| 1 | |
| 2 | * lib/bitmap.c
|
| 3 | * Helper functions for bitmap.h.
|
| 4 | *
|
| 5 | * This source code is licensed under the GNU General Public License,
|
| 6 | * Version 2. See the file COPYING for more details.
|
| 7 |
|
| 8 | #include <linux/module.h>
|
| 9 | #include <linux/ctype.h>
|
| 10 | #include <linux/errno.h>
|
| 11 | #include <linux/bitmap.h>
|
| 12 | #include <linux/bitops.h>
|
| 13 | #include <asm/uaccess.h>
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| 14 |
|
| 15 | |
| 16 | * bitmaps provide an array of bits, implemented using an an
|
| 17 | * array of unsigned longs. The number of valid bits in a
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| 18 | * given bitmap does _not_ need to be an exact multiple of
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| 19 | * BITS_PER_LONG.
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| 20 | *
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| 21 | * The possible unused bits in the last, partially used word
|
| 22 | * of a bitmap are 'don't care'. The implementation makes
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| 23 | * no particular effort to keep them zero. It ensures that
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| 24 | * their value will not affect the results of any operation.
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| 25 | * The bitmap operations that return Boolean (bitmap_empty,
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| 26 | * for example) or scalar (bitmap_weight, for example) results
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| 27 | * carefully filter out these unused bits from impacting their
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| 28 | * results.
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| 29 | *
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| 30 | * These operations actually hold to a slightly stronger rule:
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| 31 | * if you don't input any bitmaps to these ops that have some
|
| 32 | * unused bits set, then they won't output any set unused bits
|
| 33 | * in output bitmaps.
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| 34 | *
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| 35 | * The byte ordering of bitmaps is more natural on little
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| 36 | * endian architectures. See the big-endian headers
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| 37 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
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| 38 | * for the best explanations of this ordering.
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| 39 |
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| 40 |
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| 41 | int __bitmap_empty(const unsigned long *bitmap, int bits)
|
| 42 | {
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| 43 | int k, lim = bits/BITS_PER_LONG;
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| 44 | for (k = 0; k < lim; ++k)
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| 45 | if (bitmap[k])
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| 46 | return 0;
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| 47 |
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| 48 | if (bits % BITS_PER_LONG)
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| 49 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
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| 50 | return 0;
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| 51 |
|
| 52 | return 1;
|
| 53 | }
|
| 54 | EXPORT_SYMBOL(__bitmap_empty);
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| 55 |
|
| 56 | int __bitmap_full(const unsigned long *bitmap, int bits)
|
| 57 | {
|
| 58 | int k, lim = bits/BITS_PER_LONG;
|
| 59 | for (k = 0; k < lim; ++k)
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| 60 | if (~bitmap[k])
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| 61 | return 0;
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| 62 |
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| 63 | if (bits % BITS_PER_LONG)
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| 64 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
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| 65 | return 0;
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| 66 |
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| 67 | return 1;
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| 68 | }
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| 69 | EXPORT_SYMBOL(__bitmap_full);
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| 70 |
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| 71 | int __bitmap_equal(const unsigned long *bitmap1,
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| 72 | const unsigned long *bitmap2, int bits)
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| 73 | {
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| 74 | int k, lim = bits/BITS_PER_LONG;
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| 75 | for (k = 0; k < lim; ++k)
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| 76 | if (bitmap1[k] != bitmap2[k])
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| 77 | return 0;
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| 78 |
|
| 79 | if (bits % BITS_PER_LONG)
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| 80 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 81 | return 0;
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| 82 |
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| 83 | return 1;
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| 84 | }
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| 85 | EXPORT_SYMBOL(__bitmap_equal);
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| 86 |
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| 87 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits)
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| 88 | {
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| 89 | int k, lim = bits/BITS_PER_LONG;
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| 90 | for (k = 0; k < lim; ++k)
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| 91 | dst[k] = ~src[k];
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| 92 |
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| 93 | if (bits % BITS_PER_LONG)
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| 94 | dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
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| 95 | }
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| 96 | EXPORT_SYMBOL(__bitmap_complement);
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| 97 |
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| 98 | |
| 99 | * __bitmap_shift_right - logical right shift of the bits in a bitmap
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| 100 | * @dst : destination bitmap
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| 101 | * @src : source bitmap
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| 102 | * @shift : shift by this many bits
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| 103 | * @bits : bitmap size, in bits
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| 104 | *
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| 105 | * Shifting right (dividing) means moving bits in the MS -> LS bit
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| 106 | * direction. Zeros are fed into the vacated MS positions and the
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| 107 | * LS bits shifted off the bottom are lost.
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| 108 |
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| 109 | void __bitmap_shift_right(unsigned long *dst,
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| 110 | const unsigned long *src, int shift, int bits)
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| 111 | {
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| 112 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
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| 113 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 114 | unsigned long mask = (1UL << left) - 1;
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| 115 | for (k = 0; off + k < lim; ++k) {
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| 116 | unsigned long upper, lower;
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| 117 |
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| 118 | |
| 119 | * If shift is not word aligned, take lower rem bits of
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| 120 | * word above and make them the top rem bits of result.
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| 121 |
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| 122 | if (!rem || off + k + 1 >= lim)
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| 123 | upper = 0;
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| 124 | else {
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| 125 | upper = src[off + k + 1];
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| 126 | if (off + k + 1 == lim - 1 && left)
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| 127 | upper &= mask;
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| 128 | }
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| 129 | lower = src[off + k];
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| 130 | if (left && off + k == lim - 1)
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| 131 | lower &= mask;
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| 132 | dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
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| 133 | if (left && k == lim - 1)
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| 134 | dst[k] &= mask;
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| 135 | }
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| 136 | if (off)
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| 137 | memset(&dst[lim - off], 0, off*sizeof(unsigned long));
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| 138 | }
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| 139 | EXPORT_SYMBOL(__bitmap_shift_right);
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| 140 |
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| 141 |
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| 142 | |
| 143 | * __bitmap_shift_left - logical left shift of the bits in a bitmap
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| 144 | * @dst : destination bitmap
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| 145 | * @src : source bitmap
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| 146 | * @shift : shift by this many bits
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| 147 | * @bits : bitmap size, in bits
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| 148 | *
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| 149 | * Shifting left (multiplying) means moving bits in the LS -> MS
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| 150 | * direction. Zeros are fed into the vacated LS bit positions
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| 151 | * and those MS bits shifted off the top are lost.
