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mtdcore.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* Core registration and callback routines for MTD
* drivers and users.
*
* Copyright © 1999-2010 David Woodhouse <[email protected]>
* Copyright © 2006 Red Hat UK Limited
*
*/
#ifndef __UBOOT__
#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/proc_fs.h>
#include <linux/idr.h>
#include <linux/backing-dev.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#else
#include <linux/err.h>
#include <ubi_uboot.h>
#endif
#include <linux/log2.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include "mtdcore.h"
#ifndef __UBOOT__
/*
* backing device capabilities for non-mappable devices (such as NAND flash)
* - permits private mappings, copies are taken of the data
*/
static struct backing_dev_info mtd_bdi_unmappable = {
.capabilities = BDI_CAP_MAP_COPY,
};
/*
* backing device capabilities for R/O mappable devices (such as ROM)
* - permits private mappings, copies are taken of the data
* - permits non-writable shared mappings
*/
static struct backing_dev_info mtd_bdi_ro_mappable = {
.capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
};
/*
* backing device capabilities for writable mappable devices (such as RAM)
* - permits private mappings, copies are taken of the data
* - permits non-writable shared mappings
*/
static struct backing_dev_info mtd_bdi_rw_mappable = {
.capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
BDI_CAP_WRITE_MAP),
};
static int mtd_cls_suspend(struct device *dev, pm_message_t state);
static int mtd_cls_resume(struct device *dev);
static struct class mtd_class = {
.name = "mtd",
.owner = THIS_MODULE,
.suspend = mtd_cls_suspend,
.resume = mtd_cls_resume,
};
#else
struct mtd_info *mtd_table[MAX_MTD_DEVICES];
#define MAX_IDR_ID 64
struct idr_layer {
int used;
void *ptr;
};
struct idr {
struct idr_layer id[MAX_IDR_ID];
};
#define DEFINE_IDR(name) struct idr name;
void idr_remove(struct idr *idp, int id)
{
if (idp->id[id].used)
idp->id[id].used = 0;
return;
}
void *idr_find(struct idr *idp, int id)
{
if (idp->id[id].used)
return idp->id[id].ptr;
return NULL;
}
void *idr_get_next(struct idr *idp, int *next)
{
void *ret;
int id = *next;
ret = idr_find(idp, id);
if (ret) {
id ++;
if (!idp->id[id].used)
id = 0;
*next = id;
} else {
*next = 0;
}
return ret;
}
int idr_alloc(struct idr *idp, void *ptr, int start, int end, gfp_t gfp_mask)
{
struct idr_layer *idl;
int i = 0;
while (i < MAX_IDR_ID) {
idl = &idp->id[i];
if (idl->used == 0) {
idl->used = 1;
idl->ptr = ptr;
return i;
}
i++;
}
return -ENOSPC;
}
#endif
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);
#ifndef __UBOOT__
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 __maybe_unused *mtd = dev_get_drvdata(dev);
dev_t index = MTD_DEVT(mtd->index);
/* remove /dev/mtdXro node if needed */
if (index)
device_destroy(&mtd_class, index + 1);
}
static int mtd_cls_suspend(struct device *dev, pm_message_t state)
{
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 ssize_t mtd_type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
char *type;
switch (mtd->type) {
case MTD_ABSENT:
type = "absent";
break;
case MTD_RAM:
type = "ram";
break;
case MTD_ROM:
type = "rom";
break;
case MTD_NORFLASH:
type = "nor";
break;
case MTD_NANDFLASH:
type = "nand";
break;
case MTD_DATAFLASH:
type = "dataflash";
break;
case MTD_UBIVOLUME:
type = "ubi";
break;
case MTD_MLCNANDFLASH:
type = "mlc-nand";
break;
default:
type = "unknown";
}
return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
static ssize_t mtd_flags_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
}
static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
static ssize_t mtd_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%llu\n",
(unsigned long long)mtd->size);
}
static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
static ssize_t mtd_erasesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
}
static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
static ssize_t mtd_writesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
static ssize_t mtd_subpagesize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
}
static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
static ssize_t mtd_oobsize_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
