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linux/drivers/mtd/mtdcore.c
Miquel Raynal 67b967ddd9 mtd: Introduce an expert mode for forensics and debugging purposes 
When developping NAND controller drivers or when debugging filesystem
corruptions, it is quite common to need hacking locally into the
MTD/NAND core in order to get access to the content of the bad
blocks. Instead of having multiple implementations out there let's
provide a simple yet effective specific MTD-wide debugfs entry to fully
disable these checks on purpose.

A warning is added to inform the user when this mode gets enabled.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211118114659.1282855-1-miquel.raynal@bootlin.com
2021-12-09 17:51:59 +01:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Core registration and callback routines for MTD
* drivers and users.
*
* Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
* Copyright © 2006 Red Hat UK Limited
*/
#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/nvmem-provider.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);
}
#define MTD_DEVICE_ATTR_RO(name) \
static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
#define MTD_DEVICE_ATTR_RW(name) \
static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
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 sysfs_emit(buf, "%s\n", type);
}
MTD_DEVICE_ATTR_RO(type);
static ssize_t mtd_flags_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
}
MTD_DEVICE_ATTR_RO(flags);
static ssize_t mtd_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
}
MTD_DEVICE_ATTR_RO(size);
static ssize_t mtd_erasesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
}
MTD_DEVICE_ATTR_RO(erasesize);
static ssize_t mtd_writesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
}
MTD_DEVICE_ATTR_RO(writesize);
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 sysfs_emit(buf, "%u\n", subpagesize);
}
MTD_DEVICE_ATTR_RO(subpagesize);
static ssize_t mtd_oobsize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
}
MTD_DEVICE_ATTR_RO(oobsize);
static ssize_t mtd_oobavail_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%u\n", mtd->oobavail);
}
MTD_DEVICE_ATTR_RO(oobavail);
static ssize_t mtd_numeraseregions_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
}
MTD_DEVICE_ATTR_RO(numeraseregions);
static ssize_t mtd_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return sysfs_emit(buf, "%s\n", mtd->name);
}
MTD_DEVICE_ATTR_RO(name);
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 sysfs_emit(buf, "%u\n", mtd->ecc_strength);
}
MTD_DEVICE_ATTR_RO(ecc_strength);
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 sysfs_emit(buf, "%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;
}
MTD_DEVICE_ATTR_RW(bitflip_threshold);
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 sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
}
MTD_DEVICE_ATTR_RO(ecc_step_size);
static ssize_t mtd_corrected_bits_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 sysfs_emit(buf, "%u\n", ecc_stats->corrected);
}
MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
static ssize_t mtd_ecc_failures_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 sysfs_emit(buf, "%u\n", ecc_stats->failed);
}
MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
static ssize_t mtd_bad_blocks_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 sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
}
MTD_DEVICE_ATTR_RO(bad_blocks);
static ssize_t mtd_bbt_blocks_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 sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
}
MTD_DEVICE_ATTR_RO(bbt_blocks);
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_oobavail.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,
};
static int mtd_partid_debug_show(struct seq_file *s, void *p)
{
struct mtd_info *mtd = s->private;
seq_printf(s, "%s\n", mtd->dbg.partid);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(mtd_partid_debug);
static int mtd_partname_debug_show(struct seq_file *s, void *p)
{
struct mtd_info *mtd = s->private;
seq_printf(s, "%s\n", mtd->dbg.partname);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(mtd_partname_debug);
static struct dentry *dfs_dir_mtd;
static void mtd_debugfs_populate(struct mtd_info *mtd)
{
struct mtd_info *master = mtd_get_master(mtd);
struct device *dev = &mtd->dev;
struct dentry *root;
if (IS_ERR_OR_NULL(dfs_dir_mtd))
return;
root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
mtd->dbg.dfs_dir = root;
if (master->dbg.partid)
debugfs_create_file("partid", 0400, root, master,
