1 files changed, 848 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
new file mode 100644
index 00000000000..555d594d181
--- /dev/null
+++ b/drivers/mtd/ubi/build.c
@@ -0,0 +1,848 @@
+/*
+ * 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. At the
+ * moment UBI devices may only be added while UBI is initialized, but dynamic
+ * device add/remove functionality is planned. Also, 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.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/stringify.h>
+#include <linux/stat.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
+ * @data_offs: data offset
+ */
+struct mtd_dev_param
+{
+        char name[MTD_PARAM_LEN_MAX];
+        int vid_hdr_offs;
+        int data_offs;
+};
+
+/* Numbers of elements set in the @mtd_dev_param array */
+static int mtd_devs = 0;
+
+/* MTD devices specification parameters */
+static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
+
+/* Number of UBI devices in system */
+int ubi_devices_cnt;
+
+/* All UBI devices in system */
+struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+
+/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
+struct class *ubi_class;
+
+/* "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 dev_min_io_size =
+        __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_bgt_enabled =
+        __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
+
+/* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
+static ssize_t dev_attribute_show(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        const struct ubi_device *ubi;
+
+        ubi = container_of(dev, struct ubi_device, dev);
+        if (attr == &dev_eraseblock_size)
+                return sprintf(buf, "%d\n", ubi->leb_size);
+        else if (attr == &dev_avail_eraseblocks)
+                return sprintf(buf, "%d\n", ubi->avail_pebs);
+        else if (attr == &dev_total_eraseblocks)
+                return sprintf(buf, "%d\n", ubi->good_peb_count);
+        else if (attr == &dev_volumes_count)
+                return sprintf(buf, "%d\n", ubi->vol_count);
+        else if (attr == &dev_max_ec)
+                return sprintf(buf, "%d\n", ubi->max_ec);
+        else if (attr == &dev_reserved_for_bad)
+                return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
+        else if (attr == &dev_bad_peb_count)
+                return sprintf(buf, "%d\n", ubi->bad_peb_count);
+        else if (attr == &dev_max_vol_count)
+                return sprintf(buf, "%d\n", ubi->vtbl_slots);
+        else if (attr == &dev_min_io_size)
+                return sprintf(buf, "%d\n", ubi->min_io_size);
+        else if (attr == &dev_bgt_enabled)
+                return sprintf(buf, "%d\n", ubi->thread_enabled);
+        else
+                BUG();
+
+        return 0;
+}
+
+/* Fake "release" method for UBI devices */
+static void dev_release(struct device *dev) { }
+
+/**
+ * ubi_sysfs_init - initialize sysfs for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int ubi_sysfs_init(struct ubi_device *ubi)
+{
+        int err;
+
+        ubi->dev.release = dev_release;
+        ubi->dev.devt = MKDEV(ubi->major, 0);
+        ubi->dev.class = ubi_class;
+        sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
+        err = device_register(&ubi->dev);
+        if (err)
+                goto out;
+
+        err = device_create_file(&ubi->dev, &dev_eraseblock_size);
+        if (err)
+                goto out_unregister;
+        err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
+        if (err)
+                goto out_eraseblock_size;
+        err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
+        if (err)
+                goto out_avail_eraseblocks;
+        err = device_create_file(&ubi->dev, &dev_volumes_count);
+        if (err)
+                goto out_total_eraseblocks;
+        err = device_create_file(&ubi->dev, &dev_max_ec);
+        if (err)
+                goto out_volumes_count;
+        err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
+        if (err)
+                goto out_volumes_max_ec;
+        err = device_create_file(&ubi->dev, &dev_bad_peb_count);
+        if (err)
+                goto out_reserved_for_bad;
+        err = device_create_file(&ubi->dev, &dev_max_vol_count);
+        if (err)
+                goto out_bad_peb_count;
