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   1 /*
   2  * MTD device concatenation layer
   3  *
   4  * (C) 2002 Robert Kaiser <rkaiser@sysgo.de>
   5  *
   6  * NAND support by Christian Gan <cgan@iders.ca>
   7  *
   8  * This code is GPL
   9  *
  10  * $Id: mtdconcat.c,v 1.11 2005/11/07 11:14:20 gleixner Exp $
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/sched.h>
  17 #include <linux/types.h>
  18
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/concat.h>
  21
  22 #include <asm/div64.h>
  23
  24 /*
  25  * Our storage structure:
  26  * Subdev points to an array of pointers to struct mtd_info objects
  27  * which is allocated along with this structure
  28  *
  29  */
  30 struct mtd_concat {
  31         struct mtd_info mtd;
  32         int num_subdev;
  33         struct mtd_info **subdev;
  34 };
  35
  36 /*
  37  * how to calculate the size required for the above structure,
  38  * including the pointer array subdev points to:
  39  */
  40 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev)    \
  41         ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
  42
  43 /*
  44  * Given a pointer to the MTD object in the mtd_concat structure,
  45  * we can retrieve the pointer to that structure with this macro.
  46  */
  47 #define CONCAT(x)  ((struct mtd_concat *)(x))
  48
  49 /*
  50  * MTD methods which look up the relevant subdevice, translate the
  51  * effective address and pass through to the subdevice.
  52  */
  53
  54 static int
  55 concat_read(struct mtd_info *mtd, loff_t from, size_t len,
  56             size_t * retlen, u_char * buf)
  57 {
  58         struct mtd_concat *concat = CONCAT(mtd);
  59         int err = -EINVAL;
  60         int i;
  61
  62         *retlen = 0;
  63
  64         for (i = 0; i < concat->num_subdev; i++) {
  65                 struct mtd_info *subdev = concat->subdev[i];
  66                 size_t size, retsize;
  67
  68                 if (from >= subdev->size) {
  69                         /* Not destined for this subdev */
  70                         size = 0;
  71                         from -= subdev->size;
  72                         continue;
  73                 }
  74                 if (from + len > subdev->size)
  75                         /* First part goes into this subdev */
  76                         size = subdev->size - from;
  77                 else
  78                         /* Entire transaction goes into this subdev */
  79                         size = len;
  80
  81                 err = subdev->read(subdev, from, size, &retsize, buf);
  82
  83                 if (err)
  84                         break;
  85
  86                 *retlen += retsize;
  87                 len -= size;
  88                 if (len == 0)
  89                         break;
  90
  91                 err = -EINVAL;
  92                 buf += size;
  93                 from = 0;
  94         }
  95         return err;
  96 }
  97
  98 static int
  99 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
 100              size_t * retlen, const u_char * buf)
 101 {
 102         struct mtd_concat *concat = CONCAT(mtd);
 103         int err = -EINVAL;
 104         int i;
 105
 106         if (!(mtd->flags & MTD_WRITEABLE))
 107                 return -EROFS;
 108
 109         *retlen = 0;
 110
 111         for (i = 0; i < concat->num_subdev; i++) {
 112                 struct mtd_info *subdev = concat->subdev[i];
 113                 size_t size, retsize;
 114
 115                 if (to >= subdev->size) {
 116                         size = 0;
 117                         to -= subdev->size;
 118                         continue;
 119                 }
 120                 if (to + len > subdev->size)
 121                         size = subdev->size - to;
 122                 else
 123                         size = len;
 124
 125                 if (!(subdev->flags & MTD_WRITEABLE))
 126                         err = -EROFS;
 127                 else
 128                         err = subdev->write(subdev, to, size, &retsize, buf);
 129
 130                 if (err)
 131                         break;
 132
 133                 *retlen += retsize;
 134                 len -= size;
 135                 if (len == 0)
 136                         break;
 137
 138                 err = -EINVAL;
 139                 buf += size;
 140                 to = 0;
 141         }
 142         return err;
 143 }
 144
 145 static int
 146 concat_read_ecc(struct mtd_info *mtd, loff_t from, size_t len,
 147                 size_t * retlen, u_char * buf, u_char * eccbuf,
 148                 struct nand_oobinfo *oobsel)
 149 {
 150         struct mtd_concat *concat = CONCAT(mtd);
 151         int err = -EINVAL;
 152         int i;
 153
 154         *retlen = 0;
 155
 156         for (i = 0; i < concat->num_subdev; i++) {
 157                 struct mtd_info *subdev = concat->subdev[i];
 158                 size_t size, retsize;
 159
 160                 if (from >= subdev->size) {
 161                         /* Not destined for this subdev */
 162                         size = 0;
 163                         from -= subdev->size;
 164                         continue;
 165                 }
 166
 167                 if (from + len > subdev->size)
 168                         /* First part goes into this subdev */
 169                         size = subdev->size - from;
