1 files changed, 575 insertions, 0 deletions

diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
new file mode 100644
index 000000000000..d352c4575c3d
--- /dev/null
+++ b/drivers/mtd/ubi/kapi.c
@@ -0,0 +1,575 @@
+/*
+ * Copyright (c) International Business Machines Corp., 2006
+ *
+ * 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)
+ */
+
+/* This file mostly implements UBI kernel API functions */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <asm/div64.h>
+#include "ubi.h"
+
+/**
+ * ubi_get_device_info - get information about UBI device.
+ * @ubi_num: UBI device number
+ * @di: the information is stored here
+ *
+ * This function returns %0 in case of success and a %-ENODEV if there is no
+ * such UBI device.
+ */
+int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
+{
+        const struct ubi_device *ubi;
+
+        if (!try_module_get(THIS_MODULE))
+                return -ENODEV;
+
+        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES ||
+            !ubi_devices[ubi_num]) {
+                module_put(THIS_MODULE);
+                return -ENODEV;
+        }
+
+        ubi = ubi_devices[ubi_num];
+        di->ubi_num = ubi->ubi_num;
+        di->leb_size = ubi->leb_size;
+        di->min_io_size = ubi->min_io_size;
+        di->ro_mode = ubi->ro_mode;
+        di->cdev = MKDEV(ubi->major, 0);
+        module_put(THIS_MODULE);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(ubi_get_device_info);
+
+/**
+ * ubi_get_volume_info - get information about UBI volume.
+ * @desc: volume descriptor
+ * @vi: the information is stored here
+ */
+void ubi_get_volume_info(struct ubi_volume_desc *desc,
+                         struct ubi_volume_info *vi)
+{
+        const struct ubi_volume *vol = desc->vol;
+        const struct ubi_device *ubi = vol->ubi;
+
+        vi->vol_id = vol->vol_id;
+        vi->ubi_num = ubi->ubi_num;
+        vi->size = vol->reserved_pebs;
+        vi->used_bytes = vol->used_bytes;
+        vi->vol_type = vol->vol_type;
+        vi->corrupted = vol->corrupted;
+        vi->upd_marker = vol->upd_marker;
+        vi->alignment = vol->alignment;
+        vi->usable_leb_size = vol->usable_leb_size;
+        vi->name_len = vol->name_len;
+        vi->name = vol->name;
+        vi->cdev = MKDEV(ubi->major, vi->vol_id + 1);
+}
+EXPORT_SYMBOL_GPL(ubi_get_volume_info);
+
+/**
+ * ubi_open_volume - open UBI volume.
+ * @ubi_num: UBI device number
+ * @vol_id: volume ID
+ * @mode: open mode
+ *
+ * The @mode parameter specifies if the volume should be opened in read-only
+ * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
+ * nobody else will be able to open this volume. UBI allows to have many volume
+ * readers and one writer at a time.
+ *
+ * If a static volume is being opened for the first time since boot, it will be
+ * checked by this function, which means it will be fully read and the CRC
+ * checksum of each logical eraseblock will be checked.
+ *
+ * This function returns volume descriptor in case of success and a negative
+ * error code in case of failure.
+ */
+struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
+{
+        int err;
+        struct ubi_volume_desc *desc;
+        struct ubi_device *ubi = ubi_devices[ubi_num];
+        struct ubi_volume *vol;
+
+        dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+
+        err = -ENODEV;
+        if (!try_module_get(THIS_MODULE))
+                return ERR_PTR(err);
+
+        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi)
+                goto out_put;
+
+        err = -EINVAL;
+        if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+                goto out_put;
+        if (mode != UBI_READONLY && mode != UBI_READWRITE &&
+            mode != UBI_EXCLUSIVE)
+                goto out_put;
+
+        desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
+        if (!desc) {
+                err = -ENOMEM;
+                goto out_put;
+        }
+
+        spin_lock(&ubi->volumes_lock);
+        vol = ubi->volumes[vol_id];
+        if (!vol) {
+                err = -ENODEV;
+                goto out_unlock;
+        }
+
+        err = -EBUSY;
+        switch (mode) {
+        case UBI_READONLY:
+                if (vol->exclusive)
+                        goto out_unlock;
+                vol->readers += 1;
+                break;
+
+        case UBI_READWRITE:
+                if (vol->exclusive || vol->writers > 0)
+                        goto out_unlock;
+                vol->writers += 1;
+                break;
+
+        case UBI_EXCLUSIVE:
+                if (vol->exclusive || vol->writers || vol->readers)
+                        goto out_unlock;
+                vol->exclusive = 1;
+                break;
+        }
+        spin_unlock(&ubi->volumes_lock);
+
+        desc->vol = vol;
+        desc->mode = mode;
+
+        /*
+         * To prevent simultaneous checks of the same volume we use @vtbl_mutex,
+         * although it is not the purpose it was introduced for.
