/*
* Copyright (c) International Business Machines Corp., 2006
* Copyright (c) Nokia Corporation, 2007
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Artem Bityutskiy (Битюцкий Артём),
* Frank Haverkamp
*/
/*
* This file includes UBI initialization and building of UBI devices.
*
* When UBI is initialized, it attaches all the MTD devices specified as the
* module load parameters or the kernel boot parameters. If MTD devices were
* specified, UBI does not attach any MTD device, but it is possible to do
* later using the "UBI control device".
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/stringify.h>
#include <linux/namei.h>
#include <linux/stat.h>
#include <linux/miscdevice.h>
#include <linux/mtd/partitions.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include "ubi.h"
/* Maximum length of the 'mtd=' parameter */
#define MTD_PARAM_LEN_MAX 64
/* Maximum number of comma-separated items in the 'mtd=' parameter */
#define MTD_PARAM_MAX_COUNT 3
/* Maximum value for the number of bad PEBs per 1024 PEBs */
#define MAX_MTD_UBI_BEB_LIMIT 768
#ifdef CONFIG_MTD_UBI_MODULE
#define ubi_is_module() 1
#else
#define ubi_is_module() 0
#endif
/**
* struct mtd_dev_param - MTD device parameter description data structure.
* @name: MTD character device node path, MTD device name, or MTD device number
* string
* @vid_hdr_offs: VID header offset
* @max_beb_per1024: maximum expected number of bad PEBs per 1024 PEBs
*/
struct mtd_dev_param {
char name[MTD_PARAM_LEN_MAX];
int vid_hdr_offs;
int max_beb_per1024;
};
/* Numbers of elements set in the @mtd_dev_param array */
static int __initdata mtd_devs;
/* MTD devices specification parameters */
static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
#ifdef CONFIG_MTD_UBI_FASTMAP
/* UBI module parameter to enable fastmap automatically on non-fastmap images */
static bool fm_autoconvert;
#endif
/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
struct class *ubi_class;
/* Slab cache for wear-leveling entries */
struct kmem_cache *ubi_wl_entry_slab;
/* UBI control character device */
static struct miscdevice ubi_ctrl_cdev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "ubi_ctrl",
.fops = &ubi_ctrl_cdev_operations,
};
/* All UBI devices in system */
static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
/* Serializes UBI devices creations and removals */
DEFINE_MUTEX(ubi_devices_mutex);
/* Protects @ubi_devices and @ubi->ref_count */
static DEFINE_SPINLOCK(ubi_devices_lock);
/* "Show" method for files in '/<sysfs>/class/ubi/' */
static ssize_t ubi_version_show(struct class *class,
struct class_attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", UBI_VERSION);
}
/* UBI version attribute ('/<sysfs>/class/ubi/version') */
static struct class_attribute ubi_version =
__ATTR(version, S_IRUGO, ubi_version_show, NULL);
static ssize_t dev_attribute_show(struct device *dev,
struct device_attribute *attr, char *buf);
/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
static struct device_attribute dev_eraseblock_size =
__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_avail_eraseblocks =
__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_total_eraseblocks =
__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_volumes_count =
__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_ec =
__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_reserved_for_bad =
__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bad_peb_count =
__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_vol_count =
__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_min_io_size =
__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bgt_enabled =
__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_mtd_num =
__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
/**
* ubi_volume_notify - send a volume change notification.
* @ubi: UBI device description object
* @vol: volume description object of the changed volume
* @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
*
* This is a helper function which notifies all subscribers about a volume
* change event (creation, removal, re-sizing, re-naming, updating). Returns
* zero in case of success and a negative error code in case of failure.
*/
int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
{
struct ubi_notification nt;
ubi_do_get_device_info(ubi, &nt.di);
ubi_do_get_volume_info(ubi, vol, &nt.vi);
#ifdef CONFIG_MTD_UBI_FASTMAP
switch (ntype) {
case UBI_VOLUME_ADDED:
case UBI_VOLUME_REMOVED:
case UBI_VOLUME_RESIZED:
case UBI_VOLUME_RENAMED:
if (ubi_update_fastmap(ubi)) {
ubi_err("Unable to update fastmap!");
ubi_ro_mode(ubi);
}
}
#endif
return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
}
/**
* ubi_notify_all - send a notification to all volumes.
* @ubi: UBI device description object
* @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
* @nb: the notifier to call
*
* This function walks all volumes of UBI device @ubi and sends the @ntype
* notification for each volume. If @nb is %NULL, then all registered notifiers
* are called, otherwise only the @nb notifier is called. Returns the number of
* sent notifications.
*/
int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
{
struct ubi_notification nt;
int i, count = 0;
ubi_do_get_device_info(ubi, &nt.di);
mutex_lock(&ubi->device_mutex);
for (i = 0; i < ubi->vtbl_slots; i++) {
/*
* Since the @ubi->device is locked, and we are not going to
* change @ubi->volumes, we do not have to lock
* @ubi->volumes_lock.
