drivers/s390/char/tape_core.c

   1 /*
   2  *  drivers/s390/char/tape_core.c
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright (C) 2001,2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
   8  *               Michael Holzheu <holzheu@de.ibm.com>
   9  *               Tuan Ngo-Anh <ngoanh@de.ibm.com>
  10  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
  11  *               Stefan Bader <shbader@de.ibm.com>
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>      // for kernel parameters
  16 #include <linux/kmod.h>      // for requesting modules
  17 #include <linux/spinlock.h>  // for locks
  18 #include <linux/vmalloc.h>
  19 #include <linux/list.h>
  20
  21 #include <asm/types.h>       // for variable types
  22
  23 #define TAPE_DBF_AREA   tape_core_dbf
  24
  25 #include "tape.h"
  26 #include "tape_std.h"
  27
  28 #define PRINTK_HEADER "TAPE_CORE: "
  29
  30 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  31 static void tape_delayed_next_request(void * data);
  32
  33 /*
  34  * One list to contain all tape devices of all disciplines, so
  35  * we can assign the devices to minor numbers of the same major
  36  * The list is protected by the rwlock
  37  */
  38 static struct list_head tape_device_list = LIST_HEAD_INIT(tape_device_list);
  39 static DEFINE_RWLOCK(tape_device_lock);
  40
  41 /*
  42  * Pointer to debug area.
  43  */
  44 debug_info_t *TAPE_DBF_AREA = NULL;
  45 EXPORT_SYMBOL(TAPE_DBF_AREA);
  46
  47 /*
  48  * Printable strings for tape enumerations.
  49  */
  50 const char *tape_state_verbose[TS_SIZE] =
  51 {
  52         [TS_UNUSED]   = "UNUSED",
  53         [TS_IN_USE]   = "IN_USE",
  54         [TS_BLKUSE]   = "BLKUSE",
  55         [TS_INIT]     = "INIT  ",
  56         [TS_NOT_OPER] = "NOT_OP"
  57 };
  58
  59 const char *tape_op_verbose[TO_SIZE] =
  60 {
  61         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  62         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  63         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  64         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  65         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  66         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  67         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  68         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  69         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  70         [TO_READ_ATTMSG] = "RAT",
  71         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  72         [TO_UNASSIGN] = "UAS"
  73 };
  74
  75 static inline int
  76 busid_to_int(char *bus_id)
  77 {
  78         int     dec;
  79         int     d;
  80         char *  s;
  81
  82         for(s = bus_id, d = 0; *s != '\0' && *s != '.'; s++)
  83                 d = (d * 10) + (*s - '0');
  84         dec = d;
  85         for(s++, d = 0; *s != '\0' && *s != '.'; s++)
  86                 d = (d * 10) + (*s - '0');
  87         dec = (dec << 8) + d;
  88
  89         for(s++; *s != '\0'; s++) {
  90                 if (*s >= '0' && *s <= '9') {
  91                         d = *s - '0';
  92                 } else if (*s >= 'a' && *s <= 'f') {
  93                         d = *s - 'a' + 10;
  94                 } else {
  95                         d = *s - 'A' + 10;
  96                 }
  97                 dec = (dec << 4) + d;
  98         }
  99
 100         return dec;
 101 }
 102
 103 /*
 104  * Some channel attached tape specific attributes.
 105  *
 106  * FIXME: In the future the first_minor and blocksize attribute should be
 107  *        replaced by a link to the cdev tree.
 108  */
 109 static ssize_t
 110 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 111 {
 112         struct tape_device *tdev;
 113
 114         tdev = (struct tape_device *) dev->driver_data;
 115         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 116 }
 117
 118 static
 119 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 120
 121 static ssize_t
 122 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 123 {
 124         struct tape_device *tdev;
 125
 126         tdev = (struct tape_device *) dev->driver_data;
 127         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 128 }
 129
 130 static
 131 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 132
 133 static ssize_t
 134 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 135 {
 136         struct tape_device *tdev;
 137
 138         tdev = (struct tape_device *) dev->driver_data;
 139         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 140                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 141 }
 142
 143 static
 144 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 145
 146 static ssize_t
 147 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 148 {
 149         struct tape_device *tdev;
 150         ssize_t rc;
 151
 152         tdev = (struct tape_device *) dev->driver_data;
 153         if (tdev->first_minor < 0)
 154                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 155
 156         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 157         if (list_empty(&tdev->req_queue))
 158                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 159         else {
 160                 struct tape_request *req;
 161
 162                 req = list_entry(tdev->req_queue.next, struct tape_request,
 163                         list);
 164                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 165         }
 166         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 167         return rc;
