drivers/mtd/mtdconcat.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * MTD device concatenation layer
   4  *
   5  * Copyright © 2002 Robert Kaiser <rkaiser@sysgo.de>
   6  * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * NAND support by Christian Gan <cgan@iders.ca>
   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 #endif
  27
  28 #include <linux/mtd/mtd.h>
  29 #include <linux/mtd/concat.h>
  30
  31 #include <ubi_uboot.h>
  32
  33 /*
  34  * Our storage structure:
  35  * Subdev points to an array of pointers to struct mtd_info objects
  36  * which is allocated along with this structure
  37  *
  38  */
  39 struct mtd_concat {
  40         struct mtd_info mtd;
  41         int num_subdev;
  42         struct mtd_info **subdev;
  43 };
  44
  45 /*
  46  * how to calculate the size required for the above structure,
  47  * including the pointer array subdev points to:
  48  */
  49 #define SIZEOF_STRUCT_MTD_CONCAT(num_subdev)    \
  50         ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))
  51
  52 /*
  53  * Given a pointer to the MTD object in the mtd_concat structure,
  54  * we can retrieve the pointer to that structure with this macro.
  55  */
  56 #define CONCAT(x)  ((struct mtd_concat *)(x))
  57
  58 /*
  59  * MTD methods which look up the relevant subdevice, translate the
  60  * effective address and pass through to the subdevice.
  61  */
  62
  63 static int
  64 concat_read(struct mtd_info *mtd, loff_t from, size_t len,
  65             size_t * retlen, u_char * buf)
  66 {
  67         struct mtd_concat *concat = CONCAT(mtd);
  68         int ret = 0, err;
  69         int i;
  70
  71 #ifdef __UBOOT__
  72         *retlen = 0;
  73 #endif
  74
  75         for (i = 0; i < concat->num_subdev; i++) {
  76                 struct mtd_info *subdev = concat->subdev[i];
  77                 size_t size, retsize;
  78
  79                 if (from >= subdev->size) {
  80                         /* Not destined for this subdev */
  81                         size = 0;
  82                         from -= subdev->size;
  83                         continue;
  84                 }
  85                 if (from + len > subdev->size)
  86                         /* First part goes into this subdev */
  87                         size = subdev->size - from;
  88                 else
  89                         /* Entire transaction goes into this subdev */
  90                         size = len;
  91
  92                 err = mtd_read(subdev, from, size, &retsize, buf);
  93
  94                 /* Save information about bitflips! */
  95                 if (unlikely(err)) {
  96                         if (mtd_is_eccerr(err)) {
  97                                 mtd->ecc_stats.failed++;
  98                                 ret = err;
  99                         } else if (mtd_is_bitflip(err)) {
 100                                 mtd->ecc_stats.corrected++;
 101                                 /* Do not overwrite -EBADMSG !! */
 102                                 if (!ret)
 103                                         ret = err;
 104                         } else
 105                                 return err;
 106                 }
 107
 108                 *retlen += retsize;
 109                 len -= size;
 110                 if (len == 0)
 111                         return ret;
 112
 113                 buf += size;
 114                 from = 0;
 115         }
 116         return -EINVAL;
 117 }
 118
 119 static int
 120 concat_write(struct mtd_info *mtd, loff_t to, size_t len,
 121              size_t * retlen, const u_char * buf)
 122 {
 123         struct mtd_concat *concat = CONCAT(mtd);
 124         int err = -EINVAL;
 125         int i;
 126
 127 #ifdef __UBOOT__
 128         *retlen = 0;
 129 #endif
 130
 131         for (i = 0; i < concat->num_subdev; i++) {
 132                 struct mtd_info *subdev = concat->subdev[i];
 133                 size_t size, retsize;
 134
 135                 if (to >= subdev->size) {
 136                         size = 0;
 137                         to -= subdev->size;
 138                         continue;
 139                 }
 140                 if (to + len > subdev->size)
 141                         size = subdev->size - to;
 142                 else
 143                         size = len;
 144
