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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * MTD device concatenation layer4 *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#include <linux/kernel.h>12#include <linux/module.h>13#include <linux/slab.h>14#include <linux/sched.h>15#include <linux/types.h>16#include <linux/backing-dev.h>17 18#include <linux/mtd/mtd.h>19#include <linux/mtd/concat.h>20 21#include <asm/div64.h>22 23/*24 * Our storage structure:25 * Subdev points to an array of pointers to struct mtd_info objects26 * which is allocated along with this structure27 *28 */29struct mtd_concat {30 struct mtd_info mtd;31 int num_subdev;32 struct mtd_info **subdev;33};34 35/*36 * how to calculate the size required for the above structure,37 * including the pointer array subdev points to:38 */39#define SIZEOF_STRUCT_MTD_CONCAT(num_subdev) \40 ((sizeof(struct mtd_concat) + (num_subdev) * sizeof(struct mtd_info *)))41 42/*43 * Given a pointer to the MTD object in the mtd_concat structure,44 * we can retrieve the pointer to that structure with this macro.45 */46#define CONCAT(x) ((struct mtd_concat *)(x))47 48/*49 * MTD methods which look up the relevant subdevice, translate the50 * effective address and pass through to the subdevice.51 */52 53static int54concat_read(struct mtd_info *mtd, loff_t from, size_t len,55 size_t * retlen, u_char * buf)56{57 struct mtd_concat *concat = CONCAT(mtd);58 int ret = 0, err;59 int i;60 61 for (i = 0; i < concat->num_subdev; i++) {62 struct mtd_info *subdev = concat->subdev[i];63 size_t size, retsize;64 65 if (from >= subdev->size) {66 /* Not destined for this subdev */67 size = 0;68 from -= subdev->size;69 continue;70 }71 if (from + len > subdev->size)72 /* First part goes into this subdev */73 size = subdev->size - from;74 else75 /* Entire transaction goes into this subdev */76 size = len;77 78 err = mtd_read(subdev, from, size, &retsize, buf);79 80 /* Save information about bitflips! */81 if (unlikely(err)) {82 if (mtd_is_eccerr(err)) {83 mtd->ecc_stats.failed++;84 ret = err;85 } else if (mtd_is_bitflip(err)) {86 mtd->ecc_stats.corrected++;87 /* Do not overwrite -EBADMSG !! */88 if (!ret)89 ret = err;90 } else91 return err;92 }93 94 *retlen += retsize;95 len -= size;96 if (len == 0)97 return ret;98 99 buf += size;100 from = 0;101 }102 return -EINVAL;103}104 105static int106concat_panic_write(struct mtd_info *mtd, loff_t to, size_t len,107 size_t * retlen, const u_char * buf)108{109 struct mtd_concat *concat = CONCAT(mtd);110 int err = -EINVAL;111 int i;112 for (i = 0; i < concat->num_subdev; i++) {113 struct mtd_info *subdev = concat->subdev[i];114 size_t size, retsize;115 116 if (to >= subdev->size) {117 to -= subdev->size;118 continue;119 }120 if (to + len > subdev->size)121 size = subdev->size - to;122 else123 size = len;124 125 err = mtd_panic_write(subdev, to, size, &retsize, buf);126 if (err == -EOPNOTSUPP) {127 printk(KERN_ERR "mtdconcat: Cannot write from panic without panic_write\n");128 return err;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 146static int147concat_write(struct mtd_info *mtd, loff_t to, size_t len,148 size_t * retlen, const u_char * buf)149{150 struct mtd_concat *concat = CONCAT(mtd);151 int err = -EINVAL;152 int i;153 154 for (i = 0; i < concat->num_subdev; i++) {155 struct mtd_info *subdev = concat->subdev[i];156 size_t size, retsize;157 158 if (to >= subdev->size) {159 size = 0;160 to -= subdev->size;161 continue;162 }163 if (to + len > subdev->size)164 size = subdev->size - to;165 else166 size = len;167 168 err = mtd_write(subdev, to, size, &retsize, buf);169 if (err)170 break;171 172 *retlen += retsize;173 len -= size;174 if (len == 0)175 break;176 177 err = -EINVAL;178 buf += size;179 to = 0;180 }181 return err;182}183 184static int185concat_writev(struct mtd_info *mtd, const struct