| 1 | |
| 2 | * lib/bitmap.c
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| 3 | * Helper functions for bitmap.h.
|
| 4 | *
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| 5 | * This source code is licensed under the GNU General Public License,
|
| 6 | * Version 2. See the file COPYING for more details.
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| 7 |
|
| 8 | #include <linux/export.h>
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| 9 | #include <linux/thread_info.h>
|
| 10 | #include <linux/ctype.h>
|
| 11 | #include <linux/errno.h>
|
| 12 | #include <linux/bitmap.h>
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| 13 | #include <linux/bitops.h>
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| 14 | #include <linux/bug.h>
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| 15 | #include <linux/kernel.h>
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| 16 | #include <linux/mm.h>
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| 17 | #include <linux/slab.h>
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| 18 | #include <linux/string.h>
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| 19 | #include <linux/uaccess.h>
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| 20 |
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| 21 | #include <asm/page.h>
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| 22 |
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| 23 | |
| 24 | * DOC: bitmap introduction
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| 25 | *
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| 26 | * bitmaps provide an array of bits, implemented using an an
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| 27 | * array of unsigned longs. The number of valid bits in a
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| 28 | * given bitmap does _not_ need to be an exact multiple of
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| 29 | * BITS_PER_LONG.
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| 30 | *
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| 31 | * The possible unused bits in the last, partially used word
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| 32 | * of a bitmap are 'don't care'. The implementation makes
|
| 33 | * no particular effort to keep them zero. It ensures that
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| 34 | * their value will not affect the results of any operation.
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| 35 | * The bitmap operations that return Boolean (bitmap_empty,
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| 36 | * for example) or scalar (bitmap_weight, for example) results
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| 37 | * carefully filter out these unused bits from impacting their
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| 38 | * results.
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| 39 | *
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| 40 | * The byte ordering of bitmaps is more natural on little
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| 41 | * endian architectures. See the big-endian headers
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| 42 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
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| 43 | * for the best explanations of this ordering.
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| 44 |
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| 45 |
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| 46 | int __bitmap_equal(const unsigned long *bitmap1,
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| 47 | const unsigned long *bitmap2, unsigned int bits)
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| 48 | {
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| 49 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 50 | for (k = 0; k < lim; ++k)
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| 51 | if (bitmap1[k] != bitmap2[k])
|
| 52 | return 0;
|
| 53 |
|
| 54 | if (bits % BITS_PER_LONG)
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| 55 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 56 | return 0;
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| 57 |
|
| 58 | return 1;
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| 59 | }
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| 60 | EXPORT_SYMBOL(__bitmap_equal);
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| 61 |
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| 62 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
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| 63 | {
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| 64 | unsigned int k, lim = BITS_TO_LONGS(bits);
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| 65 | for (k = 0; k < lim; ++k)
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| 66 | dst[k] = ~src[k];
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| 67 | }
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| 68 | EXPORT_SYMBOL(__bitmap_complement);
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| 69 |
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| 70 | |
| 71 | * __bitmap_shift_right - logical right shift of the bits in a bitmap
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| 72 | * @dst : destination bitmap
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| 73 | * @src : source bitmap
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| 74 | * @shift : shift by this many bits
|
| 75 | * @nbits : bitmap size, in bits
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| 76 | *
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| 77 | * Shifting right (dividing) means moving bits in the MS -> LS bit
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| 78 | * direction. Zeros are fed into the vacated MS positions and the
|
| 79 | * LS bits shifted off the bottom are lost.
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| 80 |
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| 81 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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| 82 | unsigned shift, unsigned nbits)
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| 83 | {
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| 84 | unsigned k, lim = BITS_TO_LONGS(nbits);
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| 85 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 86 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
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| 87 | for (k = 0; off + k < lim; ++k) {
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| 88 | unsigned long upper, lower;
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| 89 |
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| 90 | |
| 91 | * If shift is not word aligned, take lower rem bits of
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| 92 | * word above and make them the top rem bits of result.
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| 93 |
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| 94 | if (!rem || off + k + 1 >= lim)
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| 95 | upper = 0;
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| 96 | else {
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| 97 | upper = src[off + k + 1];
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| 98 | if (off + k + 1 == lim - 1)
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| 99 | upper &= mask;
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| 100 | upper <<= (BITS_PER_LONG - rem);
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| 101 | }
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| 102 | lower = src[off + k];
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| 103 | if (off + k == lim - 1)
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| 104 | lower &= mask;
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| 105 | lower >>= rem;
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| 106 | dst[k] = lower | upper;
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| 107 | }
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| 108 | if (off)
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| 109 | memset(&dst[lim - off], 0, off*sizeof(unsigned long));
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| 110 | }
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| 111 | EXPORT_SYMBOL(__bitmap_shift_right);
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| 112 |
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| 113 |
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| 114 | |
| 115 | * __bitmap_shift_left - logical left shift of the bits in a bitmap
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| 116 | * @dst : destination bitmap
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| 117 | * @src : source bitmap
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| 118 | * @shift : shift by this many bits
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| 119 | * @nbits : bitmap size, in bits
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| 120 | *
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| 121 | * Shifting left (multiplying) means moving bits in the LS -> MS
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| 122 | * direction. Zeros are fed into the vacated LS bit positions
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| 123 | * and those MS bits shifted off the top are lost.
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| 124 |
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| 125 |
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| 126 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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| 127 | unsigned int shift, unsigned int nbits)
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| 128 | {
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| 129 | int k;
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| 130 | unsigned int lim = BITS_TO_LONGS(nbits);
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| 131 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 132 | for (k = lim - off - 1; k >= 0; --k) {
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| 133 | unsigned long upper, lower;
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| 134 |
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| 135 | |
| 136 | * If shift is not word aligned, take upper rem bits of
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| 137 | * word below and make them the bottom rem bits of result.