+        err = device_create_file(&ubi->dev, &dev_min_io_size);
+        if (err)
+                goto out_max_vol_count;
+        err = device_create_file(&ubi->dev, &dev_bgt_enabled);
+        if (err)
+                goto out_min_io_size;
+
+        return 0;
+
+out_min_io_size:
+        device_remove_file(&ubi->dev, &dev_min_io_size);
+out_max_vol_count:
+        device_remove_file(&ubi->dev, &dev_max_vol_count);
+out_bad_peb_count:
+        device_remove_file(&ubi->dev, &dev_bad_peb_count);
+out_reserved_for_bad:
+        device_remove_file(&ubi->dev, &dev_reserved_for_bad);
+out_volumes_max_ec:
+        device_remove_file(&ubi->dev, &dev_max_ec);
+out_volumes_count:
+        device_remove_file(&ubi->dev, &dev_volumes_count);
+out_total_eraseblocks:
+        device_remove_file(&ubi->dev, &dev_total_eraseblocks);
+out_avail_eraseblocks:
+        device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
+out_eraseblock_size:
+        device_remove_file(&ubi->dev, &dev_eraseblock_size);
+out_unregister:
+        device_unregister(&ubi->dev);
+out:
+        ubi_err("failed to initialize sysfs for %s", ubi->ubi_name);
+        return err;
+}
+
+/**
+ * ubi_sysfs_close - close sysfs for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void ubi_sysfs_close(struct ubi_device *ubi)
+{
+        device_remove_file(&ubi->dev, &dev_bgt_enabled);
+        device_remove_file(&ubi->dev, &dev_min_io_size);
+        device_remove_file(&ubi->dev, &dev_max_vol_count);
+        device_remove_file(&ubi->dev, &dev_bad_peb_count);
+        device_remove_file(&ubi->dev, &dev_reserved_for_bad);
+        device_remove_file(&ubi->dev, &dev_max_ec);
+        device_remove_file(&ubi->dev, &dev_volumes_count);
+        device_remove_file(&ubi->dev, &dev_total_eraseblocks);
+        device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
+        device_remove_file(&ubi->dev, &dev_eraseblock_size);
+        device_unregister(&ubi->dev);
+}
+
+/**
+ * kill_volumes - destroy all volumes.
+ * @ubi: UBI device description object
+ */
+static void kill_volumes(struct ubi_device *ubi)
+{
+        int i;
+
+        for (i = 0; i < ubi->vtbl_slots; i++)
+                if (ubi->volumes[i])
+                        ubi_free_volume(ubi, i);
+}
+
+/**
+ * uif_init - initialize user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int uif_init(struct ubi_device *ubi)
+{
+        int i, err;
+        dev_t dev;
+
+        mutex_init(&ubi->vtbl_mutex);
+        spin_lock_init(&ubi->volumes_lock);
+
+        sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
+
+        /*
+         * Major numbers for the UBI character devices are allocated
+         * dynamically. Major numbers of volume character devices are
+         * equivalent to ones of the corresponding UBI character device. Minor
+         * numbers of UBI character devices are 0, while minor numbers of
+         * volume character devices start from 1. Thus, we allocate one major
+         * number and ubi->vtbl_slots + 1 minor numbers.
+         */
+        err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
+        if (err) {
+                ubi_err("cannot register UBI character devices");
+                return err;
+        }
+
+        cdev_init(&ubi->cdev, &ubi_cdev_operations);
+        ubi->major = MAJOR(dev);
+        dbg_msg("%s major is %u", ubi->ubi_name, ubi->major);
+        ubi->cdev.owner = THIS_MODULE;
+
+        dev = MKDEV(ubi->major, 0);
+        err = cdev_add(&ubi->cdev, dev, 1);
+        if (err) {
+                ubi_err("cannot add character device %s", ubi->ubi_name);
+                goto out_unreg;
+        }
+
+        err = ubi_sysfs_init(ubi);
+        if (err)
+                goto out_cdev;
+
+        for (i = 0; i < ubi->vtbl_slots; i++)
+                if (ubi->volumes[i]) {
+                        err = ubi_add_volume(ubi, i);
+                        if (err)
+                                goto out_volumes;
+                }
+
+        return 0;
+
+out_volumes:
+        kill_volumes(ubi);
+        ubi_sysfs_close(ubi);
+out_cdev:
+        cdev_del(&ubi->cdev);
+out_unreg:
+        unregister_chrdev_region(MKDEV(ubi->major, 0),
+                                 ubi->vtbl_slots + 1);
+        return err;
+}
+
+/**
+ * uif_close - close user interfaces for an UBI device.