&mtd_partid_debug_fops);
if (master->dbg.partname)
debugfs_create_file("partname", 0400, root, master,
&mtd_partname_debug_fops);
}
#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)
{
struct mtd_info *master = mtd_get_master(mtd);
int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
if (wunit < 0 || wunit >= npairs)
return -EINVAL;
if (master->pairing && master->pairing->get_info)
return master->pairing->get_info(master, wunit, info);
info->group = 0;
info->pair = wunit;
return 0;
}
EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
/**
* mtd_pairing_info_to_wunit - 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)
{
struct mtd_info *master = mtd_get_master(mtd);
int ngroups = mtd_pairing_groups(master);
int npairs = mtd_wunit_per_eb(master) / ngroups;
if (!info || info->pair < 0 || info->pair >= npairs ||
info->group < 0 || info->group >= ngroups)
return -EINVAL;
if (master->pairing && master->pairing->get_wunit)
return mtd->pairing->get_wunit(master, 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)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->pairing || !master->pairing->ngroups)
return 1;
return master->pairing->ngroups;
}
EXPORT_SYMBOL_GPL(mtd_pairing_groups);
static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct mtd_info *mtd = priv;
size_t retlen;
int err;
err = mtd_read(mtd, offset, bytes, &retlen, val);
if (err && err != -EUCLEAN)
return err;
return retlen == bytes ? 0 : -EIO;
}
static int mtd_nvmem_add(struct mtd_info *mtd)
{
struct device_node *node = mtd_get_of_node(mtd);
struct nvmem_config config = {};
config.id = -1;
config.dev = &mtd->dev;
config.name = dev_name(&mtd->dev);
config.owner = THIS_MODULE;
config.reg_read = mtd_nvmem_reg_read;
config.size = mtd->size;
config.word_size = 1;
config.stride = 1;
config.read_only = true;
config.root_only = true;
config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
config.priv = mtd;
mtd->nvmem = nvmem_register(&config);
if (IS_ERR(mtd->nvmem)) {
/* Just ignore if there is no NVMEM support in the kernel */
if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
mtd->nvmem = NULL;
} else {
dev_err(&mtd->dev, "Failed to register NVMEM device\n");
return PTR_ERR(mtd->nvmem);
}
}
return 0;
}
/**
* 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_info *master = mtd_get_master(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);
/*
* MTD drivers should implement ->_{write,read}() or
* ->_{write,read}_oob(), but not both.
*/
if (WARN_ON((mtd->_write && mtd->_write_oob) ||
(mtd->_read && mtd->_read_oob)))
return -EINVAL;
if (WARN_ON((!mtd->erasesize || !master->_erase) &&
!(mtd->flags & MTD_NO_ERASE)))
return -EINVAL;
/*
* MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
* master is an MLC NAND and has a proper pairing scheme defined.
* We also reject masters that implement ->_writev() for now, because
* NAND controller drivers don't implement this hook, and adding the
* SLC -> MLC address/length conversion to this path is useless if we
* don't have a user.
*/
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
(!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
!master->pairing || master->_writev))
return -EINVAL;
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 (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
int ngroups = mtd_pairing_groups(master);
mtd->erasesize /= ngroups;
mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
mtd->erasesize;
}
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;
/* Add the nvmem provider */
error = mtd_nvmem_add(mtd);
if (error)
goto fail_nvmem_add;
mtd_debugfs_populate(mtd);
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_nvmem_add:
device_unregister(&mtd->dev);
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);
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 {
debugfs_remove_recursive(mtd->dbg.dfs_dir);
/* Try to remove the NVMEM provider */
if (mtd->nvmem)
nvmem_unregister(mtd->nvmem);
device_unregister(&mtd->dev);
/* Clear dev so mtd can be safely re-registered later if desired */
memset(&mtd->dev, 0, sizeof(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;
}
/*
* 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");
}
INIT_LIST_HEAD(&mtd->partitions);
mutex_init(&mtd->master.partitions_lock);
mutex_init(&mtd->master.chrdev_lock);
}
static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
{
struct otp_info *info;
ssize_t size = 0;
unsigned int i;
size_t retlen;
int ret;
info = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!info)
return -ENOMEM;
if (is_user)
ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
else
ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
if (ret)
goto err;
for (i = 0; i < retlen / sizeof(*info); i++)
size += info[i].length;
kfree(info);
return size;
err:
kfree(info);
/* ENODATA means there is no OTP region. */
return ret == -ENODATA ? 0 : ret;
}
static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
const char *compatible,
int size,
nvmem_reg_read_t reg_read)
{
struct nvmem_device *nvmem = NULL;
struct nvmem_config config = {};
struct device_node *np;
/* DT binding is optional */
np = of_get_compatible_child(mtd->dev.of_node, compatible);
/* OTP nvmem will be registered on the physical device */
config.dev = mtd->dev.parent;
config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
config.id = NVMEM_DEVID_NONE;
config.owner = THIS_MODULE;
config.type = NVMEM_TYPE_OTP;
config.root_only = true;
config.reg_read = reg_read;
config.size = size;
config.of_node = np;
config.priv = mtd;
nvmem = nvmem_register(&config);
/* Just ignore if there is no NVMEM support in the kernel */
if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
nvmem = NULL;
of_node_put(np);
kfree(config.name);
return nvmem;
}
static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct mtd_info *mtd = priv;
size_t retlen;
int ret;
ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
if (ret)
return ret;
return retlen == bytes ? 0 : -EIO;
}
static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct mtd_info *mtd = priv;
size_t retlen;
int ret;
ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
if (ret)
return ret;
return retlen == bytes ? 0 : -EIO;
}
static int mtd_otp_nvmem_add(struct mtd_info *mtd)
{
struct nvmem_device *nvmem;
ssize_t size;
int err;
if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
size = mtd_otp_size(mtd, true);
if (size < 0)
return size;
if (size > 0) {
nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
mtd_nvmem_user_otp_reg_read);
if (IS_ERR(nvmem)) {
dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
return PTR_ERR(nvmem);
}
mtd->otp_user_nvmem = nvmem;
}
}
if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
size = mtd_otp_size(mtd, false);
if (size < 0) {
err = size;
goto err;
}
if (size > 0) {
nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
mtd_nvmem_fact_otp_reg_read);
if (IS_ERR(nvmem)) {
dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
err = PTR_ERR(nvmem);
goto err;
}
mtd->otp_factory_nvmem = nvmem;
}
}
return 0;
err:
if (mtd->otp_user_nvmem)
nvmem_unregister(mtd->otp_user_nvmem);
return err;
}
/**
* 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:
*
* * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
* registered first.
* * Then It 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 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)
{
int ret;
mtd_set_dev_defaults(mtd);
if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
ret = add_mtd_device(mtd);
if (ret)
return ret;
}
/* Prefer parsed partitions over driver-provided fallback */
ret = parse_mtd_partitions(mtd, types, parser_data);
if (ret == -EPROBE_DEFER)
goto out;
if (ret > 0)
ret = 0;
else if (nr_parts)
ret = add_mtd_partitions(mtd, parts, nr_parts);
else if (!device_is_registered(&mtd->dev))
ret = add_mtd_device(mtd);
else
ret = 0;
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);
}
ret = mtd_otp_nvmem_add(mtd);
out:
if (ret && device_is_registered(&mtd->dev))
del_mtd_device(mtd);
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);
memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
}
if (master->otp_user_nvmem)
nvmem_unregister(master->otp_user_nvmem);
if (master->otp_factory_nvmem)
nvmem_unregister(master->otp_factory_nvmem);
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)
{
struct mtd_info *master = mtd_get_master(mtd);
int err;
if (!try_module_get(master->owner))
return -ENODEV;
if (master->_get_device) {
err = master->_get_device(mtd);
if (err) {
module_put(master->owner);
return err;
}
}
master->usecount++;
while (mtd->parent) {
mtd->usecount++;
mtd = mtd->parent;
}
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)
{
struct mtd_info *master = mtd_get_master(mtd);
while (mtd->parent) {
--mtd->usecount;
BUG_ON(mtd->usecount < 0);
mtd = mtd->parent;
}
master->usecount--;
if (master->_put_device)
master->_put_device(master);
module_put(master->owner);
}
EXPORT_SYMBOL_GPL(__put_mtd_device);
/*
* Erase is an synchronous operation. Device drivers are epected to return a
* negative error code if the operation failed and update instr->fail_addr
* to point the portion that was not properly erased.
