drivers/mtd/mtdconcat.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * MTD device concatenation layer
   4  *
   5  * Copyright © 2002 Robert Kaiser <[email protected]>
   6  * Copyright © 2002-2010 David Woodhouse <[email protected]>
   7  *
   8  * NAND support by Christian Gan <[email protected]>
   9  *
  10  */
  11
  12 #ifndef __UBOOT__
  13 #include <log.h>
  14 #include <dm/devres.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/sched.h>
  19 #include <linux/types.h>
  20 #include <linux/backing-dev.h>
  21 #include <asm/div64.h>
  22 #else
  23 #include <div64.h>
  24 #include <linux/bug.h>
  25 #include <linux/compat.h>
  26 #include <linux/printk.h>
  27 #endif
  28
  29 #include <linux/mtd/mtd.h>
  30 #include <linux/mtd/concat.h>
  31
  32 #include <ubi_uboot.h>
  33
  34 /*
  35  * Our storage structure:
  36  * Subdev points to an array of pointers to struct mtd_info objects
  37  * which is allocated along with this structure
  38  *
  39  */
  40 struct mtd_concat {
  41         struct mtd_info mtd;
  42         int num_subdev;
  43         struct mtd_info **subdev;
  44 };
  45
  46 /*
  47  * how to calculate the size required for the above structure,
  48  * including the pointer array subdev points to:
  49  */
  50 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev)    \
  51         ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
  52
  53 /*
  54  * Given a pointer to the MTD object in the mtd_concat structure,
  55  * we can retrieve the pointer to that structure with this macro.
  56  */
  57 #define CONCAT(x)  ((struct mtd_concat *)(x))
  58
  59 /*
  60  * MTD methods which look up the relevant subdevice, translate the
  61  * effective address and pass through to the subdevice.
  62  */
  63
  64 static int
  65 concat_read(struct mtd_info *mtd, loff_t from, size_t len,
  66             size_t * retlen, u_char * buf)
  67 {
  68         struct mtd_concat *concat = CONCAT(mtd);
  69         int ret = 0, err;
  70         int i;
  71
  72 #ifdef __UBOOT__
  73         *retlen = 0;
  74 #endif
  75
  76         for (i = 0; i < concat->num_subdev; i++) {
  77                 struct mtd_info *subdev = concat->subdev[i];
  78                 size_t size, retsize;
  79
  80                 if (from >= subdev->size) {
  81                         /* Not destined for this subdev */
  82                         size = 0;
  83                         from -= subdev->size;
  84                         continue;
  85                 }
  86                 if (from + len > subdev->size)
  87                         /* First part goes into this subdev */
  88                         size = subdev->size - from;
  89                 else
  90                         /* Entire transaction goes into this subdev */
  91                         size = len;
  92
  93                 err = mtd_read(subdev, from, size, &retsize, buf);
  94
  95                 /* Save information about bitflips! */
  96                 if (unlikely(err)) {
  97                         if (mtd_is_eccerr(err)) {
  98                                 mtd->ecc_stats.failed++;
  99                                 ret = err;
 100                         } else if (mtd_is_bitflip(err)) {
 101                                 mtd->ecc_stats.corrected++;
 102                                 /* Do not overwrite -EBADMSG !! */
 103                                 if (!ret)
 104                                         ret = err;
 105                         } else
 106                                 return err;
 107                 }
 108
 109                 *retlen += retsize;
 110                 len -= size;
 111                 if (len == 0)
 112                         return ret;
 113
 114                 buf += size;
 115                 from = 0;
 116         }
 117         return -EINVAL;
 118 }
 119
 120 static int
 121 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
 122              size_t * retlen, const u_char * buf)
 123 {
 124         struct mtd_concat *concat = CONCAT(mtd);
 125         int err = -EINVAL;
 126         int i;
 127
 128 #ifdef __UBOOT__
 129         *retlen = 0;
 130 #endif
 131
 132         for (i = 0; i < concat->num_subdev; i++) {
 133                 struct mtd_info *subdev = concat->subdev[i];
 134                 size_t size, retsize;
 135
 136                 if (to >= subdev->size) {
 137                         size = 0;
 138                         to -= subdev->size;