+ * @ubi: UBI device description object
+ */
+static void uif_close(struct ubi_device *ubi)
+{
+        kill_volumes(ubi);
+        ubi_sysfs_close(ubi);
+        cdev_del(&ubi->cdev);
+        unregister_chrdev_region(MKDEV(ubi->major, 0), ubi->vtbl_slots + 1);
+}
+
+/**
+ * attach_by_scanning - attach an MTD device using scanning method.
+ * @ubi: UBI device descriptor
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ *
+ * Note, currently this is the only method to attach UBI devices. Hopefully in
+ * the future we'll have more scalable attaching methods and avoid full media
+ * scanning. But even in this case scanning will be needed as a fall-back
+ * attaching method if there are some on-flash table corruptions.
+ */
+static int attach_by_scanning(struct ubi_device *ubi)
+{
+        int err;
+        struct ubi_scan_info *si;
+
+        si = ubi_scan(ubi);
+        if (IS_ERR(si))
+                return PTR_ERR(si);
+
+        ubi->bad_peb_count = si->bad_peb_count;
+        ubi->good_peb_count = ubi->peb_count - ubi->bad_peb_count;
+        ubi->max_ec = si->max_ec;
+        ubi->mean_ec = si->mean_ec;
+
+        err = ubi_read_volume_table(ubi, si);
+        if (err)
+                goto out_si;
+
+        err = ubi_wl_init_scan(ubi, si);
+        if (err)
+                goto out_vtbl;
+
+        err = ubi_eba_init_scan(ubi, si);
+        if (err)
+                goto out_wl;
+
+        ubi_scan_destroy_si(si);
+        return 0;
+
+out_wl:
+        ubi_wl_close(ubi);
+out_vtbl:
+        kfree(ubi->vtbl);
+out_si:
+        ubi_scan_destroy_si(si);
+        return err;
+}
+
+/**
+ * io_init - initialize I/O unit for a given UBI device.
+ * @ubi: UBI device description object
+ *
+ * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
+ * assumed:
+ *   o EC header is always at offset zero - this cannot be changed;
+ *   o VID header starts just after the EC header at the closest address
+ *   aligned to @io->@hdrs_min_io_size;
+ *   o data starts just after the VID header at the closest address aligned to
+ *     @io->@min_io_size
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int io_init(struct ubi_device *ubi)
+{
+        if (ubi->mtd->numeraseregions != 0) {
+                /*
+                 * Some flashes have several erase regions. Different regions
+                 * may have different eraseblock size and other
+                 * characteristics. It looks like mostly multi-region flashes
+                 * have one "main" region and one or more small regions to
+                 * store boot loader code or boot parameters or whatever. I
+                 * guess we should just pick the largest region. But this is
+                 * not implemented.
+                 */
+                ubi_err("multiple regions, not implemented");
+                return -EINVAL;
+        }
+
+        /*
+         * Note, in this implementation we support MTD devices with 0x7FFFFFFF
+         * physical eraseblocks maximum.