*/
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct mtd_info *master = mtd_get_master(mtd);
u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
struct erase_info adjinstr;
int ret;
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
adjinstr = *instr;
if (!mtd->erasesize || !master->_erase)
return -ENOTSUPP;
if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (!instr->len)
return 0;
ledtrig_mtd_activity();
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
master->erasesize;
adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
master->erasesize) -
adjinstr.addr;
}
adjinstr.addr += mst_ofs;
ret = master->_erase(master, &adjinstr);
if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
instr->fail_addr = adjinstr.fail_addr - mst_ofs;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
master);
instr->fail_addr *= mtd->erasesize;
}
}
return ret;
}
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)
{
struct mtd_info *master = mtd_get_master(mtd);
*retlen = 0;
*virt = NULL;
if (phys)
*phys = 0;
if (!master->_point)
return -EOPNOTSUPP;
if (from < 0 || from >= mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
from = mtd_get_master_ofs(mtd, from);
return master->_point(master, from, len, retlen, virt, phys);
}
EXPORT_SYMBOL_GPL(mtd_point);
/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_unpoint)
return -EOPNOTSUPP;
if (from < 0 || from >= mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
}
EXPORT_SYMBOL_GPL(mtd_unpoint);
/*
* Allow NOMMU mmap() to directly map the device (if not NULL)
* - return the address to which the offset maps
* - return -ENOSYS to indicate refusal to do the mapping
*/
unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
unsigned long offset, unsigned long flags)
{
size_t retlen;
void *virt;
int ret;
ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
if (ret)
return ret;
if (retlen != len) {
mtd_unpoint(mtd, offset, retlen);
return -ENOSYS;
}
return (unsigned long)virt;
}
EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
const struct mtd_ecc_stats *old_stats)
{
struct mtd_ecc_stats diff;
if (master == mtd)
return;
diff = master->ecc_stats;
diff.failed -= old_stats->failed;
diff.corrected -= old_stats->corrected;
while (mtd->parent) {
mtd->ecc_stats.failed += diff.failed;
mtd->ecc_stats.corrected += diff.corrected;
mtd = mtd->parent;
}
}
int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
u_char *buf)
{
struct mtd_oob_ops ops = {
.len = len,
.datbuf = buf,
};
int ret;
ret = mtd_read_oob(mtd, from, &ops);
*retlen = ops.retlen;
return ret;
}
EXPORT_SYMBOL_GPL(mtd_read);
int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
const u_char *buf)
{
struct mtd_oob_ops ops = {
.len = len,
.datbuf = (u8 *)buf,
};
int ret;
ret = mtd_write_oob(mtd, to, &ops);
*retlen = ops.retlen;
return ret;
}
EXPORT_SYMBOL_GPL(mtd_write);
/*
* In blackbox flight recorder like scenarios we want to make successful writes
* in interrupt context. panic_write() is only intended to be called when its
* known the kernel is about to panic and we need the write to succeed. Since
* the kernel is not going to be running for much longer, this function can
* break locks and delay to ensure the write succeeds (but not sleep).
*/
int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
const u_char *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
*retlen = 0;
if (!master->_panic_write)
return -EOPNOTSUPP;
if (to < 0 || to >= mtd->size || len > mtd->size - to)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (!len)
return 0;
if (!master->oops_panic_write)
master->oops_panic_write = true;
return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_panic_write);
static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
struct mtd_oob_ops *ops)
{
/*
* Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
* ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
* this case.
*/
if (!ops->datbuf)
ops->len = 0;
if (!ops->oobbuf)
ops->ooblen = 0;
if (offs < 0 || offs + ops->len > mtd->size)
return -EINVAL;
if (ops->ooblen) {
size_t maxooblen;
if (ops->ooboffs >= mtd_oobavail(mtd, ops))
return -EINVAL;
maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
mtd_div_by_ws(offs, mtd)) *
mtd_oobavail(mtd, ops)) - ops->ooboffs;
if (ops->ooblen > maxooblen)
return -EINVAL;
}
return 0;
}
static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
struct mtd_oob_ops *ops)
{
struct mtd_info *master = mtd_get_master(mtd);
int ret;
from = mtd_get_master_ofs(mtd, from);
if (master->_read_oob)
ret = master->_read_oob(master, from, ops);
else
ret = master->_read(master, from, ops->len, &ops->retlen,
ops->datbuf);
return ret;
}
static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
struct mtd_info *master = mtd_get_master(mtd);
int ret;
to = mtd_get_master_ofs(mtd, to);
if (master->_write_oob)
ret = master->_write_oob(master, to, ops);
else
ret = master->_write(master, to, ops->len, &ops->retlen,
ops->datbuf);
return ret;
}
static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
struct mtd_oob_ops *ops)
{
struct mtd_info *master = mtd_get_master(mtd);
int ngroups = mtd_pairing_groups(master);
int npairs = mtd_wunit_per_eb(master) / ngroups;
struct mtd_oob_ops adjops = *ops;
unsigned int wunit, oobavail;
struct mtd_pairing_info info;
int max_bitflips = 0;
u32 ebofs, pageofs;
loff_t base, pos;
ebofs = mtd_mod_by_eb(start, mtd);