 139                         continue;
 140                 }
 141                 if (to + len > subdev->size)
 142                         size = subdev->size - to;
 143                 else
 144                         size = len;
 145
 146                 err = mtd_write(subdev, to, size, &retsize, buf);
 147                 if (err)
 148                         break;
 149
 150                 *retlen += retsize;
 151                 len -= size;
 152                 if (len == 0)
 153                         break;
 154
 155                 err = -EINVAL;
 156                 buf += size;
 157                 to = 0;
 158         }
 159         return err;
 160 }
 161
 162 #ifndef __UBOOT__
 163 static int
 164 concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
 165                 unsigned long count, loff_t to, size_t * retlen)
 166 {
 167         struct mtd_concat *concat = CONCAT(mtd);
 168         struct kvec *vecs_copy;
 169         unsigned long entry_low, entry_high;
 170         size_t total_len = 0;
 171         int i;
 172         int err = -EINVAL;
 173
 174         /* Calculate total length of data */
 175         for (i = 0; i < count; i++)
 176                 total_len += vecs[i].iov_len;
 177
 178         /* Check alignment */
 179         if (mtd->writesize > 1) {
 180                 uint64_t __to = to;
 181                 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
 182                         return -EINVAL;
 183         }
 184
 185         /* make a copy of vecs */
 186         vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL);
 187         if (!vecs_copy)
 188                 return -ENOMEM;
 189
 190         entry_low = 0;
 191         for (i = 0; i < concat->num_subdev; i++) {
 192                 struct mtd_info *subdev = concat->subdev[i];
 193                 size_t size, wsize, retsize, old_iov_len;
 194
 195                 if (to >= subdev->size) {
 196                         to -= subdev->size;
 197                         continue;
 198                 }
 199
 200                 size = min_t(uint64_t, total_len, subdev->size - to);
 201                 wsize = size; /* store for future use */
 202
 203                 entry_high = entry_low;
 204                 while (entry_high < count) {
 205                         if (size <= vecs_copy[entry_high].iov_len)
 206                                 break;
 207                         size -= vecs_copy[entry_high++].iov_len;
 208                 }
 209
 210                 old_iov_len = vecs_copy[entry_high].iov_len;
 211                 vecs_copy[entry_high].iov_len = size;
 212
 213                 err = mtd_writev(subdev, &vecs_copy[entry_low],
 214                                  entry_high - entry_low + 1, to, &retsize);
 215
 216                 vecs_copy[entry_high].iov_len = old_iov_len - size;
 217                 vecs_copy[entry_high].iov_base += size;
 218
 219                 entry_low = entry_high;
 220
 221                 if (err)
 222                         break;
 223
 224                 *retlen += retsize;
 225                 total_len -= wsize;
 226
 227                 if (total_len == 0)
 228                         break;
 229
 230                 err = -EINVAL;
 231                 to = 0;
 232         }
 233
 234         kfree(vecs_copy);
 235         return err;
 236 }
 237 #endif
 238
 239 static int
 240 concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
 241 {
 242         struct mtd_concat *concat = CONCAT(mtd);
 243         struct mtd_oob_ops devops = *ops;
 244         int i, err, ret = 0;
 245
 246         ops->retlen = ops->oobretlen = 0;
 247
 248         for (i = 0; i < concat->num_subdev; i++) {
 249                 struct mtd_info *subdev = concat->subdev[i];
 250
 251                 if (from >= subdev->size) {
 252                         from -= subdev->size;
 253                         continue;
 254                 }
 255
 256                 /* partial read ? */
 257                 if (from + devops.len > subdev->size)
 258                         devops.len = subdev->size - from;
 259
 260                 err = mtd_read_oob(subdev, from, &devops);
 261                 ops->retlen += devops.retlen;
 262                 ops->oobretlen += devops.oobretlen;
 263
 264                 /* Save information about bitflips! */
 265                 if (unlikely(err)) {
 266                         if (mtd_is_eccerr(err)) {
 267                                 mtd->ecc_stats.failed++;