 170                 else
 171                         /* Entire transaction goes into this subdev */
 172                         size = len;
 173
 174                 if (subdev->read_ecc)
 175                         err = subdev->read_ecc(subdev, from, size,
 176                                                &retsize, buf, eccbuf, oobsel);
 177                 else
 178                         err = -EINVAL;
 179
 180                 if (err)
 181                         break;
 182
 183                 *retlen += retsize;
 184                 len -= size;
 185                 if (len == 0)
 186                         break;
 187
 188                 err = -EINVAL;
 189                 buf += size;
 190                 if (eccbuf) {
 191                         eccbuf += subdev->oobsize;
 192                         /* in nand.c at least, eccbufs are
 193                            tagged with 2 (int)eccstatus'; we
 194                            must account for these */
 195                         eccbuf += 2 * (sizeof (int));
 196                 }
 197                 from = 0;
 198         }
 199         return err;
 200 }
 201
 202 static int
 203 concat_write_ecc(struct mtd_info *mtd, loff_t to, size_t len,
 204                  size_t * retlen, const u_char * buf, u_char * eccbuf,
 205                  struct nand_oobinfo *oobsel)
 206 {
 207         struct mtd_concat *concat = CONCAT(mtd);
 208         int err = -EINVAL;
 209         int i;
 210
 211         if (!(mtd->flags & MTD_WRITEABLE))
 212                 return -EROFS;
 213
 214         *retlen = 0;
 215
 216         for (i = 0; i < concat->num_subdev; i++) {
 217                 struct mtd_info *subdev = concat->subdev[i];
 218                 size_t size, retsize;
 219
 220                 if (to >= subdev->size) {
 221                         size = 0;
 222                         to -= subdev->size;
 223                         continue;
 224                 }
 225                 if (to + len > subdev->size)
 226                         size = subdev->size - to;
 227                 else
 228                         size = len;
 229
 230                 if (!(subdev->flags & MTD_WRITEABLE))
 231                         err = -EROFS;
 232                 else if (subdev->write_ecc)
 233                         err = subdev->write_ecc(subdev, to, size,
 234                                                 &retsize, buf, eccbuf, oobsel);
 235                 else
 236                         err = -EINVAL;
 237
 238                 if (err)
 239                         break;
 240
 241                 *retlen += retsize;
 242                 len -= size;
 243                 if (len == 0)
 244                         break;
 245
 246                 err = -EINVAL;
 247                 buf += size;
 248                 if (eccbuf)
 249                         eccbuf += subdev->oobsize;
 250                 to = 0;
 251         }
 252         return err;
 253 }
 254
 255 static int
 256 concat_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
 257                 unsigned long count, loff_t to, size_t * retlen,
 258                 u_char *eccbuf, struct nand_oobinfo *oobsel)
 259 {
 260         struct mtd_concat *concat = CONCAT(mtd);
 261         struct kvec *vecs_copy;
 262         unsigned long entry_low, entry_high;
 263         size_t total_len = 0;
 264         int i;
 265         int err = -EINVAL;
 266
 267         if (!(mtd->flags & MTD_WRITEABLE))
 268                 return -EROFS;
 269
 270         *retlen = 0;
 271
 272         /* Calculate total length of data */
 273         for (i = 0; i < count; i++)
 274                 total_len += vecs[i].iov_len;
 275
 276         /* Do not allow write past end of device */
 277         if ((to + total_len) > mtd->size)
 278                 return -EINVAL;
 279
 280         /* Check alignment */
 281         if (mtd->oobblock > 1) {
 282                 loff_t __to = to;
 283                 if (do_div(__to, mtd->oobblock) || (total_len % mtd->oobblock))
 284                         return -EINVAL;
 285         }
 286
 287         /* make a copy of vecs */
 288         vecs_copy = kmalloc(sizeof(struct kvec) * count, GFP_KERNEL);
 289         if (!vecs_copy)
 290                 return -ENOMEM;
 291         memcpy(vecs_copy, vecs, sizeof(struct kvec) * count);
 292
 293         entry_low = 0;
 294         for (i = 0; i < concat->num_subdev; i++) {
 295                 struct mtd_info *subdev = concat->subdev[i];
 296                 size_t size, wsize, retsize, old_iov_len;
 297
 298                 if (to >= subdev->size) {
 299                         to -= subdev->size;
 300                         continue;
 301                 }
 302
 303                 size = min(total_len, (size_t)(subdev->size - to));
 304                 wsize = size; /* store for future use */
 305
 306                 entry_high = entry_low;
 307                 while (entry_high < count) {
 308                         if (size <= vecs_copy[entry_high].iov_len)
 309                                 break;
 310                         size -= vecs_copy[entry_high++].iov_len;
 311                 }
 312
 313                 old_iov_len = vecs_copy[entry_high].iov_len;
 314                 vecs_copy[entry_high].iov_len = size;
 315
 316                 if (!(subdev->flags & MTD_WRITEABLE))
 317                         err = -EROFS;
 318                 else if (eccbuf)
