drivers/s390/char/tape_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    basic function of the tape device driver
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright IBM Corp. 2001, 2009
   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 #define KMSG_COMPONENT "tape"
  15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  16
  17 #include <linux/module.h>
  18 #include <linux/init.h>      // for kernel parameters
  19 #include <linux/kmod.h>      // for requesting modules
  20 #include <linux/spinlock.h>  // for locks
  21 #include <linux/vmalloc.h>
  22 #include <linux/list.h>
  23 #include <linux/slab.h>
  24
  25 #include <asm/types.h>       // for variable types
  26
  27 #define TAPE_DBF_AREA   tape_core_dbf
  28
  29 #include "tape.h"
  30 #include "tape_std.h"
  31
  32 #define LONG_BUSY_TIMEOUT 180 /* seconds */
  33
  34 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
  35 static void tape_delayed_next_request(struct work_struct *);
  36 static void tape_long_busy_timeout(struct timer_list *t);
  37
  38 /*
  39  * One list to contain all tape devices of all disciplines, so
  40  * we can assign the devices to minor numbers of the same major
  41  * The list is protected by the rwlock
  42  */
  43 static LIST_HEAD(tape_device_list);
  44 static DEFINE_RWLOCK(tape_device_lock);
  45
  46 /*
  47  * Pointer to debug area.
  48  */
  49 debug_info_t *TAPE_DBF_AREA = NULL;
  50 EXPORT_SYMBOL(TAPE_DBF_AREA);
  51
  52 /*
  53  * Printable strings for tape enumerations.
  54  */
  55 const char *tape_state_verbose[TS_SIZE] =
  56 {
  57         [TS_UNUSED]   = "UNUSED",
  58         [TS_IN_USE]   = "IN_USE",
  59         [TS_BLKUSE]   = "BLKUSE",
  60         [TS_INIT]     = "INIT  ",
  61         [TS_NOT_OPER] = "NOT_OP"
  62 };
  63
  64 const char *tape_op_verbose[TO_SIZE] =
  65 {
  66         [TO_BLOCK] = "BLK",     [TO_BSB] = "BSB",
  67         [TO_BSF] = "BSF",       [TO_DSE] = "DSE",
  68         [TO_FSB] = "FSB",       [TO_FSF] = "FSF",
  69         [TO_LBL] = "LBL",       [TO_NOP] = "NOP",
  70         [TO_RBA] = "RBA",       [TO_RBI] = "RBI",
  71         [TO_RFO] = "RFO",       [TO_REW] = "REW",
  72         [TO_RUN] = "RUN",       [TO_WRI] = "WRI",
  73         [TO_WTM] = "WTM",       [TO_MSEN] = "MSN",
  74         [TO_LOAD] = "LOA",      [TO_READ_CONFIG] = "RCF",
  75         [TO_READ_ATTMSG] = "RAT",
  76         [TO_DIS] = "DIS",       [TO_ASSIGN] = "ASS",
  77         [TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
  78         [TO_CRYPT_OFF] = "COF", [TO_KEKL_SET] = "KLS",
  79         [TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
  80 };
  81
  82 static int devid_to_int(struct ccw_dev_id *dev_id)
  83 {
  84         return dev_id->devno + (dev_id->ssid << 16);
  85 }
  86
  87 /*
  88  * Some channel attached tape specific attributes.
  89  *
  90  * FIXME: In the future the first_minor and blocksize attribute should be
  91  *        replaced by a link to the cdev tree.
  92  */
  93 static ssize_t
  94 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
  95 {
  96         struct tape_device *tdev;
  97
  98         tdev = dev_get_drvdata(dev);
  99         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
 100 }
 101
 102 static
 103 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
 104
 105 static ssize_t
 106 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
 107 {
 108         struct tape_device *tdev;
 109
 110         tdev = dev_get_drvdata(dev);
 111         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
 112 }
 113
 114 static
 115 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
 116
 117 static ssize_t
 118 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 119 {
 120         struct tape_device *tdev;
 121
 122         tdev = dev_get_drvdata(dev);
 123         return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
 124                 "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 125 }
 126
 127 static
 128 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
 129
 130 static ssize_t
 131 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
 132 {
 133         struct tape_device *tdev;
 134         ssize_t rc;
 135
 136         tdev = dev_get_drvdata(dev);
 137         if (tdev->first_minor < 0)
 138                 return scnprintf(buf, PAGE_SIZE, "N/A\n");
 139
 140         spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 141         if (list_empty(&tdev->req_queue))
 142                 rc = scnprintf(buf, PAGE_SIZE, "---\n");
 143         else {
 144                 struct tape_request *req;
 145
 146                 req = list_entry(tdev->req_queue.next, struct tape_request,
 147                         list);
 148                 rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
 149         }
 150         spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 151         return rc;
 152 }
 153
 154 static
 155 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
 156
 157 static ssize_t
 158 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
 159 {
 160         struct tape_device *tdev;
 161
 162         tdev = dev_get_drvdata(dev);
 163
 164         return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
 165 }
 166
 167 static
 168 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
 169
 170 static struct attribute *tape_attrs[] = {
 171         &dev_attr_medium_state.attr,
 172         &dev_attr_first_minor.attr,
 173         &dev_attr_state.attr,
 174         &dev_attr_operation.attr,
 175         &dev_attr_blocksize.attr,