kvec *vecs,186 unsigned long count, loff_t to, size_t * retlen)187{188 struct mtd_concat *concat = CONCAT(mtd);189 struct kvec *vecs_copy;190 unsigned long entry_low, entry_high;191 size_t total_len = 0;192 int i;193 int err = -EINVAL;194 195 /* Calculate total length of data */196 for (i = 0; i < count; i++)197 total_len += vecs[i].iov_len;198 199 /* Check alignment */200 if (mtd->writesize > 1) {201 uint64_t __to = to;202 if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize))203 return -EINVAL;204 }205 206 /* make a copy of vecs */207 vecs_copy = kmemdup_array(vecs, count, sizeof(struct kvec), GFP_KERNEL);208 if (!vecs_copy)209 return -ENOMEM;210 211 entry_low = 0;212 for (i = 0; i < concat->num_subdev; i++) {213 struct mtd_info *subdev = concat->subdev[i];214 size_t size, wsize, retsize, old_iov_len;215 216 if (to >= subdev->size) {217 to -= subdev->size;218 continue;219 }220 221 size = min_t(uint64_t, total_len, subdev->size - to);222 wsize = size; /* store for future use */223 224 entry_high = entry_low;225 while (entry_high < count) {226 if (size <= vecs_copy[entry_high].iov_len)227 break;228 size -= vecs_copy[entry_high++].iov_len;229 }230 231 old_iov_len = vecs_copy[entry_high].iov_len;232 vecs_copy[entry_high].iov_len = size;233 234 err = mtd_writev(subdev, &vecs_copy[entry_low],235 entry_high - entry_low + 1, to, &retsize);236 237 vecs_copy[entry_high].iov_len = old_iov_len - size;238 vecs_copy[entry_high].iov_base += size;239 240 entry_low = entry_high;241 242 if (err)243 break;244 245 *retlen += retsize;246 total_len -= wsize;247 248 if (total_len == 0)249 break;250 251 err = -EINVAL;252 to = 0;253 }254 255 kfree(vecs_copy);256 return err;257}258 259static int260concat_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)261{262 struct mtd_concat *concat = CONCAT(mtd);263 struct mtd_oob_ops devops = *ops;264 int i, err, ret = 0;265 266 ops->retlen = ops->oobretlen = 0;267 268 for (i = 0; i < concat->num_subdev; i++) {269 struct mtd_info *subdev = concat->subdev[i];270 271 if (from >= subdev->size) {272 from -= subdev->size;273 continue;274 }275 276 /* partial read ? */277 if (from + devops.len > subdev->size)278 devops.len = subdev->size - from;279 280 err = mtd_read_oob(subdev, from, &devops);281 ops->retlen += devops.retlen;282 ops->oobretlen += devops.oobretlen;283 284 /* Save information about bitflips! */285 if (unlikely(err)) {286 if (mtd_is_eccerr(err)) {287 mtd->ecc_stats.failed++;288 ret = err;289 } else if (mtd_is_bitflip(err)) {290 mtd->ecc_stats.corrected++;291 /* Do not overwrite -EBADMSG !! */292 if (!ret)293 ret = err;294 } else295 return err;296 }297 298 if (devops.datbuf) {299 devops.len = ops->len - ops->retlen;300 if (!devops.len)301 return ret;302 devops.datbuf += devops.retlen;303 }304 if (devops.oobbuf) {305 devops.ooblen = ops->ooblen - ops->oobretlen;306 if (!devops.ooblen)307 return ret;308 devops.oobbuf += ops->oobretlen;309 }310 311 from = 0;312 }313 return -EINVAL;314}315 316static int317concat_write_oob(struct mtd_info *mtd, loff_t to, struct mtd_oob_ops *ops)318{319 struct mtd_concat *concat = CONCAT(mtd);320 struct mtd_oob_ops devops = *ops;321 int i, err;322 323 if (!(mtd->flags & MTD_WRITEABLE))324 return -EROFS;325 326 ops->retlen = ops->oobretlen = 0;327 328 for (i = 0; i < concat->num_subdev; i++) {329 struct mtd_info *subdev = concat->subdev[i];330 331 if (to >= subdev->size) {332 to -= subdev->size;333 continue;334 }335 336 /* partial write ? */337 if (to + devops.len > subdev->size)338 devops.len = subdev->size - to;339 340 err = mtd_write_oob(subdev, to, &devops);341 ops->retlen += devops.retlen;342 ops->oobretlen += devops.oobretlen;343 if (err)344 return err;345 346 if (devops.datbuf) {347 devops.len = ops->len - ops->retlen;348 if (!devops.len)349 return 0;350 devops.datbuf += devops.retlen;351 }352 if (devops.oobbuf) {353 