+         */
+
+        ubi->peb_size   = ubi->mtd->erasesize;
+        ubi->peb_count  = ubi->mtd->size / ubi->mtd->erasesize;
+        ubi->flash_size = ubi->mtd->size;
+
+        if (ubi->mtd->block_isbad && ubi->mtd->block_markbad)
+                ubi->bad_allowed = 1;
+
+        ubi->min_io_size = ubi->mtd->writesize;
+        ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
+
+        /* Make sure minimal I/O unit is power of 2 */
+        if (ubi->min_io_size == 0 ||
+            (ubi->min_io_size & (ubi->min_io_size - 1))) {
+                ubi_err("bad min. I/O unit");
+                return -EINVAL;
+        }
+
+        ubi_assert(ubi->hdrs_min_io_size > 0);
+        ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
+        ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
+
+        /* Calculate default aligned sizes of EC and VID headers */
+        ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
+        ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
+
+        dbg_msg("min_io_size      %d", ubi->min_io_size);
+        dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
+        dbg_msg("ec_hdr_alsize    %d", ubi->ec_hdr_alsize);
+        dbg_msg("vid_hdr_alsize   %d", ubi->vid_hdr_alsize);
+
+        if (ubi->vid_hdr_offset == 0)
+                /* Default offset */
+                ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
+                                      ubi->ec_hdr_alsize;
+        else {
+                ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
+                                                ~(ubi->hdrs_min_io_size - 1);
+                ubi->vid_hdr_shift = ubi->vid_hdr_offset -
+                                                ubi->vid_hdr_aloffset;
+        }
+
+        /* Similar for the data offset */
+        if (ubi->leb_start == 0) {
+                ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize;
+                ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
+        }
+
+        dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
+        dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
+        dbg_msg("vid_hdr_shift    %d", ubi->vid_hdr_shift);
+        dbg_msg("leb_start        %d", ubi->leb_start);
+
+        /* The shift must be aligned to 32-bit boundary */
+        if (ubi->vid_hdr_shift % 4) {
+                ubi_err("unaligned VID header shift %d",
+                        ubi->vid_hdr_shift);
+                return -EINVAL;
+        }
+
+        /* Check sanity */
+        if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
+            ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
+            ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
+            ubi->leb_start % ubi->min_io_size) {
+                ubi_err("bad VID header (%d) or data offsets (%d)",
+                        ubi->vid_hdr_offset, ubi->leb_start);
+                return -EINVAL;
+        }
+
+        /*
+         * It may happen that EC and VID headers are situated in one minimal
+         * I/O unit. In this case we can only accept this UBI image in
+         * read-only mode.
+         */
+        if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
+                ubi_warn("EC and VID headers are in the same minimal I/O unit, "
+                         "switch to read-only mode");
+                ubi->ro_mode = 1;
+        }
+
+        ubi->leb_size = ubi->peb_size - ubi->leb_start;
+
+        if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
+                ubi_msg("MTD device %d is write-protected, attach in "
+                        "read-only mode", ubi->mtd->index);
+                ubi->ro_mode = 1;
+        }
+
+        dbg_msg("leb_size         %d", ubi->leb_size);
+        dbg_msg("ro_mode          %d", ubi->ro_mode);
+
+        /*
+         * Note, ideally, we have to initialize ubi->bad_peb_count here. But
+         * unfortunately, MTD does not provide this information. We should loop
+         * over all physical eraseblocks and invoke mtd->block_is_bad() for
+         * each physical eraseblock. So, we skip ubi->bad_peb_count
+         * uninitialized and initialize it after scanning.
+         */
+
+        return 0;
+}
+
+/**
+ * attach_mtd_dev - attach an MTD device.
+ * @mtd_dev: MTD device name or number string
+ * @vid_hdr_offset: VID header offset
+ * @data_offset: data offset
+ *
+ * This function attaches an MTD device to UBI. It first treats @mtd_dev as the
+ * MTD device name, and tries to open it by this name. If it is unable to open,
+ * it tries to convert @mtd_dev to an integer and open the MTD device by its
+ * number. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
+                          int data_offset)
+{
+        struct ubi_device *ubi;
+        struct mtd_info *mtd;
+        int i, err;
+
+        mtd = get_mtd_device_nm(mtd_dev);
+        if (IS_ERR(mtd)) {
+                int mtd_num;
+                char *endp;
+
+                if (PTR_ERR(mtd) != -ENODEV)
+                        return PTR_ERR(mtd);
+
+                /*
+                 * Probably this is not MTD device name but MTD device number -
+                 * check this out.
