diff options
Diffstat (limited to 'drivers/mtd/mtdpart.c')
| -rw-r--r-- | drivers/mtd/mtdpart.c | 736 |
1 files changed, 736 insertions, 0 deletions
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c new file mode 100644 index 000000000..85f5ee6f0 --- /dev/null +++ b/drivers/mtd/mtdpart.c @@ -0,0 +1,736 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Simple MTD partitioning layer + * + * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net> + * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de> + * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org> + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/kmod.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/of_platform.h> + +#include "mtdcore.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; + 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 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; + + tmp = mtd_get_master_ofs(child, 0); + remainder = do_div(tmp, wr_alignment); + if ((child->flags & MTD_WRITEABLE) && remainder) { + /* Doesn't start on a boundary of major erase size */ + /* FIXME: Let it be writable if it is on a boundary of + * _minor_ erase size though */ + 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) { + 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; +} + +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_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_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; +} + +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); +} + +/* + * 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 device_node *child; + 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"); + + /* + * Don't create devices that are added to a bus but will never get + * probed. That'll cause fw_devlink to block probing of consumers of + * this partition until the partition device is probed. + */ + for_each_child_of_node(np, child) + if (of_device_is_compatible(child, "nvmem-cells")) + of_node_set_flag(child, OF_POPULATED); + + 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); |