 268                                 ret = err;
 269                         } else if (mtd_is_bitflip(err)) {
 270                                 mtd->ecc_stats.corrected++;
 271                                 /* Do not overwrite -EBADMSG !! */
 272                                 if (!ret)
 273                                         ret = err;
 274                         } else
 275                                 return err;
 276                 }
 277
 278                 if (devops.datbuf) {
 279                         devops.len = ops->len - ops->retlen;
 280                         if (!devops.len)
 281                                 return ret;
 282                         devops.datbuf += devops.retlen;
 283                 }
 284                 if (devops.oobbuf) {
 285                         devops.ooblen = ops->ooblen - ops->oobretlen;
 286                         if (!devops.ooblen)
 287                                 return ret;
 288                         devops.oobbuf += ops->oobretlen;
 289                 }
 290
 291                 from = 0;
 292         }
 293         return -EINVAL;
 294 }
 295
 296 static int
 297 concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
 298 {
 299         struct mtd_concat *concat = CONCAT(mtd);
 300         struct mtd_oob_ops devops = *ops;
 301         int i, err;
 302
 303         if (!(mtd->flags & MTD_WRITEABLE))
 304                 return -EROFS;
 305
 306         ops->retlen = ops->oobretlen = 0;
 307
 308         for (i = 0; i < concat->num_subdev; i++) {
 309                 struct mtd_info *subdev = concat->subdev[i];
 310
 311                 if (to >= subdev->size) {
 312                         to -= subdev->size;
 313                         continue;
 314                 }
 315
 316                 /* partial write ? */
 317                 if (to + devops.len > subdev->size)
 318                         devops.len = subdev->size - to;
 319
 320                 err = mtd_write_oob(subdev, to, &devops);
 321                 ops->retlen += devops.oobretlen;
 322                 if (err)
 323                         return err;
 324
 325                 if (devops.datbuf) {
 326                         devops.len = ops->len - ops->retlen;
 327                         if (!devops.len)
 328                                 return 0;
 329                         devops.datbuf += devops.retlen;
 330                 }
 331                 if (devops.oobbuf) {
 332                         devops.ooblen = ops->ooblen - ops->oobretlen;
 333                         if (!devops.ooblen)
 334                                 return 0;
 335                         devops.oobbuf += devops.oobretlen;
 336                 }
 337                 to = 0;
 338         }
 339         return -EINVAL;
 340 }
 341
 342 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
 343 {
 344         int err;
 345         wait_queue_head_t waitq;
 346         DECLARE_WAITQUEUE(wait, current);
 347
 348         /*
 349          * This code was stol^H^H^H^Hinspired by mtdchar.c
 350          */
 351         init_waitqueue_head(&waitq);
 352
 353         erase->mtd = mtd;
 354         erase->priv = (unsigned long) &waitq;
 355
 356         /*
 357          * FIXME: Allow INTERRUPTIBLE. Which means
 358          * not having the wait_queue head on the stack.
 359          */
 360         err = mtd_erase(mtd, erase);
 361         if (!err) {
 362                 set_current_state(TASK_UNINTERRUPTIBLE);
 363                 add_wait_queue(&waitq, &wait);
 364                 if (erase->state != MTD_ERASE_DONE
 365                     && erase->state != MTD_ERASE_FAILED)
 366                         schedule();
 367                 remove_wait_queue(&waitq, &wait);
 368                 set_current_state(TASK_RUNNING);
 369
 370                 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
 371         }
 372         return err;
 373 }
 374
 375 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
 376 {
 377         struct mtd_concat *concat = CONCAT(mtd);
 378         struct mtd_info *subdev;
 379         int i, err;
 380         uint64_t length, offset = 0;
 381         struct erase_info *erase;
 382
 383         /*
 384          * Check for proper erase block alignment of the to-be-erased area.
 385          * It is easier to do this based on the super device's erase
 386          * region info rather than looking at each particular sub-device
 387          * in turn.
