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mtdcore.c
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mtdcore.c
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/*
* Core registration and callback routines for MTD
* drivers and users.
*
* Copyright © 1999-2010 David Woodhouse <[email protected]>
* Copyright © 2006 Red Hat UK Limited
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/proc_fs.h>
#include <linux/idr.h>
#include <linux/backing-dev.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/leds.h>
#include <linux/debugfs.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include "mtdcore.h"
struct backing_dev_info *mtd_bdi;
#ifdef CONFIG_PM_SLEEP
static int mtd_cls_suspend(struct device *dev)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return mtd ? mtd_suspend(mtd) : 0;
}
static int mtd_cls_resume(struct device *dev)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
if (mtd)
mtd_resume(mtd);
return 0;
}
static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
#else
#define MTD_CLS_PM_OPS NULL
#endif
static struct class mtd_class = {
.name = "mtd",
.owner = THIS_MODULE,
.pm = MTD_CLS_PM_OPS,
};
static DEFINE_IDR(mtd_idr);
/* These are exported solely for the purpose of mtd_blkdevs.c. You
should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex);
EXPORT_SYMBOL_GPL(mtd_table_mutex);
struct mtd_info *__mtd_next_device(int i)
{
return idr_get_next(&mtd_idr, &i);
}
EXPORT_SYMBOL_GPL(__mtd_next_device);
static LIST_HEAD(mtd_notifiers);
#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
/* REVISIT once MTD uses the driver model better, whoever allocates
* the mtd_info will probably want to use the release() hook...
*/
static void mtd_release(struct device *dev)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
dev_t index = MTD_DEVT(mtd->index);
/* remove /dev/mtdXro node */
device_destroy(&mtd_class, index + 1);
}
static ssize_t mtd_type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
char *type;
switch (mtd->type) {
case MTD_ABSENT:
type = "absent";
break;
case MTD_RAM:
type = "ram";
break;
case MTD_ROM:
type = "rom";
break;
case MTD_NORFLASH:
type = "nor";
break;
case MTD_NANDFLASH:
type = "nand";
break;
case MTD_DATAFLASH:
type = "dataflash";
break;
case MTD_UBIVOLUME:
type = "ubi";
break;
case MTD_MLCNANDFLASH:
type = "mlc-nand";
break;
default:
type = "unknown";
}
return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
static ssize_t mtd_flags_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
}
static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
static ssize_t mtd_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)mtd->size);
}
static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
static ssize_t mtd_erasesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
}
static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
static ssize_t mtd_writesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
static ssize_t mtd_subpagesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
}
static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
static ssize_t mtd_oobsize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
}
static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
static ssize_t mtd_numeraseregions_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
}
static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
NULL);
static ssize_t mtd_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
static ssize_t mtd_ecc_strength_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
}
static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
static ssize_t mtd_bitflip_threshold_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
}
static ssize_t mtd_bitflip_threshold_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
unsigned int bitflip_threshold;
int retval;
retval = kstrtouint(buf, 0, &bitflip_threshold);
if (retval)
return retval;
mtd->bitflip_threshold = bitflip_threshold;
return count;
}
static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
mtd_bitflip_threshold_show,
mtd_bitflip_threshold_store);
static ssize_t mtd_ecc_step_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
}
static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
}
static DEVICE_ATTR(corrected_bits, S_IRUGO,
mtd_ecc_stats_corrected_show, NULL);
static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
}
static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
static ssize_t mtd_badblocks_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
}
static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
static ssize_t mtd_bbtblocks_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
}
static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
static struct attribute *mtd_attrs[] = {
&dev_attr_type.attr,
&dev_attr_flags.attr,
&dev_attr_size.attr,
&dev_attr_erasesize.attr,
&dev_attr_writesize.attr,
&dev_attr_subpagesize.attr,
&dev_attr_oobsize.attr,
&dev_attr_numeraseregions.attr,
&dev_attr_name.attr,
&dev_attr_ecc_strength.attr,
&dev_attr_ecc_step_size.attr,
&dev_attr_corrected_bits.attr,
&dev_attr_ecc_failures.attr,
&dev_attr_bad_blocks.attr,
&dev_attr_bbt_blocks.attr,
&dev_attr_bitflip_threshold.attr,
NULL,
};
ATTRIBUTE_GROUPS(mtd);
static const struct device_type mtd_devtype = {
.name = "mtd",
.groups = mtd_groups,
.release = mtd_release,
};
#ifndef CONFIG_MMU
unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
{
switch (mtd->type) {
case MTD_RAM:
return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
NOMMU_MAP_READ | NOMMU_MAP_WRITE;
case MTD_ROM:
return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
NOMMU_MAP_READ;
default:
return NOMMU_MAP_COPY;
}
}
EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
#endif
static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
void *cmd)
{
struct mtd_info *mtd;
mtd = container_of(n, struct mtd_info, reboot_notifier);
mtd->_reboot(mtd);
return NOTIFY_DONE;
}
/**
* mtd_wunit_to_pairing_info - get pairing information of a wunit
* @mtd: pointer to new MTD device info structure
* @wunit: write unit we are interested in
* @info: returned pairing information
*
* Retrieve pairing information associated to the wunit.