+                 */
+                mtd_num = simple_strtoul(mtd_dev, &endp, 0);
+                if (*endp != '\0' || mtd_dev == endp) {
+                        ubi_err("incorrect MTD device: \"%s\"", mtd_dev);
+                        return -ENODEV;
+                }
+
+                mtd = get_mtd_device(NULL, mtd_num);
+                if (IS_ERR(mtd))
+                        return PTR_ERR(mtd);
+        }
+
+        /* Check if we already have the same MTD device attached */
+        for (i = 0; i < ubi_devices_cnt; i++)
+                if (ubi_devices[i]->mtd->index == mtd->index) {
+                        ubi_err("mtd%d is already attached to ubi%d",
+                                mtd->index, i);
+                        err = -EINVAL;
+                        goto out_mtd;
+                }
+
+        ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
+                                                      GFP_KERNEL);
+        if (!ubi) {
+                err = -ENOMEM;
+                goto out_mtd;
+        }
+
+        ubi->ubi_num = ubi_devices_cnt;
+        ubi->mtd = mtd;
+
+        dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d",
+                ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset);
+
+        ubi->vid_hdr_offset = vid_hdr_offset;
+        ubi->leb_start = data_offset;
+        err = io_init(ubi);
+        if (err)
+                goto out_free;
+
+        err = attach_by_scanning(ubi);
+        if (err) {
+                dbg_err("failed to attach by scanning, error %d", err);
+                goto out_free;
+        }
+
+        err = uif_init(ubi);
+        if (err)
+                goto out_detach;
+
+        ubi_devices_cnt += 1;
+
+        ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi_devices_cnt);
+        ubi_msg("MTD device name:            \"%s\"", ubi->mtd->name);
+        ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
+        ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
+                ubi->peb_size, ubi->peb_size >> 10);
+        ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
+        ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
+        ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
+        ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
+        ubi_msg("VID header offset:          %d (aligned %d)",
+                ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
+        ubi_msg("data offset:                %d", ubi->leb_start);
+        ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
+        ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
+        ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
+        ubi_msg("number of user volumes:     %d",
+                ubi->vol_count - UBI_INT_VOL_COUNT);
+        ubi_msg("available PEBs:             %d", ubi->avail_pebs);
+        ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
+        ubi_msg("number of PEBs reserved for bad PEB handling: %d",
+                ubi->beb_rsvd_pebs);
+        ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
+
+        /* Enable the background thread */
+        if (!DBG_DISABLE_BGT) {
+                ubi->thread_enabled = 1;
+                wake_up_process(ubi->bgt_thread);
+        }
+
+        return 0;
+
+out_detach:
+        ubi_eba_close(ubi);
+        ubi_wl_close(ubi);
+        kfree(ubi->vtbl);
+out_free:
+        kfree(ubi);
+out_mtd:
+        put_mtd_device(mtd);
+        ubi_devices[ubi_devices_cnt] = NULL;
+        return err;
+}
+
+/**
+ * detach_mtd_dev - detach an MTD device.
+ * @ubi: UBI device description object
+ */
+static void detach_mtd_dev(struct ubi_device *ubi)
+{
+        int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index;
+
+        dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
+        uif_close(ubi);
+        ubi_eba_close(ubi);
+        ubi_wl_close(ubi);
+        kfree(ubi->vtbl);
+        put_mtd_device(ubi->mtd);
+        kfree(ubi_devices[ubi_num]);
+        ubi_devices[ubi_num] = NULL;
+        ubi_devices_cnt -= 1;
+        ubi_assert(ubi_devices_cnt >= 0);
+        ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num);
+}
+
+static int __init ubi_init(void)
+{
+        int err, i, k;
+
+        /* Ensure that EC and VID headers have correct size */
+        BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
+        BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
+
+        if (mtd_devs > UBI_MAX_DEVICES) {
+                printk("UBI error: too many MTD devices, maximum is %d\n",
+                       UBI_MAX_DEVICES);
+                return -EINVAL;
+        }
+
+        ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
+        if (IS_ERR(ubi_class))
+                return PTR_ERR(ubi_class);
+
+        err = class_create_file(ubi_class, &ubi_version);
+        if (err)
+                goto out_class;
+
+        /* Attach MTD devices */
+        for (i = 0; i < mtd_devs; i++) {
+                struct mtd_dev_param *p = &mtd_dev_param[i];
+
+                cond_resched();
+
+                if (!p->name) {
+                        dbg_err("empty name");
+                        err = -EINVAL;
+                        goto out_detach;
+                }
+
+                err = attach_mtd_dev(p->name, p->vid_hdr_offs, p->data_offs);
+                if (err)
+                        goto out_detach;
+        }
+
+        return 0;
+
+out_detach:
+        for (k = 0; k < i; k++)
+                detach_mtd_dev(ubi_devices[k]);
+        class_remove_file(ubi_class, &ubi_version);
+out_class:
+        class_destroy(ubi_class);
+        return err;
+}
+module_init(ubi_init);
+
+static void __exit ubi_exit(void)
+{
+        int i, n = ubi_devices_cnt;
+
+        for (i = 0; i < n; i++)
+                detach_mtd_dev(ubi_devices[i]);
+        class_remove_file(ubi_class, &ubi_version);
+        class_destroy(ubi_class);
+}
+module_exit(ubi_exit);
+
+/**
+ * bytes_str_to_int - convert a string representing number of bytes to an
+ * integer.