 176         NULL
 177 };
 178
 179 static const struct attribute_group tape_attr_group = {
 180         .attrs = tape_attrs,
 181 };
 182
 183 /*
 184  * Tape state functions
 185  */
 186 void
 187 tape_state_set(struct tape_device *device, enum tape_state newstate)
 188 {
 189         const char *str;
 190
 191         if (device->tape_state == TS_NOT_OPER) {
 192                 DBF_EVENT(3, "ts_set err: not oper\n");
 193                 return;
 194         }
 195         DBF_EVENT(4, "ts. dev:  %x\n", device->first_minor);
 196         DBF_EVENT(4, "old ts:\t\n");
 197         if (device->tape_state < TS_SIZE && device->tape_state >=0 )
 198                 str = tape_state_verbose[device->tape_state];
 199         else
 200                 str = "UNKNOWN TS";
 201         DBF_EVENT(4, "%s\n", str);
 202         DBF_EVENT(4, "new ts:\t\n");
 203         if (newstate < TS_SIZE && newstate >= 0)
 204                 str = tape_state_verbose[newstate];
 205         else
 206                 str = "UNKNOWN TS";
 207         DBF_EVENT(4, "%s\n", str);
 208         device->tape_state = newstate;
 209         wake_up(&device->state_change_wq);
 210 }
 211
 212 struct tape_med_state_work_data {
 213         struct tape_device *device;
 214         enum tape_medium_state state;
 215         struct work_struct  work;
 216 };
 217
 218 static void
 219 tape_med_state_work_handler(struct work_struct *work)
 220 {
 221         static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
 222         static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
 223         struct tape_med_state_work_data *p =
 224                 container_of(work, struct tape_med_state_work_data, work);
 225         struct tape_device *device = p->device;
 226         char *envp[] = { NULL, NULL };
 227
 228         switch (p->state) {
 229         case MS_UNLOADED:
 230                 pr_info("%s: The tape cartridge has been successfully "
 231                         "unloaded\n", dev_name(&device->cdev->dev));
 232                 envp[0] = env_state_unloaded;
 233                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 234                 break;
 235         case MS_LOADED:
 236                 pr_info("%s: A tape cartridge has been mounted\n",
 237                         dev_name(&device->cdev->dev));
 238                 envp[0] = env_state_loaded;
 239                 kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
 240                 break;
 241         default:
 242                 break;
 243         }
 244         tape_put_device(device);
 245         kfree(p);
 246 }
 247
 248 static void
 249 tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
 250 {
 251         struct tape_med_state_work_data *p;
 252
 253         p = kzalloc(sizeof(*p), GFP_ATOMIC);
 254         if (p) {
 255                 INIT_WORK(&p->work, tape_med_state_work_handler);
 256                 p->device = tape_get_device(device);
 257                 p->state = state;
 258                 schedule_work(&p->work);
 259         }
 260 }
 261
 262 void
 263 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
 264 {
 265         enum tape_medium_state oldstate;
 266
 267         oldstate = device->medium_state;
 268         if (oldstate == newstate)
 269                 return;
 270         device->medium_state = newstate;
 271         switch(newstate){
 272         case MS_UNLOADED:
 273                 device->tape_generic_status |= GMT_DR_OPEN(~0);
 274                 if (oldstate == MS_LOADED)
 275                         tape_med_state_work(device, MS_UNLOADED);
 276                 break;
 277         case MS_LOADED:
 278                 device->tape_generic_status &= ~GMT_DR_OPEN(~0);
 279                 if (oldstate == MS_UNLOADED)
 280                         tape_med_state_work(device, MS_LOADED);
 281                 break;
 282         default:
 283                 break;
 284         }
 285         wake_up(&device->state_change_wq);
 286 }
 287
 288 /*
 289  * Stop running ccw. Has to be called with the device lock held.
 290  */
 291 static int
 292 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
 293 {
 294         int retries;
 295         int rc;
 296
 297         /* Check if interrupt has already been processed */
 298         if (request->callback == NULL)
 299                 return 0;
 300
 301         rc = 0;
 302         for (retries = 0; retries < 5; retries++) {
 303                 rc = ccw_device_clear(device->cdev, (long) request);
 304
 305                 switch (rc) {
 306                         case 0:
 307                                 request->status = TAPE_REQUEST_DONE;
 308                                 return 0;
 309                         case -EBUSY:
 310                                 request->status = TAPE_REQUEST_CANCEL;
 311                                 schedule_delayed_work(&device->tape_dnr, 0);
 312                                 return 0;
 313                         case -ENODEV:
 314                                 DBF_EXCEPTION(2, "device gone, retry\n");
 315                                 break;
 316                         case -EIO:
 317                                 DBF_EXCEPTION(2, "I/O error, retry\n");
 318                                 break;
 319                         default:
 320                                 BUG();
 321                 }
 322         }
 323
 324         return rc;
 325 }
 326
 327 /*
 328  * Add device into the sorted list, giving it the first
 329  * available minor number.