devops.ooblen = ops->ooblen - ops->oobretlen;354 if (!devops.ooblen)355 return 0;356 devops.oobbuf += devops.oobretlen;357 }358 to = 0;359 }360 return -EINVAL;361}362 363static int concat_erase(struct mtd_info *mtd, struct erase_info *instr)364{365 struct mtd_concat *concat = CONCAT(mtd);366 struct mtd_info *subdev;367 int i, err;368 uint64_t length, offset = 0;369 struct erase_info *erase;370 371 /*372 * Check for proper erase block alignment of the to-be-erased area.373 * It is easier to do this based on the super device's erase374 * region info rather than looking at each particular sub-device375 * in turn.376 */377 if (!concat->mtd.numeraseregions) {378 /* the easy case: device has uniform erase block size */379 if (instr->addr & (concat->mtd.erasesize - 1))380 return -EINVAL;381 if (instr->len & (concat->mtd.erasesize - 1))382 return -EINVAL;383 } else {384 /* device has variable erase size */385 struct mtd_erase_region_info *erase_regions =386 concat->mtd.eraseregions;387 388 /*389 * Find the erase region where the to-be-erased area begins:390 */391 for (i = 0; i < concat->mtd.numeraseregions &&392 instr->addr >= erase_regions[i].offset; i++) ;393 --i;394 395 /*396 * Now erase_regions[i] is the region in which the397 * to-be-erased area begins. Verify that the starting398 * offset is aligned to this region's erase size:399 */400 if (i < 0 || instr->addr & (erase_regions[i].erasesize - 1))401 return -EINVAL;402 403 /*404 * now find the erase region where the to-be-erased area ends:405 */406 for (; i < concat->mtd.numeraseregions &&407 (instr->addr + instr->len) >= erase_regions[i].offset;408 ++i) ;409 --i;410 /*411 * check if the ending offset is aligned to this region's erase size412 */413 if (i < 0 || ((instr->addr + instr->len) &414 (erase_regions[i].erasesize - 1)))415 return -EINVAL;416 }417 418 /* make a local copy of instr to avoid modifying the caller's struct */419 erase = kmalloc(sizeof (struct erase_info), GFP_KERNEL);420 421 if (!erase)422 return -ENOMEM;423 424 *erase = *instr;425 length = instr->len;426 427 /*428 * find the subdevice where the to-be-erased area begins, adjust429 * starting offset to be relative to the subdevice start430 */431 for (i = 0; i < concat->num_subdev; i++) {432 subdev = concat->subdev[i];433 if (subdev->size <= erase->addr) {434 erase->addr -= subdev->size;435 offset += subdev->size;436 } else {437 break;438 }439 }440 441 /* must never happen since size limit has been verified above */442 BUG_ON(i >= concat->num_subdev);443 444 /* now do the erase: */445 err = 0;446 for (; length > 0; i++) {447 /* loop for all subdevices affected by this request */448 subdev = concat->subdev[i]; /* get current subdevice */449 450 /* limit length to subdevice's size: */451 if (erase->addr + length > subdev->size)452 erase->len = subdev->size - erase->addr;453 else454 erase->len = length;455 456 length -= erase->len;457 if ((err = mtd_erase(subdev, erase))) {458 /* sanity check: should never happen since459 * block alignment has been checked above */460 BUG_ON(err == -EINVAL);461 if (erase->fail_addr != MTD_FAIL_ADDR_UNKNOWN)462 instr->fail_addr = erase->fail_addr + offset;463 break;464 }465 /*466 * erase->addr specifies the offset of the area to be467 * erased *within the current subdevice*. It can be468 * non-zero only the first time through this loop, i.e.469 * for the first subdevice where blocks need to be erased.470 * All the following erases must begin at the start of the471 * current subdevice, i.e. at offset zero.472 */473 erase->addr = 0;474 offset += subdev->size;475 }476 kfree(erase);477 478 return err;479}480 481static int concat_xxlock(struct mtd_info *mtd, loff_t ofs, uint64_t len,482 bool is_lock)483{484 struct mtd_concat *concat = CONCAT(mtd);485 int i, err = -EINVAL;486 487 for (i = 0; i < concat->num_subdev; i++) {488 struct