 145                 err = mtd_write(subdev, to, size, &retsize, buf);
 146                 if (err)
 147                         break;
 148
 149                 *retlen += retsize;
 150                 len -= size;
 151                 if (len == 0)
 152                         break;
 153
 154                 err = -EINVAL;
 155                 buf += size;
 156                 to = 0;
 157         }
 158         return err;
 159 }
 160
 161 #ifndef __UBOOT__
 162 static int
 163 concat_writev(struct mtd_info *mtd, const struct kvec *vecs,
 164                 unsigned long count, loff_t to, size_t * retlen)
 165 {
 166         struct mtd_concat *concat = CONCAT(mtd);
 167         struct kvec *vecs_copy;
 168         unsigned long entry_low, entry_high;
 169         size_t total_len = 0;
 170         int i;
 171         int err = -EINVAL;
 172
 173         /* Calculate total length of data */
 174         for (i = 0; i < count; i++)
 175                 total_len += vecs[i].iov_len;
 176
 177         /* Check alignment */
 178         if (mtd->writesize > 1) {
 179                 uint64_t __to = to;
 180                 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))
 181                         return -EINVAL;
 182         }
 183
 184         /* make a copy of vecs */
 185         vecs_copy = kmemdup(vecs, sizeof(struct kvec) * count, GFP_KERNEL);
 186         if (!vecs_copy)
 187                 return -ENOMEM;
 188
 189         entry_low = 0;
 190         for (i = 0; i < concat->num_subdev; i++) {
 191                 struct mtd_info *subdev = concat->subdev[i];
 192                 size_t size, wsize, retsize, old_iov_len;
 193
 194                 if (to >= subdev->size) {
 195                         to -= subdev->size;
 196                         continue;
 197                 }
 198
 199                 size = min_t(uint64_t, total_len, subdev->size - to);
 200                 wsize = size; /* store for future use */
 201
 202                 entry_high = entry_low;
 203                 while (entry_high < count) {
 204                         if (size <= vecs_copy[entry_high].iov_len)
 205                                 break;
 206                         size -= vecs_copy[entry_high++].iov_len;
 207                 }
 208
 209                 old_iov_len = vecs_copy[entry_high].iov_len;
 210                 vecs_copy[entry_high].iov_len = size;
 211
 212                 err = mtd_writev(subdev, &vecs_copy[entry_low],
 213                                  entry_high - entry_low + 1, to, &retsize);
 214
 215                 vecs_copy[entry_high].iov_len = old_iov_len - size;
 216                 vecs_copy[entry_high].iov_base += size;
 217
 218                 entry_low = entry_high;
 219
 220                 if (err)
 221                         break;
 222
 223                 *retlen += retsize;
 224                 total_len -= wsize;
 225
 226                 if (total_len == 0)
 227                         break;
 228
 229                 err = -EINVAL;
 230                 to = 0;
 231         }
 232
 233         kfree(vecs_copy);
 234         return err;
 235 }
 236 #endif
 237
 238 static int
 239 concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
 240 {
 241         struct mtd_concat *concat = CONCAT(mtd);
 242         struct mtd_oob_ops devops = *ops;
 243         int i, err, ret = 0;
 244
 245         ops->retlen = ops->oobretlen = 0;
 246
 247         for (i = 0; i < concat->num_subdev; i++) {
 248                 struct mtd_info *subdev = concat->subdev[i];
 249
 250                 if (from >= subdev->size) {
 251                         from -= subdev->size;
 252                         continue;
 253                 }
 254
 255                 /* partial read ? */
 256                 if (from + devops.len > subdev->size)
 257                         devops.len = subdev->size - from;
 258
 259                 err = mtd_read_oob(subdev, from, &devops);
 260                 ops->retlen += devops.retlen;
 261                 ops->oobretlen += devops.oobretlen;
 262
 263                 /* Save information about bitflips! */
 264                 if (unlikely(err)) {
 265                         if (mtd_is_eccerr(err)) {
 266                                 mtd->ecc_stats.failed++;
 267                                 ret = err;
 268                         } else if (mtd_is_bitflip(err)) {
