mtdcore.c 29.2 KB
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/*
 * Core registration and callback routines for MTD
 * drivers and users.
 *
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 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
 * Copyright © 2006      Red Hat UK Limited 
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
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 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
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#include <linux/seq_file.h>
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#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
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#include <linux/err.h>
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#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
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#include <linux/idr.h>
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#include <linux/backing-dev.h>
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#include <linux/gfp.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/partitions.h>
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#include "mtdcore.h"
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/*
 * backing device capabilities for non-mappable devices (such as NAND flash)
 * - permits private mappings, copies are taken of the data
 */
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static struct backing_dev_info mtd_bdi_unmappable = {
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	.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
 */
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static struct backing_dev_info mtd_bdi_ro_mappable = {
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	.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
 */
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static struct backing_dev_info mtd_bdi_rw_mappable = {
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	.capabilities	= (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
			   BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
			   BDI_CAP_WRITE_MAP),
};
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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,
};
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static DEFINE_IDR(mtd_idr);

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/* These are exported solely for the purpose of mtd_blkdevs.c. You
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   should not use them for _anything_ else */
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DEFINE_MUTEX(mtd_table_mutex);
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EXPORT_SYMBOL_GPL(mtd_table_mutex);
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struct mtd_info *__mtd_next_device(int i)
{
	return idr_get_next(&mtd_idr, &i);
}
EXPORT_SYMBOL_GPL(__mtd_next_device);
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static LIST_HEAD(mtd_notifiers);

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#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
#else
#define MTD_DEVT(index) 0
#endif

/* 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)
{
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	struct mtd_info __maybe_unused *mtd = dev_get_drvdata(dev);
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	dev_t index = MTD_DEVT(mtd->index);
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	/* remove /dev/mtdXro node if needed */
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	if (index)
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		device_destroy(&mtd_class, index + 1);
}

static int mtd_cls_suspend(struct device *dev, pm_message_t state)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	return mtd ? mtd_suspend(mtd) : 0;
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}

static int mtd_cls_resume(struct device *dev)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	if (mtd)
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		mtd_resume(mtd);
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	return 0;
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}

static ssize_t mtd_type_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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;
	default:
		type = "unknown";
	}

	return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
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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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);

}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);

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static ssize_t mtd_subpagesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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);

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static ssize_t mtd_oobsize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	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)
{
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	struct mtd_info *mtd = dev_get_drvdata(dev);
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	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);

}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
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static struct attribute *mtd_attrs[] = {
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	&dev_attr_type.attr,
	&dev_attr_flags.attr,
	&dev_attr_size.attr,
	&dev_attr_erasesize.attr,
	&dev_attr_writesize.attr,
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	&dev_attr_subpagesize.attr,
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	&dev_attr_oobsize.attr,
	&dev_attr_numeraseregions.attr,
	&dev_attr_name.attr,
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	NULL,
};

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static struct attribute_group mtd_group = {
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	.attrs		= mtd_attrs,
};

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static const struct attribute_group *mtd_groups[] = {
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	&mtd_group,
	NULL,
};

static struct device_type mtd_devtype = {
	.name		= "mtd",
	.groups		= mtd_groups,
	.release	= mtd_release,
};

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/**
 *	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
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 *	if there is insufficient memory or a sysfs error.
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 */

int add_mtd_device(struct mtd_info *mtd)
{
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	struct mtd_notifier *not;
	int i, error;
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	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;
		}
	}

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	BUG_ON(mtd->writesize == 0);
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	mutex_lock(&mtd_table_mutex);
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	do {
		if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
			goto fail_locked;
		error = idr_get_new(&mtd_idr, mtd, &i);
	} while (error == -EAGAIN);
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	if (error)
		goto fail_locked;
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	mtd->index = i;
	mtd->usecount = 0;

	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 */
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	if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
		error = mtd_unlock(mtd, 0, mtd->size);
		if (error && error != -EOPNOTSUPP)
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			printk(KERN_WARNING
			       "%s: unlock failed, writes may not work\n",
			       mtd->name);
	}

	/* 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);

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	pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
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	/* No need to get a refcount on the module containing
	   the notifier, since we hold the mtd_table_mutex */
	list_for_each_entry(not, &mtd_notifiers, list)
		not->add(mtd);

	mutex_unlock(&mtd_table_mutex);
	/* We _know_ we aren't being removed, because
	   our caller is still holding us here. So none
	   of this try_ nonsense, and no bitching about it
	   either. :) */
	__module_get(THIS_MODULE);
	return 0;
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fail_added:
	idr_remove(&mtd_idr, i);
fail_locked:
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	mutex_unlock(&mtd_table_mutex);
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	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.
 */

