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			106 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
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 *
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 * Copyright (C) 2002-2010 Aleph One Ltd.
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 *   for Toby Churchill Ltd and Brightstar Engineering
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 *
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 * Created by Charles Manning <charles@aleph1.co.uk>
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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 version 2 as
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 * published by the Free Software Foundation.
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 */
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#include "yaffs_bitmap.h"
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#include "yaffs_trace.h"
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/*
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 * Chunk bitmap manipulations
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 */
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static Y_INLINE __u8 *yaffs_BlockBits(yaffs_dev_t *dev, int blk)
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{
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	if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
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		T(YAFFS_TRACE_ERROR,
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			(TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR),
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			blk));
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		YBUG();
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	}
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	return dev->chunk_bits +
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		(dev->chunk_bit_stride * (blk - dev->internal_start_block));
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}
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void yaffs_verify_chunk_bit_id(yaffs_dev_t *dev, int blk, int chunk)
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{
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	if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
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			chunk < 0 || chunk >= dev->param.chunks_per_block) {
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		T(YAFFS_TRACE_ERROR,
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		(TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR),
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			blk, chunk));
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		YBUG();
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	}
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}
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void yaffs_clear_chunk_bits(yaffs_dev_t *dev, int blk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	memset(blkBits, 0, dev->chunk_bit_stride);
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}
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void yaffs_clear_chunk_bit(yaffs_dev_t *dev, int blk, int chunk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	yaffs_verify_chunk_bit_id(dev, blk, chunk);
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	blkBits[chunk / 8] &= ~(1 << (chunk & 7));
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}
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void yaffs_set_chunk_bit(yaffs_dev_t *dev, int blk, int chunk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	yaffs_verify_chunk_bit_id(dev, blk, chunk);
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	blkBits[chunk / 8] |= (1 << (chunk & 7));
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}
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int yaffs_check_chunk_bit(yaffs_dev_t *dev, int blk, int chunk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	yaffs_verify_chunk_bit_id(dev, blk, chunk);
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	return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
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}
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int yaffs_still_some_chunks(yaffs_dev_t *dev, int blk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	int i;
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	for (i = 0; i < dev->chunk_bit_stride; i++) {
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		if (*blkBits)
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			return 1;
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		blkBits++;
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	}
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	return 0;
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}
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int yaffs_count_chunk_bits(yaffs_dev_t *dev, int blk)
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{
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	__u8 *blkBits = yaffs_BlockBits(dev, blk);
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	int i;
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	int n = 0;
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	for (i = 0; i < dev->chunk_bit_stride; i++) {
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		__u8 x = *blkBits;
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		while (x) {
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			if (x & 1)
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				n++;
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			x >>= 1;
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		}
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		blkBits++;
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	}
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	return n;
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}
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