| 1 | |
| 2 | |
| 3 | * lib/bitmap.c
|
| 4 | * Helper functions for bitmap.h.
|
| 5 |
|
| 6 | #include <linux/export.h>
|
| 7 | #include <linux/thread_info.h>
|
| 8 | #include <linux/ctype.h>
|
| 9 | #include <linux/errno.h>
|
| 10 | #include <linux/bitmap.h>
|
| 11 | #include <linux/bitops.h>
|
| 12 | #include <linux/bug.h>
|
| 13 | #include <linux/kernel.h>
|
| 14 | #include <linux/mm.h>
|
| 15 | #include <linux/slab.h>
|
| 16 | #include <linux/string.h>
|
| 17 | #include <linux/uaccess.h>
|
| 18 |
|
| 19 | #include <asm/page.h>
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| 20 |
|
| 21 | #include "kstrtox.h"
|
| 22 |
|
| 23 | |
| 24 | * DOC: bitmap introduction
|
| 25 | *
|
| 26 | * bitmaps provide an array of bits, implemented using an
|
| 27 | * array of unsigned longs. The number of valid bits in a
|
| 28 | * given bitmap does _not_ need to be an exact multiple of
|
| 29 | * BITS_PER_LONG.
|
| 30 | *
|
| 31 | * The possible unused bits in the last, partially used word
|
| 32 | * of a bitmap are 'don't care'. The implementation makes
|
| 33 | * no particular effort to keep them zero. It ensures that
|
| 34 | * their value will not affect the results of any operation.
|
| 35 | * The bitmap operations that return Boolean (bitmap_empty,
|
| 36 | * for example) or scalar (bitmap_weight, for example) results
|
| 37 | * carefully filter out these unused bits from impacting their
|
| 38 | * results.
|
| 39 | *
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| 40 | * The byte ordering of bitmaps is more natural on little
|
| 41 | * endian architectures. See the big-endian headers
|
| 42 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
|
| 43 | * for the best explanations of this ordering.
|
| 44 |
|
| 45 |
|
| 46 | int __bitmap_equal(const unsigned long *bitmap1,
|
| 47 | const unsigned long *bitmap2, unsigned int bits)
|
| 48 | {
|
| 49 | unsigned int k, lim = bits/BITS_PER_LONG;
|
| 50 | for (k = 0; k < lim; ++k)
|
| 51 | if (bitmap1[k] != bitmap2[k])
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| 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;
|
| 57 |
|
| 58 | return 1;
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| 59 | }
|
| 60 | EXPORT_SYMBOL(__bitmap_equal);
|
| 61 |
|
| 62 | bool __bitmap_or_equal(const unsigned long *bitmap1,
|
| 63 | const unsigned long *bitmap2,
|
| 64 | const unsigned long *bitmap3,
|
| 65 | unsigned int bits)
|
| 66 | {
|
| 67 | unsigned int k, lim = bits / BITS_PER_LONG;
|
| 68 | unsigned long tmp;
|
| 69 |
|
| 70 | for (k = 0; k < lim; ++k) {
|
| 71 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
|
| 72 | return false;
|
| 73 | }
|
| 74 |
|
| 75 | if (!(bits % BITS_PER_LONG))
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| 76 | return true;
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| 77 |
|
| 78 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
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| 79 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
|
| 80 | }
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| 81 |
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| 82 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
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| 83 | {
|
| 84 | unsigned int k, lim = BITS_TO_LONGS(bits);
|
| 85 | for (k = 0; k < lim; ++k)
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| 86 | dst[k] = ~src[k];
|
| 87 | }
|
| 88 | EXPORT_SYMBOL(__bitmap_complement);
|
| 89 |
|
| 90 | |
| 91 | * __bitmap_shift_right - logical right shift of the bits in a bitmap
|
| 92 | * @dst : destination bitmap
|
| 93 | * @src : source bitmap
|
| 94 | * @shift : shift by this many bits
|
| 95 | * @nbits : bitmap size, in bits
|
| 96 | *
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| 97 | * Shifting right (dividing) means moving bits in the MS -> LS bit
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| 98 | * direction. Zeros are fed into the vacated MS positions and the
|
| 99 | * LS bits shifted off the bottom are lost.