 330  */
 331 static int
 332 tape_assign_minor(struct tape_device *device)
 333 {
 334         struct tape_device *tmp;
 335         int minor;
 336
 337         minor = 0;
 338         write_lock(&tape_device_lock);
 339         list_for_each_entry(tmp, &tape_device_list, node) {
 340                 if (minor < tmp->first_minor)
 341                         break;
 342                 minor += TAPE_MINORS_PER_DEV;
 343         }
 344         if (minor >= 256) {
 345                 write_unlock(&tape_device_lock);
 346                 return -ENODEV;
 347         }
 348         device->first_minor = minor;
 349         list_add_tail(&device->node, &tmp->node);
 350         write_unlock(&tape_device_lock);
 351         return 0;
 352 }
 353
 354 /* remove device from the list */
 355 static void
 356 tape_remove_minor(struct tape_device *device)
 357 {
 358         write_lock(&tape_device_lock);
 359         list_del_init(&device->node);
 360         device->first_minor = -1;
 361         write_unlock(&tape_device_lock);
 362 }
 363
 364 /*
 365  * Set a device online.
 366  *
 367  * This function is called by the common I/O layer to move a device from the
 368  * detected but offline into the online state.
 369  * If we return an error (RC < 0) the device remains in the offline state. This
 370  * can happen if the device is assigned somewhere else, for example.
 371  */
 372 int
 373 tape_generic_online(struct tape_device *device,
 374                    struct tape_discipline *discipline)
 375 {
 376         int rc;
 377
 378         DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
 379
 380         if (device->tape_state != TS_INIT) {
 381                 DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
 382                 return -EINVAL;
 383         }
 384
 385         timer_setup(&device->lb_timeout, tape_long_busy_timeout, 0);
 386
 387         /* Let the discipline have a go at the device. */
 388         device->discipline = discipline;
 389         if (!try_module_get(discipline->owner)) {
 390                 return -EINVAL;
 391         }
 392
 393         rc = discipline->setup_device(device);
 394         if (rc)
 395                 goto out;
 396         rc = tape_assign_minor(device);
 397         if (rc)
 398                 goto out_discipline;
 399
 400         rc = tapechar_setup_device(device);
 401         if (rc)
 402                 goto out_minor;
 403
 404         tape_state_set(device, TS_UNUSED);
 405
 406         DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
 407
 408         return 0;
 409
 410 out_minor:
 411         tape_remove_minor(device);
 412 out_discipline:
 413         device->discipline->cleanup_device(device);
 414         device->discipline = NULL;
 415 out:
 416         module_put(discipline->owner);
 417         return rc;
 418 }
 419
 420 static void
 421 tape_cleanup_device(struct tape_device *device)
 422 {
 423         tapechar_cleanup_device(device);
 424         device->discipline->cleanup_device(device);
 425         module_put(device->discipline->owner);
 426         tape_remove_minor(device);
 427         tape_med_state_set(device, MS_UNKNOWN);
 428 }
 429
 430 /*
 431  * Set device offline.
 432  *
 433  * Called by the common I/O layer if the drive should set offline on user
 434  * request. We may prevent this by returning an error.
 435  * Manual offline is only allowed while the drive is not in use.
 436  */
 437 int
 438 tape_generic_offline(struct ccw_device *cdev)
 439 {
 440         struct tape_device *device;
 441
 442         device = dev_get_drvdata(&cdev->dev);
 443         if (!device) {
 444                 return -ENODEV;
 445         }
 446
 447         DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
 448                 device->cdev_id, device);
 449
 450         spin_lock_irq(get_ccwdev_lock(device->cdev));
 451         switch (device->tape_state) {
 452                 case TS_INIT:
 453                 case TS_NOT_OPER:
 454                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 455                         break;
 456                 case TS_UNUSED:
 457                         tape_state_set(device, TS_INIT);
 458                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 459                         tape_cleanup_device(device);
 460                         break;
 461                 default:
 462                         DBF_EVENT(3, "(%08x): Set offline failed "
 463                                 "- drive in use.\n",
 464                                 device->cdev_id);
 465                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 466                         return -EBUSY;
 467         }
 468
 469         DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
 470         return 0;
 471 }
 472
 473 /*
 474  * Allocate memory for a new device structure.
 475  */
 476 static struct tape_device *
 477 tape_alloc_device(void)
 478 {
 479         struct tape_device *device;
 480
 481         device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
 482         if (device == NULL) {
 483                 DBF_EXCEPTION(2, "ti:no mem\n");
 484                 return ERR_PTR(-ENOMEM);
 485         }
 486         device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
 487         if (device->modeset_byte == NULL) {
 488                 DBF_EXCEPTION(2, "ti:no mem\n");
 489                 kfree(device);
 490                 return ERR_PTR(-ENOMEM);
 491         }
 492         mutex_init(&device->mutex);
 493         INIT_LIST_HEAD(&device->req_queue);
 494         INIT_LIST_HEAD(&device->node);
 495         init_waitqueue_head(&device->state_change_wq);
 496         init_waitqueue_head(&device->wait_queue);
 497         device->tape_state = TS_INIT;
 498         device->medium_state = MS_UNKNOWN;
 499         *device->modeset_byte = 0;
 500         device->first_minor = -1;
 501         atomic_set(&device->ref_count, 1);
 502         INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
 503
 504         return device;
 505 }
 506
 507 /*
 508  * Get a reference to an existing device structure. This will automatically
 509  * increment the reference count.