 168 }
 169
 170 static
 171 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 172
 173 static ssize_t
 174 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 175 {
 176         struct tape_device *tdev;
 177
 178         tdev = (struct tape_device *) dev->driver_data;
 179
 180         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 181 }
 182
 183 static
 184 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 185
 186 static struct attribute *tape_attrs[] = {
 187         &dev_attr_medium_state.attr,
 188         &dev_attr_first_minor.attr,
 189         &dev_attr_state.attr,
 190         &dev_attr_operation.attr,
 191         &dev_attr_blocksize.attr,
 192         NULL
 193 };
 194
 195 static struct attribute_group tape_attr_group = {
 196         .attrs = tape_attrs,
 197 };
 198
 199 /*
 200  * Tape state functions
 201  */
 202 void
 203 tape_state_set(struct tape_device *device, enum tape_state newstate)
 204 {
 205         const char *str;
 206
 207         if (device->tape_state == TS_NOT_OPER) {
 208                 DBF_EVENT(3, "ts_set err: not oper\n");
 209                 return;
 210         }
 211         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 212         DBF_EVENT(4, "old ts:\t\n");
 213         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 214                 str = tape_state_verbose[device->tape_state];
 215         else
 216                 str = "UNKNOWN TS";
 217         DBF_EVENT(4, "%s\n", str);
 218         DBF_EVENT(4, "new ts:\t\n");
 219         if (newstate < TS_SIZE && newstate >= 0)
 220                 str = tape_state_verbose[newstate];
 221         else
 222                 str = "UNKNOWN TS";
 223         DBF_EVENT(4, "%s\n", str);
 224         device->tape_state = newstate;
 225         wake_up(&device->state_change_wq);
 226 }
 227
 228 void
 229 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 230 {
 231         if (device->medium_state == newstate)
 232                 return;
 233         switch(newstate){
 234         case MS_UNLOADED:
 235                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 236                 PRINT_INFO("(%s): Tape is unloaded\n",
 237                            device->cdev->dev.bus_id);
 238                 break;
 239         case MS_LOADED:
 240                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 241                 PRINT_INFO("(%s): Tape has been mounted\n",
 242                            device->cdev->dev.bus_id);
 243                 break;
 244         default:
 245                 // print nothing
 246                 break;
 247         }
 248         device->medium_state = newstate;
 249         wake_up(&device->state_change_wq);
 250 }
 251
 252 /*
 253  * Stop running ccw. Has to be called with the device lock held.
 254  */
 255 static inline int
 256 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 257 {
 258         int retries;
 259         int rc;
 260
 261         /* Check if interrupt has already been processed */
 262         if (request->callback == NULL)
 263                 return 0;
 264
 265         rc = 0;
 266         for (retries = 0; retries < 5; retries++) {
 267                 rc = ccw_device_clear(device->cdev, (long) request);
 268
 269                 switch (rc) {
 270                         case 0:
 271                                 request->status = TAPE_REQUEST_DONE;
 272                                 return 0;
 273                         case -EBUSY:
 274                                 request->status = TAPE_REQUEST_CANCEL;
 275                                 schedule_work(&device->tape_dnr);
 276                                 return 0;
 277                         case -ENODEV:
 278                                 DBF_EXCEPTION(2, "device gone, retry\n");
 279                                 break;
 280                         case -EIO:
 281                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 282                                 break;
 283                         default:
 284                                 BUG();
 285                 }
 286         }
 287
 288         return rc;
 289 }
 290
 291 /*
 292  * Add device into the sorted list, giving it the first
 293  * available minor number.
 294  */
 295 static int
 296 tape_assign_minor(struct tape_device *device)
 297 {
 298         struct tape_device *tmp;
 299         int minor;
 300
 301         minor = 0;
 302         write_lock(&tape_device_lock);
 303         list_for_each_entry(tmp, &tape_device_list, node) {
 304                 if (minor < tmp->first_minor)
 305                         break;
 306                 minor += TAPE_MINORS_PER_DEV;
 307         }
 308         if (minor >= 256) {
 309                 write_unlock(&tape_device_lock);
 310                 return -ENODEV;
 311         }
 312         device->first_minor = minor;
 313         list_add_tail(&device->node, &tmp->node);
 314         write_unlock(&tape_device_lock);
 315         return 0;
 316 }
 317
 318 /* remove device from the list */
 319 static void
 320 tape_remove_minor(struct tape_device *device)
 321 {
 322         write_lock(&tape_device_lock);
 323         list_del_init(&device->node);
 324         device->first_minor = -1;
 325         write_unlock(&tape_device_lock);
 326 }
 327
 328 /*
 329  * Set a device online.
 330  *
 331  * This function is called by the common I/O layer to move a device from the
 332  * detected but offline into the online state.
 333  * If we return an error (RC < 0) the device remains in the offline state. This
 334  * can happen if the device is assigned somewhere else, for example.