 269                                 mtd->ecc_stats.corrected++;
 270                                 /* Do not overwrite -EBADMSG !! */
 271                                 if (!ret)
 272                                         ret = err;
 273                         } else
 274                                 return err;
 275                 }
 276
 277                 if (devops.datbuf) {
 278                         devops.len = ops->len - ops->retlen;
 279                         if (!devops.len)
 280                                 return ret;
 281                         devops.datbuf += devops.retlen;
 282                 }
 283                 if (devops.oobbuf) {
 284                         devops.ooblen = ops->ooblen - ops->oobretlen;
 285                         if (!devops.ooblen)
 286                                 return ret;
 287                         devops.oobbuf += ops->oobretlen;
 288                 }
 289
 290                 from = 0;
 291         }
 292         return -EINVAL;
 293 }
 294
 295 static int
 296 concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)
 297 {
 298         struct mtd_concat *concat = CONCAT(mtd);
 299         struct mtd_oob_ops devops = *ops;
 300         int i, err;
 301
 302         if (!(mtd->flags & MTD_WRITEABLE))
 303                 return -EROFS;
 304
 305         ops->retlen = ops->oobretlen = 0;
 306
 307         for (i = 0; i < concat->num_subdev; i++) {
 308                 struct mtd_info *subdev = concat->subdev[i];
 309
 310                 if (to >= subdev->size) {
 311                         to -= subdev->size;
 312                         continue;
 313                 }
 314
 315                 /* partial write ? */
 316                 if (to + devops.len > subdev->size)
 317                         devops.len = subdev->size - to;
 318
 319                 err = mtd_write_oob(subdev, to, &devops);
 320                 ops->retlen += devops.oobretlen;
 321                 if (err)
 322                         return err;
 323
 324                 if (devops.datbuf) {
 325                         devops.len = ops->len - ops->retlen;
 326                         if (!devops.len)
 327                                 return 0;
 328                         devops.datbuf += devops.retlen;
 329                 }
 330                 if (devops.oobbuf) {
 331                         devops.ooblen = ops->ooblen - ops->oobretlen;
 332                         if (!devops.ooblen)
 333                                 return 0;
 334                         devops.oobbuf += devops.oobretlen;
 335                 }
 336                 to = 0;
 337         }
 338         return -EINVAL;
 339 }
 340
 341 static int concat_dev_erase(struct mtd_info *mtd, struct erase_info *erase)
 342 {
 343         int err;
 344         wait_queue_head_t waitq;
 345         DECLARE_WAITQUEUE(wait, current);
 346
 347         /*
 348          * This code was stol^H^H^H^Hinspired by mtdchar.c
 349          */
 350         init_waitqueue_head(&waitq);
 351
 352         erase->mtd = mtd;
 353         erase->priv = (unsigned long) &waitq;
 354
 355         /*
 356          * FIXME: Allow INTERRUPTIBLE. Which means
 357          * not having the wait_queue head on the stack.
 358          */
 359         err = mtd_erase(mtd, erase);
 360         if (!err) {
 361                 set_current_state(TASK_UNINTERRUPTIBLE);
 362                 add_wait_queue(&waitq, &wait);
 363                 if (erase->state != MTD_ERASE_DONE
 364                     && erase->state != MTD_ERASE_FAILED)
 365                         schedule();
 366                 remove_wait_queue(&waitq, &wait);
 367                 set_current_state(TASK_RUNNING);
 368
 369                 err = (erase->state == MTD_ERASE_FAILED) ? -EIO : 0;
 370         }
 371         return err;
 372 }
 373
 374 static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)
 375 {
 376         struct mtd_concat *concat = CONCAT(mtd);
 377         struct mtd_info *subdev;
 378         int i, err;
 379         uint64_t length, offset = 0;
 380         struct erase_info *erase;
 381
 382         /*
 383          * Check for proper erase block alignment of the to-be-erased area.
 384          * It is easier to do this based on the super device's erase
 385          * region info rather than looking at each particular sub-device
 386          * in turn.
