LXR uboot/fs/yaffs2/yaffs

   1/*
   2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3 *
   4 * Copyright (C) 2002-2011 Aleph One Ltd.
   5 *   for Toby Churchill Ltd and Brightstar Engineering
   6 *
   7 * Created by Charles Manning <charles@aleph1.co.uk>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 */
  13
  14#include "yaffs_bitmap.h"
  15#include "yaffs_trace.h"
  16/*
  17 * Chunk bitmap manipulations
  18 */
  19
  20static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
  21{
  22        if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
  23                yaffs_trace(YAFFS_TRACE_ERROR,
  24                        "BlockBits block %d is not valid",
  25                        blk);
  26                BUG();
  27        }
  28        return dev->chunk_bits +
  29            (dev->chunk_bit_stride * (blk - dev->internal_start_block));
  30}
  31
  32void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
  33{
  34        if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
  35            chunk < 0 || chunk >= dev->param.chunks_per_block) {
  36                yaffs_trace(YAFFS_TRACE_ERROR,
  37                        "Chunk Id (%d:%d) invalid",
  38                        blk, chunk);
  39                BUG();
  40        }
  41}
  42
  43void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
  44{
  45        u8 *blk_bits = yaffs_block_bits(dev, blk);
  46
  47        memset(blk_bits, 0, dev->chunk_bit_stride);
  48}
  49
  50void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
  51{
  52        u8 *blk_bits = yaffs_block_bits(dev, blk);
  53
  54        yaffs_verify_chunk_bit_id(dev, blk, chunk);
  55        blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
  56}
  57
  58void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
  59{
  60        u8 *blk_bits = yaffs_block_bits(dev, blk);
  61
  62        yaffs_verify_chunk_bit_id(dev, blk, chunk);
  63        blk_bits[chunk / 8] |= (1 << (chunk & 7));
  64}
  65
  66int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
  67{
  68        u8 *blk_bits = yaffs_block_bits(dev, blk);
  69
  70        yaffs_verify_chunk_bit_id(dev, blk, chunk);
  71        return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
  72}
  73
  74int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
  75{
  76        u8 *blk_bits = yaffs_block_bits(dev, blk);
  77        int i;
  78
  79        for (i = 0; i < dev->chunk_bit_stride; i++) {
  80                if (*blk_bits)
  81                        return 1;
  82                blk_bits++;
  83        }
  84        return 0;
  85}
  86
  87int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
  88{
  89        u8 *blk_bits = yaffs_block_bits(dev, blk);
  90        int i;
  91        int n = 0;
  92
  93        for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
  94                n += hweight8(*blk_bits);
  95
  96        return n;
  97}
  98