 319                         err = subdev->writev_ecc(subdev, &vecs_copy[entry_low],
 320                                 entry_high - entry_low + 1, to, &retsize,
 321                                 eccbuf, oobsel);
 322                 else
 323                         err = subdev->writev(subdev, &vecs_copy[entry_low],
 324                                 entry_high - entry_low + 1, to, &retsize);
 325
 326                 vecs_copy[entry_high].iov_len = old_iov_len - size;
 327                 vecs_copy[entry_high].iov_base += size;
 328
 329                 entry_low = entry_high;
 330
 331                 if (err)
 332                         break;
 333
 334                 *retlen += retsize;
 335                 total_len -= wsize;
 336                 if (concat->mtd.type == MTD_NANDFLASH && eccbuf)
 337                         eccbuf += mtd->oobavail * (wsize / mtd->oobblock);
 338
 339                 if (total_len == 0)
 340                         break;
 341
 342                 err = -EINVAL;
 343                 to = 0;
 344         }
 345
 346         kfree(vecs_copy);
 347         return err;
 348 }
 349
 350 static int
 351 concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
 352                 unsigned long count, loff_t to, size_t * retlen)
 353 {
 354         return concat_writev_ecc(mtd, vecs, count, to, retlen, NULL, NULL);
 355 }
 356
 357 static int
 358 concat_read_oob(struct mtd_info *mtd, loff_t from, size_t len,
 359                 size_t * retlen, u_char * buf)
 360 {
 361         struct mtd_concat *concat = CONCAT(mtd);
 362         int err = -EINVAL;
 363         int i;
 364
 365         *retlen = 0;
 366
 367         for (i = 0; i < concat->num_subdev; i++) {
 368                 struct mtd_info *subdev = concat->subdev[i];
 369                 size_t size, retsize;
 370
 371                 if (from >= subdev->size) {
 372                         /* Not destined for this subdev */
 373                         size = 0;
 374                         from -= subdev->size;
 375                         continue;
 376                 }
 377                 if (from + len > subdev->size)
 378                         /* First part goes into this subdev */
 379                         size = subdev->size - from;
 380                 else
 381                         /* Entire transaction goes into this subdev */
 382                         size = len;
 383
 384                 if (subdev->read_oob)
 385                         err = subdev->read_oob(subdev, from, size,
 386                                                &retsize, buf);
 387                 else
 388                         err = -EINVAL;
 389
 390                 if (err)
 391                         break;
 392
 393                 *retlen += retsize;
 394                 len -= size;
 395                 if (len == 0)
 396                         break;
 397
 398                 err = -EINVAL;
 399                 buf += size;
 400                 from = 0;
 401         }
 402         return err;
 403 }
 404
 405 static int
 406 concat_write_oob(struct mtd_info *mtd, loff_t to, size_t len,
 407                  size_t * retlen, const u_char * buf)
 408 {
 409         struct mtd_concat *concat = CONCAT(mtd);
 410         int err = -EINVAL;
 411         int i;
 412
 413         if (!(mtd->flags & MTD_WRITEABLE))
 414                 return -EROFS;
 415
 416         *retlen = 0;
 417
 418         for (i = 0; i < concat->num_subdev; i++) {
 419                 struct mtd_info *subdev = concat->subdev[i];
 420                 size_t size, retsize;
 421
 422                 if (to >= subdev->size) {
 423                         size = 0;
 424                         to -= subdev->size;
 425                         continue;
 426                 }
 427                 if (to + len > subdev->size)
 428                         size = subdev->size - to;
 429                 else
 430                         size = len;
 431
 432                 if (!(subdev->flags & MTD_WRITEABLE))
 433                         err = -EROFS;
 434                 else if (subdev->write_oob)
 435                         err = subdev->write_oob(subdev, to, size, &retsize,
 436                                                 buf);
 437                 else
 438                         err = -EINVAL;
 439
 440                 if (err)
 441                         break;
 442
 443                 *retlen += retsize;
 444                 len -= size;
 445                 if (len == 0)
 446                         break;
 447
 448                 err = -EINVAL;
 449                 buf += size;
 450                 to = 0;
 451         }
 452         return err;
 453 }
 454
 455 static void concat_erase_callback(struct erase_info *instr)
 456 {
 457         wake_up((wait_queue_head_t *) instr->priv);
 458 }
 459
 460 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
 461 {
 462         int err;
 463         wait_queue_head_t waitq;
 464         DECLARE_WAITQUEUE(wait, current);
 465
 466         /*
 467          * This code was stol^H^H^H^Hinspired by mtdchar.c
 468          */
 469         init_waitqueue_head(&waitq);
 470
 471         erase->mtd = mtd;
 472         erase->callback = concat_erase_callback;
 473         erase->priv = (unsigned long) &waitq;
 474
 475         /*
 476          * FIXME: Allow INTERRUPTIBLE. Which means
 477          * not having the wait_queue head on the stack.