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| 138 |
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| 139 | if (rem && k > 0)
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| 140 | lower = src[k - 1] >> (BITS_PER_LONG - rem);
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| 141 | else
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| 142 | lower = 0;
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| 143 | upper = src[k] << rem;
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| 144 | dst[k + off] = lower | upper;
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| 145 | }
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| 146 | if (off)
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| 147 | memset(dst, 0, off*sizeof(unsigned long));
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| 148 | }
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| 149 | EXPORT_SYMBOL(__bitmap_shift_left);
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| 150 |
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| 151 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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| 152 | const unsigned long *bitmap2, unsigned int bits)
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| 153 | {
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| 154 | unsigned int k;
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| 155 | unsigned int lim = bits/BITS_PER_LONG;
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| 156 | unsigned long result = 0;
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| 157 |
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| 158 | for (k = 0; k < lim; k++)
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| 159 | result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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| 160 | if (bits % BITS_PER_LONG)
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| 161 | result |= (dst[k] = bitmap1[k] & bitmap2[k] &
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| 162 | BITMAP_LAST_WORD_MASK(bits));
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| 163 | return result != 0;
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| 164 | }
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| 165 | EXPORT_SYMBOL(__bitmap_and);
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| 166 |
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| 167 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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| 168 | const unsigned long *bitmap2, unsigned int bits)
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| 169 | {
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| 170 | unsigned int k;
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| 171 | unsigned int nr = BITS_TO_LONGS(bits);
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| 172 |
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| 173 | for (k = 0; k < nr; k++)
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| 174 | dst[k] = bitmap1[k] | bitmap2[k];
|
| 175 | }
|
| 176 | EXPORT_SYMBOL(__bitmap_or);
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| 177 |
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| 178 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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| 179 | const unsigned long *bitmap2, unsigned int bits)
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| 180 | {
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| 181 | unsigned int k;
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| 182 | unsigned int nr = BITS_TO_LONGS(bits);
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| 183 |
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| 184 | for (k = 0; k < nr; k++)
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| 185 | dst[k] = bitmap1[k] ^ bitmap2[k];
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| 186 | }
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| 187 | EXPORT_SYMBOL(__bitmap_xor);
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| 188 |
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| 189 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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| 190 | const unsigned long *bitmap2, unsigned int bits)
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| 191 | {
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| 192 | unsigned int k;
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| 193 | unsigned int lim = bits/BITS_PER_LONG;
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| 194 | unsigned long result = 0;
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| 195 |
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| 196 | for (k = 0; k < lim; k++)
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| 197 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
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| 198 | if (bits % BITS_PER_LONG)
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| 199 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
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| 200 | BITMAP_LAST_WORD_MASK(bits));
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| 201 | return result != 0;
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| 202 | }
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| 203 | EXPORT_SYMBOL(__bitmap_andnot);
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| 204 |
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| 205 | int __bitmap_intersects(const unsigned long *bitmap1,
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| 206 | const unsigned long *bitmap2, unsigned int bits)
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| 207 | {
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| 208 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 209 | for (k = 0; k < lim; ++k)
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| 210 | if (bitmap1[k] & bitmap2[k])
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| 211 | return 1;
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| 212 |
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| 213 | if (bits % BITS_PER_LONG)
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| 214 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 215 | return 1;
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| 216 | return 0;
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| 217 | }
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| 218 | EXPORT_SYMBOL(__bitmap_intersects);
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| 219 |
|
| 220 | int __bitmap_subset(const unsigned long *bitmap1,
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| 221 | const unsigned long *bitmap2, unsigned int bits)
|
| 222 | {
|
| 223 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 224 | for (k = 0; k < lim; ++k)
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| 225 | if (bitmap1[k] & ~bitmap2[k])
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| 226 | return 0;
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| 227 |
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| 228 | if (bits % BITS_PER_LONG)
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| 229 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 230 | return 0;
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| 231 | return 1;
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| 232 | }
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| 233 | EXPORT_SYMBOL(__bitmap_subset);
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| 234 |
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| 235 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
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| 236 | {
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| 237 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 238 | int w = 0;
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| 239 |
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| 240 | for (k = 0; k < lim; k++)
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| 241 | w += hweight_long(bitmap[k]);
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| 242 |
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| 243 | if (bits % BITS_PER_LONG)
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| 244 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
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| 245 |
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| 246 | return w;
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| 247 | }
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| 248 | EXPORT_SYMBOL(__bitmap_weight);
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| 249 |
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| 250 | void __bitmap_set(unsigned long *map, unsigned int start, int len)
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| 251 | {
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| 252 | unsigned long *p = map + BIT_WORD(start);
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| 253 | const unsigned int size = start + len;
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| 254 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
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| 255 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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| 256 |
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| 257 | while (len - bits_to_set >= 0) {
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| 258 | *p |= mask_to_set;
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| 259 | len -= bits_to_set;
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| 260 | bits_to_set = BITS_PER_LONG;
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| 261 | mask_to_set = ~0UL;
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| 262 | p++;
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| 263 | }
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| 264 | if (len) {
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| 265 | mask_to_set &= BITMAP_LAST_WORD_MASK(size);
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| 266 | *p |= mask_to_set;
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| 267 | }
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| 268 | }
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| 269 | EXPORT_SYMBOL(__bitmap_set);
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| 270 |
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| 271 | void __bitmap_clear(unsigned long *map, unsigned int start, int len)
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| 272 | {
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| 273 | unsigned long *p = map + BIT_WORD(start);
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| 274 | const unsigned int size = start + len;
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| 275 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
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| 276 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
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| 277 |
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| 278 | while (len - bits_to_clear >= 0) {
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| 279 | *p &= ~mask_to_clear;
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| 280 | len -= bits_to_clear;
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| 281 | bits_to_clear = BITS_PER_LONG;
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| 282 | mask_to_clear = ~0UL;
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| 283 | p++;
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| 284 | }
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| 285 | if (len) {
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| 286 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
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| 287 | *p &= ~mask_to_clear;
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| 288 | }
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| 289 | }
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| 290 | EXPORT_SYMBOL(__bitmap_clear);
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| 291 |
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| 292 | |
| 293 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
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| 294 | * @map: The address to base the search on
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| 295 | * @size: The bitmap size in bits
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| 296 | * @start: The bitnumber to start searching at
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| 297 | * @nr: The number of zeroed bits we're looking for
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| 298 | * @align_mask: Alignment mask for zero area
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| 299 | * @align_offset: Alignment offset for zero area.
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| 300 | *
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| 301 | * The @align_mask should be one less than a power of 2; the effect is that
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| 302 | * the bit offset of all zero areas this function finds plus @align_offset
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| 303 | * is multiple of that power of 2.