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int del_mtd_device(struct mtd_info *mtd)
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{
	int ret;
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	struct mtd_notifier *not;
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	mutex_lock(&mtd_table_mutex);
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	if (idr_find(&mtd_idr, mtd->index) != mtd) {
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		ret = -ENODEV;
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		goto out_error;
	}

	/* No need to get a refcount on the module containing
		the notifier, since we hold the mtd_table_mutex */
	list_for_each_entry(not, &mtd_notifiers, list)
		not->remove(mtd);

	if (mtd->usecount) {
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		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
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		       mtd->index, mtd->name, mtd->usecount);
		ret = -EBUSY;
	} else {
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		device_unregister(&mtd->dev);

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		idr_remove(&mtd_idr, mtd->index);
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		module_put(THIS_MODULE);
		ret = 0;
	}

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out_error:
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	mutex_unlock(&mtd_table_mutex);
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	return ret;
}

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/**
 * 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
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 * @parser_data: MTD partition parser-specific data
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 * @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.
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 * * If any partitioning info was found, this function registers the found
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 *   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 **types,
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			      struct mtd_part_parser_data *parser_data,
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			      const struct mtd_partition *parts,
			      int nr_parts)
{
	int err;
	struct mtd_partition *real_parts;

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	err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
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	if (err <= 0 && nr_parts && parts) {
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		real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
				     GFP_KERNEL);
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		if (!real_parts)
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			err = -ENOMEM;
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		else
			err = nr_parts;
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	}

	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);

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/**
 * 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);

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/**
 *	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)
{
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	struct mtd_info *mtd;
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	mutex_lock(&mtd_table_mutex);
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	list_add(&new->list, &mtd_notifiers);

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	__module_get(THIS_MODULE);
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	mtd_for_each_device(mtd)
		new->add(mtd);
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	mutex_unlock(&mtd_table_mutex);
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}
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EXPORT_SYMBOL_GPL(register_mtd_user);
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/**
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 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 *	@old: pointer to notifier info structure
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 *
 *	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)
{
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	struct mtd_info *mtd;
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	mutex_lock(&mtd_table_mutex);
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	module_put(THIS_MODULE);

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	mtd_for_each_device(mtd)
		old->remove(mtd);
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	list_del(&old->list);
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	mutex_unlock(&mtd_table_mutex);
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	return 0;
}
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EXPORT_SYMBOL_GPL(unregister_mtd_user);
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/**
 *	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
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 *	both, return the num'th driver only if its address matches. Return
 *	error code if not.
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 */
struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
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	struct mtd_info *ret = NULL, *other;
	int err = -ENODEV;
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	mutex_lock(&mtd_table_mutex);
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	if (num == -1) {
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		mtd_for_each_device(other) {
			if (other == mtd) {
				ret = mtd;
				break;
			}
		}
585 586
	} else if (num >= 0) {
		ret = idr_find(&mtd_idr, num);
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587 588 589 590
		if (mtd && mtd != ret)
			ret = NULL;
	}

591 592 593
	if (!ret) {
		ret = ERR_PTR(err);
		goto out;
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Artem Bityutskiy 已提交
594
	}
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595

596 597 598 599
	err = __get_mtd_device(ret);
	if (err)
		ret = ERR_PTR(err);
out:
600 601
	mutex_unlock(&mtd_table_mutex);
	return ret;
602
}
603
EXPORT_SYMBOL_GPL(get_mtd_device);
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604

605 606 607 608 609 610 611 612

int __get_mtd_device(struct mtd_info *mtd)
{
	int err;

	if (!try_module_get(mtd->owner))
		return -ENODEV;

613 614
	if (mtd->_get_device) {
		err = mtd->_get_device(mtd);
615 616 617 618 619 620 621 622

		if (err) {
			module_put(mtd->owner);
			return err;
		}
	}
	mtd->usecount++;
	return 0;
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}
624
EXPORT_SYMBOL_GPL(__get_mtd_device);
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625

626 627 628 629 630 631 632 633 634 635
/**
 *	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)
{
636 637
	int err = -ENODEV;
	struct mtd_info *mtd = NULL, *other;
638 639 640

	mutex_lock(&mtd_table_mutex);

641 642 643
	mtd_for_each_device(other) {
		if (!strcmp(name, other->name)) {
			mtd = other;
644 645 646 647
			break;
		}
	}

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Artem Bityutskiy 已提交
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	if (!mtd)
649 650
		goto out_unlock;

651 652
	err = __get_mtd_device(mtd);
	if (err)
653 654
		goto out_unlock;

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655 656
	mutex_unlock(&mtd_table_mutex);
	return mtd;
657 658 659

out_unlock:
	mutex_unlock(&mtd_table_mutex);
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Artem Bityutskiy 已提交
660
	return ERR_PTR(err);
661
}
662
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
663