 335  */
 336 int
 337 tape_generic_online(struct tape_device *device,
 338                    struct tape_discipline *discipline)
 339 {
 340         int rc;
 341
 342         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 343
 344         if (device->tape_state != TS_INIT) {
 345                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 346                 return -EINVAL;
 347         }
 348
 349         /* Let the discipline have a go at the device. */
 350         device->discipline = discipline;
 351         if (!try_module_get(discipline->owner)) {
 352                 PRINT_ERR("Cannot get module. Module gone.\n");
 353                 return -EINVAL;
 354         }
 355
 356         rc = discipline->setup_device(device);
 357         if (rc)
 358                 goto out;
 359         rc = tape_assign_minor(device);
 360         if (rc)
 361                 goto out_discipline;
 362
 363         rc = tapechar_setup_device(device);
 364         if (rc)
 365                 goto out_minor;
 366         rc = tapeblock_setup_device(device);
 367         if (rc)
 368                 goto out_char;
 369
 370         tape_state_set(device, TS_UNUSED);
 371
 372         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 373
 374         return 0;
 375
 376 out_char:
 377         tapechar_cleanup_device(device);
 378 out_discipline:
 379         device->discipline->cleanup_device(device);
 380         device->discipline = NULL;
 381 out_minor:
 382         tape_remove_minor(device);
 383 out:
 384         module_put(discipline->owner);
 385         return rc;
 386 }
 387
 388 static inline void
 389 tape_cleanup_device(struct tape_device *device)
 390 {
 391         tapeblock_cleanup_device(device);
 392         tapechar_cleanup_device(device);
 393         device->discipline->cleanup_device(device);
 394         module_put(device->discipline->owner);
 395         tape_remove_minor(device);
 396         tape_med_state_set(device, MS_UNKNOWN);
 397 }
 398
 399 /*
 400  * Set device offline.
 401  *
 402  * Called by the common I/O layer if the drive should set offline on user
 403  * request. We may prevent this by returning an error.
 404  * Manual offline is only allowed while the drive is not in use.
 405  */
 406 int
 407 tape_generic_offline(struct tape_device *device)
 408 {
 409         if (!device) {
 410                 PRINT_ERR("tape_generic_offline: no such device\n");
 411                 return -ENODEV;
 412         }
 413
 414         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 415                 device->cdev_id, device);
 416
 417         spin_lock_irq(get_ccwdev_lock(device->cdev));
 418         switch (device->tape_state) {
 419                 case TS_INIT:
 420                 case TS_NOT_OPER:
 421                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 422                         break;
 423                 case TS_UNUSED:
 424                         tape_state_set(device, TS_INIT);
 425                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 426                         tape_cleanup_device(device);
 427                         break;
 428                 default:
 429                         DBF_EVENT(3, "(%08x): Set offline failed "
 430                                 "- drive in use.\n",
 431                                 device->cdev_id);
 432                         PRINT_WARN("(%s): Set offline failed "
 433                                 "- drive in use.\n",
 434                                 device->cdev->dev.bus_id);
 435                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 436                         return -EBUSY;
 437         }
 438
 439         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 440         return 0;
 441 }
 442
 443 /*
 444  * Allocate memory for a new device structure.
 445  */
 446 static struct tape_device *
 447 tape_alloc_device(void)
 448 {
 449         struct tape_device *device;
 450
 451         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 452         if (device == NULL) {
 453                 DBF_EXCEPTION(2, "ti:no mem\n");
 454                 PRINT_INFO ("can't allocate memory for "
 455                             "tape info structure\n");
 456                 return ERR_PTR(-ENOMEM);
 457         }
 458         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 459         if (device->modeset_byte == NULL) {
 460                 DBF_EXCEPTION(2, "ti:no mem\n");
 461                 PRINT_INFO("can't allocate memory for modeset byte\n");
 462                 kfree(device);
 463                 return ERR_PTR(-ENOMEM);
 464         }
 465         INIT_LIST_HEAD(&device->req_queue);
 466         INIT_LIST_HEAD(&device->node);
 467         init_waitqueue_head(&device->state_change_wq);
 468         device->tape_state = TS_INIT;
 469         device->medium_state = MS_UNKNOWN;
 470         *device->modeset_byte = 0;
 471         device->first_minor = -1;
 472         atomic_set(&device->ref_count, 1);
 473         INIT_WORK(&device->tape_dnr, tape_delayed_next_request, device);
 474
 475         return device;
 476 }
 477
 478 /*
 479  * Get a reference to an existing device structure. This will automatically
 480  * increment the reference count.
 481  */
 482 struct tape_device *
 483 tape_get_device_reference(struct tape_device *device)
 484 {
 485         DBF_EVENT(4, "tape_get_device_reference(%p) = %i\n", device,
 486                 atomic_inc_return(&device->ref_count));
 487
 488         return device;
 489 }
 490
 491 /*
 492  * Decrease the reference counter of a devices structure. If the
 493  * reference counter reaches zero free the device structure.
 494  * The function returns a NULL pointer to be used by the caller
 495  * for clearing reference pointers.
 496  */
 497 struct tape_device *
 498 tape_put_device(struct tape_device *device)
 499 {
 500         int remain;
 501
 502         remain = atomic_dec_return(&device->ref_count);
 503         if (remain > 0) {
 504                 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, remain);
 505         } else {
 506                 if (remain < 0) {
 507                         DBF_EVENT(4, "put device without reference\n");
 508                         PRINT_ERR("put device without reference\n");
 509                 } else {
 510                         DBF_EVENT(4, "tape_free_device(%p)\n", device);
 511                         kfree(device->modeset_byte);
 512                         kfree(device);
 513                 }
 514         }
 515
 516         return NULL;
 517 }
 518
 519 /*
 520  * Find tape device by a device index.
