drivers/s390/char/tape_std.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    standard tape device functions for ibm tapes.
   4  *
   5  *  S390 and zSeries version
   6  *    Copyright IBM Corp. 2001, 2002
   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/stddef.h>
  18 #include <linux/kernel.h>
  19 #include <linux/bio.h>
  20 #include <linux/timer.h>
  21
  22 #include <asm/types.h>
  23 #include <asm/idals.h>
  24 #include <asm/ebcdic.h>
  25 #include <asm/tape390.h>
  26
  27 #define TAPE_DBF_AREA   tape_core_dbf
  28
  29 #include "tape.h"
  30 #include "tape_std.h"
  31
  32 /*
  33  * tape_std_assign
  34  */
  35 static void
  36 tape_std_assign_timeout(struct timer_list *t)
  37 {
  38         struct tape_request *   request = from_timer(request, t, timer);
  39         struct tape_device *    device = request->device;
  40         int rc;
  41
  42         BUG_ON(!device);
  43
  44         DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
  45                         device->cdev_id);
  46         rc = tape_cancel_io(device, request);
  47         if(rc)
  48                 DBF_EVENT(3, "(%08x): Assign timeout: Cancel failed with rc = "
  49                           "%i\n", device->cdev_id, rc);
  50 }
  51
  52 int
  53 tape_std_assign(struct tape_device *device)
  54 {
  55         int                  rc;
  56         struct timer_list    timeout;
  57         struct tape_request *request;
  58
  59         request = tape_alloc_request(2, 11);
  60         if (IS_ERR(request))
  61                 return PTR_ERR(request);
  62
  63         request->op = TO_ASSIGN;
  64         tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
  65         tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
  66
  67         /*
  68          * The assign command sometimes blocks if the device is assigned
  69          * to another host (actually this shouldn't happen but it does).
  70          * So we set up a timeout for this call.
  71          */
  72         timer_setup(&request->timer, tape_std_assign_timeout, 0);
  73         mod_timer(&timeout, jiffies + 2 * HZ);
  74
  75         rc = tape_do_io_interruptible(device, request);
  76
  77         del_timer_sync(&request->timer);
  78
  79         if (rc != 0) {
  80                 DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
  81                         device->cdev_id);
  82         } else {
  83                 DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
  84         }
  85         tape_free_request(request);
  86         return rc;
  87 }
  88
  89 /*
  90  * tape_std_unassign
  91  */
  92 int
  93 tape_std_unassign (struct tape_device *device)
  94 {
  95         int                  rc;
  96         struct tape_request *request;
  97
  98         if (device->tape_state == TS_NOT_OPER) {
  99                 DBF_EVENT(3, "(%08x): Can't unassign device\n",
 100                         device->cdev_id);
 101                 return -EIO;
 102         }
 103
 104         request = tape_alloc_request(2, 11);
 105         if (IS_ERR(request))
 106                 return PTR_ERR(request);
 107
 108         request->op = TO_UNASSIGN;
 109         tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
 110         tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
 111
 112         if ((rc = tape_do_io(device, request)) != 0) {
 113                 DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
 114         } else {
 115                 DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
 116         }
 117         tape_free_request(request);
 118         return rc;
 119 }
 120
 121 /*
 122  * TAPE390_DISPLAY: Show a string on the tape display.
 123  */
 124 int
 125 tape_std_display(struct tape_device *device, struct display_struct *disp)
 126 {
 127         struct tape_request *request;
 128         int rc;
 129
 130         request = tape_alloc_request(2, 17);
 131         if (IS_ERR(request)) {
 132                 DBF_EVENT(3, "TAPE: load display failed\n");
 133                 return PTR_ERR(request);
 134         }
 135         request->op = TO_DIS;
 136
 137         *(unsigned char *) request->cpdata = disp->cntrl;
 138         DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
 139         memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
 140         memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
 141         ASCEBC(((unsigned char*) request->cpdata) + 1, 16);
 142
 143         tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
 144         tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
 145
 146         rc = tape_do_io_interruptible(device, request);
 147         tape_free_request(request);
 148         return rc;
 149 }
 150
 151 /*
 152  * Read block id.
