xref: /openbmc/u-boot/fs/yaffs2/yaffs_bitmap.c (revision 753ac610)
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