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void put_mtd_device(struct mtd_info *mtd)
{
I
Ingo Molnar 已提交
666
	mutex_lock(&mtd_table_mutex);
667 668 669 670
	__put_mtd_device(mtd);
	mutex_unlock(&mtd_table_mutex);

}
671
EXPORT_SYMBOL_GPL(put_mtd_device);
672 673 674 675 676 677

void __put_mtd_device(struct mtd_info *mtd)
{
	--mtd->usecount;
	BUG_ON(mtd->usecount < 0);

678 679
	if (mtd->_put_device)
		mtd->_put_device(mtd);
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	module_put(mtd->owner);
}
683
EXPORT_SYMBOL_GPL(__put_mtd_device);
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685 686 687 688 689 690 691 692 693 694 695
/*
 * 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;
696 697
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
698
	instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
699 700 701 702 703
	if (!instr->len) {
		instr->state = MTD_ERASE_DONE;
		mtd_erase_callback(instr);
		return 0;
	}
704 705 706 707 708 709 710 711 712 713 714
	return mtd->_erase(mtd, instr);
}
EXPORT_SYMBOL_GPL(mtd_erase);

/*
 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
 */
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
	      void **virt, resource_size_t *phys)
{
	*retlen = 0;
715 716 717
	*virt = NULL;
	if (phys)
		*phys = 0;
718 719 720 721
	if (!mtd->_point)
		return -EOPNOTSUPP;
	if (from < 0 || from > mtd->size || len > mtd->size - from)
		return -EINVAL;
722 723
	if (!len)
		return 0;
724 725 726 727 728 729 730 731 732 733 734
	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;
735 736
	if (!len)
		return 0;
737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
	return mtd->_unpoint(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)
{
	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)
{
760
	*retlen = 0;
761 762
	if (from < 0 || from > mtd->size || len > mtd->size - from)
		return -EINVAL;
763 764
	if (!len)
		return 0;
765 766 767 768 769 770 771 772 773 774
	return mtd->_read(mtd, from, len, retlen, buf);
}
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;
775 776
	if (!mtd->_write || !(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
777 778
	if (!len)
		return 0;
779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797
	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)
{
	*retlen = 0;
	if (!mtd->_panic_write)
		return -EOPNOTSUPP;
	if (to < 0 || to > mtd->size || len > mtd->size - to)
		return -EINVAL;
798 799
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
800 801
	if (!len)
		return 0;
802 803 804 805
	return mtd->_panic_write(mtd, to, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_panic_write);

806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878
/*
 * 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, struct otp_info *buf,
			   size_t len)
{
	if (!mtd->_get_fact_prot_info)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_get_fact_prot_info(mtd, buf, len);
}
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)
{
	*retlen = 0;
	if (!mtd->_read_fact_prot_reg)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_read_fact_prot_reg(mtd, from, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);

int mtd_get_user_prot_info(struct mtd_info *mtd, struct otp_info *buf,
			   size_t len)
{
	if (!mtd->_get_user_prot_info)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_get_user_prot_info(mtd, buf, len);
}
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)
{
	*retlen = 0;
	if (!mtd->_read_user_prot_reg)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_read_user_prot_reg(mtd, 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, u_char *buf)
{
	*retlen = 0;
	if (!mtd->_write_user_prot_reg)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_write_user_prot_reg(mtd, to, len, retlen, buf);
}
EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);

int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
{
	if (!mtd->_lock_user_prot_reg)
		return -EOPNOTSUPP;
	if (!len)
		return 0;
	return mtd->_lock_user_prot_reg(mtd, from, len);
}
EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);

879 880 881 882 883 884 885
/* Chip-supported device locking */
int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	if (!mtd->_lock)
		return -EOPNOTSUPP;
	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
		return -EINVAL;
886 887
	if (!len)
		return 0;
888 889 890 891 892 893 894 895 896 897
	return mtd->_lock(mtd, ofs, len);
}
EXPORT_SYMBOL_GPL(mtd_lock);

int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	if (!mtd->_unlock)
		return -EOPNOTSUPP;
	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
		return -EINVAL;
898 899
	if (!len)
		return 0;
900 901 902 903 904 905 906 907 908 909
	return mtd->_unlock(mtd, ofs, len);
}
EXPORT_SYMBOL_GPL(mtd_unlock);

int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	if (!mtd->_is_locked)
		return -EOPNOTSUPP;
	if (ofs < 0 || ofs > mtd->size || len > mtd->size - ofs)
		return -EINVAL;
910 911
	if (!len)
		return 0;
912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931
	return mtd->_is_locked(mtd, ofs, len);
}
EXPORT_SYMBOL_GPL(mtd_is_locked);

int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
	if (!mtd->_block_isbad)
		return 0;
	if (ofs < 0 || ofs > mtd->size)
		return -EINVAL;
	return mtd->_block_isbad(mtd, ofs);
}
EXPORT_SYMBOL_GPL(mtd_block_isbad);

int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
	if (!mtd->_block_markbad)
		return -EOPNOTSUPP;
	if (ofs < 0 || ofs > mtd->size)
		return -EINVAL;
932 933
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
934 935 936 937
	return mtd->_block_markbad(mtd, ofs);
}
EXPORT_SYMBOL_GPL(mtd_block_markbad);