+         */
+        mutex_lock(&ubi->vtbl_mutex);
+        if (!vol->checked) {
+                /* This is the first open - check the volume */
+                err = ubi_check_volume(ubi, vol_id);
+                if (err < 0) {
+                        mutex_unlock(&ubi->vtbl_mutex);
+                        ubi_close_volume(desc);
+                        return ERR_PTR(err);
+                }
+                if (err == 1) {
+                        ubi_warn("volume %d on UBI device %d is corrupted",
+                                 vol_id, ubi->ubi_num);
+                        vol->corrupted = 1;
+                }
+                vol->checked = 1;
+        }
+        mutex_unlock(&ubi->vtbl_mutex);
+        return desc;
+
+out_unlock:
+        spin_unlock(&ubi->volumes_lock);
+        kfree(desc);
+out_put:
+        module_put(THIS_MODULE);
+        return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(ubi_open_volume);
+
+/**
+ * ubi_open_volume_nm - open UBI volume by name.
+ * @ubi_num: UBI device number
+ * @name: volume name
+ * @mode: open mode
+ *
+ * This function is similar to 'ubi_open_volume()', but opens a volume by name.
+ */
+struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
+                                           int mode)
+{
+        int i, vol_id = -1, len;
+        struct ubi_volume_desc *ret;
+        struct ubi_device *ubi;
+
+        dbg_msg("open volume %s, mode %d", name, mode);
+
+        if (!name)
+                return ERR_PTR(-EINVAL);
+
+        len = strnlen(name, UBI_VOL_NAME_MAX + 1);
+        if (len > UBI_VOL_NAME_MAX)
+                return ERR_PTR(-EINVAL);
+
+        ret = ERR_PTR(-ENODEV);
+        if (!try_module_get(THIS_MODULE))
+                return ret;
+
+        if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num])
+                goto out_put;
+
+        ubi = ubi_devices[ubi_num];
+
+        spin_lock(&ubi->volumes_lock);
+        /* Walk all volumes of this UBI device */
+        for (i = 0; i < ubi->vtbl_slots; i++) {
+                struct ubi_volume *vol = ubi->volumes[i];
+
+                if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
+                        vol_id = i;
+                        break;
+                }
+        }
+        spin_unlock(&ubi->volumes_lock);
+
+        if (vol_id < 0)
+                goto out_put;
+
+        ret = ubi_open_volume(ubi_num, vol_id, mode);
+
+out_put:
+        module_put(THIS_MODULE);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
+
+/**
+ * ubi_close_volume - close UBI volume.
+ * @desc: volume descriptor
+ */
+void ubi_close_volume(struct ubi_volume_desc *desc)
+{
+        struct ubi_volume *vol = desc->vol;
+
+        dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode);
+
+        spin_lock(&vol->ubi->volumes_lock);
+        switch (desc->mode) {
+        case UBI_READONLY:
+                vol->readers -= 1;
+                break;
+        case UBI_READWRITE:
+                vol->writers -= 1;
+                break;
+        case UBI_EXCLUSIVE:
+                vol->exclusive = 0;
+        }
+        spin_unlock(&vol->ubi->volumes_lock);
+
+        kfree(desc);
+        module_put(THIS_MODULE);
+}
+EXPORT_SYMBOL_GPL(ubi_close_volume);
+
+/**
+ * ubi_leb_read - read data.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to read from
+ * @buf: buffer where to store the read data
+ * @offset: offset within the logical eraseblock to read from
+ * @len: how many bytes to read
+ * @check: whether UBI has to check the read data's CRC or not.