 387          */
 388         if (!concat->mtd.numeraseregions) {
 389                 /* the easy case: device has uniform erase block size */
 390                 if (instr->addr & (concat->mtd.erasesize - 1))
 391                         return -EINVAL;
 392                 if (instr->len & (concat->mtd.erasesize - 1))
 393                         return -EINVAL;
 394         } else {
 395                 /* device has variable erase size */
 396                 struct mtd_erase_region_info *erase_regions =
 397                     concat->mtd.eraseregions;
 398
 399                 /*
 400                  * Find the erase region where the to-be-erased area begins:
 401                  */
 402                 for (i = 0; i < concat->mtd.numeraseregions &&
 403                      instr->addr >= erase_regions[i].offset; i++) ;
 404                 --i;
 405
 406                 /*
 407                  * Now erase_regions[i] is the region in which the
 408                  * to-be-erased area begins. Verify that the starting
 409                  * offset is aligned to this region's erase size:
 410                  */
 411                 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))
 412                         return -EINVAL;
 413
 414                 /*
 415                  * now find the erase region where the to-be-erased area ends:
 416                  */
 417                 for (; i < concat->mtd.numeraseregions &&
 418                      (instr->addr + instr->len) >= erase_regions[i].offset;
 419                      ++i) ;
 420                 --i;
 421                 /*
 422                  * check if the ending offset is aligned to this region's erase size
 423                  */
 424                 if (i < 0 || ((instr->addr + instr->len) &
 425                                         (erase_regions[i].erasesize - 1)))
 426                         return -EINVAL;
 427         }
 428
 429         /* make a local copy of instr to avoid modifying the caller's struct */
 430         erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);
 431
 432         if (!erase)
 433                 return -ENOMEM;
 434
 435         *erase = *instr;
 436         length = instr->len;
 437
 438         /*
 439          * find the subdevice where the to-be-erased area begins, adjust
 440          * starting offset to be relative to the subdevice start
 441          */
 442         for (i = 0; i < concat->num_subdev; i++) {
 443                 subdev = concat->subdev[i];
 444                 if (subdev->size <= erase->addr) {
 445                         erase->addr -= subdev->size;
 446                         offset += subdev->size;
 447                 } else {
 448                         break;
 449                 }
 450         }
 451
 452         /* must never happen since size limit has been verified above */
 453         BUG_ON(i >= concat->num_subdev);
 454
 455         /* now do the erase: */
 456         err = 0;
 457         for (; length > 0; i++) {
 458                 /* loop for all subdevices affected by this request */
 459                 subdev = concat->subdev[i];     /* get current subdevice */
 460
 461                 /* limit length to subdevice's size: */
 462                 if (erase->addr + length > subdev->size)
 463                         erase->len = subdev->size - erase->addr;
 464                 else
 465                         erase->len = length;
 466
 467                 length -= erase->len;
 468                 if ((err = concat_dev_erase(subdev, erase))) {
 469                         /* sanity check: should never happen since
 470                          * block alignment has been checked above */
 471                         BUG_ON(err == -EINVAL);
 472                         if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 473                                 instr->fail_addr = erase->fail_addr + offset;
 474                         break;
 475                 }
 476                 /*
 477                  * erase->addr specifies the offset of the area to be
 478                  * erased *within the current subdevice*. It can be
 479                  * non-zero only the first time through this loop, i.e.
 480                  * for the first subdevice where blocks need to be erased.
 481                  * All the following erases must begin at the start of the
 482                  * current subdevice, i.e. at offset zero.