 153  */
 154 int
 155 tape_std_read_block_id(struct tape_device *device, __u64 *id)
 156 {
 157         struct tape_request *request;
 158         int rc;
 159
 160         request = tape_alloc_request(3, 8);
 161         if (IS_ERR(request))
 162                 return PTR_ERR(request);
 163         request->op = TO_RBI;
 164         /* setup ccws */
 165         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 166         tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
 167         tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
 168         /* execute it */
 169         rc = tape_do_io(device, request);
 170         if (rc == 0)
 171                 /* Get result from read buffer. */
 172                 *id = *(__u64 *) request->cpdata;
 173         tape_free_request(request);
 174         return rc;
 175 }
 176
 177 int
 178 tape_std_terminate_write(struct tape_device *device)
 179 {
 180         int rc;
 181
 182         if(device->required_tapemarks == 0)
 183                 return 0;
 184
 185         DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
 186                 device->required_tapemarks);
 187
 188         rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
 189         if (rc)
 190                 return rc;
 191
 192         device->required_tapemarks = 0;
 193         return tape_mtop(device, MTBSR, 1);
 194 }
 195
 196 /*
 197  * MTLOAD: Loads the tape.
 198  * The default implementation just wait until the tape medium state changes
 199  * to MS_LOADED.
 200  */
 201 int
 202 tape_std_mtload(struct tape_device *device, int count)
 203 {
 204         return wait_event_interruptible(device->state_change_wq,
 205                 (device->medium_state == MS_LOADED));
 206 }
 207
 208 /*
 209  * MTSETBLK: Set block size.
 210  */
 211 int
 212 tape_std_mtsetblk(struct tape_device *device, int count)
 213 {
 214         struct idal_buffer *new;
 215
 216         DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
 217         if (count <= 0) {
 218                 /*
 219                  * Just set block_size to 0. tapechar_read/tapechar_write
 220                  * will realloc the idal buffer if a bigger one than the
 221                  * current is needed.
 222                  */
 223                 device->char_data.block_size = 0;
 224                 return 0;
 225         }
 226         if (device->char_data.idal_buf != NULL &&
 227             device->char_data.idal_buf->size == count)
 228                 /* We already have a idal buffer of that size. */
 229                 return 0;
 230
 231         if (count > MAX_BLOCKSIZE) {
 232                 DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
 233                         count, MAX_BLOCKSIZE);
 234                 return -EINVAL;
 235         }
 236
 237         /* Allocate a new idal buffer. */
 238         new = idal_buffer_alloc(count, 0);
 239         if (IS_ERR(new))
 240                 return -ENOMEM;
 241         if (device->char_data.idal_buf != NULL)
 242                 idal_buffer_free(device->char_data.idal_buf);
 243         device->char_data.idal_buf = new;
 244         device->char_data.block_size = count;
 245
 246         DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);
 247
 248         return 0;
 249 }
 250
 251 /*
 252  * MTRESET: Set block size to 0.
 253  */
 254 int
 255 tape_std_mtreset(struct tape_device *device, int count)
 256 {
 257         DBF_EVENT(6, "TCHAR:devreset:\n");
 258         device->char_data.block_size = 0;
 259         return 0;
 260 }
 261
 262 /*
 263  * MTFSF: Forward space over 'count' file marks. The tape is positioned
 264  * at the EOT (End of Tape) side of the file mark.
 265  */
 266 int
 267 tape_std_mtfsf(struct tape_device *device, int mt_count)
 268 {
 269         struct tape_request *request;
 270         struct ccw1 *ccw;
 271
 272         request = tape_alloc_request(mt_count + 2, 0);
 273         if (IS_ERR(request))
 274                 return PTR_ERR(request);
 275         request->op = TO_FSF;
 276         /* setup ccws */
 277         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 278                           device->modeset_byte);
 279         ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
 280         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 281
 282         /* execute it */
 283         return tape_do_io_free(device, request);
 284 }
 285
 286 /*
 287  * MTFSR: Forward space over 'count' tape blocks (blocksize is set
 288  * via MTSETBLK.
 289  */
 290 int
 291 tape_std_mtfsr(struct tape_device *device, int mt_count)
 292 {
 293         struct tape_request *request;
 294         struct ccw1 *ccw;
 295         int rc;
 296
 297         request = tape_alloc_request(mt_count + 2, 0);
 298         if (IS_ERR(request))
 299                 return PTR_ERR(request);
 300         request->op = TO_FSB;
 301         /* setup ccws */
 302         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 303                           device->modeset_byte);
 304         ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
 305         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 306
 307         /* execute it */
 308         rc = tape_do_io(device, request);
 309         if (rc == 0 && request->rescnt > 0) {
 310                 DBF_LH(3, "FSR over tapemark\n");
 311                 rc = 1;
 312         }
 313         tape_free_request(request);
 314
 315         return rc;
 316 }
 317
 318 /*
 319  * MTBSR: Backward space over 'count' tape blocks.