+ *
+ * This function reads data from offset @offset of logical eraseblock @lnum and
+ * stores the data at @buf. When reading from static volumes, @check specifies
+ * whether the data has to be checked or not. If yes, the whole logical
+ * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
+ * checksum is per-eraseblock). So checking may substantially slow down the
+ * read speed. The @check argument is ignored for dynamic volumes.
+ *
+ * In case of success, this function returns zero. In case of failure, this
+ * function returns a negative error code.
+ *
+ * %-EBADMSG error code is returned:
+ * o for both static and dynamic volumes if MTD driver has detected a data
+ *   integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
+ * o for static volumes in case of data CRC mismatch.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF error code.
+ */
+int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
+                 int len, int check)
+{
+        struct ubi_volume *vol = desc->vol;
+        struct ubi_device *ubi = vol->ubi;
+        int err, vol_id = vol->vol_id;
+
+        dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
+
+        if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
+            lnum >= vol->used_ebs || offset < 0 || len < 0 ||
+            offset + len > vol->usable_leb_size)
+                return -EINVAL;
+
+        if (vol->vol_type == UBI_STATIC_VOLUME && lnum == vol->used_ebs - 1 &&
+            offset + len > vol->last_eb_bytes)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+        if (len == 0)
+                return 0;
+
+        err = ubi_eba_read_leb(ubi, vol_id, lnum, buf, offset, len, check);
+        if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
+                ubi_warn("mark volume %d as corrupted", vol_id);
+                vol->corrupted = 1;
+        }
+
+        return err;
+}
+EXPORT_SYMBOL_GPL(ubi_leb_read);
+
+/**
+ * ubi_leb_write - write data.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to write to
+ * @buf: data to write
+ * @offset: offset within the logical eraseblock where to write
+ * @len: how many bytes to write
+ * @dtype: expected data type
+ *
+ * This function writes @len bytes of data from @buf to offset @offset of
+ * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
+ * the data.
+ *
+ * This function takes care of physical eraseblock write failures. If write to
+ * the physical eraseblock write operation fails, the logical eraseblock is
+ * re-mapped to another physical eraseblock, the data is recovered, and the
+ * write finishes. UBI has a pool of reserved physical eraseblocks for this.
+ *
+ * If all the data were successfully written, zero is returned. If an error
+ * occurred and UBI has not been able to recover from it, this function returns
+ * a negative error code. Note, in case of an error, it is possible that
+ * something was still written to the flash media, but that may be some
+ * garbage.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF code.
+ */
+int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
+                  int offset, int len, int dtype)
+{
+        struct ubi_volume *vol = desc->vol;
+        struct ubi_device *ubi = vol->ubi;
+        int vol_id = vol->vol_id;
+
+        dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
+
+        if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+                return -EINVAL;
+
+        if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+                return -EROFS;
+
+        if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
+            offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
+            len % ubi->min_io_size)
+                return -EINVAL;
+
+        if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+            dtype != UBI_UNKNOWN)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+
+        if (len == 0)
+                return 0;
+
+        return ubi_eba_write_leb(ubi, vol_id, lnum, buf, offset, len, dtype);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_write);
+
+/*
+ * ubi_leb_change - change logical eraseblock atomically.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number to change
+ * @buf: data to write
+ * @len: how many bytes to write
+ * @dtype: expected data type
+ *
+ * This function changes the contents of a logical eraseblock atomically. @buf
+ * has to contain new logical eraseblock data, and @len - the length of the
+ * data, which has to be aligned. The length may be shorter then the logical
+ * eraseblock size, ant the logical eraseblock may be appended to more times
+ * later on. This function guarantees that in case of an unclean reboot the old
+ * contents is preserved. Returns zero in case of success and a negative error
+ * code in case of failure.
+ */
+int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
+                   int len, int dtype)
+{
+        struct ubi_volume *vol = desc->vol;
+        struct ubi_device *ubi = vol->ubi;
+        int vol_id = vol->vol_id;
+
+        dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
+
+        if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+                return -EINVAL;
+
+        if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+                return -EROFS;
+
+        if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
+            len > vol->usable_leb_size || len % ubi->min_io_size)
+                return -EINVAL;
+
+        if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+            dtype != UBI_UNKNOWN)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+
+        if (len == 0)
+                return 0;
+
+        return ubi_eba_atomic_leb_change(ubi, vol_id, lnum, buf, len, dtype);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_change);
+
+/**
+ * ubi_leb_erase - erase logical eraseblock.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and synchronously erases the
+ * correspondent physical eraseblock. Returns zero in case of success and a
+ * negative error code in case of failure.