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| 304 |
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| 305 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
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| 306 | unsigned long size,
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| 307 | unsigned long start,
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| 308 | unsigned int nr,
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| 309 | unsigned long align_mask,
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| 310 | unsigned long align_offset)
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| 311 | {
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| 312 | unsigned long index, end, i;
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| 313 | again:
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| 314 | index = find_next_zero_bit(map, size, start);
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| 315 |
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| 316 |
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| 317 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
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| 318 |
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| 319 | end = index + nr;
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| 320 | if (end > size)
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| 321 | return end;
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| 322 | i = find_next_bit(map, end, index);
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| 323 | if (i < end) {
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| 324 | start = i + 1;
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| 325 | goto again;
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| 326 | }
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| 327 | return index;
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| 328 | }
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| 329 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
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| 330 |
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| 331 | |
| 332 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
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| 333 | * second version by Paul Jackson, third by Joe Korty.
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| 334 |
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| 335 |
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| 336 | #define CHUNKSZ 32
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| 337 | #define nbits_to_hold_value(val) fls(val)
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| 338 | #define BASEDEC 10
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| 339 |
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| 340 | |
| 341 | * __bitmap_parse - convert an ASCII hex string into a bitmap.
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| 342 | * @buf: pointer to buffer containing string.
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| 343 | * @buflen: buffer size in bytes. If string is smaller than this
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| 344 | * then it must be terminated with a \0.
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| 345 | * @is_user: location of buffer, 0 indicates kernel space
|
| 346 | * @maskp: pointer to bitmap array that will contain result.
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| 347 | * @nmaskbits: size of bitmap, in bits.
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| 348 | *
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| 349 | * Commas group hex digits into chunks. Each chunk defines exactly 32
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| 350 | * bits of the resultant bitmask. No chunk may specify a value larger
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| 351 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
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| 352 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal
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| 353 | * characters and for grouping errors such as "1,,5", ",44", "," and "".
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| 354 | * Leading and trailing whitespace accepted, but not embedded whitespace.
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| 355 |
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| 356 | int __bitmap_parse(const char *buf, unsigned int buflen,
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| 357 | int is_user, unsigned long *maskp,
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| 358 | int nmaskbits)
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| 359 | {
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| 360 | int c, old_c, totaldigits, ndigits, nchunks, nbits;
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| 361 | u32 chunk;
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| 362 | const char __user __force *ubuf = (const char __user __force *)buf;
|
| 363 |
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| 364 | bitmap_zero(maskp, nmaskbits);
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| 365 |
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| 366 | nchunks = nbits = totaldigits = c = 0;
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| 367 | do {
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| 368 | chunk = 0;
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| 369 | ndigits = totaldigits;
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| 370 |
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| 371 |
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| 372 | while (buflen) {
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| 373 | old_c = c;
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| 374 | if (is_user) {
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| 375 | if (__get_user(c, ubuf++))
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| 376 | return -EFAULT;
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| 377 | }
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| 378 | else
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| 379 | c = *buf++;
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| 380 | buflen--;
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| 381 | if (isspace(c))
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| 382 | continue;
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| 383 |
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| 384 | |
| 385 | * If the last character was a space and the current
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| 386 | * character isn't '\0', we've got embedded whitespace.
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| 387 | * This is a no-no, so throw an error.
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| 388 |
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| 389 | if (totaldigits && c && isspace(old_c))
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| 390 | return -EINVAL;
|
| 391 |
|
| 392 |
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| 393 | if (c == '\0' || c == ',')
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| 394 | break;
|
| 395 |
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| 396 | if (!isxdigit(c))
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| 397 | return -EINVAL;
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| 398 |
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| 399 | |
| 400 | * Make sure there are at least 4 free bits in 'chunk'.
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| 401 | * If not, this hexdigit will overflow 'chunk', so
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| 402 | * throw an error.
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| 403 |
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| 404 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
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| 405 | return -EOVERFLOW;
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| 406 |
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| 407 | chunk = (chunk << 4) | hex_to_bin(c);
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| 408 | totaldigits++;
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| 409 | }
|
| 410 | if (ndigits == totaldigits)
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| 411 | return -EINVAL;
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| 412 | if (nchunks == 0 && chunk == 0)
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| 413 | continue;
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| 414 |
|
| 415 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
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| 416 | *maskp |= chunk;
|
| 417 | nchunks++;
|
| 418 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
|
| 419 | if (nbits > nmaskbits)
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| 420 | return -EOVERFLOW;
|
| 421 | } while (buflen && c == ',');
|
| 422 |
|
| 423 | return 0;
|
| 424 | }
|
| 425 | EXPORT_SYMBOL(__bitmap_parse);
|
| 426 |
|
| 427 | |
| 428 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
|
| 429 | *
|
| 430 | * @ubuf: pointer to user buffer containing string.
|
| 431 | * @ulen: buffer size in bytes. If string is smaller than this
|
| 432 | * then it must be terminated with a \0.
|
| 433 | * @maskp: pointer to bitmap array that will contain result.
|
| 434 | * @nmaskbits: size of bitmap, in bits.
|
| 435 | *
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| 436 | * Wrapper for __bitmap_parse(), providing it with user buffer.
|
| 437 | *
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| 438 | * We cannot have this as an inline function in bitmap.h because it needs
|
| 439 | * linux/uaccess.h to get the access_ok() declaration and this causes
|
| 440 | * cyclic dependencies.
|
| 441 |
|
| 442 | int bitmap_parse_user(const char __user *ubuf,
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| 443 | unsigned int ulen, unsigned long *maskp,
|
| 444 | int nmaskbits)
|
| 445 | {
|
| 446 | if (!access_ok(ubuf, ulen))
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| 447 | return -EFAULT;
|
| 448 | return __bitmap_parse((const char __force *)ubuf,
|
| 449 | ulen, 1, maskp, nmaskbits);
|
| 450 |
|
| 451 | }
|
| 452 | EXPORT_SYMBOL(bitmap_parse_user);
|
| 453 |
|
| 454 | |
| 455 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
|
| 456 | * @list: indicates whether the bitmap must be list
|
| 457 | * @buf: page aligned buffer into which string is placed
|
| 458 | * @maskp: pointer to bitmap to convert
|
| 459 | * @nmaskbits: size of bitmap, in bits
|
| 460 | *
|
| 461 | * Output format is a comma-separated list of decimal numbers and
|
| 462 | * ranges if list is specified or hex digits grouped into comma-separated
|
| 463 | * sets of 8 digits/set. Returns the number of characters written to buf.
|
| 464 | *
|
| 465 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
|
| 466 | * area and that sufficient storage remains at @buf to accommodate the
|
| 467 | * bitmap_print_to_pagebuf() output. Returns the number of characters
|
| 468 | * actually printed to @buf, excluding terminating '\0'.