*/
if (!ubi->volumes[i])
continue;
ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
if (nb)
nb->notifier_call(nb, ntype, &nt);
else
blocking_notifier_call_chain(&ubi_notifiers, ntype,
&nt);
count += 1;
}
mutex_unlock(&ubi->device_mutex);
return count;
}
/**
* ubi_enumerate_volumes - send "add" notification for all existing volumes.
* @nb: the notifier to call
*
* This function walks all UBI devices and volumes and sends the
* %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
* registered notifiers are called, otherwise only the @nb notifier is called.
* Returns the number of sent notifications.
*/
int ubi_enumerate_volumes(struct notifier_block *nb)
{
int i, count = 0;
/*
* Since the @ubi_devices_mutex is locked, and we are not going to
* change @ubi_devices, we do not have to lock @ubi_devices_lock.
*/
for (i = 0; i < UBI_MAX_DEVICES; i++) {
struct ubi_device *ubi = ubi_devices[i];
if (!ubi)
continue;
count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
}
return count;
}
/**
* ubi_get_device - get UBI device.
* @ubi_num: UBI device number
*
* This function returns UBI device description object for UBI device number
* @ubi_num, or %NULL if the device does not exist. This function increases the
* device reference count to prevent removal of the device. In other words, the
* device cannot be removed if its reference count is not zero.
*/
struct ubi_device *ubi_get_device(int ubi_num)
{
struct ubi_device *ubi;
spin_lock(&ubi_devices_lock);
ubi = ubi_devices[ubi_num];
if (ubi) {
ubi_assert(ubi->ref_count >= 0);
ubi->ref_count += 1;
get_device(&ubi->dev);
}
spin_unlock(&ubi_devices_lock);
return ubi;
}
/**
* ubi_put_device - drop an UBI device reference.
* @ubi: UBI device description object
*/
void ubi_put_device(struct ubi_device *ubi)
{
spin_lock(&ubi_devices_lock);
ubi->ref_count -= 1;
put_device(&ubi->dev);
spin_unlock(&ubi_devices_lock);
}
/**
* ubi_get_by_major - get UBI device by character device major number.
* @major: major number
*
* This function is similar to 'ubi_get_device()', but it searches the device
* by its major number.
*/
struct ubi_device *ubi_get_by_major(int major)
{
int i;
struct ubi_device *ubi;
spin_lock(&ubi_devices_lock);
for (i = 0; i < UBI_MAX_DEVICES; i++) {
ubi = ubi_devices[i];
if (ubi && MAJOR(ubi->cdev.dev) == major) {
ubi_assert(ubi->ref_count >= 0);
ubi->ref_count += 1;
get_device(&ubi->dev);
spin_unlock(&ubi_devices_lock);
return ubi;
}
}
spin_unlock(&ubi_devices_lock);
return NULL;
}
/**
* ubi_major2num - get UBI device number by character device major number.
* @major: major number
*
* This function searches UBI device number object by its major number. If UBI
* device was not found, this function returns -ENODEV, otherwise the UBI device
* number is returned.
*/
int ubi_major2num(int major)
{
int i, ubi_num = -ENODEV;
spin_lock(&ubi_devices_lock);
for (i = 0; i < UBI_MAX_DEVICES; i++) {
struct ubi_device *ubi = ubi_devices[i];
if (ubi && MAJOR(ubi->cdev.dev) == major) {
ubi_num = ubi->ubi_num;
break;
}
}
spin_unlock(&ubi_devices_lock);
return ubi_num;
}
/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
static ssize_t dev_attribute_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
ssize_t ret;
struct ubi_device *ubi;
/*
* The below code looks weird, but it actually makes sense. We get the
* UBI device reference from the contained 'struct ubi_device'. But it
* is unclear if the device was removed or not yet. Indeed, if the
* device was removed before we increased its reference count,
* 'ubi_get_device()' will return -ENODEV and we fail.
*
* Remember, 'struct ubi_device' is freed in the release function, so
* we still can use 'ubi->ubi_num'.
*/
ubi = container_of(dev, struct ubi_device, dev);
ubi = ubi_get_device(ubi->ubi_num);
if (!ubi)
return -ENODEV;
if (attr == &dev_eraseblock_size)
ret = sprintf(buf, "%d\n", ubi->leb_size);
else if (attr == &dev_avail_eraseblocks)
ret = sprintf(buf, "%d\n", ubi->avail_pebs);
else if (attr == &dev_total_eraseblocks)
ret = sprintf(buf, "%d\n", ubi->good_peb_count);
else if (attr == &dev_volumes_count)
ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
else if (attr == &dev_max_ec)
ret = sprintf(buf, "%d\n", ubi->max_ec);
else if (attr == &dev_reserved_for_bad)
ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
else if (attr == &dev_bad_peb_count)
ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
else if (attr == &dev_max_vol_count)
ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
else if (attr == &dev_min_io_size)
ret = sprintf(buf, "%d\n", ubi->min_io_size);
else if (attr == &dev_bgt_enabled)
ret = sprintf(buf, "%d\n", ubi->thread_enabled);
else if (attr == &dev_mtd_num)
ret = sprintf(buf, "%d\n", ubi->mtd->index);
else
ret = -EINVAL;
ubi_put_device(ubi);
return ret;
}
static void dev_release(struct device *dev)
{
struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
kfree(ubi);
}
/**
* ubi_sysfs_init - initialize sysfs for an UBI device.