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| 152 |
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| 153 |
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| 154 | void __bitmap_shift_left(unsigned long *dst,
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| 155 | const unsigned long *src, int shift, int bits)
|
| 156 | {
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| 157 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
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| 158 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 159 | for (k = lim - off - 1; k >= 0; --k) {
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| 160 | unsigned long upper, lower;
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| 161 |
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| 162 | |
| 163 | * If shift is not word aligned, take upper rem bits of
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| 164 | * word below and make them the bottom rem bits of result.
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| 165 |
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| 166 | if (rem && k > 0)
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| 167 | lower = src[k - 1];
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| 168 | else
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| 169 | lower = 0;
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| 170 | upper = src[k];
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| 171 | if (left && k == lim - 1)
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| 172 | upper &= (1UL << left) - 1;
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| 173 | dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
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| 174 | if (left && k + off == lim - 1)
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| 175 | dst[k + off] &= (1UL << left) - 1;
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| 176 | }
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| 177 | if (off)
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| 178 | memset(dst, 0, off*sizeof(unsigned long));
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| 179 | }
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| 180 | EXPORT_SYMBOL(__bitmap_shift_left);
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| 181 |
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| 182 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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| 183 | const unsigned long *bitmap2, int bits)
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| 184 | {
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| 185 | int k;
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| 186 | int nr = BITS_TO_LONGS(bits);
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| 187 | unsigned long result = 0;
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| 188 |
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| 189 | for (k = 0; k < nr; k++)
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| 190 | result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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| 191 | return result != 0;
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| 192 | }
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| 193 | EXPORT_SYMBOL(__bitmap_and);
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| 194 |
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| 195 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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| 196 | const unsigned long *bitmap2, int bits)
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| 197 | {
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| 198 | int k;
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| 199 | int nr = BITS_TO_LONGS(bits);
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| 200 |
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| 201 | for (k = 0; k < nr; k++)
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| 202 | dst[k] = bitmap1[k] | bitmap2[k];
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| 203 | }
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| 204 | EXPORT_SYMBOL(__bitmap_or);
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| 205 |
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| 206 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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| 207 | const unsigned long *bitmap2, int bits)
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| 208 | {
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| 209 | int k;
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| 210 | int nr = BITS_TO_LONGS(bits);
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| 211 |
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| 212 | for (k = 0; k < nr; k++)
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| 213 | dst[k] = bitmap1[k] ^ bitmap2[k];
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| 214 | }
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| 215 | EXPORT_SYMBOL(__bitmap_xor);
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| 216 |
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| 217 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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| 218 | const unsigned long *bitmap2, int bits)
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| 219 | {
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| 220 | int k;
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| 221 | int nr = BITS_TO_LONGS(bits);
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| 222 | unsigned long result = 0;
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| 223 |
|
| 224 | for (k = 0; k < nr; k++)
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| 225 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
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| 226 | return result != 0;
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| 227 | }
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| 228 | EXPORT_SYMBOL(__bitmap_andnot);
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| 229 |
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| 230 | int __bitmap_intersects(const unsigned long *bitmap1,
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| 231 | const unsigned long *bitmap2, int bits)
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| 232 | {
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| 233 | int k, lim = bits/BITS_PER_LONG;
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| 234 | for (k = 0; k < lim; ++k)
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| 235 | if (bitmap1[k] & bitmap2[k])
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| 236 | return 1;
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| 237 |
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| 238 | if (bits % BITS_PER_LONG)
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| 239 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 240 | return 1;
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| 241 | return 0;
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| 242 | }
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| 243 | EXPORT_SYMBOL(__bitmap_intersects);
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| 244 |
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| 245 | int __bitmap_subset(const unsigned long *bitmap1,
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| 246 | const unsigned long *bitmap2, int bits)
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| 247 | {
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| 248 | int k, lim = bits/BITS_PER_LONG;
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| 249 | for (k = 0; k < lim; ++k)
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| 250 | if (bitmap1[k] & ~bitmap2[k])
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| 251 | return 0;
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| 252 |
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| 253 | if (bits % BITS_PER_LONG)
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| 254 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 255 | return 0;
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| 256 | return 1;
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| 257 | }
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| 258 | EXPORT_SYMBOL(__bitmap_subset);
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| 259 |
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| 260 | int __bitmap_weight(const unsigned long *bitmap, int bits)
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| 261 | {
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| 262 | int k, w = 0, lim = bits/BITS_PER_LONG;
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| 263 |
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| 264 | for (k = 0; k < lim; k++)
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| 265 | w += hweight_long(bitmap[k]);
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| 266 |
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| 267 | if (bits % BITS_PER_LONG)
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| 268 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
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| 269 |
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| 270 | return w;
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| 271 | }
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| 272 | EXPORT_SYMBOL(__bitmap_weight);
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| 273 |
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| 274 | #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
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| 275 |
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| 276 | void bitmap_set(unsigned long *map, int start, int nr)
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| 277 | {
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| 278 | unsigned long *p = map + BIT_WORD(start);
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| 279 | const int size = start + nr;
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| 280 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
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| 281 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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| 282 |
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| 283 | while (nr - bits_to_set >= 0) {
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| 284 | *p |= mask_to_set;
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| 285 | nr -= bits_to_set;
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| 286 | bits_to_set = BITS_PER_LONG;
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| 287 | mask_to_set = ~0UL;
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| 288 | p++;
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| 289 | }
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| 290 | if (nr) {
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| 291 | mask_to_set &= BITMAP_LAST_WORD_MASK(size);
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| 292 | *p |= mask_to_set;
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| 293 | }
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| 294 | }
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| 295 | EXPORT_SYMBOL(bitmap_set);
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| 296 |
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| 297 | void bitmap_clear(unsigned long *map, int start, int nr)
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| 298 | {
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| 299 | unsigned long *p = map + BIT_WORD(start);
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| 300 | const int size = start + nr;
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| 301 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
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| 302 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
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| 303 |
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| 304 | while (nr - bits_to_clear >= 0) {
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| 305 | *p &= ~mask_to_clear;
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| 306 | nr -= bits_to_clear;
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| 307 | bits_to_clear = BITS_PER_LONG;
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| 308 | mask_to_clear = ~0UL;
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| 309 | p++;
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| 310 | }
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| 311 | if (nr) {
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| 312 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
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| 313 | *p &= ~mask_to_clear;
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| 314 | }
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| 315 | }
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| 316 | EXPORT_SYMBOL(bitmap_clear);
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| 317 |
|
| 318 | |
| 319 | * bitmap_find_next_zero_area - find a contiguous aligned zero area
|
| 320 | * @map: The address to base the search on
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| 321 | * @size: The bitmap size in bits
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| 322 | * @start: The bitnumber to start searching at
|
| 323 | * @nr: The number of zeroed bits we're looking for
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| 324 | * @align_mask: Alignment mask for zero area
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| 325 | *
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| 326 | * The @align_mask should be one less than a power of 2; the effect is that
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| 327 | * the bit offset of all zero areas this function finds is multiples of that
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| 328 | * power of 2. A @align_mask of 0 means no alignment is required.
