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-rw-r--r--drivers/mtd/mtdpart.c736
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);