mtd_info *subdev = concat->subdev[i];489 uint64_t size;490 491 if (ofs >= subdev->size) {492 size = 0;493 ofs -= subdev->size;494 continue;495 }496 if (ofs + len > subdev->size)497 size = subdev->size - ofs;498 else499 size = len;500 501 if (is_lock)502 err = mtd_lock(subdev, ofs, size);503 else504 err = mtd_unlock(subdev, ofs, size);505 if (err)506 break;507 508 len -= size;509 if (len == 0)510 break;511 512 err = -EINVAL;513 ofs = 0;514 }515 516 return err;517}518 519static int concat_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)520{521 return concat_xxlock(mtd, ofs, len, true);522}523 524static int concat_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)525{526 return concat_xxlock(mtd, ofs, len, false);527}528 529static int concat_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)530{531 struct mtd_concat *concat = CONCAT(mtd);532 int i, err = -EINVAL;533 534 for (i = 0; i < concat->num_subdev; i++) {535 struct mtd_info *subdev = concat->subdev[i];536 537 if (ofs >= subdev->size) {538 ofs -= subdev->size;539 continue;540 }541 542 if (ofs + len > subdev->size)543 break;544 545 return mtd_is_locked(subdev, ofs, len);546 }547 548 return err;549}550 551static void concat_sync(struct mtd_info *mtd)552{553 struct mtd_concat *concat = CONCAT(mtd);554 int i;555 556 for (i = 0; i < concat->num_subdev; i++) {557 struct mtd_info *subdev = concat->subdev[i];558 mtd_sync(subdev);559 }560}561 562static int concat_suspend(struct mtd_info *mtd)563{564 struct mtd_concat *concat = CONCAT(mtd);565 int i, rc = 0;566 567 for (i = 0; i < concat->num_subdev; i++) {568 struct mtd_info *subdev = concat->subdev[i];569 if ((rc = mtd_suspend(subdev)) < 0)570 return rc;571 }572 return rc;573}574 575static void concat_resume(struct mtd_info *mtd)576{577 struct mtd_concat *concat = CONCAT(mtd);578 int i;579 580 for (i = 0; i < concat->num_subdev; i++) {581 struct mtd_info *subdev = concat->subdev[i];582 mtd_resume(subdev);583 }584}585 586static int concat_block_isbad(struct mtd_info *mtd, loff_t ofs)587{588 struct mtd_concat *concat = CONCAT(mtd);589 int i, res = 0;590 591 if (!mtd_can_have_bb(concat->subdev[0]))592 return res;593 594 for (i = 0; i < concat->num_subdev; i++) {595 struct mtd_info *subdev = concat->subdev[i];596 597 if (ofs >= subdev->size) {598 ofs -= subdev->size;599 continue;600 }601 602 res = mtd_block_isbad(subdev, ofs);603 break;604 }605 606 return res;607}608 609static int concat_block_markbad(struct mtd_info *mtd, loff_t ofs)610{611 struct mtd_concat *concat = CONCAT(mtd);612 int i, err = -EINVAL;613 614 for (i = 0; i < concat->num_subdev; i++) {615 struct mtd_info *subdev = concat->subdev[i];616 617 if (ofs >= subdev->size) {618 ofs -= subdev->size;619 continue;620 }621 622 err = mtd_block_markbad(subdev, ofs);623 if (!err)624 mtd->ecc_stats.badblocks++;625 break;626 }627 628 return err;629}630 631/*632 * This function constructs a virtual MTD device by concatenating633 * num_devs MTD devices. A pointer to the new device object is634 * stored to *new_dev upon success. This function does _not_635 * register any devices: this is the caller's responsibility.636 */637struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to concatenate */638 int num_devs, /* number of subdevices */639 const char *name)640{ /* name for the new device */641 int i;642 size_t size;643 struct mtd_concat *concat;644 struct mtd_info *subdev_master = NULL;645 uint32_t max_erasesize, curr_erasesize;646 int num_erase_region;647 int max_writebufsize = 0;648 649 printk(KERN_NOTICE "Concatenating MTD devices:\n");650 for (i = 0; i < num_devs; i++)651 printk(KERN_NOTICE "(%d): \"%s\"\n", i, subdev[i]->name);652 printk(KERN_NOTICE "into device \"%s\"\n", name);653 654 /* allocate the device structure */655 size = SIZEOF_STRUCT_MTD_CONCAT(num_devs);656 concat = kzalloc(size, GFP_KERNEL);657 if (!concat) {658 printk659 ("memory allocation error while creating concatenated device \"%s\"\n",660 name);661 return NULL;662 }663 concat->subdev = (struct mtd_info **) (concat + 1);664 665 /*666 * Set up the new "super" device's MTD object structure, check for667 * incompatibilities between the subdevices.668 */669 concat->mtd.type = subdev[0]->type;670 concat->mtd.flags = subdev[0]->flags;671 concat->mtd.size = subdev[0]->size;672 concat->mtd.erasesize = subdev[0]->erasesize;673 concat->mtd.writesize = subdev[0]->writesize;674 675 for (i = 0; i < num_devs; i++)676 if (max_writebufsize < subdev[i]->writebufsize)677 max_writebufsize = subdev[i]->writebufsize;678 concat->mtd.writebufsize = max_writebufsize;679 680 concat->mtd.subpage_sft = subdev[0]->subpage_sft;681 concat->mtd.oobsize = subdev[0]->oobsize;682 concat->mtd.oobavail = subdev[0]->oobavail;683 684 subdev_master = mtd_get_master(subdev[0]);685 if (subdev_master->_writev)686 concat->mtd._writev = concat_writev;687 if (subdev_master->_read_oob)688 concat->mtd._read_oob = concat_read_oob;689 if (subdev_master->_write_oob)690 concat->mtd._write_oob = concat_write_oob;691 if (subdev_master->_block_isbad)692 concat->mtd._block_isbad = concat_block_isbad;693 if (subdev_master->_block_markbad)694 concat->mtd._block_markbad = concat_block_markbad;695 if (subdev_master->_panic_write)696 concat->mtd._panic_write = concat_panic_write;697 if (subdev_master->_read)698 concat->mtd._read = concat_read;699 if (subdev_master->_write)700 concat->mtd._write = concat_write;701 702 concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;703 704 concat->subdev[0] = subdev[0];705 706 for (i = 1; i < num_devs; i++) {707 if (concat->mtd.type != subdev[i]->type) {708 kfree(concat);709 printk("Incompatible device type on \"%s\"\n",710 subdev[i]->name);711 return NULL;712 }713 if (concat->mtd.flags != subdev[i]->flags) {714 /*715 * Expect all flags except MTD_WRITEABLE to be716 * equal on all subdevices.717 */718 if ((concat->mtd.flags ^ subdev[i]->719 flags) & ~MTD_WRITEABLE) {720 kfree(concat);721 printk("Incompatible device flags on \"%s\"\n",722 subdev[i]->name);723 return NULL;724 } else725 /* if writeable attribute differs,726 make super device writeable */727 concat->mtd.flags |=728 subdev[i]->flags & MTD_WRITEABLE;729 }730 731 subdev_master = mtd_get_master(subdev[i]);732 concat->mtd.size += subdev[i]->size;733 concat->mtd.ecc_stats.badblocks +=734 subdev[i]->ecc_stats.badblocks;735 if (concat->mtd.writesize != subdev[i]->writesize ||736 concat->mtd.subpage_sft != subdev[i]->subpage_sft ||737 concat->mtd.oobsize != subdev[i]->oobsize ||738 !concat->mtd._read_oob != !subdev_master->_read_oob ||739 !concat->mtd._write_oob != !subdev_master->_write_oob) {740 /*741 * Check against subdev[i] for data members, because742 * subdev's attributes may be different from master743 * mtd device. Check against subdev's master mtd744 * device for callbacks, because the existence of745 * subdev's callbacks is decided by master mtd device.746 */747 kfree(concat);748 printk("Incompatible OOB or ECC data on \"%s\"\n",749 subdev[i]->name);750 return NULL;751 }752 concat->subdev[i] = subdev[i];753 754 }755 756 mtd_set_ooblayout(&concat->mtd, subdev[0]->ooblayout);757 758 concat->num_subdev = num_devs;759 concat->mtd.name = name;760 761 concat->mtd._erase = concat_erase;762 concat->mtd._sync = concat_sync;763 concat->mtd._lock = concat_lock;764 concat->mtd._unlock = concat_unlock;765 concat->mtd._is_locked = concat_is_locked;766 concat->mtd._suspend = concat_suspend;767 concat->mtd._resume = concat_resume;768 769 /*770 * Combine the erase block size info of the subdevices:771 *772 * first, walk the map of the new device and see how773 * many changes in erase size we have774 */775 max_erasesize = curr_erasesize = subdev[0]->erasesize;776 num_erase_region = 1;777 