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linux/drivers/mtd/mtdcore.c
Miquel Raynal 5ab9bbf6c6 mtd: Fix possible refcounting issue when going through partition nodes 
Under normal conditions, the loop goes over all child partitions, and
'breaks' when the relevant partition is found. In this case we get a
reference to the partition node without ever releasing it. Indeed, right
after the mtd_check_of_node() function returns, we call of_node_get()
again over this very same node. It is probably safer to keep the
counters even in this helper and call of_node_put() before break-ing.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202312250546.ISzglvM2-lkp@intel.com/
Cc: Christian Marangi <ansuelsmth@gmail.com>
Cc: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240104081446.126540-1-miquel.raynal@bootlin.com
2024-02-05 13:39:33 +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/random.h>
#include <linux/slab.h>
#include <linux/reboot.h>
#include <linux/leds.h>
#include <linux/debugfs.h>
#include <linux/nvmem-provider.h>
#include <linux/root_dev.h>
#include <linux/error-injection.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",
.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);
idr_remove(&mtd_idr, mtd->index);
of_node_put(mtd_get_of_node(mtd));
if (mtd_is_partition(mtd))
release_mtd_partition(mtd);
/* remove /dev/mtdXro node */
device_destroy(&mtd_class, index + 1);
}
static void mtd_device_release(struct kref *kref)
{
struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt);
bool is_partition = mtd_is_partition(mtd);
debugfs_remove_recursive(mtd->dbg.dfs_dir);
/* Try to remove the NVMEM provider */
nvmem_unregister(mtd->nvmem);
device_unregister(&mtd->dev);
/*
* Clear dev so mtd can be safely re-registered later if desired.
* Should not be done for partition,
* as it was already destroyed in device_unregister().
*/
if (!is_partition)
memset(&mtd->dev, 0, sizeof(mtd->dev));
module_put(THIS_MODULE);
}
#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 bool mtd_expert_analysis_mode;
#ifdef CONFIG_DEBUG_FS
bool mtd_check_expert_analysis_mode(void)
{
const 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";
return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
}
EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
#endif
static struct dentry *dfs_dir_mtd;
static void mtd_debugfs_populate(struct mtd_info *mtd)
{
struct device *dev = &mtd->dev;
if (IS_ERR_OR_NULL(dfs_dir_mtd))
return;
mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
}
#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 = NVMEM_DEVID_NONE;
config.dev = &mtd->dev;
config.name = dev_name(&mtd->dev);
config.owner = THIS_MODULE;
config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
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.ignore_wp = true;
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
return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem),
"Failed to register NVMEM device\n");
}
return 0;
}
static void mtd_check_of_node(struct mtd_info *mtd)
{
struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
const char *pname, *prefix = "partition-";
int plen, mtd_name_len, offset, prefix_len;
/* Check if MTD already has a device node */
if (mtd_get_of_node(mtd))
return;
if (!mtd_is_partition(mtd))
return;
parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
if (!parent_dn)
return;
if (mtd_is_partition(mtd->parent))
partitions = of_node_get(parent_dn);
else
partitions = of_get_child_by_name(parent_dn, "partitions");
if (!partitions)
goto exit_parent;
prefix_len = strlen(prefix);
mtd_name_len = strlen(mtd->name);
/* Search if a partition is defined with the same name */
for_each_child_of_node(partitions, mtd_dn) {
/* Skip partition with no/wrong prefix */
if (!of_node_name_prefix(mtd_dn, prefix))
continue;
/* Label have priority. Check that first */
if (!of_property_read_string(mtd_dn, "label", &pname)) {
offset = 0;
} else {
pname = mtd_dn->name;
offset = prefix_len;
}
plen = strlen(pname) - offset;
if (plen == mtd_name_len &&
!strncmp(mtd->name, pname + offset, plen)) {
mtd_set_of_node(mtd, mtd_dn);
of_node_put(mtd_dn);
break;
}
}
of_node_put(partitions);
exit_parent:
of_node_put(parent_dn);
}
/**
* 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 device_node *np = mtd_get_of_node(mtd);
struct mtd_info *master = mtd_get_master(mtd);
struct mtd_notifier *not;
int i, error, ofidx;
/*
* 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);
ofidx = -1;
if (np)
ofidx = of_alias_get_id(np, "mtd");
if (ofidx >= 0)
i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
else
i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
if (i < 0) {
error = i;
goto fail_locked;
}
mtd->index = i;
kref_init(&mtd->refcnt);
/* 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);
mtd_check_of_node(mtd);
of_node_get(mtd_get_of_node(mtd));
error = device_register(&mtd->dev);
if (error) {
put_device(&mtd->dev);
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);
if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) {
if (IS_BUILTIN(CONFIG_MTD)) {
pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
} else {
pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
mtd->index, mtd->name);
}
}
/* 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);
kref_put(&mtd->refcnt, mtd_device_release);
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 = compatible;
config.id = NVMEM_DEVID_AUTO;
config.owner = THIS_MODULE;
config.add_legacy_fixed_of_cells = true;
config.type = NVMEM_TYPE_OTP;
config.root_only = true;
config.ignore_wp = 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);
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 device *dev = mtd->dev.parent;
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)) {
err = PTR_ERR(nvmem);
goto err;
}
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) {
/*
* The factory OTP contains thing such as a unique serial
* number and is small, so let's read it out and put it
* into the entropy pool.