* @ubi: UBI device description object
* @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
* taken
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
{
int err;
ubi->dev.release = dev_release;
ubi->dev.devt = ubi->cdev.dev;
ubi->dev.class = ubi_class;
dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
err = device_register(&ubi->dev);
if (err)
return err;
*ref = 1;
err = device_create_file(&ubi->dev, &dev_eraseblock_size);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_volumes_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_max_ec);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_bad_peb_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_max_vol_count);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_min_io_size);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_bgt_enabled);
if (err)
return err;
err = device_create_file(&ubi->dev, &dev_mtd_num);
return err;
}
/**
* ubi_sysfs_close - close sysfs for an UBI device.
* @ubi: UBI device description object
*/
static void ubi_sysfs_close(struct ubi_device *ubi)
{
device_remove_file(&ubi->dev, &dev_mtd_num);
device_remove_file(&ubi->dev, &dev_bgt_enabled);
device_remove_file(&ubi->dev, &dev_min_io_size);
device_remove_file(&ubi->dev, &dev_max_vol_count);
device_remove_file(&ubi->dev, &dev_bad_peb_count);
device_remove_file(&ubi->dev, &dev_reserved_for_bad);
device_remove_file(&ubi->dev, &dev_max_ec);
device_remove_file(&ubi->dev, &dev_volumes_count);
device_remove_file(&ubi->dev, &dev_total_eraseblocks);
device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
device_remove_file(&ubi->dev, &dev_eraseblock_size);
device_unregister(&ubi->dev);
}
/**
* kill_volumes - destroy all user volumes.
* @ubi: UBI device description object
*/
static void kill_volumes(struct ubi_device *ubi)
{
int i;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i])
ubi_free_volume(ubi, ubi->volumes[i]);
}
/**
* uif_init - initialize user interfaces for an UBI device.
* @ubi: UBI device description object
* @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
* taken, otherwise set to %0
*
* This function initializes various user interfaces for an UBI device. If the
* initialization fails at an early stage, this function frees all the
* resources it allocated, returns an error, and @ref is set to %0. However,
* if the initialization fails after the UBI device was registered in the
* driver core subsystem, this function takes a reference to @ubi->dev, because
* otherwise the release function ('dev_release()') would free whole @ubi
* object. The @ref argument is set to %1 in this case. The caller has to put
* this reference.
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int uif_init(struct ubi_device *ubi, int *ref)
{
int i, err;
dev_t dev;
*ref = 0;
sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
/*
* Major numbers for the UBI character devices are allocated
* dynamically. Major numbers of volume character devices are
* equivalent to ones of the corresponding UBI character device. Minor
* numbers of UBI character devices are 0, while minor numbers of
* volume character devices start from 1. Thus, we allocate one major
* number and ubi->vtbl_slots + 1 minor numbers.
*/
err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
if (err) {
ubi_err("cannot register UBI character devices");
return err;
}
ubi_assert(MINOR(dev) == 0);
cdev_init(&ubi->cdev, &ubi_cdev_operations);
dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
ubi->cdev.owner = THIS_MODULE;
err = cdev_add(&ubi->cdev, dev, 1);
if (err) {
ubi_err("cannot add character device");
goto out_unreg;
}
err = ubi_sysfs_init(ubi, ref);
if (err)
goto out_sysfs;
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i]) {
err = ubi_add_volume(ubi, ubi->volumes[i]);
if (err) {
ubi_err("cannot add volume %d", i);
goto out_volumes;
}
}
return 0;
out_volumes:
kill_volumes(ubi);
out_sysfs:
if (*ref)
get_device(&ubi->dev);
ubi_sysfs_close(ubi);
cdev_del(&ubi->cdev);
out_unreg:
unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
return err;
}
/**
* uif_close - close user interfaces for an UBI device.
* @ubi: UBI device description object
*
* Note, since this function un-registers UBI volume device objects (@vol->dev),
* the memory allocated voe the volumes is freed as well (in the release
* function).
*/
static void uif_close(struct ubi_device *ubi)
{
kill_volumes(ubi);
ubi_sysfs_close(ubi);
cdev_del(&ubi->cdev);
unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
}
/**
* ubi_free_internal_volumes - free internal volumes.
* @ubi: UBI device description object
*/
void ubi_free_internal_volumes(struct ubi_device *ubi)
{
int i;
for (i = ubi->vtbl_slots;
i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
kfree(ubi->volumes[i]->eba_tbl);
kfree(ubi->volumes[i]);
}
}
static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
{
int limit, device_pebs;
uint64_t device_size;
if (!max_beb_per1024)
return 0;
/*
* Here we are using size of the entire flash chip and
* not just the MTD partition size because the maximum
* number of bad eraseblocks is a percentage of the
* whole device and bad eraseblocks are not fairly
* distributed over the flash chip. So the worst case
* is that all the bad eraseblocks of the chip are in
* the MTD partition we are attaching (ubi->mtd).
*/
device_size = mtd_get_device_size(ubi->mtd);
device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
limit = mult_frac(device_pebs, max_beb_per1024, 1024);
/* Round it up */
if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
limit += 1;
return limit;
}
/**
* io_init - initialize I/O sub-system for a given UBI device.