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| 329 |
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| 330 | unsigned long bitmap_find_next_zero_area(unsigned long *map,
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| 331 | unsigned long size,
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| 332 | unsigned long start,
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| 333 | unsigned int nr,
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| 334 | unsigned long align_mask)
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| 335 | {
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| 336 | unsigned long index, end, i;
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| 337 | again:
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| 338 | index = find_next_zero_bit(map, size, start);
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| 339 |
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| 340 |
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| 341 | index = __ALIGN_MASK(index, align_mask);
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| 342 |
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| 343 | end = index + nr;
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| 344 | if (end > size)
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| 345 | return end;
|
| 346 | i = find_next_bit(map, end, index);
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| 347 | if (i < end) {
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| 348 | start = i + 1;
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| 349 | goto again;
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| 350 | }
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| 351 | return index;
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| 352 | }
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| 353 | EXPORT_SYMBOL(bitmap_find_next_zero_area);
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| 354 |
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| 355 | |
| 356 | * Bitmap printing & parsing functions: first version by Bill Irwin,
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| 357 | * second version by Paul Jackson, third by Joe Korty.
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| 358 |
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| 359 |
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| 360 | #define CHUNKSZ 32
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| 361 | #define nbits_to_hold_value(val) fls(val)
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| 362 | #define BASEDEC 10
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| 363 |
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| 364 | |
| 365 | * bitmap_scnprintf - convert bitmap to an ASCII hex string.
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| 366 | * @buf: byte buffer into which string is placed
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| 367 | * @buflen: reserved size of @buf, in bytes
|
| 368 | * @maskp: pointer to bitmap to convert
|
| 369 | * @nmaskbits: size of bitmap, in bits
|
| 370 | *
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| 371 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
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| 372 | * comma-separated sets of eight digits per set.
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| 373 |
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| 374 | int bitmap_scnprintf(char *buf, unsigned int buflen,
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| 375 | const unsigned long *maskp, int nmaskbits)
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| 376 | {
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| 377 | int i, word, bit, len = 0;
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| 378 | unsigned long val;
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| 379 | const char *sep = "";
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| 380 | int chunksz;
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| 381 | u32 chunkmask;
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| 382 |
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| 383 | chunksz = nmaskbits & (CHUNKSZ - 1);
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| 384 | if (chunksz == 0)
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| 385 | chunksz = CHUNKSZ;
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| 386 |
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| 387 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
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| 388 | for (; i >= 0; i -= CHUNKSZ) {
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| 389 | chunkmask = ((1ULL << chunksz) - 1);
|
| 390 | word = i / BITS_PER_LONG;
|
| 391 | bit = i % BITS_PER_LONG;
|
| 392 | val = (maskp[word] >> bit) & chunkmask;
|
| 393 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
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| 394 | (chunksz+3)/4, val);
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| 395 | chunksz = CHUNKSZ;
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| 396 | sep = ",";
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| 397 | }
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| 398 | return len;
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| 399 | }
|
| 400 | EXPORT_SYMBOL(bitmap_scnprintf);
|
| 401 |
|
| 402 | |
| 403 | * __bitmap_parse - convert an ASCII hex string into a bitmap.
|
| 404 | * @buf: pointer to buffer containing string.
|
| 405 | * @buflen: buffer size in bytes. If string is smaller than this
|
| 406 | * then it must be terminated with a \0.
|
| 407 | * @is_user: location of buffer, 0 indicates kernel space
|
| 408 | * @maskp: pointer to bitmap array that will contain result.
|
| 409 | * @nmaskbits: size of bitmap, in bits.
|
| 410 | *
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| 411 | * Commas group hex digits into chunks. Each chunk defines exactly 32
|
| 412 | * bits of the resultant bitmask. No chunk may specify a value larger
|
| 413 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
|
| 414 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal
|
| 415 | * characters and for grouping errors such as "1,,5", ",44", "," and "".
|
| 416 | * Leading and trailing whitespace accepted, but not embedded whitespace.
|
| 417 |
|
| 418 | int __bitmap_parse(const char *buf, unsigned int buflen,
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| 419 | int is_user, unsigned long *maskp,
|
| 420 | int nmaskbits)
|
| 421 | {
|
| 422 | int c, old_c, totaldigits, ndigits, nchunks, nbits;
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| 423 | u32 chunk;
|
| 424 | const char __user *ubuf = buf;
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| 425 |
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| 426 | bitmap_zero(maskp, nmaskbits);
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| 427 |
|
| 428 | nchunks = nbits = totaldigits = c = 0;
|
| 429 | do {
|
| 430 | chunk = ndigits = 0;
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| 431 |
|
| 432 |
|
| 433 | while (buflen) {
|
| 434 | old_c = c;
|
| 435 | if (is_user) {
|
| 436 | if (__get_user(c, ubuf++))
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| 437 | return -EFAULT;
|
| 438 | }
|
| 439 | else
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| 440 | c = *buf++;
|
| 441 | buflen--;
|
| 442 | if (isspace(c))
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| 443 | continue;
|
| 444 |
|
| 445 | |
| 446 | * If the last character was a space and the current
|
| 447 | * character isn't '\0', we've got embedded whitespace.