base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
info.group = 0;
info.pair = mtd_div_by_ws(ebofs, mtd);
pageofs = mtd_mod_by_ws(ebofs, mtd);
oobavail = mtd_oobavail(mtd, ops);
while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
int ret;
if (info.pair >= npairs) {
info.pair = 0;
base += master->erasesize;
}
wunit = mtd_pairing_info_to_wunit(master, &info);
pos = mtd_wunit_to_offset(mtd, base, wunit);
adjops.len = ops->len - ops->retlen;
if (adjops.len > mtd->writesize - pageofs)
adjops.len = mtd->writesize - pageofs;
adjops.ooblen = ops->ooblen - ops->oobretlen;
if (adjops.ooblen > oobavail - adjops.ooboffs)
adjops.ooblen = oobavail - adjops.ooboffs;
if (read) {
ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
if (ret > 0)
max_bitflips = max(max_bitflips, ret);
} else {
ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
}
if (ret < 0)
return ret;
max_bitflips = max(max_bitflips, ret);
ops->retlen += adjops.retlen;
ops->oobretlen += adjops.oobretlen;
adjops.datbuf += adjops.retlen;
adjops.oobbuf += adjops.oobretlen;
adjops.ooboffs = 0;
pageofs = 0;
info.pair++;
}
return max_bitflips;
}
int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
{
struct mtd_info *master = mtd_get_master(mtd);
struct mtd_ecc_stats old_stats = master->ecc_stats;
int ret_code;
ops->retlen = ops->oobretlen = 0;
ret_code = mtd_check_oob_ops(mtd, from, ops);
if (ret_code)
return ret_code;
ledtrig_mtd_activity();
/* Check the validity of a potential fallback on mtd->_read */
if (!master->_read_oob && (!master->_read || ops->oobbuf))
return -EOPNOTSUPP;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
else
ret_code = mtd_read_oob_std(mtd, from, ops);
mtd_update_ecc_stats(mtd, master, &old_stats);
/*
* In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
* similar to mtd->_read(), returning a non-negative integer
* representing max bitflips. In other cases, mtd->_read_oob() may
* return -EUCLEAN. In all cases, perform similar logic to mtd_read().
*/
if (unlikely(ret_code < 0))
return ret_code;
if (mtd->ecc_strength == 0)
return 0; /* device lacks ecc */
return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
}
EXPORT_SYMBOL_GPL(mtd_read_oob);
int mtd_write_oob(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
struct mtd_info *master = mtd_get_master(mtd);
int ret;
ops->retlen = ops->oobretlen = 0;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
ret = mtd_check_oob_ops(mtd, to, ops);
if (ret)
return ret;
ledtrig_mtd_activity();
/* Check the validity of a potential fallback on mtd->_write */
if (!master->_write_oob && (!master->_write || ops->oobbuf))
return -EOPNOTSUPP;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
return mtd_io_emulated_slc(mtd, to, false, ops);
return mtd_write_oob_std(mtd, to, ops);
}
EXPORT_SYMBOL_GPL(mtd_write_oob);
/**
* mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
* @mtd: MTD device structure
* @section: ECC section. Depending on the layout you may have all the ECC
* bytes stored in a single contiguous section, or one section
* per ECC chunk (and sometime several sections for a single ECC
* ECC chunk)
* @oobecc: OOB region struct filled with the appropriate ECC position
* information
*
* This function returns ECC section information in the OOB area. If you want
* to get all the ECC bytes information, then you should call
* mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobecc)
{
struct mtd_info *master = mtd_get_master(mtd);
memset(oobecc, 0, sizeof(*oobecc));
if (!master || section < 0)
return -EINVAL;
if (!master->ooblayout || !master->ooblayout->ecc)
return -ENOTSUPP;
return master->ooblayout->ecc(master, section, oobecc);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
/**
* mtd_ooblayout_free - Get the OOB region definition of a specific free
* section
* @mtd: MTD device structure
* @section: Free section you are interested in. Depending on the layout
* you may have all the free bytes stored in a single contiguous
* section, or one section per ECC chunk plus an extra section
* for the remaining bytes (or other funky layout).
* @oobfree: OOB region struct filled with the appropriate free position
* information
*
* This function returns free bytes position in the OOB area. If you want
* to get all the free bytes information, then you should call
* mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobfree)
{
struct mtd_info *master = mtd_get_master(mtd);
memset(oobfree, 0, sizeof(*oobfree));
if (!master || section < 0)
return -EINVAL;
if (!master->ooblayout || !master->ooblayout->free)
return -ENOTSUPP;
return master->ooblayout->free(master, section, oobfree);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
/**
* mtd_ooblayout_find_region - Find the region attached to a specific byte
* @mtd: mtd info structure
* @byte: the byte we are searching for
* @sectionp: pointer where the section id will be stored
* @oobregion: used to retrieve the ECC position
* @iter: iterator function. Should be either mtd_ooblayout_free or
* mtd_ooblayout_ecc depending on the region type you're searching for
*
* This function returns the section id and oobregion information of a
* specific byte. For example, say you want to know where the 4th ECC byte is
* stored, you'll use:
*
* mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
*
* Returns zero on success, a negative error code otherwise.