 521  */
 522 struct tape_device *
 523 tape_get_device(int devindex)
 524 {
 525         struct tape_device *device, *tmp;
 526
 527         device = ERR_PTR(-ENODEV);
 528         read_lock(&tape_device_lock);
 529         list_for_each_entry(tmp, &tape_device_list, node) {
 530                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 531                         device = tape_get_device_reference(tmp);
 532                         break;
 533                 }
 534         }
 535         read_unlock(&tape_device_lock);
 536         return device;
 537 }
 538
 539 /*
 540  * Driverfs tape probe function.
 541  */
 542 int
 543 tape_generic_probe(struct ccw_device *cdev)
 544 {
 545         struct tape_device *device;
 546
 547         device = tape_alloc_device();
 548         if (IS_ERR(device))
 549                 return -ENODEV;
 550         PRINT_INFO("tape device %s found\n", cdev->dev.bus_id);
 551         cdev->dev.driver_data = device;
 552         device->cdev = cdev;
 553         device->cdev_id = busid_to_int(cdev->dev.bus_id);
 554         cdev->handler = __tape_do_irq;
 555
 556         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP);
 557         sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 558
 559         return 0;
 560 }
 561
 562 static inline void
 563 __tape_discard_requests(struct tape_device *device)
 564 {
 565         struct tape_request *   request;
 566         struct list_head *      l, *n;
 567
 568         list_for_each_safe(l, n, &device->req_queue) {
 569                 request = list_entry(l, struct tape_request, list);
 570                 if (request->status == TAPE_REQUEST_IN_IO)
 571                         request->status = TAPE_REQUEST_DONE;
 572                 list_del(&request->list);
 573
 574                 /* Decrease ref_count for removed request. */
 575                 request->device = tape_put_device(device);
 576                 request->rc = -EIO;
 577                 if (request->callback != NULL)
 578                         request->callback(request, request->callback_data);
 579         }
 580 }
 581
 582 /*
 583  * Driverfs tape remove function.
 584  *
 585  * This function is called whenever the common I/O layer detects the device
 586  * gone. This can happen at any time and we cannot refuse.
 587  */
 588 void
 589 tape_generic_remove(struct ccw_device *cdev)
 590 {
 591         struct tape_device *    device;
 592
 593         device = cdev->dev.driver_data;
 594         if (!device) {
 595                 PRINT_ERR("No device pointer in tape_generic_remove!\n");
 596                 return;
 597         }
 598         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 599
 600         spin_lock_irq(get_ccwdev_lock(device->cdev));
 601         switch (device->tape_state) {
 602                 case TS_INIT:
 603                         tape_state_set(device, TS_NOT_OPER);
 604                 case TS_NOT_OPER:
 605                         /*
 606                          * Nothing to do.
 607                          */
 608                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 609                         break;
 610                 case TS_UNUSED:
 611                         /*
 612                          * Need only to release the device.
 613                          */
 614                         tape_state_set(device, TS_NOT_OPER);
 615                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 616                         tape_cleanup_device(device);
 617                         break;
 618                 default:
 619                         /*
 620                          * There may be requests on the queue. We will not get
 621                          * an interrupt for a request that was running. So we
 622                          * just post them all as I/O errors.
 623                          */
 624                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 625                                 device->cdev_id);
 626                         PRINT_WARN("(%s): Drive in use vanished - "
 627                                 "expect trouble!\n",
 628                                 device->cdev->dev.bus_id);
 629                         PRINT_WARN("State was %i\n", device->tape_state);
 630                         tape_state_set(device, TS_NOT_OPER);
 631                         __tape_discard_requests(device);
 632                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 633                         tape_cleanup_device(device);
 634         }
 635
 636         if (cdev->dev.driver_data != NULL) {
 637                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 638                 cdev->dev.driver_data = tape_put_device(cdev->dev.driver_data);
 639         }
 640 }
 641
 642 /*
 643  * Allocate a new tape ccw request
 644  */
 645 struct tape_request *
 646 tape_alloc_request(int cplength, int datasize)
 647 {
 648         struct tape_request *request;
 649
 650         if (datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
 651                 BUG();
 652
 653         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 654
 655         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 656         if (request == NULL) {
 657                 DBF_EXCEPTION(1, "cqra nomem\n");
 658                 return ERR_PTR(-ENOMEM);
 659         }
 660         /* allocate channel program */
 661         if (cplength > 0) {
 662                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 663                                           GFP_ATOMIC | GFP_DMA);
 664                 if (request->cpaddr == NULL) {
 665                         DBF_EXCEPTION(1, "cqra nomem\n");
 666                         kfree(request);
 667                         return ERR_PTR(-ENOMEM);
 668                 }
 669         }
 670         /* alloc small kernel buffer */
 671         if (datasize > 0) {
 672                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 673                 if (request->cpdata == NULL) {
 674                         DBF_EXCEPTION(1, "cqra nomem\n");
 675                         kfree(request->cpaddr);
 676                         kfree(request);
 677                         return ERR_PTR(-ENOMEM);
 678                 }
 679         }
 680         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 681                 request->cpdata);
 682
 683         return request;
 684 }
 685
 686 /*
 687  * Free tape ccw request
 688  */
 689 void
 690 tape_free_request (struct tape_request * request)
 691 {
 692         DBF_LH(6, "Free request %p\n", request);
 693
 694         if (request->device != NULL) {
 695                 request->device = tape_put_device(request->device);
 696         }
 697         kfree(request->cpdata);