 320  * (blocksize is set via MTSETBLK.
 321  */
 322 int
 323 tape_std_mtbsr(struct tape_device *device, int mt_count)
 324 {
 325         struct tape_request *request;
 326         struct ccw1 *ccw;
 327         int rc;
 328
 329         request = tape_alloc_request(mt_count + 2, 0);
 330         if (IS_ERR(request))
 331                 return PTR_ERR(request);
 332         request->op = TO_BSB;
 333         /* setup ccws */
 334         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 335                           device->modeset_byte);
 336         ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
 337         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 338
 339         /* execute it */
 340         rc = tape_do_io(device, request);
 341         if (rc == 0 && request->rescnt > 0) {
 342                 DBF_LH(3, "BSR over tapemark\n");
 343                 rc = 1;
 344         }
 345         tape_free_request(request);
 346
 347         return rc;
 348 }
 349
 350 /*
 351  * MTWEOF: Write 'count' file marks at the current position.
 352  */
 353 int
 354 tape_std_mtweof(struct tape_device *device, int mt_count)
 355 {
 356         struct tape_request *request;
 357         struct ccw1 *ccw;
 358
 359         request = tape_alloc_request(mt_count + 2, 0);
 360         if (IS_ERR(request))
 361                 return PTR_ERR(request);
 362         request->op = TO_WTM;
 363         /* setup ccws */
 364         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 365                           device->modeset_byte);
 366         ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
 367         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 368
 369         /* execute it */
 370         return tape_do_io_free(device, request);
 371 }
 372
 373 /*
 374  * MTBSFM: Backward space over 'count' file marks.
 375  * The tape is positioned at the BOT (Begin Of Tape) side of the
 376  * last skipped file mark.
 377  */
 378 int
 379 tape_std_mtbsfm(struct tape_device *device, int mt_count)
 380 {
 381         struct tape_request *request;
 382         struct ccw1 *ccw;
 383
 384         request = tape_alloc_request(mt_count + 2, 0);
 385         if (IS_ERR(request))
 386                 return PTR_ERR(request);
 387         request->op = TO_BSF;
 388         /* setup ccws */
 389         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 390                           device->modeset_byte);
 391         ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
 392         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 393
 394         /* execute it */
 395         return tape_do_io_free(device, request);
 396 }
 397
 398 /*
 399  * MTBSF: Backward space over 'count' file marks. The tape is positioned at
 400  * the EOT (End of Tape) side of the last skipped file mark.
 401  */
 402 int
 403 tape_std_mtbsf(struct tape_device *device, int mt_count)
 404 {
 405         struct tape_request *request;
 406         struct ccw1 *ccw;
 407         int rc;
 408
 409         request = tape_alloc_request(mt_count + 2, 0);
 410         if (IS_ERR(request))
 411                 return PTR_ERR(request);
 412         request->op = TO_BSF;
 413         /* setup ccws */
 414         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 415                           device->modeset_byte);
 416         ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
 417         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 418         /* execute it */
 419         rc = tape_do_io_free(device, request);
 420         if (rc == 0) {
 421                 rc = tape_mtop(device, MTFSR, 1);
 422                 if (rc > 0)
 423                         rc = 0;
 424         }
 425         return rc;
 426 }
 427
 428 /*
 429  * MTFSFM: Forward space over 'count' file marks.
 430  * The tape is positioned at the BOT (Begin Of Tape) side
 431  * of the last skipped file mark.
 432  */
 433 int
 434 tape_std_mtfsfm(struct tape_device *device, int mt_count)
 435 {
 436         struct tape_request *request;
 437         struct ccw1 *ccw;
 438         int rc;
 439
 440         request = tape_alloc_request(mt_count + 2, 0);
 441         if (IS_ERR(request))
 442                 return PTR_ERR(request);
 443         request->op = TO_FSF;
 444         /* setup ccws */
 445         ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 446                           device->modeset_byte);
 447         ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
 448         ccw = tape_ccw_end(ccw, NOP, 0, NULL);
 449         /* execute it */
 450         rc = tape_do_io_free(device, request);
 451         if (rc == 0) {
 452                 rc = tape_mtop(device, MTBSR, 1);
 453                 if (rc > 0)
 454                         rc = 0;
 455         }
 456
 457         return rc;
 458 }
 459
 460 /*
 461  * MTREW: Rewind the tape.