*/
static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
int *sectionp, struct mtd_oob_region *oobregion,
int (*iter)(struct mtd_info *,
int section,
struct mtd_oob_region *oobregion))
{
int pos = 0, ret, section = 0;
memset(oobregion, 0, sizeof(*oobregion));
while (1) {
ret = iter(mtd, section, oobregion);
if (ret)
return ret;
if (pos + oobregion->length > byte)
break;
pos += oobregion->length;
section++;
}
/*
* Adjust region info to make it start at the beginning at the
* 'start' ECC byte.
*/
oobregion->offset += byte - pos;
oobregion->length -= byte - pos;
*sectionp = section;
return 0;
}
/**
* mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
* ECC byte
* @mtd: mtd info structure
* @eccbyte: the byte we are searching for
* @section: pointer where the section id will be stored
* @oobregion: OOB region information
*
* Works like mtd_ooblayout_find_region() except it searches for a specific ECC
* byte.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
int *section,
struct mtd_oob_region *oobregion)
{
return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
mtd_ooblayout_ecc);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
/**
* mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
* @mtd: mtd info structure
* @buf: destination buffer to store OOB bytes
* @oobbuf: OOB buffer
* @start: first byte to retrieve
* @nbytes: number of bytes to retrieve
* @iter: section iterator
*
* Extract bytes attached to a specific category (ECC or free)
* from the OOB buffer and copy them into buf.
*
* Returns zero on success, a negative error code otherwise.
*/
static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
const u8 *oobbuf, int start, int nbytes,
int (*iter)(struct mtd_info *,
int section,
struct mtd_oob_region *oobregion))
{
struct mtd_oob_region oobregion;
int section, ret;
ret = mtd_ooblayout_find_region(mtd, start, &section,
&oobregion, iter);
while (!ret) {
int cnt;
cnt = min_t(int, nbytes, oobregion.length);
memcpy(buf, oobbuf + oobregion.offset, cnt);
buf += cnt;
nbytes -= cnt;
if (!nbytes)
break;
ret = iter(mtd, ++section, &oobregion);
}
return ret;
}
/**
* mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
* @mtd: mtd info structure
* @buf: source buffer to get OOB bytes from
* @oobbuf: OOB buffer
* @start: first OOB byte to set
* @nbytes: number of OOB bytes to set
* @iter: section iterator
*
* Fill the OOB buffer with data provided in buf. The category (ECC or free)
* is selected by passing the appropriate iterator.
*
* Returns zero on success, a negative error code otherwise.
*/
static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
u8 *oobbuf, int start, int nbytes,
int (*iter)(struct mtd_info *,
int section,
struct mtd_oob_region *oobregion))
{
struct mtd_oob_region oobregion;
int section, ret;
ret = mtd_ooblayout_find_region(mtd, start, &section,
&oobregion, iter);
while (!ret) {
int cnt;
cnt = min_t(int, nbytes, oobregion.length);
memcpy(oobbuf + oobregion.offset, buf, cnt);
buf += cnt;
nbytes -= cnt;
if (!nbytes)
break;
ret = iter(mtd, ++section, &oobregion);
}
return ret;
}
/**
* mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
* @mtd: mtd info structure
* @iter: category iterator
*
* Count the number of bytes in a given category.
*
* Returns a positive value on success, a negative error code otherwise.
*/
static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
int (*iter)(struct mtd_info *,
int section,
struct mtd_oob_region *oobregion))
{
struct mtd_oob_region oobregion;
int section = 0, ret, nbytes = 0;
while (1) {
ret = iter(mtd, section++, &oobregion);
if (ret) {
if (ret == -ERANGE)
ret = nbytes;
break;
}
nbytes += oobregion.length;
}
return ret;
}
/**
* mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
* @mtd: mtd info structure
* @eccbuf: destination buffer to store ECC bytes
* @oobbuf: OOB buffer
* @start: first ECC byte to retrieve
* @nbytes: number of ECC bytes to retrieve
*
* Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
const u8 *oobbuf, int start, int nbytes)
{
return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
mtd_ooblayout_ecc);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
/**
* mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
* @mtd: mtd info structure
* @eccbuf: source buffer to get ECC bytes from
* @oobbuf: OOB buffer
* @start: first ECC byte to set
* @nbytes: number of ECC bytes to set
*
* Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
u8 *oobbuf, int start, int nbytes)
{
return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
mtd_ooblayout_ecc);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
/**
* mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
* @mtd: mtd info structure
* @databuf: destination buffer to store ECC bytes
* @oobbuf: OOB buffer
* @start: first ECC byte to retrieve
* @nbytes: number of ECC bytes to retrieve
*
* Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
const u8 *oobbuf, int start, int nbytes)
{
return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
mtd_ooblayout_free);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
/**
* mtd_ooblayout_set_databytes - set data bytes into the oob buffer
* @mtd: mtd info structure
* @databuf: source buffer to get data bytes from
* @oobbuf: OOB buffer
* @start: first ECC byte to set
* @nbytes: number of ECC bytes to set
*
* Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
u8 *oobbuf, int start, int nbytes)
{
return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
mtd_ooblayout_free);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
/**
* mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
* @mtd: mtd info structure
*
* Works like mtd_ooblayout_count_bytes(), except it count free bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
{
return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
/**
* mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
* @mtd: mtd info structure
*
* Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
*
* Returns zero on success, a negative error code otherwise.
