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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Simple MTD partitioning layer4 *5 * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>6 * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>7 * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>8 */9 10#include <linux/module.h>11#include <linux/types.h>12#include <linux/kernel.h>13#include <linux/slab.h>14#include <linux/list.h>15#include <linux/kmod.h>16#include <linux/mtd/mtd.h>17#include <linux/mtd/partitions.h>18#include <linux/err.h>19#include <linux/of.h>20#include <linux/of_platform.h>21 22#include "mtdcore.h"23 24/*25 * MTD methods which simply translate the effective address and pass through26 * to the _real_ device.27 */28 29static inline void free_partition(struct mtd_info *mtd)30{31 kfree(mtd->name);32 kfree(mtd);33}34 35void release_mtd_partition(struct mtd_info *mtd)36{37 WARN_ON(!list_empty(&mtd->part.node));38 free_partition(mtd);39}40 41static struct mtd_info *allocate_partition(struct mtd_info *parent,42 const struct mtd_partition *part,43 int partno, uint64_t cur_offset)44{45 struct mtd_info *master = mtd_get_master(parent);46 int wr_alignment = (parent->flags & MTD_NO_ERASE) ?47 master->writesize : master->erasesize;48 u64 parent_size = mtd_is_partition(parent) ?49 parent->part.size : parent->size;50 struct mtd_info *child;51 u32 remainder;52 char *name;53 u64 tmp;54 55 /* allocate the partition structure */56 child = kzalloc(sizeof(*child), GFP_KERNEL);57 name = kstrdup(part->name, GFP_KERNEL);58 if (!name || !child) {59 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",60 parent->name);61 kfree(name);62 kfree(child);63 return ERR_PTR(-ENOMEM);64 }65 66 /* set up the MTD object for this partition */67 child->type = parent->type;68 child->part.flags = parent->flags & ~part->mask_flags;69 child->part.flags |= part->add_flags;70 child->flags = child->part.flags;71 child->part.size = part->size;72 child->writesize = parent->writesize;73 child->writebufsize = parent->writebufsize;74 child->oobsize = parent->oobsize;75 child->oobavail = parent->oobavail;76 child->subpage_sft = parent->subpage_sft;77 78 child->name = name;79 child->owner = parent->owner;80 81 /* NOTE: Historically, we didn't arrange MTDs as a tree out of82 * concern for showing the same data in multiple partitions.83 * However, it is very useful to have the master node present,84 * so the MTD_PARTITIONED_MASTER option allows that. The master85 * will have device nodes etc only if this is set, so make the86 * parent conditional on that option. Note, this is a way to87 * distinguish between the parent and its partitions in sysfs.88 */89 child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?90 &parent->dev : parent->dev.parent;91 child->dev.of_node = part->of_node;92 child->parent = parent;93 child->part.offset = part->offset;94 INIT_LIST_HEAD(&child->partitions);95 96 if (child->part.offset == MTDPART_OFS_APPEND)97 child->part.offset = cur_offset;98 if (child->part.offset == MTDPART_OFS_NXTBLK) {99 tmp = cur_offset;100 child->part.offset = cur_offset;101 remainder = do_div(tmp, wr_alignment);102 if (remainder) {103 child->part.offset += wr_alignment - remainder;104 printk(KERN_NOTICE "Moving partition %d: "105 "0x%012llx -> 0x%012llx\n", partno,106 (unsigned long long)cur_offset,107 child->part.offset);108 }109 }110 if (child->part.offset == MTDPART_OFS_RETAIN) {111 child->part.offset = cur_offset;112 if (parent_size - child->part.offset >= child->part.size) {113 child->part.size = parent_size - child->part.offset -114 child->part.size;115 } else {116 printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",117 part->name, parent_size - child->part.offset,118 child->part.size);119 /* register to preserve ordering */120 goto out_register;121 }122 }123 if (child->part.size == MTDPART_SIZ_FULL)124 child->part.size = parent_size - child->part.offset;125 126 printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n",127 child->part.offset, child->part.offset + child->part.size,128 child->name);129 130 /* let's do some sanity checks */131 if (child->part.offset >= parent_size) {132 /* let's register it anyway to preserve ordering */133 child->part.offset = 0;134 child->part.size = 0;135 136 /* Initialize ->erasesize to make add_mtd_device() happy. */137 child->erasesize = parent->erasesize;138 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",139 part->name);140 goto out_register;141 }142 if (child->part.offset + child->part.size > parent->size) {143 child->part.size = parent_size - child->part.offset;144 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",145 part->name, parent->name, child->part.size);146 }147 148 if (parent->numeraseregions > 1) {149 /* Deal with variable erase size stuff */150 int i, max = parent->numeraseregions;151 u64 end = child->part.offset + child->part.size;152 struct mtd_erase_region_info *regions = parent->eraseregions;153 154 /* Find the first erase regions which is part of this155 * partition. */156 for (i = 0; i < max && regions[i].offset <= child->part.offset;157 i++)158 ;159 /* The loop searched for the region _behind_ the first one */160 if (i > 0)161 i--;162 163 /* Pick biggest erasesize */164 for (; i < max && regions[i].offset < end; i++) {165 if (child->erasesize < regions[i].erasesize)166 child->erasesize = regions[i].erasesize;167 }168 BUG_ON(child->erasesize == 0);169 } else {170 /* Single erase size */171 child->erasesize = master->erasesize;172 }173 174 /*175 * Child erasesize might differ from the parent one if the parent176 * exposes several regions with different erasesize. Adjust177 * wr_alignment accordingly.178 */179 if (!(child->flags & MTD_NO_ERASE))180 wr_alignment = child->erasesize;181 182 tmp = mtd_get_master_ofs(child, 0);183 remainder = do_div(tmp, wr_alignment);184 if ((child->flags & MTD_WRITEABLE) && remainder) {185 /* Doesn't start on a boundary of major erase size */186 /* FIXME: Let it be writable if it is on a boundary of187 * _minor_ erase size though */188 child->flags &= ~MTD_WRITEABLE;189 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",190 part->name);191 }192 193 tmp = mtd_get_master_ofs(child, 0) + child->part.size;194 remainder = do_div(tmp, wr_alignment);195 if ((child->flags & MTD_WRITEABLE) && remainder) {196 child->flags &= ~MTD_WRITEABLE;197 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",198 part->name);199 }200 201 child->size = child->part.size;202 child->ecc_step_size = parent->ecc_step_size;203 child->ecc_strength = parent->ecc_strength;204 child->bitflip_threshold = parent->bitflip_threshold;205 206 if (master->_block_isbad) {207 uint64_t offs = 0;208 209 while (offs < child->part.size) {210 if (mtd_block_isreserved(child, offs))211 child->ecc_stats.bbtblocks++;212 else if (mtd_block_isbad(child, offs))213 child->ecc_stats.badblocks++;214 offs += child->erasesize;215 }216 }217 218out_register:219 return child;220}221 222static ssize_t offset_show(struct device *dev,223 struct device_attribute *attr, char *buf)224{225 struct mtd_info *mtd = dev_get_drvdata(dev);226 227 return sysfs_emit(buf, "%lld\n", mtd->part.offset);228}229static DEVICE_ATTR_RO(offset); /* mtd partition offset */230 231static const struct attribute *mtd_partition_attrs[] = {232 &dev_attr_offset.attr,233 NULL234};235 236static int mtd_add_partition_attrs(struct mtd_info *new)237{238 int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs);239 if (ret)240 printk(KERN_WARNING241 "mtd: failed to create partition attrs, err=%d\n", ret);242 return ret;243}244 245int mtd_add_partition(struct mtd_info *parent, const char *name,246 long long offset, long long length)247{248 struct mtd_info *master = mtd_get_master(parent);249 u64 parent_size = mtd_is_partition(parent) ?250 parent->part.size : parent->size;251 struct mtd_partition part;252 struct mtd_info *child;253 int ret = 0;254 255 /* the direct offset is expected */256 if (offset == MTDPART_OFS_APPEND ||257 offset == MTDPART_OFS_NXTBLK)258 return -EINVAL;259 260 if (length == MTDPART_SIZ_FULL)261 length = parent_size - offset;262 263 if (length <= 0)264 return -EINVAL;265 266 memset(&part, 0, sizeof(part));267 part.name = name;268 part.size = length;269 part.offset = offset;270 271 child = allocate_partition(parent, &part, -1, offset);272 if (IS_ERR(child))273 return PTR_ERR(child);274 275 mutex_lock(&master->master.partitions_lock);276 list_add_tail(&child->part.node, &parent->partitions);277 mutex_unlock(&master->master.partitions_lock);278 279 ret = add_mtd_device(child);280 if (ret)281 goto err_remove_part;282 283 mtd_add_partition_attrs(child);284 285 return 0;286 287err_remove_part:288 mutex_lock(&master->master.partitions_lock);289 list_del(&child->part.node);290 mutex_unlock(&master->master.partitions_lock);291 292 free_partition(child);293 294 return ret;295}296EXPORT_SYMBOL_GPL(mtd_add_partition);297 298/**299 * __mtd_del_partition - delete MTD partition300 *301 * @mtd: MTD structure to be deleted302 *303 * This function must be called with the partitions mutex locked.304 */305static int __mtd_del_partition(struct mtd_info *mtd)306{307 struct mtd_info *child, *next;308 int err;309 310 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {311 err = __mtd_del_partition(child);312 if (err)313 return err;314 }315 316 sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs);317 318 list_del_init(&mtd->part.node);319 err = del_mtd_device(mtd);320 if (err)321 return err;322 323 return 0;324}325 326/*327 * This function unregisters and destroy all slave MTD objects which are328 * attached to the given MTD object, recursively.329 */330static int __del_mtd_partitions(struct mtd_info *mtd)331{332 struct mtd_info *child, *next;333 int ret, err = 0;334 335 list_for_each_entry_safe(child, next, &mtd->partitions, part.node) {336 if (mtd_has_partitions(child))337 __del_mtd_partitions(child);338 339 pr_info("Deleting %s MTD partition\n", child->name);340 list_del_init(&child->part.node);341 ret = del_mtd_device(child);342 if (ret < 0) {343 pr_err("Error when deleting partition \"%s\" (%d)\n",344 child->name, ret);345 err = ret;346 continue;347 }348 }349 350 return err;351}352 353int del_mtd_partitions(struct mtd_info *mtd)354{355 struct mtd_info *master = mtd_get_master(mtd);356 int ret;357 358 pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name);359 360 mutex_lock(&master->master.partitions_lock);361 ret = __del_mtd_partitions(mtd);362 mutex_unlock(&master->master.partitions_lock);363 364 return ret;365}366 367int mtd_del_partition(struct mtd_info *mtd, int partno)368{369 struct mtd_info *child, *master = mtd_get_master(mtd);370 int ret = -EINVAL;371 372 mutex_lock(&master->master.partitions_lock);373 list_for_each_entry(child, &mtd->partitions, part.node) {374 if (child->index == partno) {375 ret = __mtd_del_partition(child);376 break;377 }378 }379 mutex_unlock(&master->master.partitions_lock);380 381 return ret;382}383EXPORT_SYMBOL_GPL(mtd_del_partition);384 385/*386 * This function, given a parent MTD object and a partition table, creates387 * and registers the child MTD objects which are bound to the parent according388 * to the partition definitions.389 *390 * For historical reasons, this function's caller only registers the parent391 * if the MTD_PARTITIONED_MASTER config option is set.392 */393 394int add_mtd_partitions(struct mtd_info *parent,395 const struct mtd_partition *parts,396 int nbparts)397{398 struct mtd_info *child, *master = mtd_get_master(parent);399 uint64_t cur_offset = 0;400 int i, ret;401 402 printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n",403 nbparts, parent->name);404 405 for (i = 0; i < nbparts; i++) {406 child = allocate_partition(parent, parts + i, i, cur_offset);407 if (IS_ERR(child)) {408 ret = PTR_ERR(child);409 goto err_del_partitions;410 }411 412 mutex_lock(&master->master.partitions_lock);413 list_add_tail(&child->part.node, &parent->partitions);414 mutex_unlock(&master->master.partitions_lock);415 416 ret = add_mtd_device(child);417 if (ret) {418 mutex_lock(&master->master.partitions_lock);419 list_del(&child->part.node);420 mutex_unlock(&master->master.partitions_lock);421 422 free_partition(child);423 goto err_del_partitions;424 }425 426 mtd_add_partition_attrs(child);427 428 /* Look for subpartitions */429 ret = parse_mtd_partitions(child, parts[i].types, NULL);430 