243         tape_proc_init();
1244         tapechar_init ();
1245         tapeblock_init ();
1246         return 0;
1247 }
1248
1249 /*
1250  * Tape exit function.
1251  */
1252 static void
1253 tape_exit(void)
1254 {
1255         DBF_EVENT(6, "tape exit\n");
1256
1257         /* Get rid of the frontends */
1258         tapechar_exit();
1259         tapeblock_exit();
1260         tape_proc_cleanup();
1261         debug_unregister (TAPE_DBF_AREA);
1262 }
1263
1264 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1265               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1266 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1267 MODULE_LICENSE("GPL");
1268
1269 module_init(tape_init);
1270 module_exit(tape_exit);
1271
1272 EXPORT_SYMBOL(tape_generic_remove);
1273 EXPORT_SYMBOL(tape_generic_probe);
1274 EXPORT_SYMBOL(tape_generic_online);
1275 EXPORT_SYMBOL(tape_generic_offline);
1276 EXPORT_SYMBOL(tape_put_device);
1277 EXPORT_SYMBOL(tape_get_device_reference);
1278 EXPORT_SYMBOL(tape_state_verbose);
1279 EXPORT_SYMBOL(tape_op_verbose);
1280 EXPORT_SYMBOL(tape_state_set);
1281 EXPORT_SYMBOL(tape_med_state_set);
1282 EXPORT_SYMBOL(tape_alloc_request);
1283 EXPORT_SYMBOL(tape_free_request);
1284 EXPORT_SYMBOL(tape_dump_sense);
1285 EXPORT_SYMBOL(tape_dump_sense_dbf);
1286 EXPORT_SYMBOL(tape_do_io);
1287 EXPORT_SYMBOL(tape_do_io_async);
1288 EXPORT_SYMBOL(tape_do_io_interruptible);
1289 EXPORT_SYMBOL(tape_mtop);