|
| 448 | * This is a no-no, so throw an error.
|
| 449 |
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| 450 | if (totaldigits && c && isspace(old_c))
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| 451 | return -EINVAL;
|
| 452 |
|
| 453 |
|
| 454 | if (c == '\0' || c == ',')
|
| 455 | break;
|
| 456 |
|
| 457 | if (!isxdigit(c))
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| 458 | return -EINVAL;
|
| 459 |
|
| 460 | |
| 461 | * Make sure there are at least 4 free bits in 'chunk'.
|
| 462 | * If not, this hexdigit will overflow 'chunk', so
|
| 463 | * throw an error.
|
| 464 |
|
| 465 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
|
| 466 | return -EOVERFLOW;
|
| 467 |
|
| 468 | chunk = (chunk << 4) | hex_to_bin(c);
|
| 469 | ndigits++; totaldigits++;
|
| 470 | }
|
| 471 | if (ndigits == 0)
|
| 472 | return -EINVAL;
|
| 473 | if (nchunks == 0 && chunk == 0)
|
| 474 | continue;
|
| 475 |
|
| 476 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
|
| 477 | *maskp |= chunk;
|
| 478 | nchunks++;
|
| 479 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
|
| 480 | if (nbits > nmaskbits)
|
| 481 | return -EOVERFLOW;
|
| 482 | } while (buflen && c == ',');
|
| 483 |
|
| 484 | return 0;
|
| 485 | }
|
| 486 | EXPORT_SYMBOL(__bitmap_parse);
|
| 487 |
|
| 488 | |
| 489 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
|
| 490 | *
|
| 491 | * @ubuf: pointer to user buffer containing string.
|
| 492 | * @ulen: buffer size in bytes. If string is smaller than this
|
| 493 | * then it must be terminated with a \0.
|
| 494 | * @maskp: pointer to bitmap array that will contain result.
|
| 495 | * @nmaskbits: size of bitmap, in bits.
|
| 496 | *
|
| 497 | * Wrapper for __bitmap_parse(), providing it with user buffer.
|
| 498 | *
|
| 499 | * We cannot have this as an inline function in bitmap.h because it needs
|
| 500 | * linux/uaccess.h to get the access_ok() declaration and this causes
|
| 501 | * cyclic dependencies.
|
| 502 |
|
| 503 | int bitmap_parse_user(const char __user *ubuf,
|
| 504 | unsigned int ulen, unsigned long *maskp,
|
| 505 | int nmaskbits)
|
| 506 | {
|
| 507 | if (!access_ok(VERIFY_READ, ubuf, ulen))
|
| 508 | return -EFAULT;
|
| 509 | return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits);
|
| 510 | }
|
| 511 | EXPORT_SYMBOL(bitmap_parse_user);
|
| 512 |
|
| 513 | |
| 514 | * bscnl_emit(buf, buflen, rbot, rtop, bp)
|
| 515 | *
|
| 516 | * Helper routine for bitmap_scnlistprintf(). Write decimal number
|
| 517 | * or range to buf, suppressing output past buf+buflen, with optional
|
| 518 | * comma-prefix. Return len of what would be written to buf, if it
|
| 519 | * all fit.
|
| 520 |
|
| 521 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
|
| 522 | {
|
| 523 | if (len > 0)
|
| 524 | len += scnprintf(buf + len, buflen - len, ",");
|
| 525 | if (rbot == rtop)
|
| 526 | len += scnprintf(buf + len, buflen - len, "%d", rbot);
|
| 527 | else
|
| 528 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
|
| 529 | return len;
|
| 530 | }
|
| 531 |
|
| 532 | |
| 533 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string
|
| 534 | * @buf: byte buffer into which string is placed
|
| 535 | * @buflen: reserved size of @buf, in bytes
|
| 536 | * @maskp: pointer to bitmap to convert
|
| 537 | * @nmaskbits: size of bitmap, in bits
|
| 538 | *
|
| 539 | * Output format is a comma-separated list of decimal numbers and
|
| 540 | * ranges. Consecutively set bits are shown as two hyphen-separated
|
| 541 | * decimal numbers, the smallest and largest bit numbers set in
|
| 542 | * the range. Output format is compatible with the format
|
| 543 | * accepted as input by bitmap_parselist().
|
| 544 | *
|
| 545 | * The return value is the number of characters which would be
|
| 546 | * generated for the given input, excluding the trailing '\0', as
|
| 547 | * per ISO C99.
|
| 548 |
|
| 549 | int bitmap_scnlistprintf(char *buf, unsigned int buflen,
|
| 550 | const unsigned long *maskp, int nmaskbits)
|
| 551 | {
|
| 552 | int len = 0;
|
| 553 |
|
| 554 | int cur, rbot, rtop;
|
| 555 |
|
| 556 | if (buflen == 0)
|
| 557 | return 0;
|
| 558 | buf[0] = 0;
|
| 559 |
|
| 560 | rbot = cur = find_first_bit(maskp, nmaskbits);
|
| 561 | while (cur < nmaskbits) {
|
| 562 | rtop = cur;
|
| 563 | cur = find_next_bit(maskp, nmaskbits, cur+1);
|
| 564 | if (cur >= nmaskbits || cur > rtop + 1) {
|
| 565 | len = bscnl_emit(buf, buflen, rbot, rtop, len);
|
| 566 | rbot = cur;
|
| 567 | }
|
| 568 | }
|
| 569 | return len;
|
| 570 | }
|
| 571 | EXPORT_SYMBOL(bitmap_scnlistprintf);
|
| 572 |
|
| 573 | |
| 574 | * bitmap_parselist - convert list format ASCII string to bitmap
|
| 575 | * @bp: read nul-terminated user string from this buffer
|
| 576 | * @maskp: write resulting mask here
|
| 577 | * @nmaskbits: number of bits in mask to be written
|
| 578 | *
|
| 579 | * Input format is a comma-separated list of decimal numbers and
|
| 580 | * ranges. Consecutively set bits are shown as two hyphen-separated
|
| 581 | * decimal numbers, the smallest and largest bit numbers set in
|
| 582 | * the range.