 698         kfree(request->cpaddr);
 699         kfree(request);
 700 }
 701
 702 static inline int
 703 __tape_start_io(struct tape_device *device, struct tape_request *request)
 704 {
 705         int rc;
 706
 707 #ifdef CONFIG_S390_TAPE_BLOCK
 708         if (request->op == TO_BLOCK)
 709                 device->discipline->check_locate(device, request);
 710 #endif
 711         rc = ccw_device_start(
 712                 device->cdev,
 713                 request->cpaddr,
 714                 (unsigned long) request,
 715                 0x00,
 716                 request->options
 717         );
 718         if (rc == 0) {
 719                 request->status = TAPE_REQUEST_IN_IO;
 720         } else if (rc == -EBUSY) {
 721                 /* The common I/O subsystem is currently busy. Retry later. */
 722                 request->status = TAPE_REQUEST_QUEUED;
 723                 schedule_work(&device->tape_dnr);
 724                 rc = 0;
 725         } else {
 726                 /* Start failed. Remove request and indicate failure. */
 727                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 728         }
 729         return rc;
 730 }
 731
 732 static inline void
 733 __tape_start_next_request(struct tape_device *device)
 734 {
 735         struct list_head *l, *n;
 736         struct tape_request *request;
 737         int rc;
 738
 739         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 740         /*
 741          * Try to start each request on request queue until one is
 742          * started successful.
 743          */
 744         list_for_each_safe(l, n, &device->req_queue) {
 745                 request = list_entry(l, struct tape_request, list);
 746
 747                 /*
 748                  * Avoid race condition if bottom-half was triggered more than
 749                  * once.
 750                  */
 751                 if (request->status == TAPE_REQUEST_IN_IO)
 752                         return;
 753                 /*
 754                  * Request has already been stopped. We have to wait until
 755                  * the request is removed from the queue in the interrupt
 756                  * handling.
 757                  */
 758                 if (request->status == TAPE_REQUEST_DONE)
 759                         return;
 760
 761                 /*
 762                  * We wanted to cancel the request but the common I/O layer
 763                  * was busy at that time. This can only happen if this
 764                  * function is called by delayed_next_request.
 765                  * Otherwise we start the next request on the queue.
 766                  */
 767                 if (request->status == TAPE_REQUEST_CANCEL) {
 768                         rc = __tape_cancel_io(device, request);
 769                 } else {
 770                         rc = __tape_start_io(device, request);
 771                 }
 772                 if (rc == 0)
 773                         return;
 774
 775                 /* Set ending status. */
 776                 request->rc = rc;
 777                 request->status = TAPE_REQUEST_DONE;
 778
 779                 /* Remove from request queue. */
 780                 list_del(&request->list);
 781
 782                 /* Do callback. */
 783                 if (request->callback != NULL)
 784                         request->callback(request, request->callback_data);
 785         }
 786 }
 787
 788 static void
 789 tape_delayed_next_request(void *data)
 790 {
 791         struct tape_device *    device;
 792
 793         device = (struct tape_device *) data;
 794         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 795         spin_lock_irq(get_ccwdev_lock(device->cdev));
 796         __tape_start_next_request(device);
 797         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 798 }
 799
 800 static inline void
 801 __tape_end_request(
 802         struct tape_device *    device,
 803         struct tape_request *   request,
 804         int                     rc)
 805 {
 806         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 807         if (request) {
 808                 request->rc = rc;
 809                 request->status = TAPE_REQUEST_DONE;
 810
 811                 /* Remove from request queue. */
 812                 list_del(&request->list);
 813
 814                 /* Do callback. */
 815                 if (request->callback != NULL)
 816                         request->callback(request, request->callback_data);
 817         }
 818
 819         /* Start next request. */
 820         if (!list_empty(&device->req_queue))
 821                 __tape_start_next_request(device);
 822 }
 823
 824 /*
 825  * Write sense data to console/dbf
 826  */
 827 void
 828 tape_dump_sense(struct tape_device* device, struct tape_request *request,
 829                 struct irb *irb)
 830 {
 831         unsigned int *sptr;
 832
 833         PRINT_INFO("-------------------------------------------------\n");
 834         PRINT_INFO("DSTAT : %02x  CSTAT: %02x   CPA: %04x\n",
 835                    irb->scsw.dstat, irb->scsw.cstat, irb->scsw.cpa);
 836         PRINT_INFO("DEVICE: %s\n", device->cdev->dev.bus_id);
 837         if (request != NULL)
 838                 PRINT_INFO("OP    : %s\n", tape_op_verbose[request->op]);
 839
 840         sptr = (unsigned int *) irb->ecw;
 841         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 842                    sptr[0], sptr[1], sptr[2], sptr[3]);
 843         PRINT_INFO("Sense data: %08X %08X %08X %08X \n",
 844                    sptr[4], sptr[5], sptr[6], sptr[7]);
 845         PRINT_INFO("--------------------------------------------------\n");
 846 }
 847
 848 /*
 849  * Write sense data to dbf
 850  */
 851 void
 852 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 853                     struct irb *irb)
 854 {
 855         unsigned int *sptr;
 856         const char* op;
 857
 858         if (request != NULL)
 859                 op = tape_op_verbose[request->op];
 860         else
 861                 op = "---";
 862         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 863                   irb->scsw.dstat,irb->scsw.cstat);
 864         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 865         sptr = (unsigned int *) irb->ecw;
 866         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 867         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 868         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 869         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 870 }
 871
 872 /*
 873  * I/O helper function. Adds the request to the request queue
 874  * and starts it if the tape is idle. Has to be called with
 875  * the device lock held.