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| 100 |
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| 101 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
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| 102 | unsigned shift, unsigned nbits)
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| 103 | {
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| 104 | unsigned k, lim = BITS_TO_LONGS(nbits);
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| 105 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 106 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
|
| 107 | for (k = 0; off + k < lim; ++k) {
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| 108 | unsigned long upper, lower;
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| 109 |
|
| 110 | |
| 111 | * If shift is not word aligned, take lower rem bits of
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| 112 | * word above and make them the top rem bits of result.
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| 113 |
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| 114 | if (!rem || off + k + 1 >= lim)
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| 115 | upper = 0;
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| 116 | else {
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| 117 | upper = src[off + k + 1];
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| 118 | if (off + k + 1 == lim - 1)
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| 119 | upper &= mask;
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| 120 | upper <<= (BITS_PER_LONG - rem);
|
| 121 | }
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| 122 | lower = src[off + k];
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| 123 | if (off + k == lim - 1)
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| 124 | lower &= mask;
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| 125 | lower >>= rem;
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| 126 | dst[k] = lower | upper;
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| 127 | }
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| 128 | if (off)
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| 129 | memset(&dst[lim - off], 0, off*sizeof(unsigned long));
|
| 130 | }
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| 131 | EXPORT_SYMBOL(__bitmap_shift_right);
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| 132 |
|
| 133 |
|
| 134 | |
| 135 | * __bitmap_shift_left - logical left shift of the bits in a bitmap
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| 136 | * @dst : destination bitmap
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| 137 | * @src : source bitmap
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| 138 | * @shift : shift by this many bits
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| 139 | * @nbits : bitmap size, in bits
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| 140 | *
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| 141 | * Shifting left (multiplying) means moving bits in the LS -> MS
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| 142 | * direction. Zeros are fed into the vacated LS bit positions
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| 143 | * and those MS bits shifted off the top are lost.
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| 144 |
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| 145 |
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| 146 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
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| 147 | unsigned int shift, unsigned int nbits)
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| 148 | {
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| 149 | int k;
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| 150 | unsigned int lim = BITS_TO_LONGS(nbits);
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| 151 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
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| 152 | for (k = lim - off - 1; k >= 0; --k) {
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| 153 | unsigned long upper, lower;
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| 154 |
|
| 155 | |
| 156 | * If shift is not word aligned, take upper rem bits of
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| 157 | * word below and make them the bottom rem bits of result.
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| 158 |
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| 159 | if (rem && k > 0)
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| 160 | lower = src[k - 1] >> (BITS_PER_LONG - rem);
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| 161 | else
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| 162 | lower = 0;
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| 163 | upper = src[k] << rem;
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| 164 | dst[k + off] = lower | upper;
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| 165 | }
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| 166 | if (off)
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| 167 | memset(dst, 0, off*sizeof(unsigned long));
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| 168 | }
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| 169 | EXPORT_SYMBOL(__bitmap_shift_left);
|
| 170 |
|
| 171 | |
| 172 | * bitmap_cut() - remove bit region from bitmap and right shift remaining bits
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| 173 | * @dst: destination bitmap, might overlap with src
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| 174 | * @src: source bitmap
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| 175 | * @first: start bit of region to be removed
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| 176 | * @cut: number of bits to remove
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| 177 | * @nbits: bitmap size, in bits
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| 178 | *
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| 179 | * Set the n-th bit of @dst iff the n-th bit of @src is set and
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| 180 | * n is less than @first, or the m-th bit of @src is set for any
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| 181 | * m such that @first <= n < nbits, and m = n + @cut.
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| 182 | *
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| 183 | * In pictures, example for a big-endian 32-bit architecture:
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| 184 | *
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| 185 | * The @src bitmap is::
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| 186 | *
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| 187 | * 31 63
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| 188 | * | |
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| 189 | * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
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| 190 | * | | | |
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| 191 | * 16 14 0 32
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| 192 | *
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| 193 | * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
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| 194 | *
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| 195 | * 31 63
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| 196 | * | |
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| 197 | * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
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| 198 | * | | |
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| 199 | * 14 (bit 17 0 32
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| 200 | * from @src)
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| 201 | *
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| 202 | * Note that @dst and @src might overlap partially or entirely.