|
| 583 | *
|
| 584 | * Returns 0 on success, -errno on invalid input strings.
|
| 585 | * Error values:
|
| 586 | * %-EINVAL: second number in range smaller than first
|
| 587 | * %-EINVAL: invalid character in string
|
| 588 | * %-ERANGE: bit number specified too large for mask
|
| 589 |
|
| 590 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
|
| 591 | {
|
| 592 | unsigned a, b;
|
| 593 |
|
| 594 | bitmap_zero(maskp, nmaskbits);
|
| 595 | do {
|
| 596 | if (!isdigit(*bp))
|
| 597 | return -EINVAL;
|
| 598 | b = a = simple_strtoul(bp, (char **)&bp, BASEDEC);
|
| 599 | if (*bp == '-') {
|
| 600 | bp++;
|
| 601 | if (!isdigit(*bp))
|
| 602 | return -EINVAL;
|
| 603 | b = simple_strtoul(bp, (char **)&bp, BASEDEC);
|
| 604 | }
|
| 605 | if (!(a <= b))
|
| 606 | return -EINVAL;
|
| 607 | if (b >= nmaskbits)
|
| 608 | return -ERANGE;
|
| 609 | while (a <= b) {
|
| 610 | set_bit(a, maskp);
|
| 611 | a++;
|
| 612 | }
|
| 613 | if (*bp == ',')
|
| 614 | bp++;
|
| 615 | } while (*bp != '\0' && *bp != '\n');
|
| 616 | return 0;
|
| 617 | }
|
| 618 | EXPORT_SYMBOL(bitmap_parselist);
|
| 619 |
|
| 620 | |
| 621 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
|
| 622 | * @buf: pointer to a bitmap
|
| 623 | * @pos: a bit position in @buf (0 <= @pos < @bits)
|
| 624 | * @bits: number of valid bit positions in @buf
|
| 625 | *
|
| 626 | * Map the bit at position @pos in @buf (of length @bits) to the
|
| 627 | * ordinal of which set bit it is. If it is not set or if @pos
|
| 628 | * is not a valid bit position, map to -1.
|
| 629 | *
|
| 630 | * If for example, just bits 4 through 7 are set in @buf, then @pos
|
| 631 | * values 4 through 7 will get mapped to 0 through 3, respectively,
|
| 632 | * and other @pos values will get mapped to 0. When @pos value 7
|
| 633 | * gets mapped to (returns) @ord value 3 in this example, that means
|
| 634 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
|
| 635 | *
|
| 636 | * The bit positions 0 through @bits are valid positions in @buf.
|
| 637 |
|
| 638 | static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
|
| 639 | {
|
| 640 | int i, ord;
|
| 641 |
|
| 642 | if (pos < 0 || pos >= bits || !test_bit(pos, buf))
|
| 643 | return -1;
|
| 644 |
|
| 645 | i = find_first_bit(buf, bits);
|
| 646 | ord = 0;
|
| 647 | while (i < pos) {
|
| 648 | i = find_next_bit(buf, bits, i + 1);
|
| 649 | ord++;
|
| 650 | }
|
| 651 | BUG_ON(i != pos);
|
| 652 |
|
| 653 | return ord;
|
| 654 | }
|
| 655 |
|
| 656 | |
| 657 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap
|
| 658 | * @buf: pointer to bitmap
|
| 659 | * @ord: ordinal bit position (n-th set bit, n >= 0)
|
| 660 | * @bits: number of valid bit positions in @buf
|
| 661 | *
|
| 662 | * Map the ordinal offset of bit @ord in @buf to its position in @buf.
|
| 663 | * Value of @ord should be in range 0 <= @ord < weight(buf), else
|
| 664 | * results are undefined.
|
| 665 | *
|
| 666 | * If for example, just bits 4 through 7 are set in @buf, then @ord
|
| 667 | * values 0 through 3 will get mapped to 4 through 7, respectively,
|
| 668 | * and all other @ord values return undefined values. When @ord value 3
|
| 669 | * gets mapped to (returns) @pos value 7 in this example, that means
|
| 670 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
|
| 671 | *
|
| 672 | * The bit positions 0 through @bits are valid positions in @buf.
|
| 673 |
|
| 674 | static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
|
| 675 | {
|
| 676 | int pos = 0;
|
| 677 |
|
| 678 | if (ord >= 0 && ord < bits) {
|
| 679 | int i;
|
| 680 |
|
| 681 | for (i = find_first_bit(buf, bits);
|
| 682 | i < bits && ord > 0;
|
| 683 | i = find_next_bit(buf, bits, i + 1))
|
| 684 | ord--;
|
| 685 | if (i < bits && ord == 0)
|
| 686 | pos = i;
|
| 687 | }
|
| 688 |
|
| 689 | return pos;
|
| 690 | }
|
| 691 |
|
| 692 | |
| 693 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
|
| 694 | * @dst: remapped result
|
| 695 | * @src: subset to be remapped
|
| 696 | * @old: defines domain of map
|
| 697 | * @new: defines range of map
|
| 698 | * @bits: number of bits in each of these bitmaps
|
| 699 | *
|
| 700 | * Let @old and @new define a mapping of bit positions, such that
|
| 701 | * whatever position is held by the n-th set bit in @old is mapped
|
| 702 | * to the n-th set bit in @new. In the more general case, allowing
|
| 703 | * for the possibility that the weight 'w' of @new is less than the
|
| 704 | * weight of @old, map the position of the n-th set bit in @old to
|
| 705 | * the position of the m-th set bit in @new, where m == n % w.