|
| 469 |
|
| 470 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
|
| 471 | int nmaskbits)
|
| 472 | {
|
| 473 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
|
| 474 |
|
| 475 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
|
| 476 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
|
| 477 | }
|
| 478 | EXPORT_SYMBOL(bitmap_print_to_pagebuf);
|
| 479 |
|
| 480 | |
| 481 | * __bitmap_parselist - convert list format ASCII string to bitmap
|
| 482 | * @buf: read nul-terminated user string from this buffer
|
| 483 | * @buflen: buffer size in bytes. If string is smaller than this
|
| 484 | * then it must be terminated with a \0.
|
| 485 | * @is_user: location of buffer, 0 indicates kernel space
|
| 486 | * @maskp: write resulting mask here
|
| 487 | * @nmaskbits: number of bits in mask to be written
|
| 488 | *
|
| 489 | * Input format is a comma-separated list of decimal numbers and
|
| 490 | * ranges. Consecutively set bits are shown as two hyphen-separated
|
| 491 | * decimal numbers, the smallest and largest bit numbers set in
|
| 492 | * the range.
|
| 493 | * Optionally each range can be postfixed to denote that only parts of it
|
| 494 | * should be set. The range will divided to groups of specific size.
|
| 495 | * From each group will be used only defined amount of bits.
|
| 496 | * Syntax: range:used_size/group_size
|
| 497 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
|
| 498 | *
|
| 499 | * Returns: 0 on success, -errno on invalid input strings. Error values:
|
| 500 | *
|
| 501 | * - ``-EINVAL``: second number in range smaller than first
|
| 502 | * - ``-EINVAL``: invalid character in string
|
| 503 | * - ``-ERANGE``: bit number specified too large for mask
|
| 504 |
|
| 505 | static int __bitmap_parselist(const char *buf, unsigned int buflen,
|
| 506 | int is_user, unsigned long *maskp,
|
| 507 | int nmaskbits)
|
| 508 | {
|
| 509 | unsigned int a, b, old_a, old_b;
|
| 510 | unsigned int group_size, used_size, off;
|
| 511 | int c, old_c, totaldigits, ndigits;
|
| 512 | const char __user __force *ubuf = (const char __user __force *)buf;
|
| 513 | int at_start, in_range, in_partial_range;
|
| 514 |
|
| 515 | totaldigits = c = 0;
|
| 516 | old_a = old_b = 0;
|
| 517 | group_size = used_size = 0;
|
| 518 | bitmap_zero(maskp, nmaskbits);
|
| 519 | do {
|
| 520 | at_start = 1;
|
| 521 | in_range = 0;
|
| 522 | in_partial_range = 0;
|
| 523 | a = b = 0;
|
| 524 | ndigits = totaldigits;
|
| 525 |
|
| 526 |
|
| 527 | while (buflen) {
|
| 528 | old_c = c;
|
| 529 | if (is_user) {
|
| 530 | if (__get_user(c, ubuf++))
|
| 531 | return -EFAULT;
|
| 532 | } else
|
| 533 | c = *buf++;
|
| 534 | buflen--;
|
| 535 | if (isspace(c))
|
| 536 | continue;
|
| 537 |
|
| 538 |
|
| 539 | if (c == '\0' || c == ',')
|
| 540 | break;
|
| 541 | |
| 542 | * whitespaces between digits are not allowed,
|
| 543 | * but it's ok if whitespaces are on head or tail.
|
| 544 | * when old_c is whilespace,
|
| 545 | * if totaldigits == ndigits, whitespace is on head.
|
| 546 | * if whitespace is on tail, it should not run here.
|
| 547 | * as c was ',' or '\0',
|
| 548 | * the last code line has broken the current loop.
|
| 549 |
|
| 550 | if ((totaldigits != ndigits) && isspace(old_c))
|
| 551 | return -EINVAL;
|
| 552 |
|
| 553 | if (c == '/') {
|
| 554 | used_size = a;
|
| 555 | at_start = 1;
|
| 556 | in_range = 0;
|
| 557 | a = b = 0;
|
| 558 | continue;
|
| 559 | }
|
| 560 |
|
| 561 | if (c == ':') {
|
| 562 | old_a = a;
|
| 563 | old_b = b;
|
| 564 | at_start = 1;
|
| 565 | in_range = 0;
|
| 566 | in_partial_range = 1;
|
| 567 | a = b = 0;
|
| 568 | continue;
|
| 569 | }
|
| 570 |
|
| 571 | if (c == '-') {
|
| 572 | if (at_start || in_range)
|
| 573 | return -EINVAL;
|
| 574 | b = 0;
|
| 575 | in_range = 1;
|
| 576 | at_start = 1;
|
| 577 | continue;
|
| 578 | }
|
| 579 |
|
| 580 | if (!isdigit(c))
|
| 581 | return -EINVAL;
|
| 582 |
|
| 583 | b = b * 10 + (c - '0');
|
| 584 | if (!in_range)
|
| 585 | a = b;
|
| 586 | at_start = 0;
|
| 587 | totaldigits++;
|
| 588 | }
|
| 589 | if (ndigits == totaldigits)
|
| 590 | continue;
|
| 591 | if (in_partial_range) {
|
| 592 | group_size = a;
|
| 593 | a = old_a;
|
| 594 | b = old_b;
|
| 595 | old_a = old_b = 0;
|
| 596 | } else {
|
| 597 | used_size = group_size = b - a + 1;
|
| 598 | }
|
| 599 |
|
| 600 | if (at_start && in_range)
|
| 601 | return -EINVAL;
|
| 602 | if (!(a <= b) || group_size == 0 || !(used_size <= group_size))
|
| 603 | return -EINVAL;
|
| 604 | if (b >= nmaskbits)
|
| 605 | return -ERANGE;
|
| 606 | while (a <= b) {
|
| 607 | off = min(b - a + 1, used_size);
|
| 608 | bitmap_set(maskp, a, off);
|
| 609 | a += group_size;
|
| 610 | }
|
| 611 | } while (buflen && c == ',');
|
| 612 | return 0;
|
| 613 | }
|
| 614 |
|
| 615 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
|
| 616 | {
|
| 617 | char *nl = strchrnul(bp, '\n');
|
| 618 | int len = nl - bp;
|
| 619 |
|
| 620 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
|
| 621 | }
|
| 622 | EXPORT_SYMBOL(bitmap_parselist);
|
| 623 |
|
| 624 |
|
| 625 | |
| 626 | * bitmap_parselist_user()
|
| 627 | *
|
| 628 | * @ubuf: pointer to user buffer containing string.