 478          */
 479         err = mtd->erase(mtd, erase);
 480         if (!err) {
 481                 set_current_state(TASK_UNINTERRUPTIBLE);
 482                 add_wait_queue(&waitq, &wait);
 483                 if (erase->state != MTD_ERASE_DONE
 484                     && erase->state != MTD_ERASE_FAILED)
 485                         schedule();
 486                 remove_wait_queue(&waitq, &wait);
 487                 set_current_state(TASK_RUNNING);
 488
 489                 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
 490         }
 491         return err;
 492 }
 493
 494 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
 495 {
 496         struct mtd_concat *concat = CONCAT(mtd);
 497         struct mtd_info *subdev;
 498         int i, err;
 499         u_int32_t length, offset = 0;
 500         struct erase_info *erase;
 501
 502         if (!(mtd->flags & MTD_WRITEABLE))
 503                 return -EROFS;
 504
 505         if (instr->addr > concat->mtd.size)
 506                 return -EINVAL;
 507
 508         if (instr->len + instr->addr > concat->mtd.size)
 509                 return -EINVAL;
 510
 511         /*
 512          * Check for proper erase block alignment of the to-be-erased area.
 513          * It is easier to do this based on the super device's erase
 514          * region info rather than looking at each particular sub-device
 515          * in turn.
 516          */
 517         if (!concat->mtd.numeraseregions) {
 518                 /* the easy case: device has uniform erase block size */
 519                 if (instr->addr & (concat->mtd.erasesize - 1))
 520                         return -EINVAL;
 521                 if (instr->len & (concat->mtd.erasesize - 1))
 522                         return -EINVAL;
 523         } else {
 524                 /* device has variable erase size */
 525                 struct mtd_erase_region_info *erase_regions =
 526                     concat->mtd.eraseregions;
 527
 528                 /*
 529                  * Find the erase region where the to-be-erased area begins:
 530                  */
 531                 for (i = 0; i < concat->mtd.numeraseregions &&
 532                      instr->addr >= erase_regions[i].offset; i++) ;
 533                 --i;
 534
 535                 /*
 536                  * Now erase_regions[i] is the region in which the
 537                  * to-be-erased area begins. Verify that the starting
 538                  * offset is aligned to this region's erase size:
 539                  */
 540                 if (instr->addr & (erase_regions[i].erasesize - 1))
 541                         return -EINVAL;
 542
 543                 /*
 544                  * now find the erase region where the to-be-erased area ends:
 545                  */
 546                 for (; i < concat->mtd.numeraseregions &&
 547                      (instr->addr + instr->len) >= erase_regions[i].offset;
 548                      ++i) ;
 549                 --i;
 550                 /*
 551                  * check if the ending offset is aligned to this region's erase size
 552                  */
 553                 if ((instr->addr + instr->len) & (erase_regions[i].erasesize -
 554                                                   1))
 555                         return -EINVAL;
 556         }
 557
 558         instr->fail_addr = 0xffffffff;
 559
 560         /* make a local copy of instr to avoid modifying the caller's struct */
 561         erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
 562
 563         if (!erase)
 564                 return -ENOMEM;
 565
 566         *erase = *instr;
 567         length = instr->len;
 568
 569         /*
 570          * find the subdevice where the to-be-erased area begins, adjust
 571          * starting offset to be relative to the subdevice start
 572          */
 573         for (i = 0; i < concat->num_subdev; i++) {
 574                 subdev = concat->subdev[i];
 575                 if (subdev->size <= erase->addr) {
 576                         erase->addr -= subdev->size;
 577                         offset += subdev->size;
 578                 } else {
 579                         break;
 580                 }
 581         }
 582
 583         /* must never happen since size limit has been verified above */