 483                  */
 484                 erase->addr = 0;
 485                 offset += subdev->size;
 486         }
 487         instr->state = erase->state;
 488         kfree(erase);
 489         if (err)
 490                 return err;
 491
 492         return 0;
 493 }
 494
 495 static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 496 {
 497         struct mtd_concat *concat = CONCAT(mtd);
 498         int i, err = -EINVAL;
 499
 500         for (i = 0; i < concat->num_subdev; i++) {
 501                 struct mtd_info *subdev = concat->subdev[i];
 502                 uint64_t size;
 503
 504                 if (ofs >= subdev->size) {
 505                         size = 0;
 506                         ofs -= subdev->size;
 507                         continue;
 508                 }
 509                 if (ofs + len > subdev->size)
 510                         size = subdev->size - ofs;
 511                 else
 512                         size = len;
 513
 514                 err = mtd_lock(subdev, ofs, size);
 515                 if (err)
 516                         break;
 517
 518                 len -= size;
 519                 if (len == 0)
 520                         break;
 521
 522                 err = -EINVAL;
 523                 ofs = 0;
 524         }
 525
 526         return err;
 527 }
 528
 529 static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 530 {
 531         struct mtd_concat *concat = CONCAT(mtd);
 532         int i, err = 0;
 533
 534         for (i = 0; i < concat->num_subdev; i++) {
 535                 struct mtd_info *subdev = concat->subdev[i];
 536                 uint64_t size;
 537
 538                 if (ofs >= subdev->size) {
 539                         size = 0;
 540                         ofs -= subdev->size;
 541                         continue;
 542                 }
 543                 if (ofs + len > subdev->size)
 544                         size = subdev->size - ofs;
 545                 else
 546                         size = len;
 547
 548                 err = mtd_unlock(subdev, ofs, size);
 549                 if (err)
 550                         break;
 551
 552                 len -= size;
 553                 if (len == 0)
 554                         break;
 555
 556                 err = -EINVAL;
 557                 ofs = 0;
 558         }
 559
 560         return err;
 561 }
 562
 563 static void concat_sync(struct mtd_info *mtd)
 564 {
 565         struct mtd_concat *concat = CONCAT(mtd);
 566         int i;
 567
 568         for (i = 0; i < concat->num_subdev; i++) {
 569                 struct mtd_info *subdev = concat->subdev[i];
 570                 mtd_sync(subdev);
 571         }
 572 }
 573
 574 #ifndef __UBOOT__
 575 static int concat_suspend(struct mtd_info *mtd)
 576 {
 577         struct mtd_concat *concat = CONCAT(mtd);
 578         int i, rc = 0;
 579
 580         for (i = 0; i < concat->num_subdev; i++) {
 581                 struct mtd_info *subdev = concat->subdev[i];
 582                 if ((rc = mtd_suspend(subdev)) < 0)
 583                         return rc;
 584         }
 585         return rc;
 586 }
 587
 588 static void concat_resume(struct mtd_info *mtd)
 589 {
 590         struct mtd_concat *concat = CONCAT(mtd);
 591         int i;
 592
 593         for (i = 0; i < concat->num_subdev; i++) {
 594                 struct mtd_info *subdev = concat->subdev[i];
 595                 mtd_resume(subdev);
 596         }
 597 }
 598 #endif
 599
 600 static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)
 601 {
 602         struct mtd_concat *concat = CONCAT(mtd);
 603         int i, res = 0;
 604
 605         if (!mtd_can_have_bb(concat->subdev[0]))
 606                 return res;
 607
 608         for (i = 0; i < concat->num_subdev; i++) {
 609                 struct mtd_info *subdev = concat->subdev[i];
 610
 611                 if (ofs >= subdev->size) {
 612                         ofs -= subdev->size;
 613                         continue;
 614                 }
 615
 616                 res = mtd_block_isbad(subdev, ofs);
 617                 break;
 618         }
 619
 620         return res;
 621 }
 622
 623 static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)
 624 {
 625         struct mtd_concat *concat = CONCAT(mtd);
 626         int i, err = -EINVAL;
 627
 628         for (i = 0; i < concat->num_subdev; i++) {
 629                 struct mtd_info *subdev = concat->subdev[i];
 630
 631                 if (ofs >= subdev->size) {
 632                         ofs -= subdev->size;
 633                         continue;
 634                 }
 635
 636                 err = mtd_block_markbad(subdev, ofs);
 637                 if (!err)
 638                         mtd->ecc_stats.badblocks++;
 639                 break;
 640         }
 641
 642         return err;
 643 }
 644
 645 /*
 646  * try to support NOMMU mmaps on concatenated devices
 647  * - we don't support subdev spanning as we can't guarantee it'll work
 648  */
 649 static unsigned long concat_get_unmapped_area(struct mtd_info *mtd,
 650                                               unsigned long len,
 651                                               unsigned long offset,
 652                                               unsigned long flags)
 653 {
 654         struct mtd_concat *concat = CONCAT(mtd);
 655         int i;
 656
 657         for (i = 0; i < concat->num_subdev; i++) {
 658                 struct mtd_info *subdev = concat->subdev[i];
 659
 660                 if (offset >= subdev->size) {
 661                         offset -= subdev->size;
 662                         continue;
 663                 }
 664
 665                 return mtd_get_unmapped_area(subdev, len, offset, flags);
 666         }
 667
 668         return (unsigned long) -ENOSYS;
 669 }
 670
 671 /*
 672  * This function constructs a virtual MTD device by concatenating
 673  * num_devs MTD devices. A pointer to the new device object is
 674  * stored to *new_dev upon success. This function does _not_
 675  * register any devices: this is the caller's responsibility.