}
static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
static ssize_t mtd_numeraseregions_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
}
static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
NULL);
static ssize_t mtd_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
static ssize_t mtd_ecc_strength_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
}
static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
static ssize_t mtd_bitflip_threshold_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
}
static ssize_t mtd_bitflip_threshold_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
unsigned int bitflip_threshold;
int retval;
retval = kstrtouint(buf, 0, &bitflip_threshold);
if (retval)
return retval;
mtd->bitflip_threshold = bitflip_threshold;
return count;
}
static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
mtd_bitflip_threshold_show,
mtd_bitflip_threshold_store);
static ssize_t mtd_ecc_step_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct mtd_info *mtd = dev_get_drvdata(dev);
return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
}
static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
static struct attribute *mtd_attrs[] = {
&dev_attr_type.attr,
&dev_attr_flags.attr,
&dev_attr_size.attr,
&dev_attr_erasesize.attr,
&dev_attr_writesize.attr,
&dev_attr_subpagesize.attr,
&dev_attr_oobsize.attr,
&dev_attr_numeraseregions.attr,
&dev_attr_name.attr,
&dev_attr_ecc_strength.attr,
&dev_attr_ecc_step_size.attr,
&dev_attr_bitflip_threshold.attr,
NULL,
};
ATTRIBUTE_GROUPS(mtd);
static struct device_type mtd_devtype = {
.name = "mtd",
.groups = mtd_groups,
.release = mtd_release,
};
#endif
/**
* 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 1 on failure, which currently will only happen
* if there is insufficient memory or a sysfs error.
*/
int add_mtd_device(struct mtd_info *mtd)
{
#ifndef __UBOOT__
struct mtd_notifier *not;
#endif
int i, error;
#ifndef __UBOOT__
if (!mtd->backing_dev_info) {
switch (mtd->type) {
case MTD_RAM:
mtd->backing_dev_info = &mtd_bdi_rw_mappable;
break;
case MTD_ROM:
mtd->backing_dev_info = &mtd_bdi_ro_mappable;
break;
default:
mtd->backing_dev_info = &mtd_bdi_unmappable;
break;
}
}
#endif
BUG_ON(mtd->writesize == 0);
mutex_lock(&mtd_table_mutex);
i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
if (i < 0)
goto fail_locked;
mtd->index = i;
mtd->usecount = 0;
INIT_LIST_HEAD(&mtd->partitions);
/* default value if not set by driver */
if (mtd->bitflip_threshold == 0)
mtd->bitflip_threshold = mtd->ecc_strength;
if (is_power_of_2(mtd->erasesize))
mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
else
mtd->erasesize_shift = 0;
if (is_power_of_2(mtd->writesize))
mtd->writesize_shift = ffs(mtd->writesize) - 1;
else
mtd->writesize_shift = 0;
mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
/* Some chips always power up locked. Unlock them now */
if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
error = mtd_unlock(mtd, 0, mtd->size);
if (error && error != -EOPNOTSUPP)
printk(KERN_WARNING
"%s: unlock failed, writes may not work\n",
mtd->name);
}
#ifndef __UBOOT__
/* Caller should have set dev.parent to match the
* physical device.
*/
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);
if (device_register(&mtd->dev) != 0)
goto fail_added;
if (MTD_DEVT(i))
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);
#else
pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
#endif
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;
#ifndef __UBOOT__
fail_added:
idr_remove(&mtd_idr, i);
#endif
fail_locked:
mutex_unlock(&mtd_table_mutex);
return 1;
}
/**
* 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;
#ifndef __UBOOT__
struct mtd_notifier *not;
#endif
mutex_lock(&mtd_table_mutex);
if (idr_find(&mtd_idr, mtd->index) != mtd) {
ret = -ENODEV;
goto out_error;
}
#ifndef __UBOOT__
/* 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);
#endif
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 {
#ifndef __UBOOT__
device_unregister(&mtd->dev);
#endif
idr_remove(&mtd_idr, mtd->index);
module_put(THIS_MODULE);
ret = 0;
}
out_error:
mutex_unlock(&mtd_table_mutex);
return ret;
}
#ifndef __UBOOT__
/**
* mtd_device_parse_register - parse partitions and register an MTD device.