 510  */
 511 struct tape_device *
 512 tape_get_device(struct tape_device *device)
 513 {
 514         int count;
 515
 516         count = atomic_inc_return(&device->ref_count);
 517         DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
 518         return device;
 519 }
 520
 521 /*
 522  * Decrease the reference counter of a devices structure. If the
 523  * reference counter reaches zero free the device structure.
 524  * The function returns a NULL pointer to be used by the caller
 525  * for clearing reference pointers.
 526  */
 527 void
 528 tape_put_device(struct tape_device *device)
 529 {
 530         int count;
 531
 532         count = atomic_dec_return(&device->ref_count);
 533         DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
 534         BUG_ON(count < 0);
 535         if (count == 0) {
 536                 kfree(device->modeset_byte);
 537                 kfree(device);
 538         }
 539 }
 540
 541 /*
 542  * Find tape device by a device index.
 543  */
 544 struct tape_device *
 545 tape_find_device(int devindex)
 546 {
 547         struct tape_device *device, *tmp;
 548
 549         device = ERR_PTR(-ENODEV);
 550         read_lock(&tape_device_lock);
 551         list_for_each_entry(tmp, &tape_device_list, node) {
 552                 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
 553                         device = tape_get_device(tmp);
 554                         break;
 555                 }
 556         }
 557         read_unlock(&tape_device_lock);
 558         return device;
 559 }
 560
 561 /*
 562  * Driverfs tape probe function.
 563  */
 564 int
 565 tape_generic_probe(struct ccw_device *cdev)
 566 {
 567         struct tape_device *device;
 568         int ret;
 569         struct ccw_dev_id dev_id;
 570
 571         device = tape_alloc_device();
 572         if (IS_ERR(device))
 573                 return -ENODEV;
 574         ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
 575                                      CCWDEV_DO_MULTIPATH);
 576         ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
 577         if (ret) {
 578                 tape_put_device(device);
 579                 return ret;
 580         }
 581         dev_set_drvdata(&cdev->dev, device);
 582         cdev->handler = __tape_do_irq;
 583         device->cdev = cdev;
 584         ccw_device_get_id(cdev, &dev_id);
 585         device->cdev_id = devid_to_int(&dev_id);
 586         return ret;
 587 }
 588
 589 static void
 590 __tape_discard_requests(struct tape_device *device)
 591 {
 592         struct tape_request *   request;
 593         struct list_head *      l, *n;
 594
 595         list_for_each_safe(l, n, &device->req_queue) {
 596                 request = list_entry(l, struct tape_request, list);
 597                 if (request->status == TAPE_REQUEST_IN_IO)
 598                         request->status = TAPE_REQUEST_DONE;
 599                 list_del(&request->list);
 600
 601                 /* Decrease ref_count for removed request. */
 602                 request->device = NULL;
 603                 tape_put_device(device);
 604                 request->rc = -EIO;
 605                 if (request->callback != NULL)
 606                         request->callback(request, request->callback_data);
 607         }
 608 }
 609
 610 /*
 611  * Driverfs tape remove function.
 612  *
 613  * This function is called whenever the common I/O layer detects the device
 614  * gone. This can happen at any time and we cannot refuse.
 615  */
 616 void
 617 tape_generic_remove(struct ccw_device *cdev)
 618 {
 619         struct tape_device *    device;
 620
 621         device = dev_get_drvdata(&cdev->dev);
 622         if (!device) {
 623                 return;
 624         }
 625         DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
 626
 627         spin_lock_irq(get_ccwdev_lock(device->cdev));
 628         switch (device->tape_state) {
 629                 case TS_INIT:
 630                         tape_state_set(device, TS_NOT_OPER);
 631                         fallthrough;
 632                 case TS_NOT_OPER:
 633                         /*
 634                          * Nothing to do.
 635                          */
 636                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 637                         break;
 638                 case TS_UNUSED:
 639                         /*
 640                          * Need only to release the device.
 641                          */
 642                         tape_state_set(device, TS_NOT_OPER);
 643                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 644                         tape_cleanup_device(device);
 645                         break;
 646                 default:
 647                         /*
 648                          * There may be requests on the queue. We will not get
 649                          * an interrupt for a request that was running. So we
 650                          * just post them all as I/O errors.