 388          */
 389         if (!concat->mtd.numeraseregions) {
 390                 /* the easy case: device has uniform erase block size */
 391                 if (instr->addr & (concat->mtd.erasesize - 1))
 392                         return -EINVAL;
 393                 if (instr->len & (concat->mtd.erasesize - 1))
 394                         return -EINVAL;
 395         } else {
 396                 /* device has variable erase size */
 397                 struct mtd_erase_region_info *erase_regions =
 398                     concat->mtd.eraseregions;
 399
 400                 /*
 401                  * Find the erase region where the to-be-erased area begins:
 402                  */
 403                 for (i = 0; i < concat->mtd.numeraseregions &&
 404                      instr->addr >= erase_regions[i].offset; i++) ;
 405                 --i;
 406
 407                 /*
 408                  * Now erase_regions[i] is the region in which the
 409                  * to-be-erased area begins. Verify that the starting
 410                  * offset is aligned to this region's erase size:
 411                  */
 412                 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
 413                         return -EINVAL;
 414
 415                 /*
 416                  * now find the erase region where the to-be-erased area ends:
 417                  */
 418                 for (; i < concat->mtd.numeraseregions &&
 419                      (instr->addr + instr->len) >= erase_regions[i].offset;
 420                      ++i) ;
 421                 --i;
 422                 /*
 423                  * check if the ending offset is aligned to this region's erase size
 424                  */
 425                 if (i < 0 || ((instr->addr + instr->len) &
 426                                         (erase_regions[i].erasesize - 1)))
 427                         return -EINVAL;
 428         }
 429
 430         /* make a local copy of instr to avoid modifying the caller's struct */
 431         erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
 432
 433         if (!erase)
 434                 return -ENOMEM;
 435
 436         *erase = *instr;
 437         length = instr->len;
 438
 439         /*
 440          * find the subdevice where the to-be-erased area begins, adjust
 441          * starting offset to be relative to the subdevice start
 442          */
 443         for (i = 0; i < concat->num_subdev; i++) {
 444                 subdev = concat->subdev[i];
 445                 if (subdev->size <= erase->addr) {
 446                         erase->addr -= subdev->size;
 447                         offset += subdev->size;
 448                 } else {
 449                         break;
 450                 }
 451         }
 452
 453         /* must never happen since size limit has been verified above */
 454         BUG_ON(i >= concat->num_subdev);
 455
 456         /* now do the erase: */
 457         err = 0;
 458         for (; length > 0; i++) {
 459                 /* loop for all subdevices affected by this request */
 460                 subdev = concat->subdev[i];     /* get current subdevice */
 461
 462                 /* limit length to subdevice's size: */
 463                 if (erase->addr + length > subdev->size)
 464                         erase->len = subdev->size - erase->addr;
 465                 else
 466                         erase->len = length;
 467
 468                 length -= erase->len;
 469                 if ((err = concat_dev_erase(subdev, erase))) {
 470                         /* sanity check: should never happen since
 471                          * block alignment has been checked above */
 472                         BUG_ON(err == -EINVAL);
 473                         if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 474                                 instr->fail_addr = erase->fail_addr + offset;
 475                         break;
 476                 }
 477                 /*
 478                  * erase->addr specifies the offset of the area to be
 479                  * erased *within the current subdevice*. It can be
 480                  * non-zero only the first time through this loop, i.e.
 481                  * for the first subdevice where blocks need to be erased.
 482                  * All the following erases must begin at the start of the
 483                  * current subdevice, i.e. at offset zero.