* @ubi: UBI device description object
* @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
*
* If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
* assumed:
* o EC header is always at offset zero - this cannot be changed;
* o VID header starts just after the EC header at the closest address
* aligned to @io->hdrs_min_io_size;
* o data starts just after the VID header at the closest address aligned to
* @io->min_io_size
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int io_init(struct ubi_device *ubi, int max_beb_per1024)
{
dbg_gen("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
dbg_gen("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
if (ubi->mtd->numeraseregions != 0) {
/*
* Some flashes have several erase regions. Different regions
* may have different eraseblock size and other
* characteristics. It looks like mostly multi-region flashes
* have one "main" region and one or more small regions to
* store boot loader code or boot parameters or whatever. I
* guess we should just pick the largest region. But this is
* not implemented.
*/
ubi_err("multiple regions, not implemented");
return -EINVAL;
}
if (ubi->vid_hdr_offset < 0)
return -EINVAL;
/*
* Note, in this implementation we support MTD devices with 0x7FFFFFFF
* physical eraseblocks maximum.
*/
ubi->peb_size = ubi->mtd->erasesize;
ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
ubi->flash_size = ubi->mtd->size;
if (mtd_can_have_bb(ubi->mtd)) {
ubi->bad_allowed = 1;
ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
}
if (ubi->mtd->type == MTD_NORFLASH) {
ubi_assert(ubi->mtd->writesize == 1);
ubi->nor_flash = 1;
}
ubi->min_io_size = ubi->mtd->writesize;
ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
/*
* Make sure minimal I/O unit is power of 2. Note, there is no
* fundamental reason for this assumption. It is just an optimization
* which allows us to avoid costly division operations.
*/
if (!is_power_of_2(ubi->min_io_size)) {
ubi_err("min. I/O unit (%d) is not power of 2",
ubi->min_io_size);
return -EINVAL;
}
ubi_assert(ubi->hdrs_min_io_size > 0);
ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
ubi->max_write_size = ubi->mtd->writebufsize;
/*
* Maximum write size has to be greater or equivalent to min. I/O
* size, and be multiple of min. I/O size.
*/
if (ubi->max_write_size < ubi->min_io_size ||
ubi->max_write_size % ubi->min_io_size ||
!is_power_of_2(ubi->max_write_size)) {
ubi_err("bad write buffer size %d for %d min. I/O unit",
ubi->max_write_size, ubi->min_io_size);
return -EINVAL;
}
/* Calculate default aligned sizes of EC and VID headers */
ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
dbg_gen("min_io_size %d", ubi->min_io_size);
dbg_gen("max_write_size %d", ubi->max_write_size);
dbg_gen("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
dbg_gen("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
dbg_gen("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
if (ubi->vid_hdr_offset == 0)
/* Default offset */
ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
ubi->ec_hdr_alsize;
else {
ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
~(ubi->hdrs_min_io_size - 1);
ubi->vid_hdr_shift = ubi->vid_hdr_offset -
ubi->vid_hdr_aloffset;
}
/* Similar for the data offset */
ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
dbg_gen("vid_hdr_offset %d", ubi->vid_hdr_offset);
dbg_gen("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
dbg_gen("vid_hdr_shift %d", ubi->vid_hdr_shift);
dbg_gen("leb_start %d", ubi->leb_start);
/* The shift must be aligned to 32-bit boundary */
if (ubi->vid_hdr_shift % 4) {
ubi_err("unaligned VID header shift %d",
ubi->vid_hdr_shift);
return -EINVAL;
}
/* Check sanity */
if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
ubi->leb_start & (ubi->min_io_size - 1)) {
ubi_err("bad VID header (%d) or data offsets (%d)",
ubi->vid_hdr_offset, ubi->leb_start);
return -EINVAL;
}
/*
* Set maximum amount of physical erroneous eraseblocks to be 10%.
* Erroneous PEB are those which have read errors.
*/
ubi->max_erroneous = ubi->peb_count / 10;
if (ubi->max_erroneous < 16)
ubi->max_erroneous = 16;
dbg_gen("max_erroneous %d", ubi->max_erroneous);
/*
* It may happen that EC and VID headers are situated in one minimal
* I/O unit. In this case we can only accept this UBI image in
* read-only mode.
*/
if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
ubi_warn("EC and VID headers are in the same minimal I/O unit, switch to read-only mode");
ubi->ro_mode = 1;
}
ubi->leb_size = ubi->peb_size - ubi->leb_start;
if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
ubi_msg("MTD device %d is write-protected, attach in read-only mode",
ubi->mtd->index);
ubi->ro_mode = 1;
}
/*
* Note, ideally, we have to initialize @ubi->bad_peb_count here. But
* unfortunately, MTD does not provide this information. We should loop
* over all physical eraseblocks and invoke mtd->block_is_bad() for
* each physical eraseblock. So, we leave @ubi->bad_peb_count
* uninitialized so far.
*/
return 0;
}
/**
* autoresize - re-size the volume which has the "auto-resize" flag set.