|
| 629 | * @ulen: buffer size in bytes. If string is smaller than this
|
| 630 | * then it must be terminated with a \0.
|
| 631 | * @maskp: pointer to bitmap array that will contain result.
|
| 632 | * @nmaskbits: size of bitmap, in bits.
|
| 633 | *
|
| 634 | * Wrapper for bitmap_parselist(), providing it with user buffer.
|
| 635 | *
|
| 636 | * We cannot have this as an inline function in bitmap.h because it needs
|
| 637 | * linux/uaccess.h to get the access_ok() declaration and this causes
|
| 638 | * cyclic dependencies.
|
| 639 |
|
| 640 | int bitmap_parselist_user(const char __user *ubuf,
|
| 641 | unsigned int ulen, unsigned long *maskp,
|
| 642 | int nmaskbits)
|
| 643 | {
|
| 644 | if (!access_ok(ubuf, ulen))
|
| 645 | return -EFAULT;
|
| 646 | return __bitmap_parselist((const char __force *)ubuf,
|
| 647 | ulen, 1, maskp, nmaskbits);
|
| 648 | }
|
| 649 | EXPORT_SYMBOL(bitmap_parselist_user);
|
| 650 |
|
| 651 |
|
| 652 | |
| 653 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
|
| 654 | * @buf: pointer to a bitmap
|
| 655 | * @pos: a bit position in @buf (0 <= @pos < @nbits)
|
| 656 | * @nbits: number of valid bit positions in @buf
|
| 657 | *
|
| 658 | * Map the bit at position @pos in @buf (of length @nbits) to the
|
| 659 | * ordinal of which set bit it is. If it is not set or if @pos
|
| 660 | * is not a valid bit position, map to -1.
|
| 661 | *
|
| 662 | * If for example, just bits 4 through 7 are set in @buf, then @pos
|
| 663 | * values 4 through 7 will get mapped to 0 through 3, respectively,
|
| 664 | * and other @pos values will get mapped to -1. When @pos value 7
|
| 665 | * gets mapped to (returns) @ord value 3 in this example, that means
|
| 666 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
|
| 667 | *
|
| 668 | * The bit positions 0 through @bits are valid positions in @buf.
|
| 669 |
|
| 670 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
|
| 671 | {
|
| 672 | if (pos >= nbits || !test_bit(pos, buf))
|
| 673 | return -1;
|
| 674 |
|
| 675 | return __bitmap_weight(buf, pos);
|
| 676 | }
|
| 677 |
|
| 678 | |
| 679 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap
|
| 680 | * @buf: pointer to bitmap
|
| 681 | * @ord: ordinal bit position (n-th set bit, n >= 0)
|
| 682 | * @nbits: number of valid bit positions in @buf
|
| 683 | *
|
| 684 | * Map the ordinal offset of bit @ord in @buf to its position in @buf.
|
| 685 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
|
| 686 | * >= weight(buf), returns @nbits.
|
| 687 | *
|
| 688 | * If for example, just bits 4 through 7 are set in @buf, then @ord
|
| 689 | * values 0 through 3 will get mapped to 4 through 7, respectively,
|
| 690 | * and all other @ord values returns @nbits. When @ord value 3
|
| 691 | * gets mapped to (returns) @pos value 7 in this example, that means
|
| 692 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
|
| 693 | *
|
| 694 | * The bit positions 0 through @nbits-1 are valid positions in @buf.
|
| 695 |
|
| 696 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
|
| 697 | {
|
| 698 | unsigned int pos;
|
| 699 |
|
| 700 | for (pos = find_first_bit(buf, nbits);
|
| 701 | pos < nbits && ord;
|
| 702 | pos = find_next_bit(buf, nbits, pos + 1))
|
| 703 | ord--;
|
| 704 |
|
| 705 | return pos;
|
| 706 | }
|
| 707 |
|
| 708 | |
| 709 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
|
| 710 | * @dst: remapped result
|
| 711 | * @src: subset to be remapped
|
| 712 | * @old: defines domain of map
|
| 713 | * @new: defines range of map
|
| 714 | * @nbits: number of bits in each of these bitmaps
|
| 715 | *
|
| 716 | * Let @old and @new define a mapping of bit positions, such that
|
| 717 | * whatever position is held by the n-th set bit in @old is mapped
|
| 718 | * to the n-th set bit in @new. In the more general case, allowing
|
| 719 | * for the possibility that the weight 'w' of @new is less than the
|
| 720 | * weight of @old, map the position of the n-th set bit in @old to
|
| 721 | * the position of the m-th set bit in @new, where m == n % w.
|
| 722 | *
|
| 723 | * If either of the @old and @new bitmaps are empty, or if @src and
|
| 724 | * @dst point to the same location, then this routine copies @src
|
| 725 | * to @dst.
|
| 726 | *
|
| 727 | * The positions of unset bits in @old are mapped to themselves
|
| 728 | * (the identify map).
|
| 729 | *
|
| 730 | * Apply the above specified mapping to @src, placing the result in
|
| 731 | * @dst, clearing any bits previously set in @dst.
|
| 732 | *
|
| 733 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 734 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 735 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 736 | * bit positions unchanged. So if say @src comes into this routine
|
| 737 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
|
| 738 | * 13 and 15 set.
|
| 739 |
|
| 740 | void bitmap_remap(unsigned long *dst, const unsigned long *src,
|
| 741 | const unsigned long *old, const unsigned long *new,
|
| 742 | unsigned int nbits)
|
| 743 | {
|
| 744 | unsigned int oldbit, w;
|
| 745 |
|
| 746 | if (dst == src)
|
| 747 | return;
|
| 748 | bitmap_zero(dst, nbits);
|
| 749 |
|
| 750 | w = bitmap_weight(new, nbits);
|
| 751 | for_each_set_bit(oldbit, src, nbits) {
|
| 752 | int n = bitmap_pos_to_ord(old, oldbit, nbits);
|
| 753 |
|
| 754 | if (n < 0 || w == 0)
|
| 755 | set_bit(oldbit, dst);
|
| 756 | else
|
| 757 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
|
| 758 | }
|
| 759 | }
|
| 760 | EXPORT_SYMBOL(bitmap_remap);
|
| 761 |
|
| 762 | |
| 763 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
|
| 764 | * @oldbit: bit position to be mapped
|
| 765 | * @old: defines domain of map
|
| 766 | * @new: defines range of map
|
| 767 | * @bits: number of bits in each of these bitmaps
|
| 768 | *
|
| 769 | * Let @old and @new define a mapping of bit positions, such that
|
| 770 | * whatever position is held by the n-th set bit in @old is mapped
|
| 771 | * to the n-th set bit in @new. In the more general case, allowing
|
| 772 | * for the possibility that the weight 'w' of @new is less than the
|
| 773 | * weight of @old, map the position of the n-th set bit in @old to
|
| 774 | * the position of the m-th set bit in @new, where m == n % w.