 676  */
 677 struct mtd_info *mtd_concat_create(struct mtd_info *subdev[],   /* subdevices to concatenate */
 678                                    int num_devs,        /* number of subdevices      */
 679 #ifndef __UBOOT__
 680                                    const char *name)
 681 #else
 682                                    char *name)
 683 #endif
 684 {                               /* name for the new device   */
 685         int i;
 686         size_t size;
 687         struct mtd_concat *concat;
 688         uint32_t max_erasesize, curr_erasesize;
 689         int num_erase_region;
 690         int max_writebufsize = 0;
 691
 692         debug("Concatenating MTD devices:\n");
 693         for (i = 0; i < num_devs; i++)
 694                 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);
 695         debug("into device \"%s\"\n", name);
 696
 697         /* allocate the device structure */
 698         size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);
 699         concat = kzalloc(size, GFP_KERNEL);
 700         if (!concat) {
 701                 printk
 702                     ("memory allocation error while creating concatenated device \"%s\"\n",
 703                      name);
 704                 return NULL;
 705         }
 706         concat->subdev = (struct mtd_info **) (concat + 1);
 707
 708         /*
 709          * Set up the new "super" device's MTD object structure, check for
 710          * incompatibilities between the subdevices.
 711          */
 712         concat->mtd.type = subdev[0]->type;
 713         concat->mtd.flags = subdev[0]->flags;
 714         concat->mtd.size = subdev[0]->size;
 715         concat->mtd.erasesize = subdev[0]->erasesize;
 716         concat->mtd.writesize = subdev[0]->writesize;
 717
 718         for (i = 0; i < num_devs; i++)
 719                 if (max_writebufsize < subdev[i]->writebufsize)
 720                         max_writebufsize = subdev[i]->writebufsize;
 721         concat->mtd.writebufsize = max_writebufsize;
 722
 723         concat->mtd.subpage_sft = subdev[0]->subpage_sft;
 724         concat->mtd.oobsize = subdev[0]->oobsize;
 725         concat->mtd.oobavail = subdev[0]->oobavail;
 726 #ifndef __UBOOT__
 727         if (subdev[0]->_writev)
 728                 concat->mtd._writev = concat_writev;
 729 #endif
 730         if (subdev[0]->_read_oob)
 731                 concat->mtd._read_oob = concat_read_oob;
 732         if (subdev[0]->_write_oob)
 733                 concat->mtd._write_oob = concat_write_oob;
 734         if (subdev[0]->_block_isbad)
 735                 concat->mtd._block_isbad = concat_block_isbad;
 736         if (subdev[0]->_block_markbad)
 737                 concat->mtd._block_markbad = concat_block_markbad;
 738
 739         concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
 740
 741 #ifndef __UBOOT__
 742         concat->mtd.backing_dev_info = subdev[0]->backing_dev_info;
 743 #endif
 744
 745         concat->subdev[0] = subdev[0];
 746
 747         for (i = 1; i < num_devs; i++) {
 748                 if (concat->mtd.type != subdev[i]->type) {
 749                         kfree(concat);
 750                         printk("Incompatible device type on \"%s\"\n",
 751                                subdev[i]->name);
 752                         return NULL;
 753                 }
 754                 if (concat->mtd.flags != subdev[i]->flags) {
 755                         /*
 756                          * Expect all flags except MTD_WRITEABLE to be
 757                          * equal on all subdevices.