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| 203 | *
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| 204 | * This is implemented in the obvious way, with a shift and carry
|
| 205 | * step for each moved bit. Optimisation is left as an exercise
|
| 206 | * for the compiler.
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| 207 |
|
| 208 | void bitmap_cut(unsigned long *dst, const unsigned long *src,
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| 209 | unsigned int first, unsigned int cut, unsigned int nbits)
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| 210 | {
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| 211 | unsigned int len = BITS_TO_LONGS(nbits);
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| 212 | unsigned long keep = 0, carry;
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| 213 | int i;
|
| 214 |
|
| 215 | if (first % BITS_PER_LONG) {
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| 216 | keep = src[first / BITS_PER_LONG] &
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| 217 | (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
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| 218 | }
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| 219 |
|
| 220 | memmove(dst, src, len * sizeof(*dst));
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| 221 |
|
| 222 | while (cut--) {
|
| 223 | for (i = first / BITS_PER_LONG; i < len; i++) {
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| 224 | if (i < len - 1)
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| 225 | carry = dst[i + 1] & 1UL;
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| 226 | else
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| 227 | carry = 0;
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| 228 |
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| 229 | dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
|
| 230 | }
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| 231 | }
|
| 232 |
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| 233 | dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
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| 234 | dst[first / BITS_PER_LONG] |= keep;
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| 235 | }
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| 236 | EXPORT_SYMBOL(bitmap_cut);
|
| 237 |
|
| 238 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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| 239 | const unsigned long *bitmap2, unsigned int bits)
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| 240 | {
|
| 241 | unsigned int k;
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| 242 | unsigned int lim = bits/BITS_PER_LONG;
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| 243 | unsigned long result = 0;
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| 244 |
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| 245 | for (k = 0; k < lim; k++)
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| 246 | result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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| 247 | if (bits % BITS_PER_LONG)
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| 248 | result |= (dst[k] = bitmap1[k] & bitmap2[k] &
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| 249 | BITMAP_LAST_WORD_MASK(bits));
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| 250 | return result != 0;
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| 251 | }
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| 252 | EXPORT_SYMBOL(__bitmap_and);
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| 253 |
|
| 254 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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| 255 | const unsigned long *bitmap2, unsigned int bits)
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| 256 | {
|
| 257 | unsigned int k;
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| 258 | unsigned int nr = BITS_TO_LONGS(bits);
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| 259 |
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| 260 | for (k = 0; k < nr; k++)
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| 261 | dst[k] = bitmap1[k] | bitmap2[k];
|
| 262 | }
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| 263 | EXPORT_SYMBOL(__bitmap_or);
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| 264 |
|
| 265 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
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| 266 | const unsigned long *bitmap2, unsigned int bits)
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| 267 | {
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| 268 | unsigned int k;
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| 269 | unsigned int nr = BITS_TO_LONGS(bits);
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| 270 |
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| 271 | for (k = 0; k < nr; k++)
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| 272 | dst[k] = bitmap1[k] ^ bitmap2[k];
|
| 273 | }
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| 274 | EXPORT_SYMBOL(__bitmap_xor);
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| 275 |
|
| 276 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
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| 277 | const unsigned long *bitmap2, unsigned int bits)
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| 278 | {
|
| 279 | unsigned int k;
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| 280 | unsigned int lim = bits/BITS_PER_LONG;
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| 281 | unsigned long result = 0;
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| 282 |
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| 283 | for (k = 0; k < lim; k++)
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| 284 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