 876  */
 877 static inline int
 878 __tape_start_request(struct tape_device *device, struct tape_request *request)
 879 {
 880         int rc;
 881
 882         switch (request->op) {
 883                 case TO_MSEN:
 884                 case TO_ASSIGN:
 885                 case TO_UNASSIGN:
 886                 case TO_READ_ATTMSG:
 887                         if (device->tape_state == TS_INIT)
 888                                 break;
 889                         if (device->tape_state == TS_UNUSED)
 890                                 break;
 891                 default:
 892                         if (device->tape_state == TS_BLKUSE)
 893                                 break;
 894                         if (device->tape_state != TS_IN_USE)
 895                                 return -ENODEV;
 896         }
 897
 898         /* Increase use count of device for the added request. */
 899         request->device = tape_get_device_reference(device);
 900
 901         if (list_empty(&device->req_queue)) {
 902                 /* No other requests are on the queue. Start this one. */
 903                 rc = __tape_start_io(device, request);
 904                 if (rc)
 905                         return rc;
 906
 907                 DBF_LH(5, "Request %p added for execution.\n", request);
 908                 list_add(&request->list, &device->req_queue);
 909         } else {
 910                 DBF_LH(5, "Request %p add to queue.\n", request);
 911                 request->status = TAPE_REQUEST_QUEUED;
 912                 list_add_tail(&request->list, &device->req_queue);
 913         }
 914         return 0;
 915 }
 916
 917 /*
 918  * Add the request to the request queue, try to start it if the
 919  * tape is idle. Return without waiting for end of i/o.
 920  */
 921 int
 922 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 923 {
 924         int rc;
 925
 926         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 927
 928         spin_lock_irq(get_ccwdev_lock(device->cdev));
 929         /* Add request to request queue and try to start it. */
 930         rc = __tape_start_request(device, request);
 931         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 932         return rc;
 933 }
 934
 935 /*
 936  * tape_do_io/__tape_wake_up
 937  * Add the request to the request queue, try to start it if the
 938  * tape is idle and wait uninterruptible for its completion.
 939  */
 940 static void
 941 __tape_wake_up(struct tape_request *request, void *data)
 942 {
 943         request->callback = NULL;
 944         wake_up((wait_queue_head_t *) data);
 945 }
 946
 947 int
 948 tape_do_io(struct tape_device *device, struct tape_request *request)
 949 {
 950         wait_queue_head_t wq;
 951         int rc;
 952
 953         init_waitqueue_head(&wq);
 954         spin_lock_irq(get_ccwdev_lock(device->cdev));
 955         /* Setup callback */
 956         request->callback = __tape_wake_up;
 957         request->callback_data = &wq;
 958         /* Add request to request queue and try to start it. */
 959         rc = __tape_start_request(device, request);
 960         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 961         if (rc)
 962                 return rc;
 963         /* Request added to the queue. Wait for its completion. */
 964         wait_event(wq, (request->callback == NULL));
 965         /* Get rc from request */
 966         return request->rc;
 967 }
 968
 969 /*
 970  * tape_do_io_interruptible/__tape_wake_up_interruptible
 971  * Add the request to the request queue, try to start it if the
 972  * tape is idle and wait uninterruptible for its completion.
 973  */
 974 static void
 975 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 976 {
 977         request->callback = NULL;
 978         wake_up_interruptible((wait_queue_head_t *) data);
 979 }
 980
 981 int
 982 tape_do_io_interruptible(struct tape_device *device,
 983                          struct tape_request *request)
 984 {
 985         wait_queue_head_t wq;
 986         int rc;
 987
 988         init_waitqueue_head(&wq);
 989         spin_lock_irq(get_ccwdev_lock(device->cdev));
 990         /* Setup callback */
 991         request->callback = __tape_wake_up_interruptible;
 992         request->callback_data = &wq;
 993         rc = __tape_start_request(device, request);
 994         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 995         if (rc)
 996                 return rc;
 997         /* Request added to the queue. Wait for its completion. */
 998         rc = wait_event_interruptible(wq, (request->callback == NULL));
 999         if (rc != -ERESTARTSYS)
1000                 /* Request finished normally. */
1001                 return request->rc;
1002
1003         /* Interrupted by a signal. We have to stop the current request. */
1004         spin_lock_irq(get_ccwdev_lock(device->cdev));
1005         rc = __tape_cancel_io(device, request);
1006         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1007         if (rc == 0) {
1008                 /* Wait for the interrupt that acknowledges the halt. */
1009                 do {
1010                         rc = wait_event_interruptible(
1011                                 wq,
1012                                 (request->callback == NULL)
1013                         );
1014                 } while (rc == -ERESTARTSYS);
1015
1016                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1017                 rc = -ERESTARTSYS;
1018         }
1019         return rc;
1020 }
1021
1022 /*
1023  * Stop running ccw.