|
| 706 | *
|
| 707 | * If either of the @old and @new bitmaps are empty, or if @src and
|
| 708 | * @dst point to the same location, then this routine copies @src
|
| 709 | * to @dst.
|
| 710 | *
|
| 711 | * The positions of unset bits in @old are mapped to themselves
|
| 712 | * (the identify map).
|
| 713 | *
|
| 714 | * Apply the above specified mapping to @src, placing the result in
|
| 715 | * @dst, clearing any bits previously set in @dst.
|
| 716 | *
|
| 717 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 718 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 719 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 720 | * bit positions unchanged. So if say @src comes into this routine
|
| 721 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
|
| 722 | * 13 and 15 set.
|
| 723 |
|
| 724 | void bitmap_remap(unsigned long *dst, const unsigned long *src,
|
| 725 | const unsigned long *old, const unsigned long *new,
|
| 726 | int bits)
|
| 727 | {
|
| 728 | int oldbit, w;
|
| 729 |
|
| 730 | if (dst == src)
|
| 731 | return;
|
| 732 | bitmap_zero(dst, bits);
|
| 733 |
|
| 734 | w = bitmap_weight(new, bits);
|
| 735 | for_each_set_bit(oldbit, src, bits) {
|
| 736 | int n = bitmap_pos_to_ord(old, oldbit, bits);
|
| 737 |
|
| 738 | if (n < 0 || w == 0)
|
| 739 | set_bit(oldbit, dst);
|
| 740 | else
|
| 741 | set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
|
| 742 | }
|
| 743 | }
|
| 744 | EXPORT_SYMBOL(bitmap_remap);
|
| 745 |
|
| 746 | |
| 747 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
|
| 748 | * @oldbit: bit position to be mapped
|
| 749 | * @old: defines domain of map
|
| 750 | * @new: defines range of map
|
| 751 | * @bits: number of bits in each of these bitmaps
|
| 752 | *
|
| 753 | * Let @old and @new define a mapping of bit positions, such that
|
| 754 | * whatever position is held by the n-th set bit in @old is mapped
|
| 755 | * to the n-th set bit in @new. In the more general case, allowing
|
| 756 | * for the possibility that the weight 'w' of @new is less than the
|
| 757 | * weight of @old, map the position of the n-th set bit in @old to
|
| 758 | * the position of the m-th set bit in @new, where m == n % w.
|
| 759 | *
|
| 760 | * The positions of unset bits in @old are mapped to themselves
|
| 761 | * (the identify map).
|
| 762 | *
|
| 763 | * Apply the above specified mapping to bit position @oldbit, returning
|
| 764 | * the new bit position.
|
| 765 | *
|
| 766 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 767 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 768 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 769 | * bit positions unchanged. So if say @oldbit is 5, then this routine
|
| 770 | * returns 13.
|
| 771 |
|
| 772 | int bitmap_bitremap(int oldbit, const unsigned long *old,
|
| 773 | const unsigned long *new, int bits)
|
| 774 | {
|
| 775 | int w = bitmap_weight(new, bits);
|
| 776 | int n = bitmap_pos_to_ord(old, oldbit, bits);
|
| 777 | if (n < 0 || w == 0)
|
| 778 | return oldbit;
|
| 779 | else
|
| 780 | return bitmap_ord_to_pos(new, n % w, bits);
|
| 781 | }
|
| 782 | EXPORT_SYMBOL(bitmap_bitremap);
|
| 783 |
|
| 784 | |
| 785 | * bitmap_onto - translate one bitmap relative to another
|
| 786 | * @dst: resulting translated bitmap
|
| 787 | * @orig: original untranslated bitmap
|
| 788 | * @relmap: bitmap relative to which translated
|
| 789 | * @bits: number of bits in each of these bitmaps
|
| 790 | *
|
| 791 | * Set the n-th bit of @dst iff there exists some m such that the
|
| 792 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and
|
| 793 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
|
| 794 | * (If you understood the previous sentence the first time your
|
| 795 | * read it, you're overqualified for your current job.)
|
| 796 | *
|
| 797 | * In other words, @orig is mapped onto (surjectively) @dst,
|
| 798 | * using the the map { <n, m> | the n-th bit of @relmap is the
|
| 799 | * m-th set bit of @relmap }.
|
| 800 | *
|
| 801 | * Any set bits in @orig above bit number W, where W is the
|
| 802 | * weight of (number of set bits in) @relmap are mapped nowhere.
|
| 803 | * In particular, if for all bits m set in @orig, m >= W, then
|
| 804 | * @dst will end up empty. In situations where the possibility
|
| 805 | * of such an empty result is not desired, one way to avoid it is
|
| 806 | * to use the bitmap_fold() operator, below, to first fold the
|
| 807 | * @orig bitmap over itself so that all its set bits x are in the
|
| 808 | * range 0 <= x < W. The bitmap_fold() operator does this by
|
| 809 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
|
| 810 | *
|
| 811 | * Example [1] for bitmap_onto():
|
| 812 | * Let's say @relmap has bits 30-39 set, and @orig has bits
|
| 813 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
|
| 814 | * @dst will have bits 31, 33, 35, 37 and 39 set.
|
| 815 | *
|
| 816 | * When bit 0 is set in @orig, it means turn on the bit in
|
| 817 | * @dst corresponding to whatever is the first bit (if any)
|
| 818 | * that is turned on in @relmap. Since bit 0 was off in the
|
| 819 | * above example, we leave off that bit (bit 30) in @dst.
|
| 820 | *
|
| 821 | * When bit 1 is set in @orig (as in the above example), it
|
| 822 | * means turn on the bit in @dst corresponding to whatever
|
| 823 | * is the second bit that is turned on in @relmap. The second
|
| 824 | * bit in @relmap that was turned on in the above example was
|
| 825 | * bit 31, so we turned on bit 31 in @dst.
|
| 826 | *
|
| 827 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
|
| 828 | * because they were the 4th, 6th, 8th and 10th set bits
|
| 829 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of
|
| 830 | * @orig (i.e. bits 3, 5, 7 and 9) were also set.