* This is mainly useful when dealing with MLC/TLC NANDs where pages can be
* paired together, and where programming a page may influence the page it is
* paired with.
* The notion of page is replaced by the term wunit (write-unit) to stay
* consistent with the ->writesize field.
*
* The @wunit argument can be extracted from an absolute offset using
* mtd_offset_to_wunit(). @info is filled with the pairing information attached
* to @wunit.
*
* From the pairing info the MTD user can find all the wunits paired with
* @wunit using the following loop:
*
* for (i = 0; i < mtd_pairing_groups(mtd); i++) {
* info.pair = i;
* mtd_pairing_info_to_wunit(mtd, &info);
* ...
* }
*/
int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
struct mtd_pairing_info *info)
{
int npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
if (wunit < 0 || wunit >= npairs)
return -EINVAL;
if (mtd->pairing && mtd->pairing->get_info)
return mtd->pairing->get_info(mtd, wunit, info);
info->group = 0;
info->pair = wunit;
return 0;
}
EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
/**
* mtd_wunit_to_pairing_info - get wunit from pairing information
* @mtd: pointer to new MTD device info structure
* @info: pairing information struct
*
* Returns a positive number representing the wunit associated to the info
* struct, or a negative error code.
*
* This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
* iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
* doc).
*
* It can also be used to only program the first page of each pair (i.e.
* page attached to group 0), which allows one to use an MLC NAND in
* software-emulated SLC mode:
*
* info.group = 0;
* npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
* for (info.pair = 0; info.pair < npairs; info.pair++) {
* wunit = mtd_pairing_info_to_wunit(mtd, &info);
* mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
* mtd->writesize, &retlen, buf + (i * mtd->writesize));
* }
*/
int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
const struct mtd_pairing_info *info)
{
int ngroups = mtd_pairing_groups(mtd);
int npairs = mtd_wunit_per_eb(mtd) / ngroups;
if (!info || info->pair < 0 || info->pair >= npairs ||
info->group < 0 || info->group >= ngroups)
return -EINVAL;
if (mtd->pairing && mtd->pairing->get_wunit)
return mtd->pairing->get_wunit(mtd, info);
return info->pair;
}
EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
/**
* mtd_pairing_groups - get the number of pairing groups
* @mtd: pointer to new MTD device info structure
*
* Returns the number of pairing groups.
*
* This number is usually equal to the number of bits exposed by a single
* cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
* to iterate over all pages of a given pair.
*/
int mtd_pairing_groups(struct mtd_info *mtd)
{
if (!mtd->pairing || !mtd->pairing->ngroups)
return 1;
return mtd->pairing->ngroups;
}
EXPORT_SYMBOL_GPL(mtd_pairing_groups);
static struct dentry *dfs_dir_mtd;
/**
* add_mtd_device - register an MTD device
* @mtd: pointer to new MTD device info structure
*
* Add a device to the list of MTD devices present in the system, and
* notify each currently active MTD 'user' of its arrival. Returns
* zero on success or non-zero on failure.
*/
int add_mtd_device(struct mtd_info *mtd)
{
struct mtd_notifier *not;
int i, error;
/*
* May occur, for instance, on buggy drivers which call
* mtd_device_parse_register() multiple times on the same master MTD,
* especially with CONFIG_MTD_PARTITIONED_MASTER=y.