*
* @mtd: the MTD device to register
* @types: the list of MTD partition probes to try, see
* 'parse_mtd_partitions()' for more information
* @parser_data: MTD partition parser-specific data
* @parts: fallback partition information to register, if parsing fails;
* only valid if %nr_parts > %0
* @nr_parts: the number of partitions in parts, if zero then the full
* MTD device is registered if no partition info is found
*
* This function aggregates MTD partitions parsing (done by
* 'parse_mtd_partitions()') and MTD device and partitions registering. It
* basically follows the most common pattern found in many MTD drivers:
*
* * It first tries to probe partitions on MTD device @mtd using parsers
* specified in @types (if @types is %NULL, then the default list of parsers
* is used, see 'parse_mtd_partitions()' for more information). If none are
* found this functions tries to fallback to information specified in
* @parts/@nr_parts.
* * If any partitioning info was found, this function registers the found
* partitions.
* * If 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 err;
struct mtd_partition *real_parts;
err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
if (err <= 0 && nr_parts && parts) {
real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
GFP_KERNEL);
if (!real_parts)
err = -ENOMEM;
else
err = nr_parts;
}
if (err > 0) {
err = add_mtd_partitions(mtd, real_parts, err);
kfree(real_parts);
} else if (err == 0) {
err = add_mtd_device(mtd);
if (err == 1)
err = -ENODEV;
}
return err;
}
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;
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);
#endif
/**
* get_mtd_device - obtain a validated handle for an MTD device
* @mtd: last known address of the required MTD device
* @num: internal device number of the required MTD device
*
* Given a number and NULL address, return the num'th entry in the device
* table, if any. Given an address and num == -1, search the device table
* for a device with that address and return if it's still present. Given
* both, return the num'th driver only if its address matches. Return
* error code if not.
*/
struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
struct mtd_info *ret = NULL, *other;
int err = -ENODEV;
mutex_lock(&mtd_table_mutex);
if (num == -1) {
mtd_for_each_device(other) {
if (other == mtd) {
ret = mtd;
break;
}
}
} else if (num >= 0) {
ret = idr_find(&mtd_idr, num);
if (mtd && mtd != ret)
ret = NULL;
}
if (!ret) {
ret = ERR_PTR(err);
goto out;
}
err = __get_mtd_device(ret);
if (err)
ret = ERR_PTR(err);
out:
mutex_unlock(&mtd_table_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(get_mtd_device);
int __get_mtd_device(struct mtd_info *mtd)
{
int err;
if (!try_module_get(mtd->owner))
return -ENODEV;
if (mtd->_get_device) {
err = mtd->_get_device(mtd);
if (err) {
module_put(mtd->owner);
return err;
}
}
mtd->usecount++;
return 0;
}
EXPORT_SYMBOL_GPL(__get_mtd_device);
/**
* get_mtd_device_nm - obtain a validated handle for an MTD device by
* device name
* @name: MTD device name to open
*
* This function returns MTD device description structure in case of
* success and an error code in case of failure.
*/
struct mtd_info *get_mtd_device_nm(const char *name)
{
int err = -ENODEV;
struct mtd_info *mtd = NULL, *other;
mutex_lock(&mtd_table_mutex);
mtd_for_each_device(other) {
if (!strcmp(name, other->name)) {
mtd = other;
break;
}
}
if (!mtd)
goto out_unlock;
err = __get_mtd_device(mtd);
if (err)
goto out_unlock;
mutex_unlock(&mtd_table_mutex);
return mtd;
out_unlock:
mutex_unlock(&mtd_table_mutex);
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
#if defined(CONFIG_CMD_MTDPARTS_SPREAD)
/**
* mtd_get_len_incl_bad
*
* Check if length including bad blocks fits into device.
