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