 484                  */
 485                 erase->addr = 0;
 486                 offset += subdev->size;
 487         }
 488         instr->state = erase->state;
 489         kfree(erase);
 490         if (err)
 491                 return err;
 492
 493         return 0;
 494 }
 495
 496 static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 497 {
 498         struct mtd_concat *concat = CONCAT(mtd);
 499         int i, err = -EINVAL;
 500
 501         for (i = 0; i < concat->num_subdev; i++) {
 502                 struct mtd_info *subdev = concat->subdev[i];
 503                 uint64_t size;
 504
 505                 if (ofs >= subdev->size) {
 506                         size = 0;
 507                         ofs -= subdev->size;
 508                         continue;
 509                 }
 510                 if (ofs + len > subdev->size)
 511                         size = subdev->size - ofs;
 512                 else
 513                         size = len;
 514
 515                 err = mtd_lock(subdev, ofs, size);
 516                 if (err)
 517                         break;
 518
 519                 len -= size;
 520                 if (len == 0)
 521                         break;
 522
 523                 err = -EINVAL;
 524                 ofs = 0;
 525         }
 526
 527         return err;
 528 }
 529
 530 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 531 {
 532         struct mtd_concat *concat = CONCAT(mtd);
 533         int i, err = 0;
 534
 535         for (i = 0; i < concat->num_subdev; i++) {
 536                 struct mtd_info *subdev = concat->subdev[i];
 537                 uint64_t size;
 538
 539                 if (ofs >= subdev->size) {
 540                         size = 0;
 541                         ofs -= subdev->size;
 542                         continue;
 543                 }
 544                 if (ofs + len > subdev->size)
 545                         size = subdev->size - ofs;
 546                 else
 547                         size = len;
 548
 549                 err = mtd_unlock(subdev, ofs, size);
 550                 if (err)
 551                         break;
 552
 553                 len -= size;
 554                 if (len == 0)
 555                         break;
 556
 557                 err = -EINVAL;
 558                 ofs = 0;
 559         }
 560
 561         return err;
 562 }
 563
 564 static void concat_sync(struct mtd_info *mtd)
 565 {
 566         struct mtd_concat *concat = CONCAT(mtd);
 567         int i;
 568
 569         for (i = 0; i < concat->num_subdev; i++) {
 570                 struct mtd_info *subdev = concat->subdev[i];
 571                 mtd_sync(subdev);
 572         }
 573 }
 574
 575 #ifndef __UBOOT__
 576 static int concat_suspend(struct mtd_info *mtd)
 577 {
 578         struct mtd_concat *concat = CONCAT(mtd);
 579         int i, rc = 0;
 580
 581         for (i = 0; i < concat->num_subdev; i++) {
 582                 struct mtd_info *subdev = concat->subdev[i];
 583                 if ((rc = mtd_suspend(subdev)) < 0)
 584                         return rc;
 585         }
 586         return rc;
 587 }
 588
 589 static void concat_resume(struct mtd_info *mtd)
 590 {
 591         struct mtd_concat *concat = CONCAT(mtd);
 592         int i;
 593
 594         for (i = 0; i < concat->num_subdev; i++) {
 595                 struct mtd_info *subdev = concat->subdev[i];
 596                 mtd_resume(subdev);
 597         }
 598 }
 599 #endif
 600
 601 static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
 602 {
 603         struct mtd_concat *concat = CONCAT(mtd);
 604         int i, res = 0;
 605
 606         if (!mtd_can_have_bb(concat->subdev[0]))
 607                 return res;
 608
 609         for (i = 0; i < concat->num_subdev; i++) {
 610                 struct mtd_info *subdev = concat->subdev[i];
 611
 612                 if (ofs >= subdev->size) {
 613                         ofs -= subdev->size;
 614                         continue;
 615                 }
 616
 617                 res = mtd_block_isbad(subdev, ofs);
 618                 break;
 619         }
 620
 621         return res;
 622 }
 623
 624 static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
 625 {
 626         struct mtd_concat *concat = CONCAT(mtd);
 627         int i, err = -EINVAL;
 628
 629         for (i = 0; i < concat->num_subdev; i++) {
 630                 struct mtd_info *subdev = concat->subdev[i];
 631
 632                 if (ofs >= subdev->size) {
 633                         ofs -= subdev->size;
 634                         continue;
 635                 }
 636
 637                 err = mtd_block_markbad(subdev, ofs);
 638                 if (!err)
 639                         mtd->ecc_stats.badblocks++;
 640                 break;
 641         }
 642
 643         return err;
 644 }
 645
 646 /*
 647  * try to support NOMMU mmaps on concatenated devices
 648  * - we don't support subdev spanning as we can't guarantee it'll work
 649  */
 650 static unsigned long concat_get_unmapped_area(struct mtd_info *mtd,
 651                                               unsigned long len,
 652                                               unsigned long offset,
 653                                               unsigned long flags)
 654 {
 655         struct mtd_concat *concat = CONCAT(mtd);
 656         int i;
 657
 658         for (i = 0; i < concat->num_subdev; i++) {
 659                 struct mtd_info *subdev = concat->subdev[i];
 660
 661                 if (offset >= subdev->size) {
 662                         offset -= subdev->size;
 663                         continue;
 664                 }
 665
 666                 return mtd_get_unmapped_area(subdev, len, offset, flags);
 667         }
 668
 669         return (unsigned long) -ENOSYS;
 670 }
 671
 672 /*
 673  * This function constructs a virtual MTD device by concatenating
 674  * num_devs MTD devices. A pointer to the new device object is
 675  * stored to *new_dev upon success. This function does _not_
 676  * register any devices: this is the caller's responsibility.