|
| 775 | *
|
| 776 | * The positions of unset bits in @old are mapped to themselves
|
| 777 | * (the identify map).
|
| 778 | *
|
| 779 | * Apply the above specified mapping to bit position @oldbit, returning
|
| 780 | * the new bit position.
|
| 781 | *
|
| 782 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 783 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 784 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 785 | * bit positions unchanged. So if say @oldbit is 5, then this routine
|
| 786 | * returns 13.
|
| 787 |
|
| 788 | int bitmap_bitremap(int oldbit, const unsigned long *old,
|
| 789 | const unsigned long *new, int bits)
|
| 790 | {
|
| 791 | int w = bitmap_weight(new, bits);
|
| 792 | int n = bitmap_pos_to_ord(old, oldbit, bits);
|
| 793 | if (n < 0 || w == 0)
|
| 794 | return oldbit;
|
| 795 | else
|
| 796 | return bitmap_ord_to_pos(new, n % w, bits);
|
| 797 | }
|
| 798 | EXPORT_SYMBOL(bitmap_bitremap);
|
| 799 |
|
| 800 | |
| 801 | * bitmap_onto - translate one bitmap relative to another
|
| 802 | * @dst: resulting translated bitmap
|
| 803 | * @orig: original untranslated bitmap
|
| 804 | * @relmap: bitmap relative to which translated
|
| 805 | * @bits: number of bits in each of these bitmaps
|
| 806 | *
|
| 807 | * Set the n-th bit of @dst iff there exists some m such that the
|
| 808 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and
|
| 809 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
|
| 810 | * (If you understood the previous sentence the first time your
|
| 811 | * read it, you're overqualified for your current job.)
|
| 812 | *
|
| 813 | * In other words, @orig is mapped onto (surjectively) @dst,
|
| 814 | * using the map { <n, m> | the n-th bit of @relmap is the
|
| 815 | * m-th set bit of @relmap }.
|
| 816 | *
|
| 817 | * Any set bits in @orig above bit number W, where W is the
|
| 818 | * weight of (number of set bits in) @relmap are mapped nowhere.
|
| 819 | * In particular, if for all bits m set in @orig, m >= W, then
|
| 820 | * @dst will end up empty. In situations where the possibility
|
| 821 | * of such an empty result is not desired, one way to avoid it is
|
| 822 | * to use the bitmap_fold() operator, below, to first fold the
|
| 823 | * @orig bitmap over itself so that all its set bits x are in the
|
| 824 | * range 0 <= x < W. The bitmap_fold() operator does this by
|
| 825 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
|
| 826 | *
|
| 827 | * Example [1] for bitmap_onto():
|
| 828 | * Let's say @relmap has bits 30-39 set, and @orig has bits
|
| 829 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
|
| 830 | * @dst will have bits 31, 33, 35, 37 and 39 set.
|
| 831 | *
|
| 832 | * When bit 0 is set in @orig, it means turn on the bit in
|
| 833 | * @dst corresponding to whatever is the first bit (if any)
|
| 834 | * that is turned on in @relmap. Since bit 0 was off in the
|
| 835 | * above example, we leave off that bit (bit 30) in @dst.
|
| 836 | *
|
| 837 | * When bit 1 is set in @orig (as in the above example), it
|
| 838 | * means turn on the bit in @dst corresponding to whatever
|
| 839 | * is the second bit that is turned on in @relmap. The second
|
| 840 | * bit in @relmap that was turned on in the above example was
|
| 841 | * bit 31, so we turned on bit 31 in @dst.
|
| 842 | *
|
| 843 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
|
| 844 | * because they were the 4th, 6th, 8th and 10th set bits
|
| 845 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of
|
| 846 | * @orig (i.e. bits 3, 5, 7 and 9) were also set.
|
| 847 | *
|
| 848 | * When bit 11 is set in @orig, it means turn on the bit in
|
| 849 | * @dst corresponding to whatever is the twelfth bit that is
|
| 850 | * turned on in @relmap. In the above example, there were
|
| 851 | * only ten bits turned on in @relmap (30..39), so that bit
|
| 852 | * 11 was set in @orig had no affect on @dst.
|
| 853 | *
|
| 854 | * Example [2] for bitmap_fold() + bitmap_onto():
|
| 855 | * Let's say @relmap has these ten bits set::
|
| 856 | *
|
| 857 | * 40 41 42 43 45 48 53 61 74 95
|
| 858 | *
|
| 859 | * (for the curious, that's 40 plus the first ten terms of the
|
| 860 | * Fibonacci sequence.)
|
| 861 | *
|
| 862 | * Further lets say we use the following code, invoking
|
| 863 | * bitmap_fold() then bitmap_onto, as suggested above to
|
| 864 | * avoid the possibility of an empty @dst result::
|
| 865 | *
|
| 866 | * unsigned long *tmp; // a temporary bitmap's bits
|
| 867 | *
|
| 868 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
|
| 869 | * bitmap_onto(dst, tmp, relmap, bits);
|
| 870 | *
|
| 871 | * Then this table shows what various values of @dst would be, for
|
| 872 | * various @orig's. I list the zero-based positions of each set bit.
|
| 873 | * The tmp column shows the intermediate result, as computed by
|
| 874 | * using bitmap_fold() to fold the @orig bitmap modulo ten
|
| 875 | * (the weight of @relmap):
|
| 876 | *
|
| 877 | * =============== ============== =================
|
| 878 | * @orig tmp @dst
|
| 879 | * 0 0 40
|
| 880 | * 1 1 41
|
| 881 | * 9 9 95
|
| 882 | * 10 0 40 [#f1]_
|
| 883 | * 1 3 5 7 1 3 5 7 41 43 48 61
|
| 884 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
|
| 885 | * 0 9 18 27 0 9 8 7 40 61 74 95
|
| 886 | * 0 10 20 30 0 40
|
| 887 | * 0 11 22 33 0 1 2 3 40 41 42 43
|
| 888 | * 0 12 24 36 0 2 4 6 40 42 45 53
|
| 889 | * 78 102 211 1 2 8 41 42 74 [#f1]_
|
| 890 | * =============== ============== =================
|
| 891 | *
|
| 892 | * .. [#f1]
|
| 893 | *
|
| 894 | * For these marked lines, if we hadn't first done bitmap_fold()
|
| 895 | * into tmp, then the @dst result would have been empty.
