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| Rev | Author | Line No. | Line |
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| 1200 | jermar | 1 | /* |
| 2 | * Copyright (C) 2006 Jakub Jermar |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #include <adt/bitmap.h> |
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| 30 | #include <typedefs.h> |
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| 31 | #include <arch/types.h> |
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| 32 | #include <align.h> |
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| 33 | #include <debug.h> |
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| 34 | |||
| 35 | #define ALL_ONES 0xff |
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| 36 | #define ALL_ZEROES 0x00 |
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| 37 | |||
| 38 | /** Initialize bitmap. |
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| 39 | * |
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| 40 | * No portion of the bitmap is set or cleared by this function. |
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| 41 | * |
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| 42 | * @param bitmap Bitmap structure. |
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| 43 | * @param map Address of the memory used to hold the map. |
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| 44 | * @param bits Number of bits stored in bitmap. |
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| 45 | */ |
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| 46 | void bitmap_initialize(bitmap_t *bitmap, __u8 *map, count_t bits) |
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| 47 | { |
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| 48 | bitmap->map = map; |
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| 49 | bitmap->bits = bits; |
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| 50 | } |
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| 51 | |||
| 52 | /** Set range of bits. |
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| 53 | * |
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| 54 | * @param bitmap Bitmap structure. |
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| 55 | * @param start Starting bit. |
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| 56 | * @param bits Number of bits to set. |
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| 57 | */ |
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| 58 | void bitmap_set_range(bitmap_t *bitmap, index_t start, count_t bits) |
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| 59 | { |
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| 60 | index_t i; |
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| 61 | index_t aligned_start; |
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| 62 | count_t lub; /* leading unaligned bits */ |
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| 63 | count_t tub; /* trailing unaligned bits */ |
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| 64 | |||
| 65 | ASSERT(start + bits <= bitmap->bits); |
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| 66 | |||
| 67 | aligned_start = ALIGN_UP(start, 8); |
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| 68 | lub = aligned_start - start; |
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| 69 | tub = (bits - lub) % 8; |
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| 70 | |||
| 71 | if (lub) { |
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| 72 | /* |
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| 73 | * Make sure to set any leading unaligned bits. |
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| 74 | */ |
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| 75 | bitmap->map[start / 8] |= ~((1 << (8 - lub)) - 1); |
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| 76 | } |
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| 77 | for (i = 0; i < (bits - lub) / 8; i++) { |
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| 78 | /* |
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| 79 | * The middle bits can be set byte by byte. |
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| 80 | */ |
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| 81 | bitmap->map[aligned_start / 8 + i] = ALL_ONES; |
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| 82 | } |
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| 83 | if (tub) { |
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| 84 | /* |
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| 85 | * Make sure to set any trailing unaligned bits. |
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| 86 | */ |
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| 87 | bitmap->map[aligned_start / 8 + i] |= (1 << tub) - 1; |
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| 88 | } |
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| 89 | |||
| 90 | } |
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| 91 | |||
| 92 | /** Clear range of bits. |
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| 93 | * |
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| 94 | * @param bitmap Bitmap structure. |
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| 95 | * @param start Starting bit. |
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| 96 | * @param bits Number of bits to clear. |
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| 97 | */ |
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| 98 | void bitmap_clear_range(bitmap_t *bitmap, index_t start, count_t bits) |
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| 99 | { |
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| 100 | index_t i; |
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| 101 | index_t aligned_start; |
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| 102 | count_t lub; /* leading unaligned bits */ |
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| 103 | count_t tub; /* trailing unaligned bits */ |
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| 104 | |||
| 105 | ASSERT(start + bits <= bitmap->bits); |
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| 106 | |||
| 107 | aligned_start = ALIGN_UP(start, 8); |
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| 108 | lub = aligned_start - start; |
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| 109 | tub = (bits - lub) % 8; |
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| 110 | |||
| 111 | if (lub) { |
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| 112 | /* |
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| 113 | * Make sure to clear any leading unaligned bits. |
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| 114 | */ |
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| 115 | bitmap->map[start / 8] &= (1 << (8 - lub)) - 1; |
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| 116 | } |
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| 117 | for (i = 0; i < (bits - lub) / 8; i++) { |
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| 118 | /* |
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| 119 | * The middle bits can be cleared byte by byte. |
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| 120 | */ |
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| 121 | bitmap->map[aligned_start / 8 + i] = ALL_ZEROES; |
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| 122 | } |
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| 123 | if (tub) { |
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| 124 | /* |
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| 125 | * Make sure to clear any trailing unaligned bits. |
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| 126 | */ |
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| 127 | bitmap->map[aligned_start / 8 + i] &= ~((1 << tub) - 1); |
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| 128 | } |
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| 129 | |||
| 130 | } |
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| 131 | |||
| 132 | /** Copy portion of one bitmap into another bitmap. |
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| 133 | * |
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| 134 | * @param dst Destination bitmap. |
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| 135 | * @param src Source bitmap. |
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| 136 | * @param bits Number of bits to copy. |
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| 137 | */ |
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| 138 | void bitmap_copy(bitmap_t *dst, bitmap_t *src, count_t bits) |
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| 139 | { |
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| 140 | index_t i; |
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| 141 | |||
| 142 | ASSERT(bits <= dst->bits); |
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| 143 | ASSERT(bits <= src->bits); |
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| 144 | |||
| 145 | for (i = 0; i < bits / 8; i++) |
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| 146 | dst->map[i] = src->map[i]; |
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| 147 | |||
| 148 | if (bits % 8) { |
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| 149 | bitmap_clear_range(dst, i * 8, bits % 8); |
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| 150 | dst->map[i] |= src->map[i] & ((1 << (bits % 8)) - 1); |
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| 151 | } |
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| 152 | } |