+ *
+ * If the volume is damaged because of an interrupted update this function just
+ * returns immediately with %-EBADF code.
+ */
+int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
+{
+        struct ubi_volume *vol = desc->vol;
+        struct ubi_device *ubi = vol->ubi;
+        int err, vol_id = vol->vol_id;
+
+        dbg_msg("erase LEB %d:%d", vol_id, lnum);
+
+        if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+                return -EROFS;
+
+        if (lnum < 0 || lnum >= vol->reserved_pebs)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+
+        err = ubi_eba_unmap_leb(ubi, vol_id, lnum);
+        if (err)
+                return err;
+
+        return ubi_wl_flush(ubi);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_erase);
+
+/**
+ * ubi_leb_unmap - un-map logical eraseblock.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function un-maps logical eraseblock @lnum and schedules the
+ * corresponding physical eraseblock for erasure, so that it will eventually be
+ * physically erased in background. This operation is much faster then the
+ * erase operation.
+ *
+ * Unlike erase, the un-map operation does not guarantee that the logical
+ * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
+ * example, if several logical eraseblocks are un-mapped, and an unclean reboot
+ * happens after this, the logical eraseblocks will not necessarily be
+ * un-mapped again when this MTD device is attached. They may actually be
+ * mapped to the same physical eraseblocks again. So, this function has to be
+ * used with care.
+ *
+ * In other words, when un-mapping a logical eraseblock, UBI does not store
+ * any information about this on the flash media, it just marks the logical
+ * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
+ * eraseblock is physically erased, it will be mapped again to the same logical
+ * eraseblock when the MTD device is attached again.
+ *
+ * The main and obvious use-case of this function is when the contents of a
+ * logical eraseblock has to be re-written. Then it is much more efficient to
+ * first un-map it, then write new data, rather then first erase it, then write
+ * new data. Note, once new data has been written to the logical eraseblock,
+ * UBI guarantees that the old contents has gone forever. In other words, if an
+ * unclean reboot happens after the logical eraseblock has been un-mapped and
+ * then written to, it will contain the last written data.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure. If the volume is damaged because of an interrupted update
+ * this function just returns immediately with %-EBADF code.
+ */
+int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
+{
+        struct ubi_volume *vol = desc->vol;
+        struct ubi_device *ubi = vol->ubi;
+        int vol_id = vol->vol_id;
+
+        dbg_msg("unmap LEB %d:%d", vol_id, lnum);
+
+        if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+                return -EROFS;
+
+        if (lnum < 0 || lnum >= vol->reserved_pebs)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+
+        return ubi_eba_unmap_leb(ubi, vol_id, lnum);
+}
+EXPORT_SYMBOL_GPL(ubi_leb_unmap);
+
+/**
+ * ubi_is_mapped - check if logical eraseblock is mapped.
+ * @desc: volume descriptor
+ * @lnum: logical eraseblock number
+ *
+ * This function checks if logical eraseblock @lnum is mapped to a physical
+ * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
+ * mean it will still be un-mapped after the UBI device is re-attached. The
+ * logical eraseblock may become mapped to the physical eraseblock it was last
+ * mapped to.
+ *
+ * This function returns %1 if the LEB is mapped, %0 if not, and a negative
+ * error code in case of failure. If the volume is damaged because of an
+ * interrupted update this function just returns immediately with %-EBADF error
+ * code.
+ */
+int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
+{
+        struct ubi_volume *vol = desc->vol;
+
+        dbg_msg("test LEB %d:%d", vol->vol_id, lnum);
+
+        if (lnum < 0 || lnum >= vol->reserved_pebs)
+                return -EINVAL;
+
+        if (vol->upd_marker)
+                return -EBADF;
+
+        return vol->eba_tbl[lnum] >= 0;
+}
+EXPORT_SYMBOL_GPL(ubi_is_mapped);