path: root/drivers/mtd/ubi/build.c

/*
 * Copyright (c) International Business Machines Corp., 2006
 * Copyright (c) Nokia Corporation, 2007
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Artem Bityutskiy (Битюцкий Артём),
 *         Frank Haverkamp
 */

/*
 * This file includes UBI initialization and building of UBI devices.
 *
 * When UBI is initialized, it attaches all the MTD devices specified as the
 * module load parameters or the kernel boot parameters. If MTD devices were
 * specified, UBI does not attach any MTD device, but it is possible to do
 * later using the "UBI control device".
 *
 * At the moment we only attach UBI devices by scanning, which will become a
 * bottleneck when flashes reach certain large size. Then one may improve UBI
 * and add other methods, although it does not seem to be easy to do.
 */

#include <linux/err.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/stringify.h>
#include <linux/stat.h>
#include <linux/miscdevice.h>
#include <linux/log2.h>
#include <linux/kthread.h>
#include "ubi.h"

/* Maximum length of the 'mtd=' parameter */
#define MTD_PARAM_LEN_MAX 64

/**
 * struct mtd_dev_param - MTD device parameter description data structure.
 * @name: MTD device name or number string
 * @vid_hdr_offs: VID header offset
 */
struct mtd_dev_param {
	char name[MTD_PARAM_LEN_MAX];
	int vid_hdr_offs;
};

/* Numbers of elements set in the @mtd_dev_param array */
static int mtd_devs;

/* MTD devices specification parameters */
static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];

/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
struct class *ubi_class;

/* Slab cache for wear-leveling entries */
struct kmem_cache *ubi_wl_entry_slab;

/* UBI control character device */
static struct miscdevice ubi_ctrl_cdev = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "ubi_ctrl",
	.fops = &ubi_ctrl_cdev_operations,
};

/* All UBI devices in system */
static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];

/* Serializes UBI devices creations and removals */
DEFINE_MUTEX(ubi_devices_mutex);

/* Protects @ubi_devices and @ubi->ref_count */
static DEFINE_SPINLOCK(ubi_devices_lock);

/* "Show" method for files in '/<sysfs>/class/ubi/' */
static ssize_t ubi_version_show(struct class *class, char *buf)
{
	return sprintf(buf, "%d\n", UBI_VERSION);
}

/* UBI version attribute ('/<sysfs>/class/ubi/version') */
static struct class_attribute ubi_version =
	__ATTR(version, S_IRUGO, ubi_version_show, NULL);

static ssize_t dev_attribute_show(struct device *dev,
				  struct device_attribute *attr, char *buf);

/* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
static struct device_attribute dev_eraseblock_size =
	__ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_avail_eraseblocks =
	__ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_total_eraseblocks =
	__ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_volumes_count =
	__ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_ec =
	__ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_reserved_for_bad =
	__ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_bad_peb_count =
	__ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute dev_max_vol_count =
	__ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
static struct device_attribute