+ * @str: the string to convert
+ *
+ * This function returns positive resulting integer in case of success and a
+ * negative error code in case of failure.
+ */
+static int __init bytes_str_to_int(const char *str)
+{
+        char *endp;
+        unsigned long result;
+
+        result = simple_strtoul(str, &endp, 0);
+        if (str == endp || result < 0) {
+                printk("UBI error: incorrect bytes count: \"%s\"\n", str);
+                return -EINVAL;
+        }
+
+        switch (*endp) {
+        case 'G':
+                result *= 1024;
+        case 'M':
+                result *= 1024;
+        case 'K':
+        case 'k':
+                result *= 1024;
+                if (endp[1] == 'i' && (endp[2] == '\0' ||
+                          endp[2] == 'B'  || endp[2] == 'b'))
+                        endp += 2;
+        case '\0':
+                break;
+        default:
+                printk("UBI error: incorrect bytes count: \"%s\"\n", str);
+                return -EINVAL;
+        }
+
+        return result;
+}
+
+/**
+ * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
+ * @val: the parameter value to parse
+ * @kp: not used
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of error.
+ */
+static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
+{
+        int i, len;
+        struct mtd_dev_param *p;
+        char buf[MTD_PARAM_LEN_MAX];
+        char *pbuf = &buf[0];
+        char *tokens[3] = {NULL, NULL, NULL};
+
+        if (mtd_devs == UBI_MAX_DEVICES) {
+                printk("UBI error: too many parameters, max. is %d\n",
+                       UBI_MAX_DEVICES);
+                return -EINVAL;
+        }
+
+        len = strnlen(val, MTD_PARAM_LEN_MAX);
+        if (len == MTD_PARAM_LEN_MAX) {
+                printk("UBI error: parameter \"%s\" is too long, max. is %d\n",
+                       val, MTD_PARAM_LEN_MAX);
+                return -EINVAL;
+        }
+
+        if (len == 0) {
+                printk("UBI warning: empty 'mtd=' parameter - ignored\n");
+                return 0;
+        }
+
+        strcpy(buf, val);
+
+        /* Get rid of the final newline */
+        if (buf[len - 1] == '\n')
+                buf[len - 1] = 0;
+
+        for (i = 0; i < 3; i++)
+                tokens[i] = strsep(&pbuf, ",");
+
+        if (pbuf) {
+                printk("UBI error: too many arguments at \"%s\"\n", val);
+                return -EINVAL;
+        }
+
+        if (tokens[0] == '\0')
+                return -EINVAL;
+
+        p = &mtd_dev_param[mtd_devs];
+        strcpy(&p->name[0], tokens[0]);
+
+        if (tokens[1])
+                p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
+        if (tokens[2])
+                p->data_offs = bytes_str_to_int(tokens[2]);
+
+        if (p->vid_hdr_offs < 0)
+                return p->vid_hdr_offs;
+        if (p->data_offs < 0)
+                return p->data_offs;
+
+        mtd_devs += 1;
+        return 0;
+}
+
+module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
+MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
+                      "mtd=<name|num>[,<vid_hdr_offs>,<data_offs>]. "
+                      "Multiple \"mtd\" parameters may be specified.\n"
+                      "MTD devices may be specified by their number or name. "
+                      "Optional \"vid_hdr_offs\" and \"data_offs\" parameters "
+                      "specify UBI VID header position and data starting "
+                      "position to be used by UBI.\n"
+                      "Example: mtd=content,1984,2048 mtd=4 - attach MTD device"
+                      "with name content using VID header offset 1984 and data "
+                      "start 2048, and MTD device number 4 using default "
+                      "offsets");
+
+MODULE_VERSION(__stringify(UBI_VERSION));
+MODULE_DESCRIPTION("UBI - Unsorted Block Images");
+MODULE_AUTHOR("Artem Bityutskiy");
+MODULE_LICENSE("GPL");