* @ubi: UBI device description object
* @vol_id: ID of the volume to re-size
*
* This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
* the volume table to the largest possible size. See comments in ubi-header.h
* for more description of the flag. Returns zero in case of success and a
* negative error code in case of failure.
*/
static int autoresize(struct ubi_device *ubi, int vol_id)
{
struct ubi_volume_desc desc;
struct ubi_volume *vol = ubi->volumes[vol_id];
int err, old_reserved_pebs = vol->reserved_pebs;
if (ubi->ro_mode) {
ubi_warn("skip auto-resize because of R/O mode");
return 0;
}
/*
* Clear the auto-resize flag in the volume in-memory copy of the
* volume table, and 'ubi_resize_volume()' will propagate this change
* to the flash.
*/
ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
if (ubi->avail_pebs == 0) {
struct ubi_vtbl_record vtbl_rec;
/*
* No available PEBs to re-size the volume, clear the flag on
* flash and exit.
*/
vtbl_rec = ubi->vtbl[vol_id];
err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
if (err)
ubi_err("cannot clean auto-resize flag for volume %d",
vol_id);
} else {
desc.vol = vol;
err = ubi_resize_volume(&desc,
old_reserved_pebs + ubi->avail_pebs);
if (err)
ubi_err("cannot auto-resize volume %d", vol_id);
}
if (err)
return err;
ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
vol->name, old_reserved_pebs, vol->reserved_pebs);
return 0;
}
/**
* ubi_attach_mtd_dev - attach an MTD device.
* @mtd: MTD device description object
* @ubi_num: number to assign to the new UBI device
* @vid_hdr_offset: VID header offset
* @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
*
* This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
* to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
* which case this function finds a vacant device number and assigns it
* automatically. Returns the new UBI device number in case of success and a
* negative error code in case of failure.
*
* Note, the invocations of this function has to be serialized by the
* @ubi_devices_mutex.
*/
int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
int vid_hdr_offset, int max_beb_per1024)
{
struct ubi_device *ubi;
int i, err, ref = 0;
if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
return -EINVAL;
if (!max_beb_per1024)
max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
/*
* Check if we already have the same MTD device attached.
*
* Note, this function assumes that UBI devices creations and deletions
* are serialized, so it does not take the &ubi_devices_lock.
*/
for (i = 0; i < UBI_MAX_DEVICES; i++) {
ubi = ubi_devices[i];
if (ubi && mtd->index == ubi->mtd->index) {
ubi_err("mtd%d is already attached to ubi%d",
mtd->index, i);
return -EEXIST;
}
}
/*
* Make sure this MTD device is not emulated on top of an UBI volume
* already. Well, generally this recursion works fine, but there are
* different problems like the UBI module takes a reference to itself
* by attaching (and thus, opening) the emulated MTD device. This
* results in inability to unload the module. And in general it makes
* no sense to attach emulated MTD devices, so we prohibit this.
*/
if (mtd->type == MTD_UBIVOLUME) {
ubi_err("refuse attaching mtd%d - it is already emulated on top of UBI",
mtd->index);
return -EINVAL;
}
if (ubi_num == UBI_DEV_NUM_AUTO) {
/* Search for an empty slot in the @ubi_devices array */
for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
if (!ubi_devices[ubi_num])
break;
if (ubi_num == UBI_MAX_DEVICES) {
ubi_err("only %d UBI devices may be created",
UBI_MAX_DEVICES);
return -ENFILE;
}
} else {
if (ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
/* Make sure ubi_num is not busy */
if (ubi_devices[ubi_num]) {
ubi_err("ubi%d already exists", ubi_num);
return -EEXIST;
}
}
ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
if (!ubi)
return -ENOMEM;
ubi->mtd = mtd;
ubi->ubi_num = ubi_num;
ubi->vid_hdr_offset = vid_hdr_offset;
ubi->autoresize_vol_id = -1;
#ifdef CONFIG_MTD_UBI_FASTMAP
ubi->fm_pool.used = ubi->fm_pool.size = 0;
ubi->fm_wl_pool.used = ubi->fm_wl_pool.size = 0;
/*
* fm_pool.max_size is 5% of the total number of PEBs but it's also
* between UBI_FM_MAX_POOL_SIZE and UBI_FM_MIN_POOL_SIZE.