for (i = 0; i < num_devs; i++) {778 if (subdev[i]->numeraseregions == 0) {779 /* current subdevice has uniform erase size */780 if (subdev[i]->erasesize != curr_erasesize) {781 /* if it differs from the last subdevice's erase size, count it */782 ++num_erase_region;783 curr_erasesize = subdev[i]->erasesize;784 if (curr_erasesize > max_erasesize)785 max_erasesize = curr_erasesize;786 }787 } else {788 /* current subdevice has variable erase size */789 int j;790 for (j = 0; j < subdev[i]->numeraseregions; j++) {791 792 /* walk the list of erase regions, count any changes */793 if (subdev[i]->eraseregions[j].erasesize !=794 curr_erasesize) {795 ++num_erase_region;796 curr_erasesize =797 subdev[i]->eraseregions[j].798 erasesize;799 if (curr_erasesize > max_erasesize)800 max_erasesize = curr_erasesize;801 }802 }803 }804 }805 806 if (num_erase_region == 1) {807 /*808 * All subdevices have the same uniform erase size.809 * This is easy:810 */811 concat->mtd.erasesize = curr_erasesize;812 concat->mtd.numeraseregions = 0;813 } else {814 uint64_t tmp64;815 816 /*817 * erase block size varies across the subdevices: allocate818 * space to store the data describing the variable erase regions819 */820 struct mtd_erase_region_info *erase_region_p;821 uint64_t begin, position;822 823 concat->mtd.erasesize = max_erasesize;824 concat->mtd.numeraseregions = num_erase_region;825 concat->mtd.eraseregions = erase_region_p =826 kmalloc_array(num_erase_region,827 sizeof(struct mtd_erase_region_info),828 GFP_KERNEL);829 if (!erase_region_p) {830 kfree(concat);831 printk832 ("memory allocation error while creating erase region list"833 " for device \"%s\"\n", name);834 return NULL;835 }836 837 /*838 * walk the map of the new device once more and fill in839 * erase region info:840 */841 curr_erasesize = subdev[0]->erasesize;842 begin = position = 0;843 for (i = 0; i < num_devs; i++) {844 if (subdev[i]->numeraseregions == 0) {845 /* current subdevice has uniform erase size */846 if (subdev[i]->erasesize != curr_erasesize) {847 /*848 * fill in an mtd_erase_region_info structure for the area849 * we have walked so far:850 */851 erase_region_p->offset = begin;852 erase_region_p->erasesize =853 curr_erasesize;854 tmp64 = position - begin;855 do_div(tmp64, curr_erasesize);856 erase_region_p->numblocks = tmp64;857 begin = position;858 859 curr_erasesize = subdev[i]->erasesize;860 ++erase_region_p;861 }862 position += subdev[i]->size;863 } else {864 /* current subdevice has variable erase size */865 int j;866 for (j = 0; j < subdev[i]->numeraseregions; j++) {867 /* walk the list of erase regions, count any changes */868 if (subdev[i]->eraseregions[j].869 erasesize != curr_erasesize) {870 erase_region_p->offset = begin;871 erase_region_p->erasesize =872 curr_erasesize;873 tmp64 = position - begin;874 do_div(tmp64, curr_erasesize);875 erase_region_p->numblocks = tmp64;876 begin = position;877 878 curr_erasesize =879 subdev[i]->eraseregions[j].880 erasesize;881 ++erase_region_p;882 }883 position +=884 subdev[i]->eraseregions[j].885 numblocks * (uint64_t)curr_erasesize;886 }887 }888 }889 /* Now write the final entry */890 erase_region_p->offset = begin;891 erase_region_p->erasesize = curr_erasesize;892 tmp64 = position - begin;893 do_div(tmp64, curr_erasesize);894 erase_region_p->numblocks = tmp64;895 }896 897 return &concat->mtd;898}899 900/* Cleans the context obtained from mtd_concat_create() */901void mtd_concat_destroy(struct mtd_info *mtd)902{903 struct mtd_concat *concat = CONCAT(mtd);904 if (concat->mtd.numeraseregions)905 kfree(concat->mtd.eraseregions);906 kfree(concat);907}908 909EXPORT_SYMBOL(mtd_concat_create);910EXPORT_SYMBOL(mtd_concat_destroy);911 912MODULE_LICENSE("GPL");913MODULE_AUTHOR("Robert Kaiser <rkaiser@sysgo.de>");914MODULE_DESCRIPTION("Generic support for concatenating of MTD devices");915