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
yaffs_block_bits(struct yaffs_dev * dev,int blk)20 static 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
yaffs_verify_chunk_bit_id(struct yaffs_dev * dev,int blk,int chunk)32 void 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
yaffs_clear_chunk_bits(struct yaffs_dev * dev,int blk)43 void 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
yaffs_clear_chunk_bit(struct yaffs_dev * dev,int blk,int chunk)50 void 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
yaffs_set_chunk_bit(struct yaffs_dev * dev,int blk,int chunk)58 void 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
yaffs_check_chunk_bit(struct yaffs_dev * dev,int blk,int chunk)66 int 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
yaffs_still_some_chunks(struct yaffs_dev * dev,int blk)74 int 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
yaffs_count_chunk_bits(struct yaffs_dev * dev,int blk)87 int 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