*/
ubi->fm_pool.max_size = min(((int)mtd_div_by_eb(ubi->mtd->size,
ubi->mtd) / 100) * 5, UBI_FM_MAX_POOL_SIZE);
if (ubi->fm_pool.max_size < UBI_FM_MIN_POOL_SIZE)
ubi->fm_pool.max_size = UBI_FM_MIN_POOL_SIZE;
ubi->fm_wl_pool.max_size = UBI_FM_WL_POOL_SIZE;
ubi->fm_disabled = !fm_autoconvert;
if (!ubi->fm_disabled && (int)mtd_div_by_eb(ubi->mtd->size, ubi->mtd)
<= UBI_FM_MAX_START) {
ubi_err("More than %i PEBs are needed for fastmap, sorry.",
UBI_FM_MAX_START);
ubi->fm_disabled = 1;
}
ubi_msg("default fastmap pool size: %d", ubi->fm_pool.max_size);
ubi_msg("default fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
#else
ubi->fm_disabled = 1;
#endif
mutex_init(&ubi->buf_mutex);
mutex_init(&ubi->ckvol_mutex);
mutex_init(&ubi->device_mutex);
spin_lock_init(&ubi->volumes_lock);
mutex_init(&ubi->fm_mutex);
init_rwsem(&ubi->fm_sem);
ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
err = io_init(ubi, max_beb_per1024);
if (err)
goto out_free;
err = -ENOMEM;
ubi->peb_buf = vmalloc(ubi->peb_size);
if (!ubi->peb_buf)
goto out_free;
#ifdef CONFIG_MTD_UBI_FASTMAP
ubi->fm_size = ubi_calc_fm_size(ubi);
ubi->fm_buf = vzalloc(ubi->fm_size);
if (!ubi->fm_buf)
goto out_free;
#endif
err = ubi_attach(ubi, 0);
if (err) {
ubi_err("failed to attach mtd%d, error %d", mtd->index, err);
goto out_free;
}
if (ubi->autoresize_vol_id != -1) {
err = autoresize(ubi, ubi->autoresize_vol_id);
if (err)
goto out_detach;
}
err = uif_init(ubi, &ref);
if (err)
goto out_detach;
err = ubi_debugfs_init_dev(ubi);
if (err)
goto out_uif;
ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
if (IS_ERR(ubi->bgt_thread)) {
err = PTR_ERR(ubi->bgt_thread);
ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
err);
goto out_debugfs;
}
ubi_msg("attached mtd%d (name \"%s\", size %llu MiB) to ubi%d",
mtd->index, mtd->name, ubi->flash_size >> 20, ubi_num);
ubi_msg("PEB size: %d bytes (%d KiB), LEB size: %d bytes",
ubi->peb_size, ubi->peb_size >> 10, ubi->leb_size);
ubi_msg("min./max. I/O unit sizes: %d/%d, sub-page size %d",
ubi->min_io_size, ubi->max_write_size, ubi->hdrs_min_io_size);
ubi_msg("VID header offset: %d (aligned %d), data offset: %d",
ubi->vid_hdr_offset, ubi->vid_hdr_aloffset, ubi->leb_start);
ubi_msg("good PEBs: %d, bad PEBs: %d, corrupted PEBs: %d",
ubi->good_peb_count, ubi->bad_peb_count, ubi->corr_peb_count);
ubi_msg("user volume: %d, internal volumes: %d, max. volumes count: %d",
ubi->vol_count - UBI_INT_VOL_COUNT, UBI_INT_VOL_COUNT,
ubi->vtbl_slots);
ubi_msg("max/mean erase counter: %d/%d, WL threshold: %d, image sequence number: %u",
ubi->max_ec, ubi->mean_ec, CONFIG_MTD_UBI_WL_THRESHOLD,
ubi->image_seq);
ubi_msg("available PEBs: %d, total reserved PEBs: %d, PEBs reserved for bad PEB handling: %d",
ubi->avail_pebs, ubi->rsvd_pebs, ubi->beb_rsvd_pebs);
/*
* The below lock makes sure we do not race with 'ubi_thread()' which
* checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
*/
spin_lock(&ubi->wl_lock);
ubi->thread_enabled = 1;
wake_up_process(ubi->bgt_thread);
spin_unlock(&ubi->wl_lock);
ubi_devices[ubi_num] = ubi;
ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
return ubi_num;
out_debugfs:
ubi_debugfs_exit_dev(ubi);
out_uif:
get_device(&ubi->dev);
ubi_assert(ref);
uif_close(ubi);
out_detach:
ubi_wl_close(ubi);
ubi_free_internal_volumes(ubi);
vfree(ubi->vtbl);
out_free:
vfree(ubi->peb_buf);
vfree(ubi->fm_buf);
if (ref)
put_device(&ubi->dev);
else
kfree(ubi);
return err;
}
/**
* ubi_detach_mtd_dev - detach an MTD device.
* @ubi_num: UBI device number to detach from
* @anyway: detach MTD even if device reference count is not zero
*
* This function destroys an UBI device number @ubi_num and detaches the
* underlying MTD device. Returns zero in case of success and %-EBUSY if the
* UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
* exist.
*
* Note, the invocations of this function has to be serialized by the
* @ubi_devices_mutex.
*/
int ubi_detach_mtd_dev(int ubi_num, int anyway)
{
struct ubi_device *ubi;
if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
return -EINVAL;
ubi = ubi_get_device(ubi_num);
if (!ubi)
return -EINVAL;
spin_lock(&ubi_devices_lock);
put_device(&ubi->dev);
ubi->ref_count -= 1;
if (ubi->ref_count) {
if (!anyway) {
spin_unlock(&ubi_devices_lock);
return -EBUSY;
}
/* This may only happen if there is a bug */
ubi_err("%s reference count %d, destroy anyway",
ubi->ubi_name, ubi->ref_count);
}
ubi_devices[ubi_num] = NULL;
spin_unlock(&ubi_devices_lock);
ubi_assert(ubi_num == ubi->ubi_num);
ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
ubi_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
#ifdef CONFIG_MTD_UBI_FASTMAP
/* If we don't write a new fastmap at detach time we lose all
* EC updates that have been made since the last written fastmap. */
ubi_update_fastmap(ubi);
#endif
/*
* Before freeing anything, we have to stop the background thread to
* prevent it from doing anything on this device while we are freeing.