 758                          */
 759                         if ((concat->mtd.flags ^ subdev[i]->
 760                              flags) & ~MTD_WRITEABLE) {
 761                                 kfree(concat);
 762                                 printk("Incompatible device flags on \"%s\"\n",
 763                                        subdev[i]->name);
 764                                 return NULL;
 765                         } else
 766                                 /* if writeable attribute differs,
 767                                    make super device writeable */
 768                                 concat->mtd.flags |=
 769                                     subdev[i]->flags & MTD_WRITEABLE;
 770                 }
 771
 772 #ifndef __UBOOT__
 773                 /* only permit direct mapping if the BDIs are all the same
 774                  * - copy-mapping is still permitted
 775                  */
 776                 if (concat->mtd.backing_dev_info !=
 777                     subdev[i]->backing_dev_info)
 778                         concat->mtd.backing_dev_info =
 779                                 &default_backing_dev_info;
 780 #endif
 781
 782                 concat->mtd.size += subdev[i]->size;
 783                 concat->mtd.ecc_stats.badblocks +=
 784                         subdev[i]->ecc_stats.badblocks;
 785                 if (concat->mtd.writesize   !=  subdev[i]->writesize ||
 786                     concat->mtd.subpage_sft != subdev[i]->subpage_sft ||
 787                     concat->mtd.oobsize    !=  subdev[i]->oobsize ||
 788                     !concat->mtd._read_oob  != !subdev[i]->_read_oob ||
 789                     !concat->mtd._write_oob != !subdev[i]->_write_oob) {
 790                         kfree(concat);
 791                         printk("Incompatible OOB or ECC data on \"%s\"\n",
 792                                subdev[i]->name);
 793                         return NULL;
 794                 }
 795                 concat->subdev[i] = subdev[i];
 796
 797         }
 798
 799         concat->mtd.ecclayout = subdev[0]->ecclayout;
 800
 801         concat->num_subdev = num_devs;
 802         concat->mtd.name = name;
 803
 804         concat->mtd._erase = concat_erase;
 805         concat->mtd._read = concat_read;
 806         concat->mtd._write = concat_write;
 807         concat->mtd._sync = concat_sync;
 808         concat->mtd._lock = concat_lock;
 809         concat->mtd._unlock = concat_unlock;
 810 #ifndef __UBOOT__
 811         concat->mtd._suspend = concat_suspend;
 812         concat->mtd._resume = concat_resume;
 813 #endif
 814         concat->mtd._get_unmapped_area = concat_get_unmapped_area;
 815
 816         /*
 817          * Combine the erase block size info of the subdevices:
 818          *
 819          * first, walk the map of the new device and see how
 820          * many changes in erase size we have
 821          */
 822         max_erasesize = curr_erasesize = subdev[0]->erasesize;
 823         num_erase_region = 1;
 824         for (i = 0; i < num_devs; i++) {
 825                 if (subdev[i]->numeraseregions == 0) {
 826                         /* current subdevice has uniform erase size */
 827                         if (subdev[i]->erasesize != curr_erasesize) {
 828                                 /* if it differs from the last subdevice's erase size, count it */
 829                                 ++num_erase_region;
 830                                 curr_erasesize = subdev[i]->erasesize;
 831                                 if (curr_erasesize > max_erasesize)
 832                                         max_erasesize = curr_erasesize;
 833                         }
 834                 } else {
 835                         /* current subdevice has variable erase size */
 836                         int j;
 837                         for (j = 0; j < subdev[i]->numeraseregions; j++) {
 838
 839                                 /* walk the list of erase regions, count any changes */
 840                                 if (subdev[i]->eraseregions[j].erasesize !=
 841                                     curr_erasesize) {
 842                                         ++num_erase_region;
 843                                         curr_erasesize =
 844                                             subdev[i]->eraseregions[j].
 845                                             erasesize;
 846                                         if (curr_erasesize > max_erasesize)
 847                                                 max_erasesize = curr_erasesize;
 848                                 }
 849                         }
 850                 }
 851         }
 852
 853         if (num_erase_region == 1) {
 854                 /*
 855                  * All subdevices have the same uniform erase size.