*/
int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
{
return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
}
EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
/*
* Method to access the protection register area, present in some flash
* devices. The user data is one time programmable but the factory data is read
* only.
*/
int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
struct otp_info *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_get_fact_prot_info)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_get_fact_prot_info(master, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
*retlen = 0;
if (!master->_read_fact_prot_reg)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_read_fact_prot_reg(master, from, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
struct otp_info *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_get_user_prot_info)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_get_user_prot_info(master, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
*retlen = 0;
if (!master->_read_user_prot_reg)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_read_user_prot_reg(master, from, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct mtd_info *master = mtd_get_master(mtd);
int ret;
*retlen = 0;
if (!master->_write_user_prot_reg)
return -EOPNOTSUPP;
if (!len)
return 0;
ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
if (ret)
return ret;
/*
* If no data could be written at all, we are out of memory and
* must return -ENOSPC.
*/
return (*retlen) ? 0 : -ENOSPC;
}
EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_lock_user_prot_reg)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_lock_user_prot_reg(master, from, len);
}
EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_erase_user_prot_reg)
return -EOPNOTSUPP;
if (!len)
return 0;
return master->_erase_user_prot_reg(master, from, len);
}
EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_lock)
return -EOPNOTSUPP;
if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
}
return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
}
EXPORT_SYMBOL_GPL(mtd_lock);
int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_unlock)
return -EOPNOTSUPP;
if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
}
return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
}
EXPORT_SYMBOL_GPL(mtd_unlock);
int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_info *master = mtd_get_master(mtd);
if (!master->_is_locked)
return -EOPNOTSUPP;
if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
return -EINVAL;
if (!len)
return 0;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
}
return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
}
EXPORT_SYMBOL_GPL(mtd_is_locked);
int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_info *master = mtd_get_master(mtd);
if (ofs < 0 || ofs >= mtd->size)
return -EINVAL;
if (!master->_block_isreserved)
return 0;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
}
EXPORT_SYMBOL_GPL(mtd_block_isreserved);
int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_info *master = mtd_get_master(mtd);
if (ofs < 0 || ofs >= mtd->size)
return -EINVAL;
if (!master->_block_isbad)
return 0;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
}
EXPORT_SYMBOL_GPL(mtd_block_isbad);
int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_info *master = mtd_get_master(mtd);
int ret;
if (!master->_block_markbad)
return -EOPNOTSUPP;
if (ofs < 0 || ofs >= mtd->size)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
if (ret)
return ret;
while (mtd->parent) {
mtd->ecc_stats.badblocks++;
mtd = mtd->parent;
}
return 0;
}
EXPORT_SYMBOL_GPL(mtd_block_markbad);
/*
* default_mtd_writev - the default writev method
* @mtd: mtd device description object pointer
* @vecs: the vectors to write
* @count: count of vectors in @vecs
* @to: the MTD device offset to write to
* @retlen: on exit contains the count of bytes written to the MTD device.
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen)
{
unsigned long i;
size_t totlen = 0, thislen;
int ret = 0;
for (i = 0; i < count; i++) {
if (!vecs[i].iov_len)
continue;
ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
vecs[i].iov_base);
totlen += thislen;
if (ret || thislen != vecs[i].iov_len)
break;
to += vecs[i].iov_len;
}
*retlen = totlen;
return ret;
}
/*
* mtd_writev - the vector-based MTD write method
* @mtd: mtd device description object pointer
* @vecs: the vectors to write
* @count: count of vectors in @vecs
* @to: the MTD device offset to write to
* @retlen: on exit contains the count of bytes written to the MTD device.