|
| 831 | *
|
| 832 | * When bit 11 is set in @orig, it means turn on the bit in
|
| 833 | * @dst corresponding to whatever is the twelfth bit that is
|
| 834 | * turned on in @relmap. In the above example, there were
|
| 835 | * only ten bits turned on in @relmap (30..39), so that bit
|
| 836 | * 11 was set in @orig had no affect on @dst.
|
| 837 | *
|
| 838 | * Example [2] for bitmap_fold() + bitmap_onto():
|
| 839 | * Let's say @relmap has these ten bits set:
|
| 840 | * 40 41 42 43 45 48 53 61 74 95
|
| 841 | * (for the curious, that's 40 plus the first ten terms of the
|
| 842 | * Fibonacci sequence.)
|
| 843 | *
|
| 844 | * Further lets say we use the following code, invoking
|
| 845 | * bitmap_fold() then bitmap_onto, as suggested above to
|
| 846 | * avoid the possitility of an empty @dst result:
|
| 847 | *
|
| 848 | * unsigned long *tmp; // a temporary bitmap's bits
|
| 849 | *
|
| 850 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
|
| 851 | * bitmap_onto(dst, tmp, relmap, bits);
|
| 852 | *
|
| 853 | * Then this table shows what various values of @dst would be, for
|
| 854 | * various @orig's. I list the zero-based positions of each set bit.
|
| 855 | * The tmp column shows the intermediate result, as computed by
|
| 856 | * using bitmap_fold() to fold the @orig bitmap modulo ten
|
| 857 | * (the weight of @relmap).
|
| 858 | *
|
| 859 | * @orig tmp @dst
|
| 860 | * 0 0 40
|
| 861 | * 1 1 41
|
| 862 | * 9 9 95
|
| 863 | * 10 0 40 (*)
|
| 864 | * 1 3 5 7 1 3 5 7 41 43 48 61
|
| 865 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
|
| 866 | * 0 9 18 27 0 9 8 7 40 61 74 95
|
| 867 | * 0 10 20 30 0 40
|
| 868 | * 0 11 22 33 0 1 2 3 40 41 42 43
|
| 869 | * 0 12 24 36 0 2 4 6 40 42 45 53
|
| 870 | * 78 102 211 1 2 8 41 42 74 (*)
|
| 871 | *
|
| 872 | * (*) For these marked lines, if we hadn't first done bitmap_fold()
|
| 873 | * into tmp, then the @dst result would have been empty.
|
| 874 | *
|
| 875 | * If either of @orig or @relmap is empty (no set bits), then @dst
|
| 876 | * will be returned empty.
|
| 877 | *
|
| 878 | * If (as explained above) the only set bits in @orig are in positions
|
| 879 | * m where m >= W, (where W is the weight of @relmap) then @dst will
|
| 880 | * once again be returned empty.
|
| 881 | *
|
| 882 | * All bits in @dst not set by the above rule are cleared.
|
| 883 |
|
| 884 | void bitmap_onto(unsigned long *dst, const unsigned long *orig,
|
| 885 | const unsigned long *relmap, int bits)
|
| 886 | {
|
| 887 | int n, m;
|
| 888 |
|
| 889 | if (dst == orig)
|
| 890 | return;
|
| 891 | bitmap_zero(dst, bits);
|
| 892 |
|
| 893 | |
| 894 | * The following code is a more efficient, but less
|
| 895 | * obvious, equivalent to the loop:
|
| 896 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
|
| 897 | * n = bitmap_ord_to_pos(orig, m, bits);
|
| 898 | * if (test_bit(m, orig))
|
| 899 | * set_bit(n, dst);
|
| 900 | * }
|
| 901 |
|
| 902 |
|
| 903 | m = 0;
|
| 904 | for_each_set_bit(n, relmap, bits) {
|
| 905 |
|
| 906 | if (test_bit(m, orig))
|
| 907 | set_bit(n, dst);
|
| 908 | m++;
|
| 909 | }
|
| 910 | }
|
| 911 | EXPORT_SYMBOL(bitmap_onto);
|
| 912 |
|
| 913 | |
| 914 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size
|
| 915 | * @dst: resulting smaller bitmap
|
| 916 | * @orig: original larger bitmap
|
| 917 | * @sz: specified size
|
| 918 | * @bits: number of bits in each of these bitmaps
|
| 919 | *
|
| 920 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
|
| 921 | * Clear all other bits in @dst. See further the comment and
|
| 922 | * Example [2] for bitmap_onto() for why and how to use this.
|
| 923 |
|
| 924 | void bitmap_fold(unsigned long *dst, const unsigned long *orig,
|
| 925 | int sz, int bits)
|
| 926 | {
|
| 927 | int oldbit;
|
| 928 |
|
| 929 | if (dst == orig)
|
| 930 | return;
|
| 931 | bitmap_zero(dst, bits);
|
| 932 |
|
| 933 | for_each_set_bit(oldbit, orig, bits)
|
| 934 | set_bit(oldbit % sz, dst);
|
| 935 | }
|
| 936 | EXPORT_SYMBOL(bitmap_fold);
|
| 937 |
|
| 938 | |
| 939 | * Common code for bitmap_*_region() routines.
|
| 940 | * bitmap: array of unsigned longs corresponding to the bitmap
|
| 941 | * pos: the beginning of the region
|
| 942 | * order: region size (log base 2 of number of bits)
|
| 943 | * reg_op: operation(s) to perform on that region of bitmap
|
| 944 | *
|
| 945 | * Can set, verify and/or release a region of bits in a bitmap,
|
| 946 | * depending on which combination of REG_OP_* flag bits is set.
|
| 947 | *
|
| 948 | * A region of a bitmap is a sequence of bits in the bitmap, of
|
| 949 | * some size '1 << order' (a power of two), aligned to that same
|
| 950 | * '1 << order' power of two.
|
| 951 | *
|
| 952 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
|
| 953 | * Returns 0 in all other cases and reg_ops.