 677  */
 678 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],   /* subdevices to concatenate */
 679                                    int num_devs,        /* number of subdevices      */
 680 #ifndef __UBOOT__
 681                                    const char *name)
 682 #else
 683                                    char *name)
 684 #endif
 685 {                               /* name for the new device   */
 686         int i;
 687         size_t size;
 688         struct mtd_concat *concat;
 689         uint32_t max_erasesize, curr_erasesize;
 690         int num_erase_region;
 691         int max_writebufsize = 0;
 692
 693         debug("Concatenating MTD devices:\n");
 694         for (i = 0; i < num_devs; i++)
 695                 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
 696         debug("into device \"%s\"\n", name);
 697
 698         /* allocate the device structure */
 699         size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
 700         concat = kzalloc(size, GFP_KERNEL);
 701         if (!concat) {
 702                 printk
 703                     ("memory allocation error while creating concatenated device \"%s\"\n",
 704                      name);
 705                 return NULL;
 706         }
 707         concat->subdev = (struct mtd_info **) (concat + 1);
 708
 709         /*
 710          * Set up the new "super" device's MTD object structure, check for
 711          * incompatibilities between the subdevices.
 712          */
 713         concat->mtd.type = subdev[0]->type;
 714         concat->mtd.flags = subdev[0]->flags;
 715         concat->mtd.size = subdev[0]->size;
 716         concat->mtd.erasesize = subdev[0]->erasesize;
 717         concat->mtd.writesize = subdev[0]->writesize;
 718
 719         for (i = 0; i < num_devs; i++)
 720                 if (max_writebufsize < subdev[i]->writebufsize)
 721                         max_writebufsize = subdev[i]->writebufsize;
 722         concat->mtd.writebufsize = max_writebufsize;
 723
 724         concat->mtd.subpage_sft = subdev[0]->subpage_sft;
 725         concat->mtd.oobsize = subdev[0]->oobsize;
 726         concat->mtd.oobavail = subdev[0]->oobavail;
 727 #ifndef __UBOOT__
 728         if (subdev[0]->_writev)
 729                 concat->mtd._writev = concat_writev;
 730 #endif
 731         if (subdev[0]->_read_oob)
 732                 concat->mtd._read_oob = concat_read_oob;
 733         if (subdev[0]->_write_oob)
 734                 concat->mtd._write_oob = concat_write_oob;
 735         if (subdev[0]->_block_isbad)
 736                 concat->mtd._block_isbad = concat_block_isbad;
 737         if (subdev[0]->_block_markbad)
 738                 concat->mtd._block_markbad = concat_block_markbad;
 739
 740         concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
 741
 742 #ifndef __UBOOT__
 743         concat->mtd.backing_dev_info = subdev[0]->backing_dev_info;
 744 #endif
 745
 746         concat->subdev[0] = subdev[0];
 747
 748         for (i = 1; i < num_devs; i++) {
 749                 if (concat->mtd.type != subdev[i]->type) {
 750                         kfree(concat);
 751                         printk("Incompatible device type on \"%s\"\n",
 752                                subdev[i]->name);
 753                         return NULL;
 754                 }
 755                 if (concat->mtd.flags != subdev[i]->flags) {
 756                         /*
 757                          * Expect all flags except MTD_WRITEABLE to be
 758                          * equal on all subdevices.