|
| 896 | *
|
| 897 | * If either of @orig or @relmap is empty (no set bits), then @dst
|
| 898 | * will be returned empty.
|
| 899 | *
|
| 900 | * If (as explained above) the only set bits in @orig are in positions
|
| 901 | * m where m >= W, (where W is the weight of @relmap) then @dst will
|
| 902 | * once again be returned empty.
|
| 903 | *
|
| 904 | * All bits in @dst not set by the above rule are cleared.
|
| 905 |
|
| 906 | void bitmap_onto(unsigned long *dst, const unsigned long *orig,
|
| 907 | const unsigned long *relmap, unsigned int bits)
|
| 908 | {
|
| 909 | unsigned int n, m;
|
| 910 |
|
| 911 | if (dst == orig)
|
| 912 | return;
|
| 913 | bitmap_zero(dst, bits);
|
| 914 |
|
| 915 | |
| 916 | * The following code is a more efficient, but less
|
| 917 | * obvious, equivalent to the loop:
|
| 918 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
|
| 919 | * n = bitmap_ord_to_pos(orig, m, bits);
|
| 920 | * if (test_bit(m, orig))
|
| 921 | * set_bit(n, dst);
|
| 922 | * }
|
| 923 |
|
| 924 |
|
| 925 | m = 0;
|
| 926 | for_each_set_bit(n, relmap, bits) {
|
| 927 |
|
| 928 | if (test_bit(m, orig))
|
| 929 | set_bit(n, dst);
|
| 930 | m++;
|
| 931 | }
|
| 932 | }
|
| 933 | EXPORT_SYMBOL(bitmap_onto);
|
| 934 |
|
| 935 | |
| 936 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size
|
| 937 | * @dst: resulting smaller bitmap
|
| 938 | * @orig: original larger bitmap
|
| 939 | * @sz: specified size
|
| 940 | * @nbits: number of bits in each of these bitmaps
|
| 941 | *
|
| 942 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
|
| 943 | * Clear all other bits in @dst. See further the comment and
|
| 944 | * Example [2] for bitmap_onto() for why and how to use this.
|
| 945 |
|
| 946 | void bitmap_fold(unsigned long *dst, const unsigned long *orig,
|
| 947 | unsigned int sz, unsigned int nbits)
|
| 948 | {
|
| 949 | unsigned int oldbit;
|
| 950 |
|
| 951 | if (dst == orig)
|
| 952 | return;
|
| 953 | bitmap_zero(dst, nbits);
|
| 954 |
|
| 955 | for_each_set_bit(oldbit, orig, nbits)
|
| 956 | set_bit(oldbit % sz, dst);
|
| 957 | }
|
| 958 | EXPORT_SYMBOL(bitmap_fold);
|
| 959 |
|
| 960 | |
| 961 | * Common code for bitmap_*_region() routines.
|
| 962 | * bitmap: array of unsigned longs corresponding to the bitmap
|
| 963 | * pos: the beginning of the region
|
| 964 | * order: region size (log base 2 of number of bits)
|
| 965 | * reg_op: operation(s) to perform on that region of bitmap
|
| 966 | *
|
| 967 | * Can set, verify and/or release a region of bits in a bitmap,
|
| 968 | * depending on which combination of REG_OP_* flag bits is set.
|
| 969 | *
|
| 970 | * A region of a bitmap is a sequence of bits in the bitmap, of
|
| 971 | * some size '1 << order' (a power of two), aligned to that same
|
| 972 | * '1 << order' power of two.
|
| 973 | *
|
| 974 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
|
| 975 | * Returns 0 in all other cases and reg_ops.
|
| 976 |
|
| 977 |
|
| 978 | enum {
|
| 979 | REG_OP_ISFREE,
|
| 980 | REG_OP_ALLOC,
|
| 981 | REG_OP_RELEASE,
|
| 982 | };
|
| 983 |
|
| 984 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
|
| 985 | {
|
| 986 | int nbits_reg;
|
| 987 | int index;
|
| 988 | int offset;
|
| 989 | int nlongs_reg;
|
| 990 | int nbitsinlong;
|
| 991 | unsigned long mask;
|
| 992 | int i;
|
| 993 | int ret = 0;
|
| 994 |
|
| 995 | |
| 996 | * Either nlongs_reg == 1 (for small orders that fit in one long)
|
| 997 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
|
| 998 |
|
| 999 | nbits_reg = 1 << order;
|
| 1000 | index = pos / BITS_PER_LONG;
|
| 1001 | offset = pos - (index * BITS_PER_LONG);
|
| 1002 | nlongs_reg = BITS_TO_LONGS(nbits_reg);
|
| 1003 | nbitsinlong = min(nbits_reg, BITS_PER_LONG);
|
| 1004 |
|
| 1005 | |
| 1006 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that
|
| 1007 | * overflows if nbitsinlong == BITS_PER_LONG.
|
| 1008 |
|
| 1009 | mask = (1UL << (nbitsinlong - 1));
|
| 1010 | mask += mask - 1;
|
| 1011 | mask <<= offset;
|
| 1012 |
|
| 1013 | switch (reg_op) {
|
| 1014 | case REG_OP_ISFREE:
|
| 1015 | for (i = 0; i < nlongs_reg; i++) {
|
| 1016 | if (bitmap[index + i] & mask)
|
| 1017 | goto done;
|
| 1018 | }
|
| 1019 | ret = 1;
|
| 1020 | break;
|
| 1021 |
|
| 1022 | case REG_OP_ALLOC:
|
| 1023 | for (i = 0; i < nlongs_reg; i++)
|
| 1024 | bitmap[index + i] |= mask;
|
| 1025 | break;
|
| 1026 |
|
| 1027 | case REG_OP_RELEASE:
|
| 1028 | for (i = 0; i < nlongs_reg; i++)
|
| 1029 | bitmap[index + i] &= ~mask;
|
| 1030 | break;
|
| 1031 | }
|
| 1032 | done:
|
| 1033 | return ret;
|
| 1034 | }
|
| 1035 |
|
| 1036 | |
| 1037 | * bitmap_find_free_region - find a contiguous aligned mem region
|
| 1038 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1039 | * @bits: number of bits in the bitmap
|
| 1040 | * @order: region size (log base 2 of number of bits) to find
|
| 1041 | *
|
| 1042 | * Find a region of free (zero) bits in a @bitmap of @bits bits and
|
| 1043 | * allocate them (set them to one). Only consider regions of length
|
| 1044 | * a power (@order) of two, aligned to that power of two, which
|
| 1045 | * makes the search algorithm much faster.