 651                          */
 652                         DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
 653                                 device->cdev_id);
 654                         pr_warn("%s: A tape unit was detached while in use\n",
 655                                 dev_name(&device->cdev->dev));
 656                         tape_state_set(device, TS_NOT_OPER);
 657                         __tape_discard_requests(device);
 658                         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 659                         tape_cleanup_device(device);
 660         }
 661
 662         device = dev_get_drvdata(&cdev->dev);
 663         if (device) {
 664                 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
 665                 dev_set_drvdata(&cdev->dev, NULL);
 666                 tape_put_device(device);
 667         }
 668 }
 669
 670 /*
 671  * Allocate a new tape ccw request
 672  */
 673 struct tape_request *
 674 tape_alloc_request(int cplength, int datasize)
 675 {
 676         struct tape_request *request;
 677
 678         BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
 679
 680         DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
 681
 682         request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
 683         if (request == NULL) {
 684                 DBF_EXCEPTION(1, "cqra nomem\n");
 685                 return ERR_PTR(-ENOMEM);
 686         }
 687         /* allocate channel program */
 688         if (cplength > 0) {
 689                 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
 690                                           GFP_ATOMIC | GFP_DMA);
 691                 if (request->cpaddr == NULL) {
 692                         DBF_EXCEPTION(1, "cqra nomem\n");
 693                         kfree(request);
 694                         return ERR_PTR(-ENOMEM);
 695                 }
 696         }
 697         /* alloc small kernel buffer */
 698         if (datasize > 0) {
 699                 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
 700                 if (request->cpdata == NULL) {
 701                         DBF_EXCEPTION(1, "cqra nomem\n");
 702                         kfree(request->cpaddr);
 703                         kfree(request);
 704                         return ERR_PTR(-ENOMEM);
 705                 }
 706         }
 707         DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
 708                 request->cpdata);
 709
 710         return request;
 711 }
 712
 713 /*
 714  * Free tape ccw request
 715  */
 716 void
 717 tape_free_request (struct tape_request * request)
 718 {
 719         DBF_LH(6, "Free request %p\n", request);
 720
 721         if (request->device)
 722                 tape_put_device(request->device);
 723         kfree(request->cpdata);
 724         kfree(request->cpaddr);
 725         kfree(request);
 726 }
 727
 728 static int
 729 __tape_start_io(struct tape_device *device, struct tape_request *request)
 730 {
 731         int rc;
 732
 733         rc = ccw_device_start(
 734                 device->cdev,
 735                 request->cpaddr,
 736                 (unsigned long) request,
 737                 0x00,
 738                 request->options
 739         );
 740         if (rc == 0) {
 741                 request->status = TAPE_REQUEST_IN_IO;
 742         } else if (rc == -EBUSY) {
 743                 /* The common I/O subsystem is currently busy. Retry later. */
 744                 request->status = TAPE_REQUEST_QUEUED;
 745                 schedule_delayed_work(&device->tape_dnr, 0);
 746                 rc = 0;
 747         } else {
 748                 /* Start failed. Remove request and indicate failure. */
 749                 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
 750         }
 751         return rc;
 752 }
 753
 754 static void
 755 __tape_start_next_request(struct tape_device *device)
 756 {
 757         struct list_head *l, *n;
 758         struct tape_request *request;
 759         int rc;
 760
 761         DBF_LH(6, "__tape_start_next_request(%p)\n", device);
 762         /*
 763          * Try to start each request on request queue until one is
 764          * started successful.
 765          */
 766         list_for_each_safe(l, n, &device->req_queue) {
 767                 request = list_entry(l, struct tape_request, list);
 768
 769                 /*
 770                  * Avoid race condition if bottom-half was triggered more than
 771                  * once.
 772                  */
 773                 if (request->status == TAPE_REQUEST_IN_IO)
 774                         return;
 775                 /*
 776                  * Request has already been stopped. We have to wait until
 777                  * the request is removed from the queue in the interrupt
 778                  * handling.
 779                  */
 780                 if (request->status == TAPE_REQUEST_DONE)
 781                         return;
 782
 783                 /*
 784                  * We wanted to cancel the request but the common I/O layer
 785                  * was busy at that time. This can only happen if this
 786                  * function is called by delayed_next_request.
 787                  * Otherwise we start the next request on the queue.
 788                  */
 789                 if (request->status == TAPE_REQUEST_CANCEL) {
 790                         rc = __tape_cancel_io(device, request);
 791                 } else {
 792                         rc = __tape_start_io(device, request);
 793                 }
 794                 if (rc == 0)
 795                         return;
 796
 797                 /* Set ending status. */
 798                 request->rc = rc;
 799                 request->status = TAPE_REQUEST_DONE;
 800
 801                 /* Remove from request queue. */
 802                 list_del(&request->list);
 803
 804                 /* Do callback. */
 805                 if (request->callback != NULL)
 806                         request->callback(request, request->callback_data);
 807         }
 808 }
 809
 810 static void
 811 tape_delayed_next_request(struct work_struct *work)
 812 {
 813         struct tape_device *device =
 814                 container_of(work, struct tape_device, tape_dnr.work);
 815
 816         DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
 817         spin_lock_irq(get_ccwdev_lock(device->cdev));
 818         __tape_start_next_request(device);
 819         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 820 }
 821
 822 static void tape_long_busy_timeout(struct timer_list *t)
 823 {
 824         struct tape_device *device = from_timer(device, t, lb_timeout);
 825         struct tape_request *request;
 826
 827         spin_lock_irq(get_ccwdev_lock(device->cdev));
 828         request = list_entry(device->req_queue.next, struct tape_request, list);
 829         BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
 830         DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
 831         __tape_start_next_request(device);
 832         tape_put_device(device);
 833         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 834 }
 835
 836 static void
 837 __tape_end_request(
 838         struct tape_device *    device,
 839         struct tape_request *   request,
 840         int                     rc)
 841 {
 842         DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
 843         if (request) {
 844                 request->rc = rc;
 845                 request->status = TAPE_REQUEST_DONE;
 846
 847                 /* Remove from request queue. */
 848                 list_del(&request->list);
 849
 850                 /* Do callback. */
 851                 if (request->callback != NULL)
 852                         request->callback(request, request->callback_data);
 853         }
 854
 855         /* Start next request. */
 856         if (!list_empty(&device->req_queue))
 857                 __tape_start_next_request(device);
 858 }
 859
 860 /*
 861  * Write sense data to dbf
 862  */
 863 void
 864 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
 865                     struct irb *irb)
 866 {
 867         unsigned int *sptr;
 868         const char* op;
 869
 870         if (request != NULL)
 871                 op = tape_op_verbose[request->op];
 872         else
 873                 op = "---";
 874         DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
 875                   irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
 876         DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
 877         sptr = (unsigned int *) irb->ecw;
 878         DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
 879         DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
 880         DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
 881         DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
 882 }
 883
 884 /*
 885  * I/O helper function. Adds the request to the request queue
 886  * and starts it if the tape is idle. Has to be called with
 887  * the device lock held.