 759                          */
 760                         if ((concat->mtd.flags ^ subdev[i]->
 761                              flags) & ~MTD_WRITEABLE) {
 762                                 kfree(concat);
 763                                 printk("Incompatible device flags on \"%s\"\n",
 764                                        subdev[i]->name);
 765                                 return NULL;
 766                         } else
 767                                 /* if writeable attribute differs,
 768                                    make super device writeable */
 769                                 concat->mtd.flags |=
 770                                     subdev[i]->flags & MTD_WRITEABLE;
 771                 }
 772
 773 #ifndef __UBOOT__
 774                 /* only permit direct mapping if the BDIs are all the same
 775                  * - copy-mapping is still permitted
 776                  */
 777                 if (concat->mtd.backing_dev_info !=
 778                     subdev[i]->backing_dev_info)
 779                         concat->mtd.backing_dev_info =
 780                                 &default_backing_dev_info;
 781 #endif
 782
 783                 concat->mtd.size += subdev[i]->size;
 784                 concat->mtd.ecc_stats.badblocks +=
 785                         subdev[i]->ecc_stats.badblocks;
 786                 if (concat->mtd.writesize   !=  subdev[i]->writesize ||
 787                     concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
 788                     concat->mtd.oobsize    !=  subdev[i]->oobsize ||
 789                     !concat->mtd._read_oob  != !subdev[i]->_read_oob ||
 790                     !concat->mtd._write_oob != !subdev[i]->_write_oob) {
 791                         kfree(concat);
 792                         printk("Incompatible OOB or ECC data on \"%s\"\n",
 793                                subdev[i]->name);
 794                         return NULL;
 795                 }
 796                 concat->subdev[i] = subdev[i];
 797
 798         }
 799
 800         concat->mtd.ecclayout = subdev[0]->ecclayout;
 801
 802         concat->num_subdev = num_devs;
 803         concat->mtd.name = name;
 804
 805         concat->mtd._erase = concat_erase;
 806         concat->mtd._read = concat_read;
 807         concat->mtd._write = concat_write;
 808         concat->mtd._sync = concat_sync;
 809         concat->mtd._lock = concat_lock;
 810         concat->mtd._unlock = concat_unlock;
 811 #ifndef __UBOOT__
 812         concat->mtd._suspend = concat_suspend;
 813         concat->mtd._resume = concat_resume;
 814 #endif
 815         concat->mtd._get_unmapped_area = concat_get_unmapped_area;
 816
 817         /*
 818          * Combine the erase block size info of the subdevices:
 819          *
 820          * first, walk the map of the new device and see how
 821          * many changes in erase size we have
 822          */
 823         max_erasesize = curr_erasesize = subdev[0]->erasesize;
 824         num_erase_region = 1;
 825         for (i = 0; i < num_devs; i++) {
 826                 if (subdev[i]->numeraseregions == 0) {
 827                         /* current subdevice has uniform erase size */
 828                         if (subdev[i]->erasesize != curr_erasesize) {
 829                                 /* if it differs from the last subdevice's erase size, count it */
 830                                 ++num_erase_region;
 831                                 curr_erasesize = subdev[i]->erasesize;
 832                                 if (curr_erasesize > max_erasesize)
 833                                         max_erasesize = curr_erasesize;
 834                         }
 835                 } else {
 836                         /* current subdevice has variable erase size */
 837                         int j;
 838                         for (j = 0; j < subdev[i]->numeraseregions; j++) {
 839
 840                                 /* walk the list of erase regions, count any changes */
 841                                 if (subdev[i]->eraseregions[j].erasesize !=
 842                                     curr_erasesize) {
 843                                         ++num_erase_region;
 844                                         curr_erasesize =
 845                                             subdev[i]->eraseregions[j].
 846                                             erasesize;
 847                                         if (curr_erasesize > max_erasesize)
 848                                                 max_erasesize = curr_erasesize;
 849                                 }
 850                         }
 851                 }
 852         }
 853
 854         if (num_erase_region == 1) {
 855                 /*
 856                  * All subdevices have the same uniform erase size.