*/
void *otp;
otp = kmalloc(size, GFP_KERNEL);
if (!otp) {
err = -ENOMEM;
goto err;
}
err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size);
if (err < 0) {
kfree(otp);
goto err;
}
add_device_randomness(otp, err);
kfree(otp);
nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
mtd_nvmem_fact_otp_reg_read);
if (IS_ERR(nvmem)) {
err = PTR_ERR(nvmem);
goto err;
}
mtd->otp_factory_nvmem = nvmem;
}
}
return 0;
err:
nvmem_unregister(mtd->otp_user_nvmem);
return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
}
/**
* mtd_device_parse_register - parse partitions and register an MTD device.
*
* @mtd: the MTD device to register
* @types: the list of MTD partition probes to try, see
* 'parse_mtd_partitions()' for more information
* @parser_data: MTD partition parser-specific data
* @parts: fallback partition information to register, if parsing fails;
* only valid if %nr_parts > %0
* @nr_parts: the number of partitions in parts, if zero then the full
* MTD device is registered if no partition info is found
*
* This function aggregates MTD partitions parsing (done by
* 'parse_mtd_partitions()') and MTD device and partitions registering. It
* basically follows the most common pattern found in many MTD drivers:
*
* * 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);
ret = mtd_otp_nvmem_add(mtd);
if (ret)
goto out;
if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
ret = add_mtd_device(mtd);
if (ret)
goto out;
}
/* 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);
}
out:
if (ret) {
nvmem_unregister(mtd->otp_user_nvmem);
nvmem_unregister(mtd->otp_factory_nvmem);
}
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));
}
nvmem_unregister(master->otp_user_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 (master->_get_device) {
err = master->_get_device(mtd);
if (err)
return err;
}
if (!try_module_get(master->owner)) {
if (master->_put_device)
master->_put_device(master);
return -ENODEV;
}
while (mtd) {
if (mtd != master)
kref_get(&mtd->refcnt);
mtd = mtd->parent;
}
if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
kref_get(&master->refcnt);
return 0;
}
EXPORT_SYMBOL_GPL(__get_mtd_device);
/**
* of_get_mtd_device_by_node - obtain an MTD device associated with a given node
*
* @np: device tree node
*/
struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
{
struct mtd_info *mtd = NULL;
struct mtd_info *tmp;
int err;
mutex_lock(&mtd_table_mutex);
err = -EPROBE_DEFER;
mtd_for_each_device(tmp) {
if (mtd_get_of_node(tmp) == np) {
mtd = tmp;
err = __get_mtd_device(mtd);
break;
}
}
mutex_unlock(&mtd_table_mutex);
return err ? ERR_PTR(err) : mtd;
}
EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
/**
* 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) {
/* kref_put() can relese mtd, so keep a reference mtd->parent */
struct mtd_info *parent = mtd->parent;
if (mtd != master)
kref_put(&mtd->refcnt, mtd_device_release);
mtd = parent;
}
if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
kref_put(&master->refcnt, mtd_device_release);
module_put(master->owner);
/* must be the last as master can be freed in the _put_device */
if (master->_put_device)
master->_put_device(master);
}
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);
ALLOW_ERROR_INJECTION(mtd_erase, ERRNO);
/*
* 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;
WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
return ret;
}
EXPORT_SYMBOL_GPL(mtd_read);
ALLOW_ERROR_INJECTION(mtd_read, ERRNO);
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);
ALLOW_ERROR_INJECTION(mtd_write, ERRNO);
/*
* 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 (ops->stats)
memset(ops->stats, 0, sizeof(*ops->stats));
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 */
if (ops->stats)
ops->stats->max_bitflips = ret_code;
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);
ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO);
/*
* 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;
}
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_unregister(mtd_bdi);
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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