1024  */
1025 int
1026 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1027 {
1028         int rc;
1029
1030         spin_lock_irq(get_ccwdev_lock(device->cdev));
1031         rc = __tape_cancel_io(device, request);
1032         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1033         return rc;
1034 }
1035
1036 /*
1037  * Tape interrupt routine, called from the ccw_device layer
1038  */
1039 static void
1040 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1041 {
1042         struct tape_device *device;
1043         struct tape_request *request;
1044         int rc;
1045
1046         device = (struct tape_device *) cdev->dev.driver_data;
1047         if (device == NULL) {
1048                 PRINT_ERR("could not get device structure for %s "
1049                           "in interrupt\n", cdev->dev.bus_id);
1050                 return;
1051         }
1052         request = (struct tape_request *) intparm;
1053
1054         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1055
1056         /* On special conditions irb is an error pointer */
1057         if (IS_ERR(irb)) {
1058                 /* FIXME: What to do with the request? */
1059                 switch (PTR_ERR(irb)) {
1060                         case -ETIMEDOUT:
1061                                 PRINT_WARN("(%s): Request timed out\n",
1062                                         cdev->dev.bus_id);
1063                         case -EIO:
1064                                 __tape_end_request(device, request, -EIO);
1065                                 break;
1066                         default:
1067                                 PRINT_ERR("(%s): Unexpected i/o error %li\n",
1068                                         cdev->dev.bus_id,
1069                                         PTR_ERR(irb));
1070                 }
1071                 return;
1072         }
1073
1074         /*
1075          * If the condition code is not zero and the start function bit is
1076          * still set, this is an deferred error and the last start I/O did
1077          * not succeed. At this point the condition that caused the deferred
1078          * error might still apply. So we just schedule the request to be
1079          * started later.
1080          */
1081         if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC) &&
1082             (request->status == TAPE_REQUEST_IN_IO)) {
1083                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1084                         device->cdev_id, irb->scsw.cc, irb->scsw.fctl);
1085                 request->status = TAPE_REQUEST_QUEUED;
1086                 schedule_delayed_work(&device->tape_dnr, HZ);
1087                 return;
1088         }
1089
1090         /* May be an unsolicited irq */
1091         if(request != NULL)
1092                 request->rescnt = irb->scsw.count;
1093
1094         if (irb->scsw.dstat != 0x0c) {
1095                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1096                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1097                         device->tape_generic_status |= GMT_ONLINE(~0);
1098                 else
1099                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1100
1101                 /*
1102                  * Any request that does not come back with channel end
1103                  * and device end is unusual. Log the sense data.
1104                  */
1105                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1106                 tape_dump_sense_dbf(device, request, irb);
1107         } else {
1108                 /* Upon normal completion the device _is_ online */
1109                 device->tape_generic_status |= GMT_ONLINE(~0);
1110         }
1111         if (device->tape_state == TS_NOT_OPER) {
1112                 DBF_EVENT(6, "tape:device is not operational\n");
1113                 return;
1114         }
1115
1116         /*
1117          * Request that were canceled still come back with an interrupt.
1118          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1119          */
1120         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1121                 __tape_end_request(device, request, -EIO);
1122                 return;
1123         }
1124
1125         rc = device->discipline->irq(device, request, irb);
1126         /*
1127          * rc < 0 : request finished unsuccessfully.
1128          * rc == TAPE_IO_SUCCESS: request finished successfully.
1129          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1130          * rc == TAPE_IO_RETRY: request finished but needs another go.
1131          * rc == TAPE_IO_STOP: request needs to get terminated.
1132          */
1133         switch (rc) {
1134                 case TAPE_IO_SUCCESS:
1135                         /* Upon normal completion the device _is_ online */
1136                         device->tape_generic_status |= GMT_ONLINE(~0);
1137                         __tape_end_request(device, request, rc);
1138                         break;
1139                 case TAPE_IO_PENDING:
1140                         break;
1141                 case TAPE_IO_RETRY:
1142                         rc = __tape_start_io(device, request);
1143                         if (rc)
1144                                 __tape_end_request(device, request, rc);
1145                         break;
1146                 case TAPE_IO_STOP:
1147                         rc = __tape_cancel_io(device, request);
1148                         if (rc)
1149                                 __tape_end_request(device, request, rc);
1150                         break;
1151                 default:
1152                         if (rc > 0) {
1153                                 DBF_EVENT(6, "xunknownrc\n");
1154                                 PRINT_ERR("Invalid return code from discipline "
1155                                         "interrupt function.\n");
1156                                 __tape_end_request(device, request, -EIO);
1157                         } else {
1158                                 __tape_end_request(device, request, rc);
1159                         }
1160                         break;
1161         }
1162 }
1163
1164 /*
1165  * Tape device open function used by tape_char & tape_block frontends.