 584         BUG_ON(i >= concat->num_subdev);
 585
 586         /* now do the erase: */
 587         err = 0;
 588         for (; length > 0; i++) {
 589                 /* loop for all subdevices affected by this request */
 590                 subdev = concat->subdev[i];     /* get current subdevice */
 591
 592                 /* limit length to subdevice's size: */
 593                 if (erase->addr + length > subdev->size)
 594                         erase->len = subdev->size - erase->addr;
 595                 else
 596                         erase->len = length;
 597
 598                 if (!(subdev->flags & MTD_WRITEABLE)) {
 599                         err = -EROFS;
 600                         break;
 601                 }
 602                 length -= erase->len;
 603                 if ((err = concat_dev_erase(subdev, erase))) {
 604                         /* sanity check: should never happen since
 605                          * block alignment has been checked above */
 606                         BUG_ON(err == -EINVAL);
 607                         if (erase->fail_addr != 0xffffffff)
 608                                 instr->fail_addr = erase->fail_addr + offset;
 609                         break;
 610                 }
 611                 /*
 612                  * erase->addr specifies the offset of the area to be
 613                  * erased *within the current subdevice*. It can be
 614                  * non-zero only the first time through this loop, i.e.
 615                  * for the first subdevice where blocks need to be erased.
 616                  * All the following erases must begin at the start of the
 617                  * current subdevice, i.e. at offset zero.
 618                  */
 619                 erase->addr = 0;
 620                 offset += subdev->size;
 621         }
 622         instr->state = erase->state;
 623         kfree(erase);
 624         if (err)
 625                 return err;
 626
 627         if (instr->callback)
 628                 instr->callback(instr);
 629         return 0;
 630 }
 631
 632 static int concat_lock(struct mtd_info *mtd, loff_t ofs, size_t len)
 633 {
 634         struct mtd_concat *concat = CONCAT(mtd);
 635         int i, err = -EINVAL;
 636
 637         if ((len + ofs) > mtd->size)
 638                 return -EINVAL;
 639
 640         for (i = 0; i < concat->num_subdev; i++) {
 641                 struct mtd_info *subdev = concat->subdev[i];
 642                 size_t size;
 643
 644                 if (ofs >= subdev->size) {
 645                         size = 0;
 646                         ofs -= subdev->size;
 647                         continue;
 648                 }
 649                 if (ofs + len > subdev->size)
 650                         size = subdev->size - ofs;
 651                 else
 652                         size = len;
 653
 654                 err = subdev->lock(subdev, ofs, size);
 655
 656                 if (err)
 657                         break;
 658
 659                 len -= size;
 660                 if (len == 0)
 661                         break;
 662
 663                 err = -EINVAL;
 664                 ofs = 0;
 665         }
 666
 667         return err;
 668 }
 669
 670 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, size_t len)
 671 {
 672         struct mtd_concat *concat = CONCAT(mtd);
 673         int i, err = 0;
 674
 675         if ((len + ofs) > mtd->size)
 676                 return -EINVAL;
 677
 678         for (i = 0; i < concat->num_subdev; i++) {
 679                 struct mtd_info *subdev = concat->subdev[i];
 680                 size_t size;
 681
 682                 if (ofs >= subdev->size) {
 683                         size = 0;
 684                         ofs -= subdev->size;
 685                         continue;
 686                 }
 687                 if (ofs + len > subdev->size)
 688                         size = subdev->size - ofs;
 689                 else
 690                         size = len;
 691
 692                 err = subdev->unlock(subdev, ofs, size);
 693
 694                 if (err)
 695                         break;
 696
 697                 len -= size;
 698                 if (len == 0)
 699                         break;
 700
 701                 err = -EINVAL;
 702                 ofs = 0;