 888  */
 889 static int
 890 __tape_start_request(struct tape_device *device, struct tape_request *request)
 891 {
 892         int rc;
 893
 894         switch (request->op) {
 895                 case TO_MSEN:
 896                 case TO_ASSIGN:
 897                 case TO_UNASSIGN:
 898                 case TO_READ_ATTMSG:
 899                 case TO_RDC:
 900                         if (device->tape_state == TS_INIT)
 901                                 break;
 902                         if (device->tape_state == TS_UNUSED)
 903                                 break;
 904                         fallthrough;
 905                 default:
 906                         if (device->tape_state == TS_BLKUSE)
 907                                 break;
 908                         if (device->tape_state != TS_IN_USE)
 909                                 return -ENODEV;
 910         }
 911
 912         /* Increase use count of device for the added request. */
 913         request->device = tape_get_device(device);
 914
 915         if (list_empty(&device->req_queue)) {
 916                 /* No other requests are on the queue. Start this one. */
 917                 rc = __tape_start_io(device, request);
 918                 if (rc)
 919                         return rc;
 920
 921                 DBF_LH(5, "Request %p added for execution.\n", request);
 922                 list_add(&request->list, &device->req_queue);
 923         } else {
 924                 DBF_LH(5, "Request %p add to queue.\n", request);
 925                 request->status = TAPE_REQUEST_QUEUED;
 926                 list_add_tail(&request->list, &device->req_queue);
 927         }
 928         return 0;
 929 }
 930
 931 /*
 932  * Add the request to the request queue, try to start it if the
 933  * tape is idle. Return without waiting for end of i/o.
 934  */
 935 int
 936 tape_do_io_async(struct tape_device *device, struct tape_request *request)
 937 {
 938         int rc;
 939
 940         DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
 941
 942         spin_lock_irq(get_ccwdev_lock(device->cdev));
 943         /* Add request to request queue and try to start it. */
 944         rc = __tape_start_request(device, request);
 945         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 946         return rc;
 947 }
 948
 949 /*
 950  * tape_do_io/__tape_wake_up
 951  * Add the request to the request queue, try to start it if the
 952  * tape is idle and wait uninterruptible for its completion.
 953  */
 954 static void
 955 __tape_wake_up(struct tape_request *request, void *data)
 956 {
 957         request->callback = NULL;
 958         wake_up((wait_queue_head_t *) data);
 959 }
 960
 961 int
 962 tape_do_io(struct tape_device *device, struct tape_request *request)
 963 {
 964         int rc;
 965
 966         spin_lock_irq(get_ccwdev_lock(device->cdev));
 967         /* Setup callback */
 968         request->callback = __tape_wake_up;
 969         request->callback_data = &device->wait_queue;
 970         /* Add request to request queue and try to start it. */
 971         rc = __tape_start_request(device, request);
 972         spin_unlock_irq(get_ccwdev_lock(device->cdev));
 973         if (rc)
 974                 return rc;
 975         /* Request added to the queue. Wait for its completion. */
 976         wait_event(device->wait_queue, (request->callback == NULL));
 977         /* Get rc from request */
 978         return request->rc;
 979 }
 980
 981 /*
 982  * tape_do_io_interruptible/__tape_wake_up_interruptible
 983  * Add the request to the request queue, try to start it if the
 984  * tape is idle and wait uninterruptible for its completion.
 985  */
 986 static void
 987 __tape_wake_up_interruptible(struct tape_request *request, void *data)
 988 {
 989         request->callback = NULL;
 990         wake_up_interruptible((wait_queue_head_t *) data);
 991 }
 992
 993 int
 994 tape_do_io_interruptible(struct tape_device *device,
 995                          struct tape_request *request)
 996 {
 997         int rc;
 998
 999         spin_lock_irq(get_ccwdev_lock(device->cdev));
1000         /* Setup callback */
1001         request->callback = __tape_wake_up_interruptible;
1002         request->callback_data = &device->wait_queue;
1003         rc = __tape_start_request(device, request);
1004         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1005         if (rc)
1006                 return rc;
1007         /* Request added to the queue. Wait for its completion. */
1008         rc = wait_event_interruptible(device->wait_queue,
1009                                       (request->callback == NULL));
1010         if (rc != -ERESTARTSYS)
1011                 /* Request finished normally. */
1012                 return request->rc;
1013
1014         /* Interrupted by a signal. We have to stop the current request. */
1015         spin_lock_irq(get_ccwdev_lock(device->cdev));
1016         rc = __tape_cancel_io(device, request);
1017         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1018         if (rc == 0) {
1019                 /* Wait for the interrupt that acknowledges the halt. */
1020                 do {
1021                         rc = wait_event_interruptible(
1022                                 device->wait_queue,
1023                                 (request->callback == NULL)
1024                         );
1025                 } while (rc == -ERESTARTSYS);
1026
1027                 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1028                 rc = -ERESTARTSYS;
1029         }
1030         return rc;
1031 }
1032
1033 /*
1034  * Stop running ccw.
