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fs/yaffs2/yaffs_bitmap.c
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d41ce506b Initial Release, ... |
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/* * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. * * Copyright (C) 2002-2011 Aleph One Ltd. * for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include "yaffs_bitmap.h" #include "yaffs_trace.h" /* * Chunk bitmap manipulations */ static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk) { if (blk < dev->internal_start_block || blk > dev->internal_end_block) { yaffs_trace(YAFFS_TRACE_ERROR, "BlockBits block %d is not valid", blk); BUG(); } return dev->chunk_bits + (dev->chunk_bit_stride * (blk - dev->internal_start_block)); } void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk) { if (blk < dev->internal_start_block || blk > dev->internal_end_block || chunk < 0 || chunk >= dev->param.chunks_per_block) { yaffs_trace(YAFFS_TRACE_ERROR, "Chunk Id (%d:%d) invalid", blk, chunk); BUG(); } } void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk) { u8 *blk_bits = yaffs_block_bits(dev, blk); memset(blk_bits, 0, dev->chunk_bit_stride); } void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk) { u8 *blk_bits = yaffs_block_bits(dev, blk); yaffs_verify_chunk_bit_id(dev, blk, chunk); blk_bits[chunk / 8] &= ~(1 << (chunk & 7)); } void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk) { u8 *blk_bits = yaffs_block_bits(dev, blk); yaffs_verify_chunk_bit_id(dev, blk, chunk); blk_bits[chunk / 8] |= (1 << (chunk & 7)); } int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk) { u8 *blk_bits = yaffs_block_bits(dev, blk); yaffs_verify_chunk_bit_id(dev, blk, chunk); return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0; } int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk) { u8 *blk_bits = yaffs_block_bits(dev, blk); int i; for (i = 0; i < dev->chunk_bit_stride; i++) { if (*blk_bits) return 1; blk_bits++; } return 0; } int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk) { u8 *blk_bits = yaffs_block_bits(dev, blk); int i; int n = 0; for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++) n += hweight8(*blk_bits); return n; } |