 462  */
 463 int
 464 tape_std_mtrew(struct tape_device *device, int mt_count)
 465 {
 466         struct tape_request *request;
 467
 468         request = tape_alloc_request(3, 0);
 469         if (IS_ERR(request))
 470                 return PTR_ERR(request);
 471         request->op = TO_REW;
 472         /* setup ccws */
 473         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
 474                     device->modeset_byte);
 475         tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
 476         tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
 477
 478         /* execute it */
 479         return tape_do_io_free(device, request);
 480 }
 481
 482 /*
 483  * MTOFFL: Rewind the tape and put the drive off-line.
 484  * Implement 'rewind unload'
 485  */
 486 int
 487 tape_std_mtoffl(struct tape_device *device, int mt_count)
 488 {
 489         struct tape_request *request;
 490
 491         request = tape_alloc_request(3, 0);
 492         if (IS_ERR(request))
 493                 return PTR_ERR(request);
 494         request->op = TO_RUN;
 495         /* setup ccws */
 496         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 497         tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
 498         tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
 499
 500         /* execute it */
 501         return tape_do_io_free(device, request);
 502 }
 503
 504 /*
 505  * MTNOP: 'No operation'.
 506  */
 507 int
 508 tape_std_mtnop(struct tape_device *device, int mt_count)
 509 {
 510         struct tape_request *request;
 511
 512         request = tape_alloc_request(2, 0);
 513         if (IS_ERR(request))
 514                 return PTR_ERR(request);
 515         request->op = TO_NOP;
 516         /* setup ccws */
 517         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 518         tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
 519         /* execute it */
 520         return tape_do_io_free(device, request);
 521 }
 522
 523 /*
 524  * MTEOM: positions at the end of the portion of the tape already used
 525  * for recordind data. MTEOM positions after the last file mark, ready for
 526  * appending another file.
 527  */
 528 int
 529 tape_std_mteom(struct tape_device *device, int mt_count)
 530 {
 531         int rc;
 532
 533         /*
 534          * Seek from the beginning of tape (rewind).
 535          */
 536         if ((rc = tape_mtop(device, MTREW, 1)) < 0)
 537                 return rc;
 538
 539         /*
 540          * The logical end of volume is given by two sewuential tapemarks.
 541          * Look for this by skipping to the next file (over one tapemark)
 542          * and then test for another one (fsr returns 1 if a tapemark was
 543          * encountered).
 544          */
 545         do {
 546                 if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
 547                         return rc;
 548                 if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
 549                         return rc;
 550         } while (rc == 0);
 551
 552         return tape_mtop(device, MTBSR, 1);
 553 }
 554
 555 /*
 556  * MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
 557  */
 558 int
 559 tape_std_mtreten(struct tape_device *device, int mt_count)
 560 {
 561         struct tape_request *request;
 562
 563         request = tape_alloc_request(4, 0);
 564         if (IS_ERR(request))
 565                 return PTR_ERR(request);
 566         request->op = TO_FSF;
 567         /* setup ccws */
 568         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 569         tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
 570         tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
 571         tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
 572         /* execute it, MTRETEN rc gets ignored */
 573         tape_do_io_interruptible(device, request);
 574         tape_free_request(request);
 575         return tape_mtop(device, MTREW, 1);
 576 }
 577
 578 /*
 579  * MTERASE: erases the tape.
 580  */
 581 int
 582 tape_std_mterase(struct tape_device *device, int mt_count)
 583 {
 584         struct tape_request *request;
 585
 586         request = tape_alloc_request(6, 0);
 587         if (IS_ERR(request))
 588                 return PTR_ERR(request);
 589         request->op = TO_DSE;
 590         /* setup ccws */
 591         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 592         tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
 593         tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
 594         tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
 595         tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
 596         tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);
 597
 598         /* execute it */
 599         return tape_do_io_free(device, request);
 600 }
 601
 602 /*
 603  * MTUNLOAD: Rewind the tape and unload it.
 604  */
 605 int
 606 tape_std_mtunload(struct tape_device *device, int mt_count)
 607 {
 608         return tape_mtop(device, MTOFFL, mt_count);
 609 }
 610
 611 /*
 612  * MTCOMPRESSION: used to enable compression.
 613  * Sets the IDRC on/off.
