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