linux/drivers/mtd/ubi/misc.c
Artem Bityutskiy 89b96b6929 UBI: improve internal interfaces
Pass volume description object to the EBA function which makes
more sense, and EBA function do not have to find the volume
description object by volume ID.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2007-12-26 19:15:15 +02:00

106 lines
3.0 KiB
C

/*
* 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)
*/
/* Here we keep miscellaneous functions which are used all over the UBI code */
#include "ubi.h"
/**
* calc_data_len - calculate how much real data is stored in a buffer.
* @ubi: UBI device description object
* @buf: a buffer with the contents of the physical eraseblock
* @length: the buffer length
*
* This function calculates how much "real data" is stored in @buf and returnes
* the length. Continuous 0xFF bytes at the end of the buffer are not
* considered as "real data".
*/
int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
int length)
{
int i;
ubi_assert(length % ubi->min_io_size == 0);
for (i = length - 1; i >= 0; i--)
if (((const uint8_t *)buf)[i] != 0xFF)
break;
/* The resulting length must be aligned to the minimum flash I/O size */
length = ALIGN(i + 1, ubi->min_io_size);
return length;
}
/**
* ubi_check_volume - check the contents of a static volume.
* @ubi: UBI device description object
* @vol_id: ID of the volume to check
*
* This function checks if static volume @vol_id is corrupted by fully reading
* it and checking data CRC. This function returns %0 if the volume is not
* corrupted, %1 if it is corrupted and a negative error code in case of
* failure. Dynamic volumes are not checked and zero is returned immediately.
*/
int ubi_check_volume(struct ubi_device *ubi, int vol_id)
{
void *buf;
int err = 0, i;
struct ubi_volume *vol = ubi->volumes[vol_id];
if (vol->vol_type != UBI_STATIC_VOLUME)
return 0;
buf = vmalloc(vol->usable_leb_size);
if (!buf)
return -ENOMEM;
for (i = 0; i < vol->used_ebs; i++) {
int size;
if (i == vol->used_ebs - 1)
size = vol->last_eb_bytes;
else
size = vol->usable_leb_size;
err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
if (err) {
if (err == -EBADMSG)
err = 1;
break;
}
}
vfree(buf);
return err;
}
/**
* ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
* eraseblock handling.
* @ubi: UBI device description object
*/
void ubi_calculate_reserved(struct ubi_device *ubi)
{
ubi->beb_rsvd_level = ubi->good_peb_count/100;
ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
}