*/
if (ubi->bgt_thread)
kthread_stop(ubi->bgt_thread);
/*
* Get a reference to the device in order to prevent 'dev_release()'
* from freeing the @ubi object.
*/
get_device(&ubi->dev);
ubi_debugfs_exit_dev(ubi);
uif_close(ubi);
ubi_wl_close(ubi);
ubi_free_internal_volumes(ubi);
vfree(ubi->vtbl);
put_mtd_device(ubi->mtd);
vfree(ubi->peb_buf);
vfree(ubi->fm_buf);
ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
put_device(&ubi->dev);
return 0;
}
/**
* open_mtd_by_chdev - open an MTD device by its character device node path.
* @mtd_dev: MTD character device node path
*
* This helper function opens an MTD device by its character node device path.
* Returns MTD device description object in case of success and a negative
* error code in case of failure.
*/
static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
{
int err, major, minor, mode;
struct path path;
/* Probably this is an MTD character device node path */
err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
if (err)
return ERR_PTR(err);
/* MTD device number is defined by the major / minor numbers */
major = imajor(path.dentry->d_inode);
minor = iminor(path.dentry->d_inode);
mode = path.dentry->d_inode->i_mode;
path_put(&path);
if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
return ERR_PTR(-EINVAL);
if (minor & 1)
/*
* Just do not think the "/dev/mtdrX" devices support is need,
* so do not support them to avoid doing extra work.
*/
return ERR_PTR(-EINVAL);
return get_mtd_device(NULL, minor / 2);
}
/**
* open_mtd_device - open MTD device by name, character device path, or number.
* @mtd_dev: name, character device node path, or MTD device device number
*
* This function tries to open and MTD device described by @mtd_dev string,
* which is first treated as ASCII MTD device number, and if it is not true, it
* is treated as MTD device name, and if that is also not true, it is treated
* as MTD character device node path. Returns MTD device description object in
* case of success and a negative error code in case of failure.
*/
static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
{
struct mtd_info *mtd;
int mtd_num;
char *endp;
mtd_num = simple_strtoul(mtd_dev, &endp, 0);
if (*endp != '\0' || mtd_dev == endp) {
/*
* This does not look like an ASCII integer, probably this is
* MTD device name.
*/
mtd = get_mtd_device_nm(mtd_dev);
if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
/* Probably this is an MTD character device node path */
mtd = open_mtd_by_chdev(mtd_dev);
} else
mtd = get_mtd_device(NULL, mtd_num);
return mtd;
}
static int __init ubi_init(void)
{
int err, i, k;
/* Ensure that EC and VID headers have correct size */
BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
if (mtd_devs > UBI_MAX_DEVICES) {
ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
return -EINVAL;
}
/* Create base sysfs directory and sysfs files */
ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
if (IS_ERR(ubi_class)) {
err = PTR_ERR(ubi_class);
ubi_err("cannot create UBI class");
goto out;
}
err = class_create_file(ubi_class, &ubi_version);
if (err) {
ubi_err("cannot create sysfs file");
goto out_class;
}
err = misc_register(&ubi_ctrl_cdev);
if (err) {
ubi_err("cannot register device");
goto out_version;
}
ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
sizeof(struct ubi_wl_entry),
0, 0, NULL);
if (!ubi_wl_entry_slab)
goto out_dev_unreg;
err = ubi_debugfs_init();
if (err)
goto out_slab;
/* Attach MTD devices */
for (i = 0; i < mtd_devs; i++) {
struct mtd_dev_param *p = &mtd_dev_param[i];
struct mtd_info *mtd;
cond_resched();
mtd = open_mtd_device(p->name);
if (IS_ERR(mtd)) {
err = PTR_ERR(mtd);
goto out_detach;
}
mutex_lock(&ubi_devices_mutex);
err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
p->vid_hdr_offs, p->max_beb_per1024);
mutex_unlock(&ubi_devices_mutex);
if (err < 0) {
ubi_err("cannot attach mtd%d", mtd->index);
put_mtd_device(mtd);
/*
* Originally UBI stopped initializing on any error.
* However, later on it was found out that this
* behavior is not very good when UBI is compiled into
* the kernel and the MTD devices to attach are passed
* through the command line. Indeed, UBI failure
* stopped whole boot sequence.
*
* To fix this, we changed the behavior for the
* non-module case, but preserved the old behavior for
* the module case, just for compatibility. This is a
* little inconsistent, though.