*
* @param mtd an MTD device
* @param offset offset in flash
* @param length image length
* @return image length including bad blocks in *len_incl_bad and whether or not
* the length returned was truncated in *truncated
*/
void mtd_get_len_incl_bad(struct mtd_info *mtd, uint64_t offset,
const uint64_t length, uint64_t *len_incl_bad,
int *truncated)
{
*truncated = 0;
*len_incl_bad = 0;
if (!mtd->_block_isbad) {
*len_incl_bad = length;
return;
}
uint64_t len_excl_bad = 0;
uint64_t block_len;
while (len_excl_bad < length) {
if (offset >= mtd->size) {
*truncated = 1;
return;
}
block_len = mtd->erasesize - (offset & (mtd->erasesize - 1));
if (!mtd->_block_isbad(mtd, offset & ~(mtd->erasesize - 1)))
len_excl_bad += block_len;
*len_incl_bad += block_len;
offset += block_len;
}
}
#endif /* defined(CONFIG_CMD_MTDPARTS_SPREAD) */
void put_mtd_device(struct mtd_info *mtd)
{
mutex_lock(&mtd_table_mutex);
__put_mtd_device(mtd);
mutex_unlock(&mtd_table_mutex);
}
EXPORT_SYMBOL_GPL(put_mtd_device);
void __put_mtd_device(struct mtd_info *mtd)
{
--mtd->usecount;
BUG_ON(mtd->usecount < 0);
if (mtd->_put_device)
mtd->_put_device(mtd);
module_put(mtd->owner);
}
EXPORT_SYMBOL_GPL(__put_mtd_device);
/*
* Erase is an asynchronous operation. Device drivers are supposed
* to call instr->callback() whenever the operation completes, even
* if it completes with a failure.
* Callers are supposed to pass a callback function and wait for it
* to be called before writing to the block.
*/
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
if (instr->addr > mtd->size || instr->len > mtd->size - instr->addr)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
if (!instr->len) {
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
return mtd->_erase(mtd, instr);
}
EXPORT_SYMBOL_GPL(mtd_erase);
#ifndef __UBOOT__
/*
* This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
*/
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
void **virt, resource_size_t *phys)
{
*retlen = 0;
*virt = NULL;
if (phys)
*phys = 0;
if (!mtd->_point)
return -EOPNOTSUPP;
if (from < 0 || from > mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
return mtd->_point(mtd, from, len, retlen, virt, phys);
}
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)
{
if (!mtd->_point)
return -EOPNOTSUPP;
if (from < 0 || from > mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
return mtd->_unpoint(mtd, from, len);
}
EXPORT_SYMBOL_GPL(mtd_unpoint);
#endif
/*
* 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)
{
if (!mtd->_get_unmapped_area)
return -EOPNOTSUPP;
if (offset > mtd->size || len > mtd->size - offset)
return -EINVAL;
return mtd->_get_unmapped_area(mtd, len, offset, flags);
}
EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
u_char *buf)
{
int ret_code;
*retlen = 0;
if (from < 0 || from > mtd->size || len > mtd->size - from)
return -EINVAL;
if (!len)
return 0;
/*
* In the absence of an error, drivers return a non-negative integer
* representing the maximum number of bitflips that were corrected on
* any one ecc region (if applicable; zero otherwise).
*/
if (mtd->_read) {
ret_code = mtd->_read(mtd, from, len, retlen, buf);
} else if (mtd->_read_oob) {
struct mtd_oob_ops ops = {
.len = len,
.datbuf = buf,
};
ret_code = mtd->_read_oob(mtd, from, &ops);
*retlen = ops.retlen;
} else {
return -ENOTSUPP;
}
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);
int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
const u_char *buf)
{
*retlen = 0;
if (to < 0 || to > mtd->size || len > mtd->size - to)
return -EINVAL;
if ((!mtd->_write && !mtd->_write_oob) ||
!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
if (!len)
return 0;
if (!mtd->_write) {
struct mtd_oob_ops ops = {
.len = len,
.datbuf = (u8 *)buf,
};
int ret;
ret = mtd->_write_oob(mtd, to, &ops);
*retlen = ops.retlen;
return ret;
}
return mtd->_write(mtd, to, len, retlen, buf);
}
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)