1166  */
1167 int
1168 tape_open(struct tape_device *device)
1169 {
1170         int rc;
1171
1172         spin_lock(get_ccwdev_lock(device->cdev));
1173         if (device->tape_state == TS_NOT_OPER) {
1174                 DBF_EVENT(6, "TAPE:nodev\n");
1175                 rc = -ENODEV;
1176         } else if (device->tape_state == TS_IN_USE) {
1177                 DBF_EVENT(6, "TAPE:dbusy\n");
1178                 rc = -EBUSY;
1179         } else if (device->tape_state == TS_BLKUSE) {
1180                 DBF_EVENT(6, "TAPE:dbusy\n");
1181                 rc = -EBUSY;
1182         } else if (device->discipline != NULL &&
1183                    !try_module_get(device->discipline->owner)) {
1184                 DBF_EVENT(6, "TAPE:nodisc\n");
1185                 rc = -ENODEV;
1186         } else {
1187                 tape_state_set(device, TS_IN_USE);
1188                 rc = 0;
1189         }
1190         spin_unlock(get_ccwdev_lock(device->cdev));
1191         return rc;
1192 }
1193
1194 /*
1195  * Tape device release function used by tape_char & tape_block frontends.
1196  */
1197 int
1198 tape_release(struct tape_device *device)
1199 {
1200         spin_lock(get_ccwdev_lock(device->cdev));
1201         if (device->tape_state == TS_IN_USE)
1202                 tape_state_set(device, TS_UNUSED);
1203         module_put(device->discipline->owner);
1204         spin_unlock(get_ccwdev_lock(device->cdev));
1205         return 0;
1206 }
1207
1208 /*
1209  * Execute a magnetic tape command a number of times.
1210  */
1211 int
1212 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1213 {
1214         tape_mtop_fn fn;
1215         int rc;
1216
1217         DBF_EVENT(6, "TAPE:mtio\n");
1218         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1219         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1220
1221         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1222                 return -EINVAL;
1223         fn = device->discipline->mtop_array[mt_op];
1224         if (fn == NULL)
1225                 return -EINVAL;
1226
1227         /* We assume that the backends can handle count up to 500. */
1228         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1229             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1230                 rc = 0;
1231                 for (; mt_count > 500; mt_count -= 500)
1232                         if ((rc = fn(device, 500)) != 0)
1233                                 break;
1234                 if (rc == 0)
1235                         rc = fn(device, mt_count);
1236         } else
1237                 rc = fn(device, mt_count);
1238         return rc;
1239
1240 }
1241
1242 /*
1243  * Tape init function.
1244  */
1245 static int
1246 tape_init (void)
1247 {
1248         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1249         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1250 #ifdef DBF_LIKE_HELL
1251         debug_set_level(TAPE_DBF_AREA, 6);
1252 #endif
1253         DBF_EVENT(3, "tape init\n");
1254         tape_proc_init();
1255         tapechar_init ();
1256         tapeblock_init ();
1257         return 0;
1258 }
1259
1260 /*
1261  * Tape exit function.
1262  */
1263 static void
1264 tape_exit(void)
1265 {
1266         DBF_EVENT(6, "tape exit\n");
1267
1268         /* Get rid of the frontends */
1269         tapechar_exit();
1270         tapeblock_exit();
1271         tape_proc_cleanup();
1272         debug_unregister (TAPE_DBF_AREA);
1273 }
1274
1275 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1276               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1277 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1278 MODULE_LICENSE("GPL");
1279
1280 module_init(tape_init);
1281 module_exit(tape_exit);
1282
1283 EXPORT_SYMBOL(tape_generic_remove);
1284 EXPORT_SYMBOL(tape_generic_probe);
1285 EXPORT_SYMBOL(tape_generic_online);
1286 EXPORT_SYMBOL(tape_generic_offline);
1287 EXPORT_SYMBOL(tape_put_device);
1288 EXPORT_SYMBOL(tape_get_device_reference);
1289 EXPORT_SYMBOL(tape_state_verbose);
1290 EXPORT_SYMBOL(tape_op_verbose);
1291 EXPORT_SYMBOL(tape_state_set);
1292 EXPORT_SYMBOL(tape_med_state_set);
1293 EXPORT_SYMBOL(tape_alloc_request);
1294 EXPORT_SYMBOL(tape_free_request);
1295 EXPORT_SYMBOL(tape_dump_sense);
1296 EXPORT_SYMBOL(tape_dump_sense_dbf);
1297 EXPORT_SYMBOL(tape_do_io);
1298 EXPORT_SYMBOL(tape_do_io_async);
1299 EXPORT_SYMBOL(tape_do_io_interruptible);
1300 EXPORT_SYMBOL(tape_cancel_io);
1301 EXPORT_SYMBOL(tape_mtop);