*/
if (ubi_is_module())
goto out_detach;
}
}
return 0;
out_detach:
for (k = 0; k < i; k++)
if (ubi_devices[k]) {
mutex_lock(&ubi_devices_mutex);
ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
mutex_unlock(&ubi_devices_mutex);
}
ubi_debugfs_exit();
out_slab:
kmem_cache_destroy(ubi_wl_entry_slab);
out_dev_unreg:
misc_deregister(&ubi_ctrl_cdev);
out_version:
class_remove_file(ubi_class, &ubi_version);
out_class:
class_destroy(ubi_class);
out:
ubi_err("UBI error: cannot initialize UBI, error %d", err);
return err;
}
late_initcall(ubi_init);
static void __exit ubi_exit(void)
{
int i;
for (i = 0; i < UBI_MAX_DEVICES; i++)
if (ubi_devices[i]) {
mutex_lock(&ubi_devices_mutex);
ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
mutex_unlock(&ubi_devices_mutex);
}
ubi_debugfs_exit();
kmem_cache_destroy(ubi_wl_entry_slab);
misc_deregister(&ubi_ctrl_cdev);
class_remove_file(ubi_class, &ubi_version);
class_destroy(ubi_class);
}
module_exit(ubi_exit);
/**
* bytes_str_to_int - convert a number of bytes string into an integer.
* @str: the string to convert
*
* This function returns positive resulting integer in case of success and a
* negative error code in case of failure.
*/
static int __init bytes_str_to_int(const char *str)
{
char *endp;
unsigned long result;
result = simple_strtoul(str, &endp, 0);
if (str == endp || result >= INT_MAX) {
ubi_err("UBI error: incorrect bytes count: \"%s\"\n", str);
return -EINVAL;
}
switch (*endp) {
case 'G':
result *= 1024;
case 'M':
result *= 1024;
case 'K':
result *= 1024;
if (endp[1] == 'i' && endp[2] == 'B')
endp += 2;
case '\0':
break;
default:
ubi_err("UBI error: incorrect bytes count: \"%s\"\n", str);
return -EINVAL;
}
return result;
}
/**
* ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
* @val: the parameter value to parse
* @kp: not used
*
* This function returns zero in case of success and a negative error code in
* case of error.
*/
static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
{
int i, len;
struct mtd_dev_param *p;
char buf[MTD_PARAM_LEN_MAX];
char *pbuf = &buf[0];
char *tokens[MTD_PARAM_MAX_COUNT];
if (!val)
return -EINVAL;
if (mtd_devs == UBI_MAX_DEVICES) {
ubi_err("UBI error: too many parameters, max. is %d\n",
UBI_MAX_DEVICES);
return -EINVAL;
}
len = strnlen(val, MTD_PARAM_LEN_MAX);
if (len == MTD_PARAM_LEN_MAX) {
ubi_err("UBI error: parameter \"%s\" is too long, max. is %d\n",
val, MTD_PARAM_LEN_MAX);
return -EINVAL;
}
if (len == 0) {
pr_warn("UBI warning: empty 'mtd=' parameter - ignored\n");
return 0;
}
strcpy(buf, val);
/* Get rid of the final newline */
if (buf[len - 1] == '\n')
buf[len - 1] = '\0';
for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
tokens[i] = strsep(&pbuf, ",");
if (pbuf) {
ubi_err("UBI error: too many arguments at \"%s\"\n", val);
return -EINVAL;
}
p = &mtd_dev_param[mtd_devs];
strcpy(&p->name[0], tokens[0]);
if (tokens[1])
p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
if (p->vid_hdr_offs < 0)
return p->vid_hdr_offs;
if (tokens[2]) {
int err = kstrtoint(tokens[2], 10, &p->max_beb_per1024);
if (err) {
ubi_err("UBI error: bad value for max_beb_per1024 parameter: %s",
tokens[2]);
return -EINVAL;
}
}
mtd_devs += 1;
return 0;
}
module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: mtd=<name|num|path>[,<vid_hdr_offs>[,max_beb_per1024]].\n"
"Multiple \"mtd\" parameters may be specified.\n"
"MTD devices may be specified by their number, name, or path to the MTD character device node.\n"
"Optional \"vid_hdr_offs\" parameter specifies UBI VID header position to be used by UBI. (default value if 0)\n"
"Optional \"max_beb_per1024\" parameter specifies the maximum expected bad eraseblock per 1024 eraseblocks. (default value ("
__stringify(CONFIG_MTD_UBI_BEB_LIMIT) ") if 0)\n"
"\n"
"Example 1: mtd=/dev/mtd0 - attach MTD device /dev/mtd0.\n"
"Example 2: mtd=content,1984 mtd=4 - attach MTD device with name \"content\" using VID header offset 1984, and MTD device number 4 with default VID header offset.\n"
"Example 3: mtd=/dev/mtd1,0,25 - attach MTD device /dev/mtd1 using default VID header offset and reserve 25*nand_size_in_blocks/1024 erase blocks for bad block handling.\n"
"\t(e.g. if the NAND *chipset* has 4096 PEB, 100 will be reserved for this UBI device).");
#ifdef CONFIG_MTD_UBI_FASTMAP
module_param(fm_autoconvert, bool, 0644);
MODULE_PARM_DESC(fm_autoconvert, "Set this parameter to enable fastmap automatically on images without a fastmap.");
#endif
MODULE_VERSION(__stringify(UBI_VERSION));
MODULE_DESCRIPTION("UBI - Unsorted Block Images");
MODULE_AUTHOR("Artem Bityutskiy");
MODULE_LICENSE("GPL");