|
| 1046 | *
|
| 1047 | * Return the bit offset in bitmap of the allocated region,
|
| 1048 | * or -errno on failure.
|
| 1049 |
|
| 1050 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
|
| 1051 | {
|
| 1052 | unsigned int pos, end;
|
| 1053 |
|
| 1054 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
|
| 1055 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1056 | continue;
|
| 1057 | __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1058 | return pos;
|
| 1059 | }
|
| 1060 | return -ENOMEM;
|
| 1061 | }
|
| 1062 | EXPORT_SYMBOL(bitmap_find_free_region);
|
| 1063 |
|
| 1064 | |
| 1065 | * bitmap_release_region - release allocated bitmap region
|
| 1066 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1067 | * @pos: beginning of bit region to release
|
| 1068 | * @order: region size (log base 2 of number of bits) to release
|
| 1069 | *
|
| 1070 | * This is the complement to __bitmap_find_free_region() and releases
|
| 1071 | * the found region (by clearing it in the bitmap).
|
| 1072 | *
|
| 1073 | * No return value.
|
| 1074 |
|
| 1075 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
|
| 1076 | {
|
| 1077 | __reg_op(bitmap, pos, order, REG_OP_RELEASE);
|
| 1078 | }
|
| 1079 | EXPORT_SYMBOL(bitmap_release_region);
|
| 1080 |
|
| 1081 | |
| 1082 | * bitmap_allocate_region - allocate bitmap region
|
| 1083 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1084 | * @pos: beginning of bit region to allocate
|
| 1085 | * @order: region size (log base 2 of number of bits) to allocate
|
| 1086 | *
|
| 1087 | * Allocate (set bits in) a specified region of a bitmap.
|
| 1088 | *
|
| 1089 | * Return 0 on success, or %-EBUSY if specified region wasn't
|
| 1090 | * free (not all bits were zero).
|
| 1091 |
|
| 1092 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
|
| 1093 | {
|
| 1094 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1095 | return -EBUSY;
|
| 1096 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1097 | }
|
| 1098 | EXPORT_SYMBOL(bitmap_allocate_region);
|
| 1099 |
|
| 1100 | |
| 1101 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
|
| 1102 | * @dst: destination buffer
|
| 1103 | * @src: bitmap to copy
|
| 1104 | * @nbits: number of bits in the bitmap
|
| 1105 | *
|
| 1106 | * Require nbits % BITS_PER_LONG == 0.
|
| 1107 |
|
| 1108 | #ifdef __BIG_ENDIAN
|
| 1109 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
|
| 1110 | {
|
| 1111 | unsigned int i;
|
| 1112 |
|
| 1113 | for (i = 0; i < nbits/BITS_PER_LONG; i++) {
|
| 1114 | if (BITS_PER_LONG == 64)
|
| 1115 | dst[i] = cpu_to_le64(src[i]);
|
| 1116 | else
|
| 1117 | dst[i] = cpu_to_le32(src[i]);
|
| 1118 | }
|
| 1119 | }
|
| 1120 | EXPORT_SYMBOL(bitmap_copy_le);
|
| 1121 | #endif
|
| 1122 |
|
| 1123 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
|
| 1124 | {
|
| 1125 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
| 1126 | flags);
|
| 1127 | }
|
| 1128 | EXPORT_SYMBOL(bitmap_alloc);
|
| 1129 |
|
| 1130 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
|
| 1131 | {
|
| 1132 | return bitmap_alloc(nbits, flags | __GFP_ZERO);
|
| 1133 | }
|
| 1134 | EXPORT_SYMBOL(bitmap_zalloc);
|
| 1135 |
|
| 1136 | void bitmap_free(const unsigned long *bitmap)
|
| 1137 | {
|
| 1138 | kfree(bitmap);
|
| 1139 | }
|
| 1140 | EXPORT_SYMBOL(bitmap_free);
|
| 1141 |
|
| 1142 | #if BITS_PER_LONG == 64
|
| 1143 | |
| 1144 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
|
| 1145 | * @bitmap: array of unsigned longs, the destination bitmap
|
| 1146 | * @buf: array of u32 (in host byte order), the source bitmap
|
| 1147 | * @nbits: number of bits in @bitmap
|
| 1148 |
|
| 1149 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
|
| 1150 | {
|
| 1151 | unsigned int i, halfwords;
|
| 1152 |
|
| 1153 | halfwords = DIV_ROUND_UP(nbits, 32);
|
| 1154 | for (i = 0; i < halfwords; i++) {
|
| 1155 | bitmap[i/2] = (unsigned long) buf[i];
|
| 1156 | if (++i < halfwords)
|
| 1157 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
|
| 1158 | }
|
| 1159 |
|
| 1160 |
|
| 1161 | if (nbits % BITS_PER_LONG)
|
| 1162 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
|
| 1163 | }
|
| 1164 | EXPORT_SYMBOL(bitmap_from_arr32);
|
| 1165 |
|
| 1166 | |
| 1167 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
|
| 1168 | * @buf: array of u32 (in host byte order), the dest bitmap
|
| 1169 | * @bitmap: array of unsigned longs, the source bitmap
|
| 1170 | * @nbits: number of bits in @bitmap
|
| 1171 |
|
| 1172 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
|
| 1173 | {
|
| 1174 | unsigned int i, halfwords;
|
| 1175 |
|
| 1176 | halfwords = DIV_ROUND_UP(nbits, 32);
|
| 1177 | for (i = 0; i < halfwords; i++) {
|
| 1178 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
|
| 1179 | if (++i < halfwords)
|
| 1180 | buf[i] = (u32) (bitmap[i/2] >> 32);
|
| 1181 | }
|
| 1182 |
|
| 1183 |
|
| 1184 | if (nbits % BITS_PER_LONG)
|
| 1185 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
|
| 1186 | }
|
| 1187 | EXPORT_SYMBOL(bitmap_to_arr32);
|
| 1188 |
|
| 1189 | #endif
|