 857                  * This is easy:
 858                  */
 859                 concat->mtd.erasesize = curr_erasesize;
 860                 concat->mtd.numeraseregions = 0;
 861         } else {
 862                 uint64_t tmp64;
 863
 864                 /*
 865                  * erase block size varies across the subdevices: allocate
 866                  * space to store the data describing the variable erase regions
 867                  */
 868                 struct mtd_erase_region_info *erase_region_p;
 869                 uint64_t begin, position;
 870
 871                 concat->mtd.erasesize = max_erasesize;
 872                 concat->mtd.numeraseregions = num_erase_region;
 873                 concat->mtd.eraseregions = erase_region_p =
 874                     kmalloc(num_erase_region *
 875                             sizeof (struct mtd_erase_region_info), GFP_KERNEL);
 876                 if (!erase_region_p) {
 877                         kfree(concat);
 878                         printk
 879                             ("memory allocation error while creating erase region list"
 880                              " for device \"%s\"\n", name);
 881                         return NULL;
 882                 }
 883
 884                 /*
 885                  * walk the map of the new device once more and fill in
 886                  * in erase region info:
 887                  */
 888                 curr_erasesize = subdev[0]->erasesize;
 889                 begin = position = 0;
 890                 for (i = 0; i < num_devs; i++) {
 891                         if (subdev[i]->numeraseregions == 0) {
 892                                 /* current subdevice has uniform erase size */
 893                                 if (subdev[i]->erasesize != curr_erasesize) {
 894                                         /*
 895                                          *  fill in an mtd_erase_region_info structure for the area
 896                                          *  we have walked so far:
 897                                          */
 898                                         erase_region_p->offset = begin;
 899                                         erase_region_p->erasesize =
 900                                             curr_erasesize;
 901                                         tmp64 = position - begin;
 902                                         do_div(tmp64, curr_erasesize);
 903                                         erase_region_p->numblocks = tmp64;
 904                                         begin = position;
 905
 906                                         curr_erasesize = subdev[i]->erasesize;
 907                                         ++erase_region_p;
 908                                 }
 909                                 position += subdev[i]->size;
 910                         } else {
 911                                 /* current subdevice has variable erase size */
 912                                 int j;
 913                                 for (j = 0; j < subdev[i]->numeraseregions; j++) {
 914                                         /* walk the list of erase regions, count any changes */
 915                                         if (subdev[i]->eraseregions[j].
 916                                             erasesize != curr_erasesize) {
 917                                                 erase_region_p->offset = begin;
 918                                                 erase_region_p->erasesize =
 919                                                     curr_erasesize;
 920                                                 tmp64 = position - begin;
 921                                                 do_div(tmp64, curr_erasesize);
 922                                                 erase_region_p->numblocks = tmp64;
 923                                                 begin = position;
 924
 925                                                 curr_erasesize =
 926                                                     subdev[i]->eraseregions[j].
 927                                                     erasesize;
 928                                                 ++erase_region_p;
 929                                         }
 930                                         position +=
 931                                             subdev[i]->eraseregions[j].
 932                                             numblocks * (uint64_t)curr_erasesize;
 933                                 }
 934                         }
 935                 }
 936                 /* Now write the final entry */
 937                 erase_region_p->offset = begin;
 938                 erase_region_p->erasesize = curr_erasesize;
 939                 tmp64 = position - begin;
 940                 do_div(tmp64, curr_erasesize);
 941                 erase_region_p->numblocks = tmp64;
 942         }
 943
 944         return &concat->mtd;
 945 }
 946
 947 /*
 948  * This function destroys an MTD object obtained from concat_mtd_devs()
 949  */
 950
 951 void mtd_concat_destroy(struct mtd_info *mtd)
 952 {
 953         struct mtd_concat *concat = CONCAT(mtd);
 954         if (concat->mtd.numeraseregions)
 955                 kfree(concat->mtd.eraseregions);
 956         kfree(concat);
 957 }
 958
 959 EXPORT_SYMBOL(mtd_concat_create);
 960 EXPORT_SYMBOL(mtd_concat_destroy);
 961
 962 MODULE_LICENSE("GPL");
 963 MODULE_AUTHOR("Robert Kaiser <[email protected]>");
 964 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");