*/
if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
return -EEXIST;
BUG_ON(mtd->writesize == 0);
mutex_lock(&mtd_table_mutex);
i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
if (i < 0) {
error = i;
goto fail_locked;
}
mtd->index = i;
mtd->usecount = 0;
/* default value if not set by driver */
if (mtd->bitflip_threshold == 0)
mtd->bitflip_threshold = mtd->ecc_strength;
if (is_power_of_2(mtd->erasesize))
mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
else
mtd->erasesize_shift = 0;
if (is_power_of_2(mtd->writesize))
mtd->writesize_shift = ffs(mtd->writesize) - 1;
else
mtd->writesize_shift = 0;
mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
/* Some chips always power up locked. Unlock them now */
if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
error = mtd_unlock(mtd, 0, mtd->size);
if (error && error != -EOPNOTSUPP)
printk(KERN_WARNING
"%s: unlock failed, writes may not work\n",
mtd->name);
/* Ignore unlock failures? */
error = 0;
}
/* Caller should have set dev.parent to match the
* physical device, if appropriate.
*/
mtd->dev.type = &mtd_devtype;
mtd->dev.class = &mtd_class;
mtd->dev.devt = MTD_DEVT(i);
dev_set_name(&mtd->dev, "mtd%d", i);
dev_set_drvdata(&mtd->dev, mtd);
of_node_get(mtd_get_of_node(mtd));
error = device_register(&mtd->dev);
if (error)
goto fail_added;
if (!IS_ERR_OR_NULL(dfs_dir_mtd)) {
mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(&mtd->dev), dfs_dir_mtd);
if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir)) {
pr_debug("mtd device %s won't show data in debugfs\n",
dev_name(&mtd->dev));
}
}
device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
"mtd%dro", i);
pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
/* No need to get a refcount on the module containing
the notifier, since we hold the mtd_table_mutex */
list_for_each_entry(not, &mtd_notifiers, list)
not->add(mtd);
mutex_unlock(&mtd_table_mutex);
/* We _know_ we aren't being removed, because
our caller is still holding us here. So none
of this try_ nonsense, and no bitching about it
either. :) */
__module_get(THIS_MODULE);
return 0;
fail_added:
of_node_put(mtd_get_of_node(mtd));
idr_remove(&mtd_idr, i);
fail_locked:
mutex_unlock(&mtd_table_mutex);
return error;
}
/**
* del_mtd_device - unregister an MTD device
* @mtd: pointer to MTD device info structure
*
* Remove a device from the list of MTD devices present in the system,
* and notify each currently active MTD 'user' of its departure.
* Returns zero on success or 1 on failure, which currently will happen
* if the requested device does not appear to be present in the list.
*/
int del_mtd_device(struct mtd_info *mtd)
{
int ret;
struct mtd_notifier *not;
mutex_lock(&mtd_table_mutex);
debugfs_remove_recursive(mtd->dbg.dfs_dir);
if (idr_find(&mtd_idr, mtd->index) != mtd) {
ret = -ENODEV;
goto out_error;
}
/* No need to get a refcount on the module containing
the notifier, since we hold the mtd_table_mutex */
list_for_each_entry(not, &mtd_notifiers, list)
not->remove(mtd);
if (mtd->usecount) {
printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
mtd->index, mtd->name, mtd->usecount);
ret = -EBUSY;
} else {
device_unregister(&mtd->dev);
idr_remove(&mtd_idr, mtd->index);
of_node_put(mtd_get_of_node(mtd));
module_put(THIS_MODULE);
ret = 0;
}
out_error:
mutex_unlock(&mtd_table_mutex);
return ret;
}
static int mtd_add_device_partitions(struct mtd_info *mtd,
struct mtd_partitions *parts)
{
const struct mtd_partition *real_parts = parts->parts;
int nbparts = parts->nr_parts;
int ret;
if (nbparts == 0 || IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
ret = add_mtd_device(mtd);
if (ret)
return ret;
}
if (nbparts > 0) {
ret = add_mtd_partitions(mtd, real_parts, nbparts);
if (ret && IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
del_mtd_device(mtd);
return ret;
}
return 0;
}
/*
* Set a few defaults based on the parent devices, if not provided by the
* driver
*/
static void mtd_set_dev_defaults(struct mtd_info *mtd)
{
if (mtd->dev.parent) {
if (!mtd->owner && mtd->dev.parent->driver)
mtd->owner = mtd->dev.parent->driver->owner;
if (!mtd->name)
mtd->name = dev_name(mtd->dev.parent);
} else {
pr_debug("mtd device won't show a device symlink in sysfs\n");
}
}
/**
* mtd_device_parse_register - parse partitions and register an MTD device.