if (ret < 0) {431 pr_err("Failed to parse subpartitions: %d\n", ret);432 goto err_del_partitions;433 }434 435 cur_offset = child->part.offset + child->part.size;436 }437 438 return 0;439 440err_del_partitions:441 del_mtd_partitions(master);442 443 return ret;444}445 446static DEFINE_SPINLOCK(part_parser_lock);447static LIST_HEAD(part_parsers);448 449static struct mtd_part_parser *mtd_part_parser_get(const char *name)450{451 struct mtd_part_parser *p, *ret = NULL;452 453 spin_lock(&part_parser_lock);454 455 list_for_each_entry(p, &part_parsers, list)456 if (!strcmp(p->name, name) && try_module_get(p->owner)) {457 ret = p;458 break;459 }460 461 spin_unlock(&part_parser_lock);462 463 return ret;464}465 466static inline void mtd_part_parser_put(const struct mtd_part_parser *p)467{468 module_put(p->owner);469}470 471/*472 * Many partition parsers just expected the core to kfree() all their data in473 * one chunk. Do that by default.474 */475static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,476 int nr_parts)477{478 kfree(pparts);479}480 481int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)482{483 p->owner = owner;484 485 if (!p->cleanup)486 p->cleanup = &mtd_part_parser_cleanup_default;487 488 spin_lock(&part_parser_lock);489 list_add(&p->list, &part_parsers);490 spin_unlock(&part_parser_lock);491 492 return 0;493}494EXPORT_SYMBOL_GPL(__register_mtd_parser);495 496void deregister_mtd_parser(struct mtd_part_parser *p)497{498 spin_lock(&part_parser_lock);499 list_del(&p->list);500 spin_unlock(&part_parser_lock);501}502EXPORT_SYMBOL_GPL(deregister_mtd_parser);503 504/*505 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you506 * are changing this array!507 */508static const char * const default_mtd_part_types[] = {509 "cmdlinepart",510 "ofpart",511 NULL512};513 514/* Check DT only when looking for subpartitions. */515static const char * const default_subpartition_types[] = {516 "ofpart",517 NULL518};519 520static int mtd_part_do_parse(struct mtd_part_parser *parser,521 struct mtd_info *master,522 struct mtd_partitions *pparts,523 struct mtd_part_parser_data *data)524{525 int ret;526 527 ret = (*parser->parse_fn)(master, &pparts->parts, data);528 pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);529 if (ret <= 0)530 return ret;531 532 pr_notice("%d %s partitions found on MTD device %s\n", ret,533 parser->name, master->name);534 535 pparts->nr_parts = ret;536 pparts->parser = parser;537 538 return ret;539}540 541/**542 * mtd_part_get_compatible_parser - find MTD parser by a compatible string543 *544 * @compat: compatible string describing partitions in a device tree545 *546 * MTD parsers can specify supported partitions by providing a table of547 * compatibility strings. This function finds a parser that advertises support548 * for a passed value of "compatible".549 */550static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)551{552 struct mtd_part_parser *p, *ret = NULL;553 554 spin_lock(&part_parser_lock);555 556 list_for_each_entry(p, &part_parsers, list) {557 const struct of_device_id *matches;558 559 matches = p->of_match_table;560 if (!matches)561 continue;562 563 for (; matches->compatible[0]; matches++) {564 if (!strcmp(matches->compatible, compat) &&565 try_module_get(p->owner)) {566 ret = p;567 break;568 }569 }570 571 if (ret)572 break;573 }574 575 spin_unlock(&part_parser_lock);576 577 return ret;578}579 580static int mtd_part_of_parse(struct mtd_info *master,581 struct mtd_partitions *pparts)582{583 struct mtd_part_parser *parser;584 struct device_node *np;585 struct device_node *child;586 struct property *prop;587 struct device *dev;588 const char *compat;589 const char *fixed = "fixed-partitions";590 int ret, err = 0;591 592 dev = &master->dev;593 /* Use parent device (controller) if the top level MTD is not registered */594 if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master))595 dev = master->dev.parent;596 597 np = mtd_get_of_node(master);598 if (mtd_is_partition(master))599 of_node_get(np);600 else601 np = of_get_child_by_name(np, "partitions");602 603 /*604 * Don't create devices that