 703         }
 704
 705         return err;
 706 }
 707
 708 static void concat_sync(struct mtd_info *mtd)
 709 {
 710         struct mtd_concat *concat = CONCAT(mtd);
 711         int i;
 712
 713         for (i = 0; i < concat->num_subdev; i++) {
 714                 struct mtd_info *subdev = concat->subdev[i];
 715                 subdev->sync(subdev);
 716         }
 717 }
 718
 719 static int concat_suspend(struct mtd_info *mtd)
 720 {
 721         struct mtd_concat *concat = CONCAT(mtd);
 722         int i, rc = 0;
 723
 724         for (i = 0; i < concat->num_subdev; i++) {
 725                 struct mtd_info *subdev = concat->subdev[i];
 726                 if ((rc = subdev->suspend(subdev)) < 0)
 727                         return rc;
 728         }
 729         return rc;
 730 }
 731
 732 static void concat_resume(struct mtd_info *mtd)
 733 {
 734         struct mtd_concat *concat = CONCAT(mtd);
 735         int i;
 736
 737         for (i = 0; i < concat->num_subdev; i++) {
 738                 struct mtd_info *subdev = concat->subdev[i];
 739                 subdev->resume(subdev);
 740         }
 741 }
 742
 743 static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
 744 {
 745         struct mtd_concat *concat = CONCAT(mtd);
 746         int i, res = 0;
 747
 748         if (!concat->subdev[0]->block_isbad)
 749                 return res;
 750
 751         if (ofs > mtd->size)
 752                 return -EINVAL;
 753
 754         for (i = 0; i < concat->num_subdev; i++) {
 755                 struct mtd_info *subdev = concat->subdev[i];
 756
 757                 if (ofs >= subdev->size) {
 758                         ofs -= subdev->size;
 759                         continue;
 760                 }
 761
 762                 res = subdev->block_isbad(subdev, ofs);
 763                 break;
 764         }
 765
 766         return res;
 767 }
 768
 769 static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
 770 {
 771         struct mtd_concat *concat = CONCAT(mtd);
 772         int i, err = -EINVAL;
 773
 774         if (!concat->subdev[0]->block_markbad)
 775                 return 0;
 776
 777         if (ofs > mtd->size)
 778                 return -EINVAL;
 779
 780         for (i = 0; i < concat->num_subdev; i++) {
 781                 struct mtd_info *subdev = concat->subdev[i];
 782
 783                 if (ofs >= subdev->size) {
 784                         ofs -= subdev->size;
 785                         continue;
 786                 }
 787
 788                 err = subdev->block_markbad(subdev, ofs);
 789                 break;
 790         }
 791
 792         return err;
 793 }
 794
 795 /*
 796  * This function constructs a virtual MTD device by concatenating
 797  * num_devs MTD devices. A pointer to the new device object is
 798  * stored to *new_dev upon success. This function does _not_
 799  * register any devices: this is the caller's responsibility.
 800  */
 801 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],   /* subdevices to concatenate */
 802                                    int num_devs,        /* number of subdevices      */
 803                                    char *name)
 804 {                               /* name for the new device   */
 805         int i;
 806         size_t size;
 807         struct mtd_concat *concat;
 808         u_int32_t max_erasesize, curr_erasesize;
 809         int num_erase_region;
 810
 811         printk(KERN_NOTICE "Concatenating MTD devices:\n");
 812         for (i = 0; i < num_devs; i++)
 813                 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
 814         printk(KERN_NOTICE "into device \"%s\"\n", name);
 815
 816         /* allocate the device structure */
 817         size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
 818         concat = kmalloc(size, GFP_KERNEL);
 819         if (!concat) {
 820                 printk
 821                     ("memory allocation error while creating concatenated device \"%s\"\n",
 822                      name);
 823                 return NULL;
 824         }
 825         memset(concat, 0, size);
 826         concat->subdev = (struct mtd_info **) (concat + 1);
 827
 828         /*
 829          * Set up the new "super" device's MTD object structure, check for
 830          * incompatibilites between the subdevices.