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen)
{
struct mtd_info *master = mtd_get_master(mtd);
*retlen = 0;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (!master->_writev)
return default_mtd_writev(mtd, vecs, count, to, retlen);
return master->_writev(master, vecs, count,
mtd_get_master_ofs(mtd, to), retlen);
}
EXPORT_SYMBOL_GPL(mtd_writev);
/**
* mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
* @mtd: mtd device description object pointer
* @size: a pointer to the ideal or maximum size of the allocation, points
* to the actual allocation size on success.
*
* This routine attempts to allocate a contiguous kernel buffer up to
* the specified size, backing off the size of the request exponentially
* until the request succeeds or until the allocation size falls below
* the system page size. This attempts to make sure it does not adversely
* impact system performance, so when allocating more than one page, we
* ask the memory allocator to avoid re-trying, swapping, writing back
* or performing I/O.
*
* Note, this function also makes sure that the allocated buffer is aligned to
* the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
*
* This is called, for example by mtd_{read,write} and jffs2_scan_medium,
* to handle smaller (i.e. degraded) buffer allocations under low- or
* fragmented-memory situations where such reduced allocations, from a
* requested ideal, are allowed.
*
* Returns a pointer to the allocated buffer on success; otherwise, NULL.
*/
void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
{
gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
void *kbuf;
*size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
while (*size > min_alloc) {
kbuf = kmalloc(*size, flags);
if (kbuf)
return kbuf;
*size >>= 1;
*size = ALIGN(*size, mtd->writesize);
}
/*
* For the last resort allocation allow 'kmalloc()' to do all sorts of
* things (write-back, dropping caches, etc) by using GFP_KERNEL.
*/
return kmalloc(*size, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
#ifdef CONFIG_PROC_FS
/*====================================================================*/
/* Support for /proc/mtd */
static int mtd_proc_show(struct seq_file *m, void *v)
{
struct mtd_info *mtd;
seq_puts(m, "dev: size erasesize name\n");
mutex_lock(&mtd_table_mutex);
mtd_for_each_device(mtd) {
seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
mtd->index, (unsigned long long)mtd->size,
mtd->erasesize, mtd->name);
}
mutex_unlock(&mtd_table_mutex);
return 0;
}
#endif /* CONFIG_PROC_FS */
/*====================================================================*/
/* Init code */
static struct backing_dev_info * __init mtd_bdi_init(const char *name)
{
struct backing_dev_info *bdi;
int ret;
bdi = bdi_alloc(NUMA_NO_NODE);
if (!bdi)
return ERR_PTR(-ENOMEM);
bdi->ra_pages = 0;
bdi->io_pages = 0;
/*
* We put '-0' suffix to the name to get the same name format as we
* used to get. Since this is called only once, we get a unique name.
*/
ret = bdi_register(bdi, "%.28s-0", name);
if (ret)
bdi_put(bdi);
return ret ? ERR_PTR(ret) : bdi;
}
char *mtd_expert_analysis_warning =
"Bad block checks have been entirely disabled.\n"
"This is only reserved for post-mortem forensics and debug purposes.\n"
"Never enable this mode if you do not know what you are doing!\n";
EXPORT_SYMBOL_GPL(mtd_expert_analysis_warning);
bool mtd_expert_analysis_mode;
EXPORT_SYMBOL_GPL(mtd_expert_analysis_mode);
static struct proc_dir_entry *proc_mtd;
static int __init init_mtd(void)
{
int ret;
ret = class_register(&mtd_class);
if (ret)
goto err_reg;
mtd_bdi = mtd_bdi_init("mtd");
if (IS_ERR(mtd_bdi)) {
ret = PTR_ERR(mtd_bdi);
goto err_bdi;
}
proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
ret = init_mtdchar();
if (ret)
goto out_procfs;
dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
&mtd_expert_analysis_mode);
return 0;
out_procfs:
if (proc_mtd)
remove_proc_entry("mtd", NULL);
bdi_put(mtd_bdi);
err_bdi:
class_unregister(&mtd_class);
err_reg:
pr_err("Error registering mtd class or bdi: %d\n", ret);
return ret;
}
static void __exit cleanup_mtd(void)
{
debugfs_remove_recursive(dfs_dir_mtd);
cleanup_mtdchar();
if (proc_mtd)
remove_proc_entry("mtd", NULL);
class_unregister(&mtd_class);
bdi_unregister(mtd_bdi);
bdi_put(mtd_bdi);
idr_destroy(&mtd_idr);
}
module_init(init_mtd);
module_exit(cleanup_mtd);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");
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