diff options
Diffstat (limited to 'target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c')
| -rw-r--r-- | target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c b/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c new file mode 100644 index 0000000000..1769e9b47e --- /dev/null +++ b/target/linux/generic/files/fs/yaffs2/yaffs_bitmap.c @@ -0,0 +1,105 @@ +/* + * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. + * + * Copyright (C) 2002-2010 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 Y_INLINE __u8 *yaffs_BlockBits(yaffs_dev_t *dev, int blk) +{ + if (blk < dev->internal_start_block || blk > dev->internal_end_block) { + T(YAFFS_TRACE_ERROR, + (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR), + blk)); + YBUG(); + } + return dev->chunk_bits + + (dev->chunk_bit_stride * (blk - dev->internal_start_block)); +} + +void yaffs_verify_chunk_bit_id(yaffs_dev_t *dev, int blk, int chunk) +{ + if (blk < dev->internal_start_block || blk > dev->internal_end_block || + chunk < 0 || chunk >= dev->param.chunks_per_block) { + T(YAFFS_TRACE_ERROR, + (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR), + blk, chunk)); + YBUG(); + } +} + +void yaffs_clear_chunk_bits(yaffs_dev_t *dev, int blk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + + memset(blkBits, 0, dev->chunk_bit_stride); +} + +void yaffs_clear_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + + yaffs_verify_chunk_bit_id(dev, blk, chunk); + + blkBits[chunk / 8] &= ~(1 << (chunk & 7)); +} + +void yaffs_set_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + + yaffs_verify_chunk_bit_id(dev, blk, chunk); + + blkBits[chunk / 8] |= (1 << (chunk & 7)); +} + +int yaffs_check_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + yaffs_verify_chunk_bit_id(dev, blk, chunk); + + return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0; +} + +int yaffs_still_some_chunks(yaffs_dev_t *dev, int blk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + int i; + for (i = 0; i < dev->chunk_bit_stride; i++) { + if (*blkBits) + return 1; + blkBits++; + } + return 0; +} + +int yaffs_count_chunk_bits(yaffs_dev_t *dev, int blk) +{ + __u8 *blkBits = yaffs_BlockBits(dev, blk); + int i; + int n = 0; + for (i = 0; i < dev->chunk_bit_stride; i++) { + __u8 x = *blkBits; + while (x) { + if (x & 1) + n++; + x >>= 1; + } + + blkBits++; + } + return n; +} + |