|
| 954 |
|
| 955 |
|
| 956 | enum {
|
| 957 | REG_OP_ISFREE,
|
| 958 | REG_OP_ALLOC,
|
| 959 | REG_OP_RELEASE,
|
| 960 | };
|
| 961 |
|
| 962 | static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
|
| 963 | {
|
| 964 | int nbits_reg;
|
| 965 | int index;
|
| 966 | int offset;
|
| 967 | int nlongs_reg;
|
| 968 | int nbitsinlong;
|
| 969 | unsigned long mask;
|
| 970 | int i;
|
| 971 | int ret = 0;
|
| 972 |
|
| 973 | |
| 974 | * Either nlongs_reg == 1 (for small orders that fit in one long)
|
| 975 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
|
| 976 |
|
| 977 | nbits_reg = 1 << order;
|
| 978 | index = pos / BITS_PER_LONG;
|
| 979 | offset = pos - (index * BITS_PER_LONG);
|
| 980 | nlongs_reg = BITS_TO_LONGS(nbits_reg);
|
| 981 | nbitsinlong = min(nbits_reg, BITS_PER_LONG);
|
| 982 |
|
| 983 | |
| 984 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that
|
| 985 | * overflows if nbitsinlong == BITS_PER_LONG.
|
| 986 |
|
| 987 | mask = (1UL << (nbitsinlong - 1));
|
| 988 | mask += mask - 1;
|
| 989 | mask <<= offset;
|
| 990 |
|
| 991 | switch (reg_op) {
|
| 992 | case REG_OP_ISFREE:
|
| 993 | for (i = 0; i < nlongs_reg; i++) {
|
| 994 | if (bitmap[index + i] & mask)
|
| 995 | goto done;
|
| 996 | }
|
| 997 | ret = 1;
|
| 998 | break;
|
| 999 |
|
| 1000 | case REG_OP_ALLOC:
|
| 1001 | for (i = 0; i < nlongs_reg; i++)
|
| 1002 | bitmap[index + i] |= mask;
|
| 1003 | break;
|
| 1004 |
|
| 1005 | case REG_OP_RELEASE:
|
| 1006 | for (i = 0; i < nlongs_reg; i++)
|
| 1007 | bitmap[index + i] &= ~mask;
|
| 1008 | break;
|
| 1009 | }
|
| 1010 | done:
|
| 1011 | return ret;
|
| 1012 | }
|
| 1013 |
|
| 1014 | |
| 1015 | * bitmap_find_free_region - find a contiguous aligned mem region
|
| 1016 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1017 | * @bits: number of bits in the bitmap
|
| 1018 | * @order: region size (log base 2 of number of bits) to find
|
| 1019 | *
|
| 1020 | * Find a region of free (zero) bits in a @bitmap of @bits bits and
|
| 1021 | * allocate them (set them to one). Only consider regions of length
|
| 1022 | * a power (@order) of two, aligned to that power of two, which
|
| 1023 | * makes the search algorithm much faster.
|
| 1024 | *
|
| 1025 | * Return the bit offset in bitmap of the allocated region,
|
| 1026 | * or -errno on failure.
|
| 1027 |
|
| 1028 | int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
|
| 1029 | {
|
| 1030 | int pos, end;
|
| 1031 |
|
| 1032 | for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
|
| 1033 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1034 | continue;
|
| 1035 | __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1036 | return pos;
|
| 1037 | }
|
| 1038 | return -ENOMEM;
|
| 1039 | }
|
| 1040 | EXPORT_SYMBOL(bitmap_find_free_region);
|
| 1041 |
|
| 1042 | |
| 1043 | * bitmap_release_region - release allocated bitmap region
|
| 1044 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1045 | * @pos: beginning of bit region to release
|
| 1046 | * @order: region size (log base 2 of number of bits) to release
|
| 1047 | *
|
| 1048 | * This is the complement to __bitmap_find_free_region() and releases
|
| 1049 | * the found region (by clearing it in the bitmap).
|
| 1050 | *
|
| 1051 | * No return value.
|
| 1052 |
|
| 1053 | void bitmap_release_region(unsigned long *bitmap, int pos, int order)
|
| 1054 | {
|
| 1055 | __reg_op(bitmap, pos, order, REG_OP_RELEASE);
|
| 1056 | }
|
| 1057 | EXPORT_SYMBOL(bitmap_release_region);
|
| 1058 |
|
| 1059 | |
| 1060 | * bitmap_allocate_region - allocate bitmap region
|
| 1061 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1062 | * @pos: beginning of bit region to allocate
|
| 1063 | * @order: region size (log base 2 of number of bits) to allocate
|
| 1064 | *
|
| 1065 | * Allocate (set bits in) a specified region of a bitmap.
|
| 1066 | *
|
| 1067 | * Return 0 on success, or %-EBUSY if specified region wasn't
|
| 1068 | * free (not all bits were zero).
|
| 1069 |
|
| 1070 | int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
|
| 1071 | {
|
| 1072 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1073 | return -EBUSY;
|
| 1074 | __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1075 | return 0;
|
| 1076 | }
|
| 1077 | EXPORT_SYMBOL(bitmap_allocate_region);
|
| 1078 |
|
| 1079 | |
| 1080 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
|
| 1081 | * @dst: destination buffer
|
| 1082 | * @src: bitmap to copy
|
| 1083 | * @nbits: number of bits in the bitmap
|
| 1084 | *
|
| 1085 | * Require nbits % BITS_PER_LONG == 0.
|
| 1086 |
|
| 1087 | void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
|
| 1088 | {
|
| 1089 | unsigned long *d = dst;
|
| 1090 | int i;
|
| 1091 |
|
| 1092 | for (i = 0; i < nbits/BITS_PER_LONG; i++) {
|
| 1093 | if (BITS_PER_LONG == 64)
|
| 1094 | d[i] = cpu_to_le64(src[i]);
|
| 1095 | else
|
| 1096 | d[i] = cpu_to_le32(src[i]);
|
| 1097 | }
|
| 1098 | }
|
| 1099 | EXPORT_SYMBOL(bitmap_copy_le);
|