 856                  * This is easy:
 857                  */
 858                 concat->mtd.erasesize = curr_erasesize;
 859                 concat->mtd.numeraseregions = 0;
 860         } else {
 861                 uint64_t tmp64;
 862
 863                 /*
 864                  * erase block size varies across the subdevices: allocate
 865                  * space to store the data describing the variable erase regions
 866                  */
 867                 struct mtd_erase_region_info *erase_region_p;
 868                 uint64_t begin, position;
 869
 870                 concat->mtd.erasesize = max_erasesize;
 871                 concat->mtd.numeraseregions = num_erase_region;
 872                 concat->mtd.eraseregions = erase_region_p =
 873                     kmalloc(num_erase_region *
 874                             sizeof (struct mtd_erase_region_info), GFP_KERNEL);
 875                 if (!erase_region_p) {
 876                         kfree(concat);
 877                         printk
 878                             ("memory allocation error while creating erase region list"
 879                              " for device \"%s\"\n", name);
 880                         return NULL;
 881                 }
 882
 883                 /*
 884                  * walk the map of the new device once more and fill in
 885                  * in erase region info:
 886                  */
 887                 curr_erasesize = subdev[0]->erasesize;
 888                 begin = position = 0;
 889                 for (i = 0; i < num_devs; i++) {
 890                         if (subdev[i]->numeraseregions == 0) {
 891                                 /* current subdevice has uniform erase size */
 892                                 if (subdev[i]->erasesize != curr_erasesize) {
 893                                         /*
 894                                          *  fill in an mtd_erase_region_info structure for the area
 895                                          *  we have walked so far:
 896                                          */
 897                                         erase_region_p->offset = begin;
 898                                         erase_region_p->erasesize =
 899                                             curr_erasesize;
 900                                         tmp64 = position - begin;
 901                                         do_div(tmp64, curr_erasesize);
 902                                         erase_region_p->numblocks = tmp64;
 903                                         begin = position;
 904
 905                                         curr_erasesize = subdev[i]->erasesize;
 906                                         ++erase_region_p;
 907                                 }
 908                                 position += subdev[i]->size;
 909                         } else {
 910                                 /* current subdevice has variable erase size */
 911                                 int j;
 912                                 for (j = 0; j < subdev[i]->numeraseregions; j++) {
 913                                         /* walk the list of erase regions, count any changes */
 914                                         if (subdev[i]->eraseregions[j].
 915                                             erasesize != curr_erasesize) {
 916                                                 erase_region_p->offset = begin;
 917                                                 erase_region_p->erasesize =
 918                                                     curr_erasesize;
 919                                                 tmp64 = position - begin;
 920                                                 do_div(tmp64, curr_erasesize);
 921                                                 erase_region_p->numblocks = tmp64;
 922                                                 begin = position;
 923
 924                                                 curr_erasesize =
 925                                                     subdev[i]->eraseregions[j].
 926                                                     erasesize;
 927                                                 ++erase_region_p;
 928                                         }
 929                                         position +=
 930                                             subdev[i]->eraseregions[j].
 931                                             numblocks * (uint64_t)curr_erasesize;
 932                                 }
 933                         }
 934                 }
 935                 /* Now write the final entry */
 936                 erase_region_p->offset = begin;
 937                 erase_region_p->erasesize = curr_erasesize;
 938                 tmp64 = position - begin;
 939                 do_div(tmp64, curr_erasesize);
 940                 erase_region_p->numblocks = tmp64;
 941         }
 942
 943         return &concat->mtd;
 944 }
 945
 946 /*
 947  * This function destroys an MTD object obtained from concat_mtd_devs()
 948  */
 949
 950 void mtd_concat_destroy(struct mtd_info *mtd)
 951 {
 952         struct mtd_concat *concat = CONCAT(mtd);
 953         if (concat->mtd.numeraseregions)
 954                 kfree(concat->mtd.eraseregions);
 955         kfree(concat);
 956 }
 957
 958 EXPORT_SYMBOL(mtd_concat_create);
 959 EXPORT_SYMBOL(mtd_concat_destroy);
 960
 961 MODULE_LICENSE("GPL");
 962 MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");
 963 MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");