 614  */
 615 int
 616 tape_std_mtcompression(struct tape_device *device, int mt_count)
 617 {
 618         struct tape_request *request;
 619
 620         if (mt_count < 0 || mt_count > 1) {
 621                 DBF_EXCEPTION(6, "xcom parm\n");
 622                 return -EINVAL;
 623         }
 624         request = tape_alloc_request(2, 0);
 625         if (IS_ERR(request))
 626                 return PTR_ERR(request);
 627         request->op = TO_NOP;
 628         /* setup ccws */
 629         if (mt_count == 0)
 630                 *device->modeset_byte &= ~0x08;
 631         else
 632                 *device->modeset_byte |= 0x08;
 633         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 634         tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
 635         /* execute it */
 636         return tape_do_io_free(device, request);
 637 }
 638
 639 /*
 640  * Read Block
 641  */
 642 struct tape_request *
 643 tape_std_read_block(struct tape_device *device, size_t count)
 644 {
 645         struct tape_request *request;
 646
 647         /*
 648          * We have to alloc 4 ccws in order to be able to transform request
 649          * into a read backward request in error case.
 650          */
 651         request = tape_alloc_request(4, 0);
 652         if (IS_ERR(request)) {
 653                 DBF_EXCEPTION(6, "xrbl fail");
 654                 return request;
 655         }
 656         request->op = TO_RFO;
 657         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 658         tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
 659                           device->char_data.idal_buf);
 660         DBF_EVENT(6, "xrbl ccwg\n");
 661         return request;
 662 }
 663
 664 /*
 665  * Read Block backward transformation function.
 666  */
 667 void
 668 tape_std_read_backward(struct tape_device *device, struct tape_request *request)
 669 {
 670         /*
 671          * We have allocated 4 ccws in tape_std_read, so we can now
 672          * transform the request to a read backward, followed by a
 673          * forward space block.
 674          */
 675         request->op = TO_RBA;
 676         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 677         tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
 678                          device->char_data.idal_buf);
 679         tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
 680         tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
 681         DBF_EVENT(6, "xrop ccwg");}
 682
 683 /*
 684  * Write Block
 685  */
 686 struct tape_request *
 687 tape_std_write_block(struct tape_device *device, size_t count)
 688 {
 689         struct tape_request *request;
 690
 691         request = tape_alloc_request(2, 0);
 692         if (IS_ERR(request)) {
 693                 DBF_EXCEPTION(6, "xwbl fail\n");
 694                 return request;
 695         }
 696         request->op = TO_WRI;
 697         tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
 698         tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
 699                           device->char_data.idal_buf);
 700         DBF_EVENT(6, "xwbl ccwg\n");
 701         return request;
 702 }
 703
 704 /*
 705  * This routine is called by frontend after an ENOSP on write
 706  */
 707 void
 708 tape_std_process_eov(struct tape_device *device)
 709 {
 710         /*
 711          * End of volume: We have to backspace the last written record, then
 712          * we TRY to write a tapemark and then backspace over the written TM
 713          */
 714         if (tape_mtop(device, MTBSR, 1) == 0 &&
 715             tape_mtop(device, MTWEOF, 1) == 0) {
 716                 tape_mtop(device, MTBSR, 1);
 717         }
 718 }
 719
 720 EXPORT_SYMBOL(tape_std_assign);
 721 EXPORT_SYMBOL(tape_std_unassign);
 722 EXPORT_SYMBOL(tape_std_display);
 723 EXPORT_SYMBOL(tape_std_read_block_id);
 724 EXPORT_SYMBOL(tape_std_mtload);
 725 EXPORT_SYMBOL(tape_std_mtsetblk);
 726 EXPORT_SYMBOL(tape_std_mtreset);
 727 EXPORT_SYMBOL(tape_std_mtfsf);
 728 EXPORT_SYMBOL(tape_std_mtfsr);
 729 EXPORT_SYMBOL(tape_std_mtbsr);
 730 EXPORT_SYMBOL(tape_std_mtweof);
 731 EXPORT_SYMBOL(tape_std_mtbsfm);
 732 EXPORT_SYMBOL(tape_std_mtbsf);
 733 EXPORT_SYMBOL(tape_std_mtfsfm);
 734 EXPORT_SYMBOL(tape_std_mtrew);
 735 EXPORT_SYMBOL(tape_std_mtoffl);
 736 EXPORT_SYMBOL(tape_std_mtnop);
 737 EXPORT_SYMBOL(tape_std_mteom);
 738 EXPORT_SYMBOL(tape_std_mtreten);
 739 EXPORT_SYMBOL(tape_std_mterase);
 740 EXPORT_SYMBOL(tape_std_mtunload);
 741 EXPORT_SYMBOL(tape_std_mtcompression);
 742 EXPORT_SYMBOL(tape_std_read_block);
 743 EXPORT_SYMBOL(tape_std_read_backward);
 744 EXPORT_SYMBOL(tape_std_write_block);
 745 EXPORT_SYMBOL(tape_std_process_eov);