1035  */
1036 int
1037 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1038 {
1039         int rc;
1040
1041         spin_lock_irq(get_ccwdev_lock(device->cdev));
1042         rc = __tape_cancel_io(device, request);
1043         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1044         return rc;
1045 }
1046
1047 /*
1048  * Tape interrupt routine, called from the ccw_device layer
1049  */
1050 static void
1051 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1052 {
1053         struct tape_device *device;
1054         struct tape_request *request;
1055         int rc;
1056
1057         device = dev_get_drvdata(&cdev->dev);
1058         if (device == NULL) {
1059                 return;
1060         }
1061         request = (struct tape_request *) intparm;
1062
1063         DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1064
1065         /* On special conditions irb is an error pointer */
1066         if (IS_ERR(irb)) {
1067                 /* FIXME: What to do with the request? */
1068                 switch (PTR_ERR(irb)) {
1069                         case -ETIMEDOUT:
1070                                 DBF_LH(1, "(%08x): Request timed out\n",
1071                                        device->cdev_id);
1072                                 fallthrough;
1073                         case -EIO:
1074                                 __tape_end_request(device, request, -EIO);
1075                                 break;
1076                         default:
1077                                 DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
1078                                        device->cdev_id, PTR_ERR(irb));
1079                 }
1080                 return;
1081         }
1082
1083         /*
1084          * If the condition code is not zero and the start function bit is
1085          * still set, this is an deferred error and the last start I/O did
1086          * not succeed. At this point the condition that caused the deferred
1087          * error might still apply. So we just schedule the request to be
1088          * started later.
1089          */
1090         if (irb->scsw.cmd.cc != 0 &&
1091             (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1092             (request->status == TAPE_REQUEST_IN_IO)) {
1093                 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1094                         device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1095                 request->status = TAPE_REQUEST_QUEUED;
1096                 schedule_delayed_work(&device->tape_dnr, HZ);
1097                 return;
1098         }
1099
1100         /* May be an unsolicited irq */
1101         if(request != NULL)
1102                 request->rescnt = irb->scsw.cmd.count;
1103         else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1104                  !list_empty(&device->req_queue)) {
1105                 /* Not Ready to Ready after long busy ? */
1106                 struct tape_request *req;
1107                 req = list_entry(device->req_queue.next,
1108                                  struct tape_request, list);
1109                 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1110                         DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1111                         if (del_timer(&device->lb_timeout)) {
1112                                 tape_put_device(device);
1113                                 __tape_start_next_request(device);
1114                         }
1115                         return;
1116                 }
1117         }
1118         if (irb->scsw.cmd.dstat != 0x0c) {
1119                 /* Set the 'ONLINE' flag depending on sense byte 1 */
1120                 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1121                         device->tape_generic_status |= GMT_ONLINE(~0);
1122                 else
1123                         device->tape_generic_status &= ~GMT_ONLINE(~0);
1124
1125                 /*
1126                  * Any request that does not come back with channel end
1127                  * and device end is unusual. Log the sense data.
1128                  */
1129                 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1130                 tape_dump_sense_dbf(device, request, irb);
1131         } else {
1132                 /* Upon normal completion the device _is_ online */
1133                 device->tape_generic_status |= GMT_ONLINE(~0);
1134         }
1135         if (device->tape_state == TS_NOT_OPER) {
1136                 DBF_EVENT(6, "tape:device is not operational\n");
1137                 return;
1138         }
1139
1140         /*
1141          * Request that were canceled still come back with an interrupt.
1142          * To detect these request the state will be set to TAPE_REQUEST_DONE.
1143          */
1144         if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1145                 __tape_end_request(device, request, -EIO);
1146                 return;
1147         }
1148
1149         rc = device->discipline->irq(device, request, irb);
1150         /*
1151          * rc < 0 : request finished unsuccessfully.
1152          * rc == TAPE_IO_SUCCESS: request finished successfully.
1153          * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1154          * rc == TAPE_IO_RETRY: request finished but needs another go.
1155          * rc == TAPE_IO_STOP: request needs to get terminated.
1156          */
1157         switch (rc) {
1158                 case TAPE_IO_SUCCESS:
1159                         /* Upon normal completion the device _is_ online */
1160                         device->tape_generic_status |= GMT_ONLINE(~0);
1161                         __tape_end_request(device, request, rc);
1162                         break;
1163                 case TAPE_IO_PENDING:
1164                         break;
1165                 case TAPE_IO_LONG_BUSY:
1166                         device->lb_timeout.expires = jiffies +
1167                                 LONG_BUSY_TIMEOUT * HZ;
1168                         DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1169                         add_timer(&device->lb_timeout);
1170                         request->status = TAPE_REQUEST_LONG_BUSY;
1171                         break;
1172                 case TAPE_IO_RETRY:
1173                         rc = __tape_start_io(device, request);
1174                         if (rc)
1175                                 __tape_end_request(device, request, rc);
1176                         break;
1177                 case TAPE_IO_STOP:
1178                         rc = __tape_cancel_io(device, request);
1179                         if (rc)
1180                                 __tape_end_request(device, request, rc);
1181                         break;
1182                 default:
1183                         if (rc > 0) {
1184                                 DBF_EVENT(6, "xunknownrc\n");
1185                                 __tape_end_request(device, request, -EIO);
1186                         } else {
1187                                 __tape_end_request(device, request, rc);
1188                         }
1189                         break;
1190         }
1191 }
1192
1193 /*
1194  * Tape device open function used by tape_char frontend.