938 939 940 941 942 943 944 945 946 947
/*
 * 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.
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Linus Torvalds 已提交
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 */
949 950
static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
			      unsigned long count, loff_t to, size_t *retlen)
L
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951 952 953 954 955
{
	unsigned long i;
	size_t totlen = 0, thislen;
	int ret = 0;

956 957 958 959 960 961 962 963 964
	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;
L
Linus Torvalds 已提交
965
	}
966
	*retlen = totlen;
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967 968
	return ret;
}
969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984

/*
 * 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)
{
	*retlen = 0;
985 986
	if (!(mtd->flags & MTD_WRITEABLE))
		return -EROFS;
987
	if (!mtd->_writev)
988
		return default_mtd_writev(mtd, vecs, count, to, retlen);
989
	return mtd->_writev(mtd, vecs, count, to, retlen);
990 991
}
EXPORT_SYMBOL_GPL(mtd_writev);
L
Linus Torvalds 已提交
992

993 994
/**
 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
995 996
 * @mtd: mtd device description object pointer
 * @size: a pointer to the ideal or maximum size of the allocation, points
997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041
 *        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_WAIT |
		       __GFP_NORETRY | __GFP_NO_KSWAPD;
	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);
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P
Pavel Machek 已提交
1043 1044
#ifdef CONFIG_PROC_FS

L
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1045 1046 1047 1048 1049
/*====================================================================*/
/* Support for /proc/mtd */

static struct proc_dir_entry *proc_mtd;

1050
static int mtd_proc_show(struct seq_file *m, void *v)
L
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1051
{
1052
	struct mtd_info *mtd;
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1053

1054
	seq_puts(m, "dev:    size   erasesize  name\n");
I
Ingo Molnar 已提交
1055
	mutex_lock(&mtd_table_mutex);
1056
	mtd_for_each_device(mtd) {
1057 1058 1059
		seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
			   mtd->index, (unsigned long long)mtd->size,
			   mtd->erasesize, mtd->name);
1060
	}
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Ingo Molnar 已提交
1061
	mutex_unlock(&mtd_table_mutex);
1062
	return 0;
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1063 1064
}

1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075
static int mtd_proc_open(struct inode *inode, struct file *file)
{
	return single_open(file, mtd_proc_show, NULL);
}

static const struct file_operations mtd_proc_ops = {
	.open		= mtd_proc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};
1076 1077
#endif /* CONFIG_PROC_FS */

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1078 1079 1080
/*====================================================================*/
/* Init code */

1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094
static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
{
	int ret;

	ret = bdi_init(bdi);
	if (!ret)
		ret = bdi_register(bdi, NULL, name);

	if (ret)
		bdi_destroy(bdi);

	return ret;
}

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1095 1096
static int __init init_mtd(void)
{
1097
	int ret;
1098

1099
	ret = class_register(&mtd_class);
1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113
	if (ret)
		goto err_reg;

	ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
	if (ret)
		goto err_bdi1;

	ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
	if (ret)
		goto err_bdi2;

	ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
	if (ret)
		goto err_bdi3;
1114

1115
#ifdef CONFIG_PROC_FS
1116
	proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
1117
#endif /* CONFIG_PROC_FS */
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1118
	return 0;
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128

err_bdi3:
	bdi_destroy(&mtd_bdi_ro_mappable);
err_bdi2:
	bdi_destroy(&mtd_bdi_unmappable);
err_bdi1:
	class_unregister(&mtd_class);
err_reg:
	pr_err("Error registering mtd class or bdi: %d\n", ret);
	return ret;
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1129 1130 1131 1132
}

static void __exit cleanup_mtd(void)
{
1133
#ifdef CONFIG_PROC_FS
1134
	if (proc_mtd)
L
Linus Torvalds 已提交
1135
		remove_proc_entry( "mtd", NULL);
1136
#endif /* CONFIG_PROC_FS */
1137
	class_unregister(&mtd_class);
1138 1139 1140
	bdi_destroy(&mtd_bdi_unmappable);
	bdi_destroy(&mtd_bdi_ro_mappable);
	bdi_destroy(&mtd_bdi_rw_mappable);
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1141 1142 1143 1144 1145 1146 1147 1148
}

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");