*
* @mtd: the MTD device to register
* @types: the list of MTD partition probes to try, see
* 'parse_mtd_partitions()' for more information
* @parser_data: MTD partition parser-specific data
* @parts: fallback partition information to register, if parsing fails;
* only valid if %nr_parts > %0
* @nr_parts: the number of partitions in parts, if zero then the full
* MTD device is registered if no partition info is found
*
* This function aggregates MTD partitions parsing (done by
* 'parse_mtd_partitions()') and MTD device and partitions registering. It
* basically follows the most common pattern found in many MTD drivers:
*
* * It first tries to probe partitions on MTD device @mtd using parsers
* specified in @types (if @types is %NULL, then the default list of parsers
* is used, see 'parse_mtd_partitions()' for more information). If none are
* found this functions tries to fallback to information specified in
* @parts/@nr_parts.
* * If any partitioning info was found, this function registers the found
* partitions. If the MTD_PARTITIONED_MASTER option is set, then the device
* as a whole is registered first.
* * If no partitions were found this function just registers the MTD device
* @mtd and exits.
*
* Returns zero in case of success and a negative error code in case of failure.
*/
int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
struct mtd_part_parser_data *parser_data,
const struct mtd_partition *parts,
int nr_parts)
{
struct mtd_partitions parsed;
int ret;
mtd_set_dev_defaults(mtd);
memset(&parsed, 0, sizeof(parsed));
ret = parse_mtd_partitions(mtd, types, &parsed, parser_data);
if ((ret < 0 || parsed.nr_parts == 0) && parts && nr_parts) {
/* Fall back to driver-provided partitions */
parsed = (struct mtd_partitions){
.parts = parts,
.nr_parts = nr_parts,
};
} else if (ret < 0) {
/* Didn't come up with parsed OR fallback partitions */
pr_info("mtd: failed to find partitions; one or more parsers reports errors (%d)\n",
ret);
/* Don't abort on errors; we can still use unpartitioned MTD */
memset(&parsed, 0, sizeof(parsed));
}
ret = mtd_add_device_partitions(mtd, &parsed);
if (ret)
goto out;
/*
* FIXME: some drivers unfortunately call this function more than once.
* So we have to check if we've already assigned the reboot notifier.
*
* Generally, we can make multiple calls work for most cases, but it
* does cause problems with parse_mtd_partitions() above (e.g.,
* cmdlineparts will register partitions more than once).
*/
WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
"MTD already registered\n");
if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
register_reboot_notifier(&mtd->reboot_notifier);
}
out:
/* Cleanup any parsed partitions */
mtd_part_parser_cleanup(&parsed);
return ret;
}
EXPORT_SYMBOL_GPL(mtd_device_parse_register);
/**
* mtd_device_unregister - unregister an existing MTD device.
*
* @master: the MTD device to unregister. This will unregister both the master
* and any partitions if registered.
*/
int mtd_device_unregister(struct mtd_info *master)
{
int err;
if (master->_reboot)
unregister_reboot_notifier(&master->reboot_notifier);
err = del_mtd_partitions(master);
if (err)
return err;
if (!device_is_registered(&master->dev))
return 0;
return del_mtd_device(master);
}
EXPORT_SYMBOL_GPL(mtd_device_unregister);
/**
* register_mtd_user - register a 'user' of MTD devices.
* @new: pointer to notifier info structure
*
* Registers a pair of callbacks function to be called upon addition
* or removal of MTD devices. Causes the 'add' callback to be immediately
* invoked for each MTD device currently present in the system.
*/
void register_mtd_user (struct mtd_notifier *new)
{
struct mtd_info *mtd;
mutex_lock(&mtd_table_mutex);
list_add(&new->list, &mtd_notifiers);
__module_get(THIS_MODULE);
mtd_for_each_device(mtd)
new->add(mtd);
mutex_unlock(&mtd_table_mutex);
}
EXPORT_SYMBOL_GPL(register_mtd_user);
/**
* unregister_mtd_user - unregister a 'user' of MTD devices.
