linux/drivers/mtd/mtdpart.c
Rafał Miłecki bcdf0315a6 mtd: call of_platform_populate() for MTD partitions
Until this change MTD subsystem supported handling partitions only with
MTD partitions parsers. That's a specific / limited API designed around
partitions.

Some MTD partitions may however require different handling. They may
contain specific data that needs to be parsed and somehow extracted. For
that purpose MTD subsystem should allow binding of standard platform
drivers.

An example can be U-Boot (sub)partition with environment variables.
There exist a "u-boot,env" DT binding for MTD (sub)partition that
requires an NVMEM driver.

Ref: 5db1c2dbc0 ("dt-bindings: nvmem: add U-Boot environment variables binding")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220510131259.555-1-zajec5@gmail.com
2022-05-16 18:37:48 +02:00

727 lines
19 KiB
C

// 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 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);