// SPDX-License-Identifier: GPL-2.0-or-later /* * Simple MTD partitioning layer * * Copyright © 2000 Nicolas Pitre * Copyright © 2002 Thomas Gleixner * Copyright © 2000-2010 David Woodhouse */ #include #include #include #include #include #include #include #include #include #include #include #include #include "mtdcore.h" #include "mtdsplit/mtdsplit.h" /* * MTD methods which simply translate the effective address and pass through * to the _real_ device. */ static inline void free_partition(struct mtd_info *mtd) { kfree(mtd->name); kfree(mtd); } static struct mtd_info *allocate_partition(struct mtd_info *parent, const struct mtd_partition *part, int partno, uint64_t cur_offset) { struct mtd_info *master = mtd_get_master(parent); int wr_alignment = (parent->flags & MTD_NO_ERASE) ? master->writesize : master->erasesize; int wr_alignment_minor = 0; u64 parent_size = mtd_is_partition(parent) ? parent->part.size : parent->size; struct mtd_info *child; u32 remainder; char *name; u64 tmp; /* allocate the partition structure */ child = kzalloc(sizeof(*child), GFP_KERNEL); name = kstrdup(part->name, GFP_KERNEL); if (!name || !child) { printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n", parent->name); kfree(name); kfree(child); return ERR_PTR(-ENOMEM); } /* set up the MTD object for this partition */ child->type = parent->type; child->part.flags = parent->flags & ~part->mask_flags; child->part.flags |= part->add_flags; child->flags = child->part.flags; child->part.size = part->size; child->writesize = parent->writesize; child->writebufsize = parent->writebufsize; child->oobsize = parent->oobsize; child->oobavail = parent->oobavail; child->subpage_sft = parent->subpage_sft; child->name = name; child->owner = parent->owner; /* NOTE: Historically, we didn't arrange MTDs as a tree out of * concern for showing the same data in multiple partitions. * However, it is very useful to have the master node present, * so the MTD_PARTITIONED_MASTER option allows that. The master * will have device nodes etc only if this is set, so make the * parent conditional on that option. Note, this is a way to * distinguish between the parent and its partitions in sysfs. */ child->dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ? &parent->dev : parent->dev.parent; child->dev.of_node = part->of_node; child->parent = parent; child->part.offset = part->offset; INIT_LIST_HEAD(&child->partitions); if (child->part.offset == MTDPART_OFS_APPEND) child->part.offset = cur_offset; if (child->part.offset == MTDPART_OFS_NXTBLK) { tmp = cur_offset; child->part.offset = cur_offset; remainder = do_div(tmp, wr_alignment); if (remainder) { child->part.offset += wr_alignment - remainder; printk(KERN_NOTICE "Moving partition %d: " "0x%012llx -> 0x%012llx\n", partno, (unsigned long long)cur_offset, child->part.offset); } } if (child->part.offset == MTDPART_OFS_RETAIN) { child->part.offset = cur_offset; if (parent_size - child->part.offset >= child->part.size) { child->part.size = parent_size - child->part.offset - child->part.size; } else { printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n", part->name, parent_size - child->part.offset, child->part.size); /* register to preserve ordering */ goto out_register; } } if (child->part.size == MTDPART_SIZ_FULL) child->part.size = parent_size - child->part.offset; printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", child->part.offset, child->part.offset + child->part.size, child->name); /* let's do some sanity checks */ if (child->part.offset >= parent_size) { /* let's register it anyway to preserve ordering */ child->part.offset = 0; child->part.size = 0; /* Initialize ->erasesize to make add_mtd_device() happy. */ child->erasesize = parent->erasesize; printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n", part->name); goto out_register; } if (child->part.offset + child->part.size > parent->size) { child->part.size = parent_size - child->part.offset; printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n", part->name, parent->name, child->part.size); } if (parent->numeraseregions > 1) { /* Deal with variable erase size stuff */ int i, max = parent->numeraseregions; u64 end = child->part.offset + child->part.size; struct mtd_erase_region_info *regions = parent->eraseregions; /* Find the first erase regions which is part of this * partition. */ for (i = 0; i < max && regions[i].offset <= child->part.offset; i++) ; /* The loop searched for the region _behind_ the first one */ if (i > 0) i--; /* Pick biggest erasesize */ for (; i < max && regions[i].offset < end; i++) { if (child->erasesize < regions[i].erasesize) child->erasesize = regions[i].erasesize; } BUG_ON(child->erasesize == 0); } else { /* Single erase size */ child->erasesize = master->erasesize; child->erasesize_minor = master->erasesize_minor; } /* * Child erasesize might differ from the parent one if the parent * exposes several regions with different erasesize. Adjust * wr_alignment accordingly. */ if (!(child->flags & MTD_NO_ERASE)) { wr_alignment = child->erasesize; wr_alignment_minor = child->erasesize_minor; } tmp = mtd_get_master_ofs(child, 0); remainder = do_div(tmp, wr_alignment); if ((child->flags & MTD_WRITEABLE) && remainder) { if (wr_alignment_minor) { /* rely on minor being a factor of major erasesize */ tmp = remainder; remainder = do_div(tmp, wr_alignment_minor); } if (remainder) { child->flags &= ~MTD_WRITEABLE; printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", part->name); } } tmp = mtd_get_master_ofs(child, 0) + child->part.size; remainder = do_div(tmp, wr_alignment); if ((child->flags & MTD_WRITEABLE) && remainder) { if (wr_alignment_minor) { tmp = remainder; remainder = do_div(tmp, wr_alignment_minor); } if (remainder) { child->flags &= ~MTD_WRITEABLE; printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", part->name); } } child->size = child->part.size; child->ecc_step_size = parent->ecc_step_size; child->ecc_strength = parent->ecc_strength; child->bitflip_threshold = parent->bitflip_threshold; if (master->_block_isbad) { uint64_t offs = 0; while (offs < child->part.size) { if (mtd_block_isreserved(child, offs)) child->ecc_stats.bbtblocks++; else if (mtd_block_isbad(child, offs)) child->ecc_stats.badblocks++; offs += child->erasesize; } } out_register: return child; } static ssize_t offset_show(struct device *dev, struct device_attribute *attr, char *buf) { struct mtd_info *mtd = dev_get_drvdata(dev); return sysfs_emit(buf, "%lld\n", mtd->part.offset); } static DEVICE_ATTR_RO(offset); /* mtd partition offset */ static const struct attribute *mtd_partition_attrs[] = { &dev_attr_offset.attr, NULL }; static int mtd_add_partition_attrs(struct mtd_info *new) { int ret = sysfs_create_files(&new->dev.kobj, mtd_partition_attrs); if (ret) printk(KERN_WARNING "mtd: failed to create partition attrs, err=%d\n", ret); return ret; } static DEFINE_SPINLOCK(part_parser_lock); static LIST_HEAD(part_parsers); static struct mtd_part_parser *mtd_part_parser_get(const char *name) { struct mtd_part_parser *p, *ret = NULL; spin_lock(&part_parser_lock); list_for_each_entry(p, &part_parsers, list) if (!strcmp(p->name, name) && try_module_get(p->owner)) { ret = p; break; } spin_unlock(&part_parser_lock); return ret; } static inline void mtd_part_parser_put(const struct mtd_part_parser *p) { module_put(p->owner); } static struct mtd_part_parser * get_partition_parser_by_type(enum mtd_parser_type type, struct mtd_part_parser *start) { struct mtd_part_parser *p, *ret = NULL; spin_lock(&part_parser_lock); p = list_prepare_entry(start, &part_parsers, list); if (start) mtd_part_parser_put(start); list_for_each_entry_continue(p, &part_parsers, list) { if (p->type == type && try_module_get(p->owner)) { ret = p; break; } } spin_unlock(&part_parser_lock); return ret; } static int parse_mtd_partitions_by_type(struct mtd_info *master, enum mtd_parser_type type, const struct mtd_partition **pparts, struct mtd_part_parser_data *data) { struct mtd_part_parser *prev = NULL; int ret = 0; while (1) { struct mtd_part_parser *parser; parser = get_partition_parser_by_type(type, prev); if (!parser) break; ret = (*parser->parse_fn)(master, pparts, data); if (ret > 0) { mtd_part_parser_put(parser); printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n", ret, parser->name, master->name); break; } prev = parser; } return ret; } static int run_parsers_by_type(struct mtd_info *child, enum mtd_parser_type type) { struct mtd_partition *parts; int nr_parts; int i; nr_parts = parse_mtd_partitions_by_type(child, type, (const struct mtd_partition **)&parts, NULL); if (nr_parts <= 0) return nr_parts; if (WARN_ON(!parts)) return 0; for (i = 0; i < nr_parts; i++) { /* adjust partition offsets */ parts[i].offset += child->part.offset; mtd_add_partition(child->parent, parts[i].name, parts[i].offset, parts[i].size); } kfree(parts); return nr_parts; } #ifdef CONFIG_MTD_SPLIT_FIRMWARE_NAME #define SPLIT_FIRMWARE_NAME CONFIG_MTD_SPLIT_FIRMWARE_NAME #else #define SPLIT_FIRMWARE_NAME "unused" #endif static void split_firmware(struct mtd_info *master, struct mtd_info *part) { run_parsers_by_type(part, MTD_PARSER_TYPE_FIRMWARE); } static void mtd_partition_split(struct mtd_info *master, struct mtd_info *part) { static int rootfs_found = 0; if (rootfs_found) return; if (of_find_property(mtd_get_of_node(part), "linux,rootfs", NULL) || !strcmp(part->name, "rootfs")) { run_parsers_by_type(part, MTD_PARSER_TYPE_ROOTFS); rootfs_found = 1; } if (IS_ENABLED(CONFIG_MTD_SPLIT_FIRMWARE) && !strcmp(part->name, SPLIT_FIRMWARE_NAME) && !of_find_property(mtd_get_of_node(part), "compatible", NULL)) split_firmware(master, part); } int mtd_add_partition(struct mtd_info *parent, const char *name, long long offset, long long length) { struct mtd_info *master = mtd_get_master(parent); u64 parent_size = mtd_is_partition(parent) ? parent->part.size : parent->size; struct mtd_partition part; struct mtd_info *child; int ret = 0; /* the direct offset is expected */ if (offset == MTDPART_OFS_APPEND || offset == MTDPART_OFS_NXTBLK) return -EINVAL; if (length == MTDPART_SIZ_FULL) length = parent_size - offset; if (length <= 0) return -EINVAL; memset(&part, 0, sizeof(part)); part.name = name; part.size = length; part.offset = offset; child = allocate_partition(parent, &part, -1, offset); if (IS_ERR(child)) return PTR_ERR(child); mutex_lock(&master->master.partitions_lock); list_add_tail(&child->part.node, &parent->partitions); mutex_unlock(&master->master.partitions_lock); ret = add_mtd_device(child); if (ret) goto err_remove_part; mtd_partition_split(parent, child); mtd_add_partition_attrs(child); return 0; err_remove_part: mutex_lock(&master->master.partitions_lock); list_del(&child->part.node); mutex_unlock(&master->master.partitions_lock); free_partition(child); return ret; } EXPORT_SYMBOL_GPL(mtd_add_partition); /** * __mtd_del_partition - delete MTD partition * * @mtd: MTD structure to be deleted * * This function must be called with the partitions mutex locked. */ static int __mtd_del_partition(struct mtd_info *mtd) { struct mtd_info *child, *next; int err; list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { err = __mtd_del_partition(child); if (err) return err; } sysfs_remove_files(&mtd->dev.kobj, mtd_partition_attrs); err = del_mtd_device(mtd); if (err) return err; list_del(&mtd->part.node); free_partition(mtd); return 0; } /* * This function unregisters and destroy all slave MTD objects which are * attached to the given MTD object, recursively. */ static int __del_mtd_partitions(struct mtd_info *mtd) { struct mtd_info *child, *next; LIST_HEAD(tmp_list); int ret, err = 0; list_for_each_entry_safe(child, next, &mtd->partitions, part.node) { if (mtd_has_partitions(child)) __del_mtd_partitions(child); pr_info("Deleting %s MTD partition\n", child->name); ret = del_mtd_device(child); if (ret < 0) { pr_err("Error when deleting partition \"%s\" (%d)\n", child->name, ret); err = ret; continue; } list_del(&child->part.node); free_partition(child); } return err; } int del_mtd_partitions(struct mtd_info *mtd) { struct mtd_info *master = mtd_get_master(mtd); int ret; pr_info("Deleting MTD partitions on \"%s\":\n", mtd->name); mutex_lock(&master->master.partitions_lock); ret = __del_mtd_partitions(mtd); mutex_unlock(&master->master.partitions_lock); return ret; } int mtd_del_partition(struct mtd_info *mtd, int partno) { struct mtd_info *child, *master = mtd_get_master(mtd); int ret = -EINVAL; mutex_lock(&master->master.partitions_lock); list_for_each_entry(child, &mtd->partitions, part.node) { if (child->index == partno) { ret = __mtd_del_partition(child); break; } } mutex_unlock(&master->master.partitions_lock); return ret; } EXPORT_SYMBOL_GPL(mtd_del_partition); /* * This function, given a parent MTD object and a partition table, creates * and registers the child MTD objects which are bound to the parent according * to the partition definitions. * * For historical reasons, this function's caller only registers the parent * if the MTD_PARTITIONED_MASTER config option is set. */ int add_mtd_partitions(struct mtd_info *parent, const struct mtd_partition *parts, int nbparts) { struct mtd_info *child, *master = mtd_get_master(parent); uint64_t cur_offset = 0; int i, ret; printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, parent->name); for (i = 0; i < nbparts; i++) { child = allocate_partition(parent, parts + i, i, cur_offset); if (IS_ERR(child)) { ret = PTR_ERR(child); goto err_del_partitions; } mutex_lock(&master->master.partitions_lock); list_add_tail(&child->part.node, &parent->partitions); mutex_unlock(&master->master.partitions_lock); ret = add_mtd_device(child); if (ret) { mutex_lock(&master->master.partitions_lock); list_del(&child->part.node); mutex_unlock(&master->master.partitions_lock); free_partition(child); goto err_del_partitions; } mtd_partition_split(master, child); mtd_add_partition_attrs(child); /* Look for subpartitions */ parse_mtd_partitions(child, parts[i].types, NULL); cur_offset = child->part.offset + child->part.size; } return 0; err_del_partitions: del_mtd_partitions(master); return ret; } /* * Many partition parsers just expected the core to kfree() all their data in * one chunk. Do that by default. */ static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts, int nr_parts) { kfree(pparts); } int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner) { p->owner = owner; if (!p->cleanup) p->cleanup = &mtd_part_parser_cleanup_default; spin_lock(&part_parser_lock); list_add(&p->list, &part_parsers); spin_unlock(&part_parser_lock); return 0; } EXPORT_SYMBOL_GPL(__register_mtd_parser); void deregister_mtd_parser(struct mtd_part_parser *p) { spin_lock(&part_parser_lock); list_del(&p->list); spin_unlock(&part_parser_lock); } EXPORT_SYMBOL_GPL(deregister_mtd_parser); /* * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you * are changing this array! */ static const char * const default_mtd_part_types[] = { "cmdlinepart", "ofpart", NULL }; /* Check DT only when looking for subpartitions. */ static const char * const default_subpartition_types[] = { "ofpart", NULL }; static int mtd_part_do_parse(struct mtd_part_parser *parser, struct mtd_info *master, struct mtd_partitions *pparts, struct mtd_part_parser_data *data) { int ret; ret = (*parser->parse_fn)(master, &pparts->parts, data); pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret); if (ret <= 0) return ret; pr_notice("%d %s partitions found on MTD device %s\n", ret, parser->name, master->name); pparts->nr_parts = ret; pparts->parser = parser; return ret; } /** * mtd_part_get_compatible_parser - find MTD parser by a compatible string * * @compat: compatible string describing partitions in a device tree * * MTD parsers can specify supported partitions by providing a table of * compatibility strings. This function finds a parser that advertises support * for a passed value of "compatible". */ static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat) { struct mtd_part_parser *p, *ret = NULL; spin_lock(&part_parser_lock); list_for_each_entry(p, &part_parsers, list) { const struct of_device_id *matches; matches = p->of_match_table; if (!matches) continue; for (; matches->compatible[0]; matches++) { if (!strcmp(matches->compatible, compat) && try_module_get(p->owner)) { ret = p; break; } } if (ret) break; } spin_unlock(&part_parser_lock); return ret; } static int mtd_part_of_parse(struct mtd_info *master, struct mtd_partitions *pparts) { struct mtd_part_parser *parser; struct device_node *np; struct property *prop; struct device *dev; const char *compat; const char *fixed = "fixed-partitions"; int ret, err = 0; dev = &master->dev; /* Use parent device (controller) if the top level MTD is not registered */ if (!IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) && !mtd_is_partition(master)) dev = master->dev.parent; np = mtd_get_of_node(master); if (mtd_is_partition(master)) of_node_get(np); else np = of_get_child_by_name(np, "partitions"); of_property_for_each_string(np, "compatible", prop, compat) { parser = mtd_part_get_compatible_parser(compat); if (!parser) continue; ret = mtd_part_do_parse(parser, master, pparts, NULL); if (ret > 0) { of_platform_populate(np, NULL, NULL, dev); of_node_put(np); return ret; } mtd_part_parser_put(parser); if (ret < 0 && !err) err = ret; } of_platform_populate(np, NULL, NULL, dev); of_node_put(np); /* * For backward compatibility we have to try the "fixed-partitions" * parser. It supports old DT format with partitions specified as a * direct subnodes of a flash device DT node without any compatibility * specified we could match. */ parser = mtd_part_parser_get(fixed); if (!parser && !request_module("%s", fixed)) parser = mtd_part_parser_get(fixed); if (parser) { ret = mtd_part_do_parse(parser, master, pparts, NULL); if (ret > 0) return ret; mtd_part_parser_put(parser); if (ret < 0 && !err) err = ret; } return err; } /** * parse_mtd_partitions - parse and register MTD partitions * * @master: the master partition (describes whole MTD device) * @types: names of partition parsers to try or %NULL * @data: MTD partition parser-specific data * * This function tries to find & register partitions on MTD device @master. It * uses MTD partition parsers, specified in @types. However, if @types is %NULL, * then the default list of parsers is used. The default list contains only the * "cmdlinepart" and "ofpart" parsers ATM. * Note: If there are more then one parser in @types, the kernel only takes the * partitions parsed out by the first parser. * * This function may return: * o a negative error code in case of failure * o number of found partitions otherwise */ int parse_mtd_partitions(struct mtd_info *master, const char *const *types, struct mtd_part_parser_data *data) { struct mtd_partitions pparts = { }; struct mtd_part_parser *parser; int ret, err = 0; if (!types) types = mtd_is_partition(master) ? default_subpartition_types : default_mtd_part_types; for ( ; *types; types++) { /* * ofpart is a special type that means OF partitioning info * should be used. It requires a bit different logic so it is * handled in a separated function. */ if (!strcmp(*types, "ofpart")) { ret = mtd_part_of_parse(master, &pparts); } else { pr_debug("%s: parsing partitions %s\n", master->name, *types); parser = mtd_part_parser_get(*types); if (!parser && !request_module("%s", *types)) parser = mtd_part_parser_get(*types); pr_debug("%s: got parser %s\n", master->name, parser ? parser->name : NULL); if (!parser) continue; ret = mtd_part_do_parse(parser, master, &pparts, data); if (ret <= 0) mtd_part_parser_put(parser); } /* Found partitions! */ if (ret > 0) { err = add_mtd_partitions(master, pparts.parts, pparts.nr_parts); mtd_part_parser_cleanup(&pparts); return err ? err : pparts.nr_parts; } /* * Stash the first error we see; only report it if no parser * succeeds */ if (ret < 0 && !err) err = ret; } return err; } void mtd_part_parser_cleanup(struct mtd_partitions *parts) { const struct mtd_part_parser *parser; if (!parts) return; parser = parts->parser; if (parser) { if (parser->cleanup) parser->cleanup(parts->parts, parts->nr_parts); mtd_part_parser_put(parser); } } /* Returns the size of the entire flash chip */ uint64_t mtd_get_device_size(const struct mtd_info *mtd) { struct mtd_info *master = mtd_get_master((struct mtd_info *)mtd); return master->size; } EXPORT_SYMBOL_GPL(mtd_get_device_size);