* @old: pointer to notifier info structure
*
* Removes a callback function pair from the list of 'users' to be
* notified upon addition or removal of MTD devices. Causes the
* 'remove' callback to be immediately invoked for each MTD device
* currently present in the system.
*/
int unregister_mtd_user (struct mtd_notifier *old)
{
struct mtd_info *mtd;
mutex_lock(&mtd_table_mutex);
module_put(THIS_MODULE);
mtd_for_each_device(mtd)
old->remove(mtd);
list_del(&old->list);
mutex_unlock(&mtd_table_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(unregister_mtd_user);
/**
* get_mtd_device - obtain a validated handle for an MTD device
* @mtd: last known address of the required MTD device
* @num: internal device number of the required MTD device
*
* Given a number and NULL address, return the num'th entry in the device
* table, if any. Given an address and num == -1, search the device table
* for a device with that address and return if it's still present. Given
* both, return the num'th driver only if its address matches. Return
* error code if not.
*/
struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
struct mtd_info *ret = NULL, *other;
int err = -ENODEV;
mutex_lock(&mtd_table_mutex);
if (num == -1) {
mtd_for_each_device(other) {
if (other == mtd) {
ret = mtd;
break;
}
}
} else if (num >= 0) {
ret = idr_find(&mtd_idr, num);
if (mtd && mtd != ret)
ret = NULL;
}
if (!ret) {
ret = ERR_PTR(err);
goto out;
}
err = __get_mtd_device(ret);
if (err)
ret = ERR_PTR(err);
out:
mutex_unlock(&mtd_table_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(get_mtd_device);
int __get_mtd_device(struct mtd_info *mtd)
{
int err;
if (!try_module_get(mtd->owner))
return -ENODEV;
if (mtd->_get_device) {
err = mtd->_get_device(mtd);
if (err) {
module_put(mtd->owner);
return err;
}
}
mtd->usecount++;
return 0;
}
EXPORT_SYMBOL_GPL(__get_mtd_device);
/**
* get_mtd_device_nm - obtain a validated handle for an MTD device by
* device name
* @name: MTD device name to open
*
* This function returns MTD device description structure in case of
* success and an error code in case of failure.
*/
struct mtd_info *get_mtd_device_nm(const char *name)
{
int err = -ENODEV;
struct mtd_info *mtd = NULL, *other;
mutex_lock(&mtd_table_mutex);
mtd_for_each_device(other) {
if (!strcmp(name, other->name)) {
mtd = other;
break;
}
}
if (!mtd)
goto out_unlock;
err = __get_mtd_device(mtd);
if (err)
goto out_unlock;
mutex_unlock(&mtd_table_mutex);
return mtd;
out_unlock:
mutex_unlock(&mtd_table_mutex);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
void put_mtd_device(struct mtd_info *mtd)
{
mutex_lock(&mtd_table_mutex);
__put_mtd_device(mtd);
mutex_unlock(&mtd_table_mutex);
}
EXPORT_SYMBOL_GPL(put_mtd_device);
void __put_mtd_device(struct mtd_info *mtd)
{
--mtd->usecount;
BUG_ON(mtd->usecount < 0);
if (mtd->_put_device)
mtd->_put_device(mtd);
module_put(mtd->owner);
}
EXPORT_SYMBOL_GPL(__put_mtd_device);
/*
* Erase is an asynchronous operation. Device drivers are supposed
* to call instr->callback() whenever the operation completes, even
* if it completes with a failure.
* Callers are supposed to pass a callback function and wait for it
* to be called before writing to the block.
*/
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
if (!instr->len) {
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
ledtrig_mtd_activity();
return mtd->_erase(mtd, instr);
}
EXPORT_SYMBOL_GPL(mtd_erase);
/*
* This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
*/
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
void **virt, resource_size_t *phys)
{
*retlen = 0;
*virt = NULL;
if (phys)
*phys = 0;
if (!mtd->_point)
return -EOPNOTSUPP;
if (from < 0 || from >= mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
return mtd->_point(mtd, from, len, retlen, virt, phys);