1195  */
1196 int
1197 tape_open(struct tape_device *device)
1198 {
1199         int rc;
1200
1201         spin_lock_irq(get_ccwdev_lock(device->cdev));
1202         if (device->tape_state == TS_NOT_OPER) {
1203                 DBF_EVENT(6, "TAPE:nodev\n");
1204                 rc = -ENODEV;
1205         } else if (device->tape_state == TS_IN_USE) {
1206                 DBF_EVENT(6, "TAPE:dbusy\n");
1207                 rc = -EBUSY;
1208         } else if (device->tape_state == TS_BLKUSE) {
1209                 DBF_EVENT(6, "TAPE:dbusy\n");
1210                 rc = -EBUSY;
1211         } else if (device->discipline != NULL &&
1212                    !try_module_get(device->discipline->owner)) {
1213                 DBF_EVENT(6, "TAPE:nodisc\n");
1214                 rc = -ENODEV;
1215         } else {
1216                 tape_state_set(device, TS_IN_USE);
1217                 rc = 0;
1218         }
1219         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1220         return rc;
1221 }
1222
1223 /*
1224  * Tape device release function used by tape_char frontend.
1225  */
1226 int
1227 tape_release(struct tape_device *device)
1228 {
1229         spin_lock_irq(get_ccwdev_lock(device->cdev));
1230         if (device->tape_state == TS_IN_USE)
1231                 tape_state_set(device, TS_UNUSED);
1232         module_put(device->discipline->owner);
1233         spin_unlock_irq(get_ccwdev_lock(device->cdev));
1234         return 0;
1235 }
1236
1237 /*
1238  * Execute a magnetic tape command a number of times.
1239  */
1240 int
1241 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1242 {
1243         tape_mtop_fn fn;
1244         int rc;
1245
1246         DBF_EVENT(6, "TAPE:mtio\n");
1247         DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1248         DBF_EVENT(6, "TAPE:arg:  %x\n", mt_count);
1249
1250         if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1251                 return -EINVAL;
1252         fn = device->discipline->mtop_array[mt_op];
1253         if (fn == NULL)
1254                 return -EINVAL;
1255
1256         /* We assume that the backends can handle count up to 500. */
1257         if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1258             mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1259                 rc = 0;
1260                 for (; mt_count > 500; mt_count -= 500)
1261                         if ((rc = fn(device, 500)) != 0)
1262                                 break;
1263                 if (rc == 0)
1264                         rc = fn(device, mt_count);
1265         } else
1266                 rc = fn(device, mt_count);
1267         return rc;
1268
1269 }
1270
1271 /*
1272  * Tape init function.
1273  */
1274 static int
1275 tape_init (void)
1276 {
1277         TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1278         debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1279 #ifdef DBF_LIKE_HELL
1280         debug_set_level(TAPE_DBF_AREA, 6);
1281 #endif
1282         DBF_EVENT(3, "tape init\n");
1283         tape_proc_init();
1284         tapechar_init ();
1285         return 0;
1286 }
1287
1288 /*
1289  * Tape exit function.
1290  */
1291 static void
1292 tape_exit(void)
1293 {
1294         DBF_EVENT(6, "tape exit\n");
1295
1296         /* Get rid of the frontends */
1297         tapechar_exit();
1298         tape_proc_cleanup();
1299         debug_unregister (TAPE_DBF_AREA);
1300 }
1301
1302 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1303               "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1304 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1305 MODULE_LICENSE("GPL");
1306
1307 module_init(tape_init);
1308 module_exit(tape_exit);
1309
1310 EXPORT_SYMBOL(tape_generic_remove);
1311 EXPORT_SYMBOL(tape_generic_probe);
1312 EXPORT_SYMBOL(tape_generic_online);
1313 EXPORT_SYMBOL(tape_generic_offline);
1314 EXPORT_SYMBOL(tape_put_device);
1315 EXPORT_SYMBOL(tape_get_device);
1316 EXPORT_SYMBOL(tape_state_verbose);
1317 EXPORT_SYMBOL(tape_op_verbose);
1318 EXPORT_SYMBOL(tape_state_set);
1319 EXPORT_SYMBOL(tape_med_state_set);
1320 EXPORT_SYMBOL(tape_alloc_request);
1321 EXPORT_SYMBOL(tape_free_request);
1322 EXPORT_SYMBOL(tape_dump_sense_dbf);
1323 EXPORT_SYMBOL(tape_do_io);
1324 EXPORT_SYMBOL(tape_do_io_async);
1325 EXPORT_SYMBOL(tape_do_io_interruptible);
1326 EXPORT_SYMBOL(tape_cancel_io);
1327 EXPORT_SYMBOL(tape_mtop);