are added to a bus but will never get605 * probed. That'll cause fw_devlink to block probing of consumers of606 * this partition until the partition device is probed.607 */608 for_each_child_of_node(np, child)609 if (of_device_is_compatible(child, "nvmem-cells"))610 of_node_set_flag(child, OF_POPULATED);611 612 of_property_for_each_string(np, "compatible", prop, compat) {613 parser = mtd_part_get_compatible_parser(compat);614 if (!parser)615 continue;616 ret = mtd_part_do_parse(parser, master, pparts, NULL);617 if (ret > 0) {618 of_platform_populate(np, NULL, NULL, dev);619 of_node_put(np);620 return ret;621 }622 mtd_part_parser_put(parser);623 if (ret < 0 && !err)624 err = ret;625 }626 of_platform_populate(np, NULL, NULL, dev);627 of_node_put(np);628 629 /*630 * For backward compatibility we have to try the "fixed-partitions"631 * parser. It supports old DT format with partitions specified as a632 * direct subnodes of a flash device DT node without any compatibility633 * specified we could match.634 */635 parser = mtd_part_parser_get(fixed);636 if (!parser && !request_module("%s", fixed))637 parser = mtd_part_parser_get(fixed);638 if (parser) {639 ret = mtd_part_do_parse(parser, master, pparts, NULL);640 if (ret > 0)641 return ret;642 mtd_part_parser_put(parser);643 if (ret < 0 && !err)644 err = ret;645 }646 647 return err;648}649 650/**651 * parse_mtd_partitions - parse and register MTD partitions652 *653 * @master: the master partition (describes whole MTD device)654 * @types: names of partition parsers to try or %NULL655 * @data: MTD partition parser-specific data656 *657 * This function tries to find & register partitions on MTD device @master. It658 * uses MTD partition parsers, specified in @types. However, if @types is %NULL,659 * then the default list of parsers is used. The default list contains only the660 * "cmdlinepart" and "ofpart" parsers ATM.661 * Note: If there are more then one parser in @types, the kernel only takes the662 * partitions parsed out by the first parser.663 *664 * This function may return:665 * o a negative error code in case of failure666 * o number of found partitions otherwise667 */668int parse_mtd_partitions(struct mtd_info *master, const char *const *types,669 struct mtd_part_parser_data *data)670{671 struct mtd_partitions pparts = { };672 struct mtd_part_parser *parser;673 int ret, err = 0;674 675 if (!types)676 types = mtd_is_partition(master) ? default_subpartition_types :677 default_mtd_part_types;678 679 for ( ; *types; types++) {680 /*681 * ofpart is a special type that means OF partitioning info682 * should be used. It requires a bit different logic so it is683 * handled in a separated function.684 */685 if (!strcmp(*types, "ofpart")) {686 ret = mtd_part_of_parse(master, &pparts);687 } else {688 pr_debug("%s: parsing partitions %s\n", master->name,689 *types);690 parser = mtd_part_parser_get(*types);691 if (!parser && !request_module("%s", *types))692 parser = mtd_part_parser_get(*types);693 pr_debug("%s: got parser %s\n", master->name,694 parser ? parser->name : NULL);695 if (!parser)696 continue;697 ret = mtd_part_do_parse(parser, master, &pparts, data);698 if (ret <= 0)699 mtd_part_parser_put(parser);700 }701 /* Found partitions! */702 if (ret > 0) {703 err = add_mtd_partitions(master, pparts.parts,704 pparts.nr_parts);705 mtd_part_parser_cleanup(&pparts);706 return err ? err : pparts.nr_parts;707 }708 /*709 * Stash the first error we see; only report it if no parser710 * succeeds711 */712 if (ret < 0 && !err)713 err = ret;714 }715 return err;716}717 718void mtd_part_parser_cleanup(struct mtd_partitions *parts)719{720 const struct mtd_part_parser *parser;721 722 if (!parts)723 return;724 725 parser = parts->parser;726 if (parser) {727 if (parser->cleanup)728 parser->cleanup(parts->parts, parts->nr_parts);729 730 mtd_part_parser_put(parser);731 }732}733 734/* Returns the size of the entire flash chip */735uint64_t mtd_get_device_size(const struct mtd_info *mtd)736{737 struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd);738 739 return master->size;740}741EXPORT_SYMBOL_GPL(mtd_get_device_size);742