 831          */
 832         concat->mtd.type = subdev[0]->type;
 833         concat->mtd.flags = subdev[0]->flags;
 834         concat->mtd.size = subdev[0]->size;
 835         concat->mtd.erasesize = subdev[0]->erasesize;
 836         concat->mtd.oobblock = subdev[0]->oobblock;
 837         concat->mtd.oobsize = subdev[0]->oobsize;
 838         concat->mtd.ecctype = subdev[0]->ecctype;
 839         concat->mtd.eccsize = subdev[0]->eccsize;
 840         if (subdev[0]->read_ecc)
 841                 concat->mtd.read_ecc = concat_read_ecc;
 842         if (subdev[0]->write_ecc)
 843                 concat->mtd.write_ecc = concat_write_ecc;
 844         if (subdev[0]->writev)
 845                 concat->mtd.writev = concat_writev;
 846         if (subdev[0]->writev_ecc)
 847                 concat->mtd.writev_ecc = concat_writev_ecc;
 848         if (subdev[0]->read_oob)
 849                 concat->mtd.read_oob = concat_read_oob;
 850         if (subdev[0]->write_oob)
 851                 concat->mtd.write_oob = concat_write_oob;
 852         if (subdev[0]->block_isbad)
 853                 concat->mtd.block_isbad = concat_block_isbad;
 854         if (subdev[0]->block_markbad)
 855                 concat->mtd.block_markbad = concat_block_markbad;
 856
 857         concat->subdev[0] = subdev[0];
 858
 859         for (i = 1; i < num_devs; i++) {
 860                 if (concat->mtd.type != subdev[i]->type) {
 861                         kfree(concat);
 862                         printk("Incompatible device type on \"%s\"\n",
 863                                subdev[i]->name);
 864                         return NULL;
 865                 }
 866                 if (concat->mtd.flags != subdev[i]->flags) {
 867                         /*
 868                          * Expect all flags except MTD_WRITEABLE to be
 869                          * equal on all subdevices.
 870                          */
 871                         if ((concat->mtd.flags ^ subdev[i]->
 872                              flags) & ~MTD_WRITEABLE) {
 873                                 kfree(concat);
 874                                 printk("Incompatible device flags on \"%s\"\n",
 875                                        subdev[i]->name);
 876                                 return NULL;
 877                         } else
 878                                 /* if writeable attribute differs,
 879                                    make super device writeable */
 880                                 concat->mtd.flags |=
 881                                     subdev[i]->flags & MTD_WRITEABLE;
 882                 }
 883                 concat->mtd.size += subdev[i]->size;
 884                 if (concat->mtd.oobblock   !=  subdev[i]->oobblock ||
 885                     concat->mtd.oobsize    !=  subdev[i]->oobsize ||
 886                     concat->mtd.ecctype    !=  subdev[i]->ecctype ||
 887                     concat->mtd.eccsize    !=  subdev[i]->eccsize ||
 888                     !concat->mtd.read_ecc  != !subdev[i]->read_ecc ||
 889                     !concat->mtd.write_ecc != !subdev[i]->write_ecc ||
 890                     !concat->mtd.read_oob  != !subdev[i]->read_oob ||
 891                     !concat->mtd.write_oob != !subdev[i]->write_oob) {
 892                         kfree(concat);
 893                         printk("Incompatible OOB or ECC data on \"%s\"\n",
 894                                subdev[i]->name);
 895                         return NULL;
 896                 }
 897                 concat->subdev[i] = subdev[i];
 898
 899         }
 900
 901         if(concat->mtd.type == MTD_NANDFLASH)
 902                 memcpy(&concat->mtd.oobinfo, &subdev[0]->oobinfo,
 903                         sizeof(struct nand_oobinfo));
 904
 905         concat->num_subdev = num_devs;
 906         concat->mtd.name = name;
 907
 908         concat->mtd.erase = concat_erase;
 909         concat->mtd.read = concat_read;
 910         concat->mtd.write = concat_write;
 911         concat->mtd.sync = concat_sync;
 912         concat->mtd.lock = concat_lock;
 913         concat->mtd.unlock = concat_unlock;
 914         concat->mtd.suspend = concat_suspend;
 915         concat->mtd.resume = concat_resume;
 916
 917         /*
 918          * Combine the erase block size info of the subdevices:
 919          *
 920          * first, walk the map of the new device and see how
 921          * many changes in erase size we have
 922          */
 923         max_erasesize = curr_erasesize = subdev[0]->erasesize;
 924         num_erase_region = 1;
 925         for (i = 0; i < num_devs; i++) {
 926                 if (subdev[i]->numeraseregions == 0) {
 927                         /* current subdevice has uniform erase size */
 928                         if (subdev[i]->erasesize != curr_erasesize) {
 929                                 /* if it differs from the last subdevice's erase size, count it */
 930                                 ++num_erase_region;
 931                                 curr_erasesize = subdev[i]->erasesize;
 932                                 if (curr_erasesize > max_erasesize)
 933                                         max_erasesize = curr_erasesize;
 934                         }
 935                 } else {
 936                         /* current subdevice has variable erase size */
 937                         int j;
 938                         for (j = 0; j < subdev[i]->numeraseregions; j++) {
 939
 940                                 /* walk the list of erase regions, count any changes */
 941                                 if (subdev[i]->eraseregions[j].erasesize !=
 942                                     curr_erasesize) {
 943                                         ++num_erase_region;
 944                                         curr_erasesize =
 945                                             subdev[i]->eraseregions[j].
