106 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) International Business Machines Corp., 2006
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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|  * the GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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|  *
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|  * Author: Artem Bityutskiy (Битюцкий Артём)
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|  */
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| 
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| /* Here we keep miscellaneous functions which are used all over the UBI code */
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| 
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| #include "ubi.h"
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| 
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| /**
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|  * calc_data_len - calculate how much real data is stored in a buffer.
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|  * @ubi: UBI device description object
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|  * @buf: a buffer with the contents of the physical eraseblock
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|  * @length: the buffer length
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|  *
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|  * This function calculates how much "real data" is stored in @buf and returnes
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|  * the length. Continuous 0xFF bytes at the end of the buffer are not
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|  * considered as "real data".
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|  */
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| int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
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| 		      int length)
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| {
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| 	int i;
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| 
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| 	ubi_assert(!(length & (ubi->min_io_size - 1)));
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| 
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| 	for (i = length - 1; i >= 0; i--)
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| 		if (((const uint8_t *)buf)[i] != 0xFF)
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| 			break;
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| 
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| 	/* The resulting length must be aligned to the minimum flash I/O size */
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| 	length = ALIGN(i + 1, ubi->min_io_size);
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| 	return length;
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| }
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| 
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| /**
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|  * ubi_check_volume - check the contents of a static volume.
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|  * @ubi: UBI device description object
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|  * @vol_id: ID of the volume to check
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|  *
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|  * This function checks if static volume @vol_id is corrupted by fully reading
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|  * it and checking data CRC. This function returns %0 if the volume is not
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|  * corrupted, %1 if it is corrupted and a negative error code in case of
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|  * failure. Dynamic volumes are not checked and zero is returned immediately.
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|  */
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| int ubi_check_volume(struct ubi_device *ubi, int vol_id)
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| {
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| 	void *buf;
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| 	int err = 0, i;
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| 	struct ubi_volume *vol = ubi->volumes[vol_id];
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| 
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| 	if (vol->vol_type != UBI_STATIC_VOLUME)
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| 		return 0;
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| 
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| 	buf = vmalloc(vol->usable_leb_size);
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| 	if (!buf)
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| 		return -ENOMEM;
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| 
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| 	for (i = 0; i < vol->used_ebs; i++) {
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| 		int size;
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| 
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| 		if (i == vol->used_ebs - 1)
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| 			size = vol->last_eb_bytes;
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| 		else
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| 			size = vol->usable_leb_size;
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| 
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| 		err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
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| 		if (err) {
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| 			if (err == -EBADMSG)
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| 				err = 1;
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| 			break;
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| 		}
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| 	}
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| 
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| 	vfree(buf);
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| 	return err;
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| }
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| 
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| /**
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|  * ubi_calculate_rsvd_pool - calculate how many PEBs must be reserved for bad
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|  * eraseblock handling.
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|  * @ubi: UBI device description object
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|  */
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| void ubi_calculate_reserved(struct ubi_device *ubi)
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| {
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| 	ubi->beb_rsvd_level = ubi->good_peb_count/100;
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| 	ubi->beb_rsvd_level *= CONFIG_MTD_UBI_BEB_RESERVE;
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| 	if (ubi->beb_rsvd_level < MIN_RESEVED_PEBS)
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| 		ubi->beb_rsvd_level = MIN_RESEVED_PEBS;
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| }
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