| 1 | /* |
| 2 | * YAFFS: Yet Another Flash File System. A NAND-flash specific file system. |
| 3 | * |
| 4 | * Copyright (C) 2002-2010 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 | |
| 20 | static Y_INLINE __u8 *yaffs_BlockBits(yaffs_dev_t *dev, int blk) |
| 21 | { |
| 22 | if (blk < dev->internal_start_block || blk > dev->internal_end_block) { |
| 23 | T(YAFFS_TRACE_ERROR, |
| 24 | (TSTR("**>> yaffs: BlockBits block %d is not valid" TENDSTR), |
| 25 | blk)); |
| 26 | YBUG(); |
| 27 | } |
| 28 | return dev->chunk_bits + |
| 29 | (dev->chunk_bit_stride * (blk - dev->internal_start_block)); |
| 30 | } |
| 31 | |
| 32 | void yaffs_verify_chunk_bit_id(yaffs_dev_t *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 | T(YAFFS_TRACE_ERROR, |
| 37 | (TSTR("**>> yaffs: Chunk Id (%d:%d) invalid"TENDSTR), |
| 38 | blk, chunk)); |
| 39 | YBUG(); |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | void yaffs_clear_chunk_bits(yaffs_dev_t *dev, int blk) |
| 44 | { |
| 45 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 46 | |
| 47 | memset(blkBits, 0, dev->chunk_bit_stride); |
| 48 | } |
| 49 | |
| 50 | void yaffs_clear_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) |
| 51 | { |
| 52 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 53 | |
| 54 | yaffs_verify_chunk_bit_id(dev, blk, chunk); |
| 55 | |
| 56 | blkBits[chunk / 8] &= ~(1 << (chunk & 7)); |
| 57 | } |
| 58 | |
| 59 | void yaffs_set_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) |
| 60 | { |
| 61 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 62 | |
| 63 | yaffs_verify_chunk_bit_id(dev, blk, chunk); |
| 64 | |
| 65 | blkBits[chunk / 8] |= (1 << (chunk & 7)); |
| 66 | } |
| 67 | |
| 68 | int yaffs_check_chunk_bit(yaffs_dev_t *dev, int blk, int chunk) |
| 69 | { |
| 70 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 71 | yaffs_verify_chunk_bit_id(dev, blk, chunk); |
| 72 | |
| 73 | return (blkBits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0; |
| 74 | } |
| 75 | |
| 76 | int yaffs_still_some_chunks(yaffs_dev_t *dev, int blk) |
| 77 | { |
| 78 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 79 | int i; |
| 80 | for (i = 0; i < dev->chunk_bit_stride; i++) { |
| 81 | if (*blkBits) |
| 82 | return 1; |
| 83 | blkBits++; |
| 84 | } |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | int yaffs_count_chunk_bits(yaffs_dev_t *dev, int blk) |
| 89 | { |
| 90 | __u8 *blkBits = yaffs_BlockBits(dev, blk); |
| 91 | int i; |
| 92 | int n = 0; |
| 93 | for (i = 0; i < dev->chunk_bit_stride; i++) { |
| 94 | __u8 x = *blkBits; |
| 95 | while (x) { |
| 96 | if (x & 1) |
| 97 | n++; |
| 98 | x >>= 1; |
| 99 | } |
| 100 | |
| 101 | blkBits++; |
| 102 | } |
| 103 | return n; |
| 104 | } |
| 105 | |
| 106 | |
