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