 946                                             erasesize;
 947                                         if (curr_erasesize > max_erasesize)
 948                                                 max_erasesize = curr_erasesize;
 949                                 }
 950                         }
 951                 }
 952         }
 953
 954         if (num_erase_region == 1) {
 955                 /*
 956                  * All subdevices have the same uniform erase size.
 957                  * This is easy:
 958                  */
 959                 concat->mtd.erasesize = curr_erasesize;
 960                 concat->mtd.numeraseregions = 0;
 961         } else {
 962                 /*
 963                  * erase block size varies across the subdevices: allocate
 964                  * space to store the data describing the variable erase regions
 965                  */
 966                 struct mtd_erase_region_info *erase_region_p;
 967                 u_int32_t begin, position;
 968
 969                 concat->mtd.erasesize = max_erasesize;
 970                 concat->mtd.numeraseregions = num_erase_region;
 971                 concat->mtd.eraseregions = erase_region_p =
 972                     kmalloc(num_erase_region *
 973                             sizeof (struct mtd_erase_region_info), GFP_KERNEL);
 974                 if (!erase_region_p) {
 975                         kfree(concat);
 976                         printk
 977                             ("memory allocation error while creating erase region list"
 978                              " for device \"%s\"\n", name);
 979                         return NULL;
 980                 }
 981
 982                 /*
 983                  * walk the map of the new device once more and fill in
 984                  * in erase region info:
 985                  */
 986                 curr_erasesize = subdev[0]->erasesize;
 987                 begin = position = 0;
 988                 for (i = 0; i < num_devs; i++) {
 989                         if (subdev[i]->numeraseregions == 0) {
 990                                 /* current subdevice has uniform erase size */
 991                                 if (subdev[i]->erasesize != curr_erasesize) {
 992                                         /*
 993                                          *  fill in an mtd_erase_region_info structure for the area
 994                                          *  we have walked so far:
 995                                          */
 996                                         erase_region_p->offset = begin;
 997                                         erase_region_p->erasesize =
 998                                             curr_erasesize;
 999                                         erase_region_p->numblocks =
1000                                             (position - begin) / curr_erasesize;
1001                                         begin = position;
1002
1003                                         curr_erasesize = subdev[i]->erasesize;
1004                                         ++erase_region_p;
1005                                 }
1006                                 position += subdev[i]->size;
1007                         } else {
1008                                 /* current subdevice has variable erase size */
1009                                 int j;
1010                                 for (j = 0; j < subdev[i]->numeraseregions; j++) {
1011                                         /* walk the list of erase regions, count any changes */
1012                                         if (subdev[i]->eraseregions[j].
1013                                             erasesize != curr_erasesize) {
1014                                                 erase_region_p->offset = begin;
1015                                                 erase_region_p->erasesize =
1016                                                     curr_erasesize;
1017                                                 erase_region_p->numblocks =
1018                                                     (position -
1019                                                      begin) / curr_erasesize;
1020                                                 begin = position;
1021
1022                                                 curr_erasesize =
1023                                                     subdev[i]->eraseregions[j].
1024                                                     erasesize;
1025                                                 ++erase_region_p;
1026                                         }
1027                                         position +=
1028                                             subdev[i]->eraseregions[j].
1029                                             numblocks * curr_erasesize;
1030                                 }
1031                         }
1032                 }
1033                 /* Now write the final entry */
1034                 erase_region_p->offset = begin;
1035                 erase_region_p->erasesize = curr_erasesize;
1036                 erase_region_p->numblocks = (position - begin) / curr_erasesize;
1037         }
1038
1039         return &concat->mtd;
1040 }
1041
1042 /*
1043  * This function destroys an MTD object obtained from concat_mtd_devs()
1044  */
1045
1046 void mtd_concat_destroy(struct mtd_info *mtd)
1047 {
1048         struct mtd_concat *concat = CONCAT(mtd);
1049         if (concat->mtd.numeraseregions)
1050                 kfree(concat->mtd.eraseregions);
1051         kfree(concat);
1052 }
1053
1054 EXPORT_SYMBOL(mtd_concat_create);
1055 EXPORT_SYMBOL(mtd_concat_destroy);
1056
1057 MODULE_LICENSE("GPL");
1058 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
1059 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");