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| 285 | if (bits % BITS_PER_LONG)
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| 286 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
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| 287 | BITMAP_LAST_WORD_MASK(bits));
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| 288 | return result != 0;
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| 289 | }
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| 290 | EXPORT_SYMBOL(__bitmap_andnot);
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| 291 |
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| 292 | void __bitmap_replace(unsigned long *dst,
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| 293 | const unsigned long *old, const unsigned long *new,
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| 294 | const unsigned long *mask, unsigned int nbits)
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| 295 | {
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| 296 | unsigned int k;
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| 297 | unsigned int nr = BITS_TO_LONGS(nbits);
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| 298 |
|
| 299 | for (k = 0; k < nr; k++)
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| 300 | dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
|
| 301 | }
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| 302 | EXPORT_SYMBOL(__bitmap_replace);
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| 303 |
|
| 304 | int __bitmap_intersects(const unsigned long *bitmap1,
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| 305 | const unsigned long *bitmap2, unsigned int bits)
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| 306 | {
|
| 307 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 308 | for (k = 0; k < lim; ++k)
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| 309 | if (bitmap1[k] & bitmap2[k])
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| 310 | return 1;
|
| 311 |
|
| 312 | if (bits % BITS_PER_LONG)
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| 313 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
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| 314 | return 1;
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| 315 | return 0;
|
| 316 | }
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| 317 | EXPORT_SYMBOL(__bitmap_intersects);
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| 318 |
|
| 319 | int __bitmap_subset(const unsigned long *bitmap1,
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| 320 | const unsigned long *bitmap2, unsigned int bits)
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| 321 | {
|
| 322 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 323 | for (k = 0; k < lim; ++k)
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| 324 | if (bitmap1[k] & ~bitmap2[k])
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| 325 | return 0;
|
| 326 |
|
| 327 | if (bits % BITS_PER_LONG)
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| 328 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
|
| 329 | return 0;
|
| 330 | return 1;
|
| 331 | }
|
| 332 | EXPORT_SYMBOL(__bitmap_subset);
|
| 333 |
|
| 334 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
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| 335 | {
|
| 336 | unsigned int k, lim = bits/BITS_PER_LONG;
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| 337 | int w = 0;
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| 338 |
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| 339 | for (k = 0; k < lim; k++)
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| 340 | w += hweight_long(bitmap[k]);
|
| 341 |
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| 342 | if (bits % BITS_PER_LONG)
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| 343 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
|
| 344 |
|
| 345 | return w;
|
| 346 | }
|
| 347 | EXPORT_SYMBOL(__bitmap_weight);
|
| 348 |
|
| 349 | void __bitmap_set(unsigned long *map, unsigned int start, int len)
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| 350 | {
|
| 351 | unsigned long *p = map + BIT_WORD(start);
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| 352 | const unsigned int size = start + len;
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| 353 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
|
| 354 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
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| 355 |
|
| 356 | while (len - bits_to_set >= 0) {
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| 357 | *p |= mask_to_set;
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| 358 | len -= bits_to_set;
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| 359 | bits_to_set = BITS_PER_LONG;
|
| 360 | mask_to_set = ~0UL;
|
| 361 | p++;
|
| 362 | }
|
| 363 | if (len) {
|
| 364 | mask_to_set &= BITMAP_LAST_WORD_MASK(size);
|
| 365 | *p |= mask_to_set;
|
| 366 | }
|
| 367 | }
|
| 368 | EXPORT_SYMBOL(__bitmap_set);
|
| 369 |
|
| 370 | void __bitmap_clear(unsigned long *map, unsigned int start, int len)
|
| 371 | {
|
| 372 | unsigned long *p = map + BIT_WORD(start);
|
| 373 | const unsigned int size = start + len;
|
| 374 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
|
| 375 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
|
| 376 |
|
| 377 | while (len - bits_to_clear >= 0) {
|
| 378 | *p &= ~mask_to_clear;
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| 379 | len -= bits_to_clear;
|
| 380 | bits_to_clear = BITS_PER_LONG;
|
| 381 | mask_to_clear = ~0UL;
|
| 382 | p++;
|
| 383 | }
|
| 384 | if (len) {
|
| 385 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
|
| 386 | *p &= ~mask_to_clear;
|
| 387 | }
|
| 388 | }
|
| 389 | EXPORT_SYMBOL(__bitmap_clear);
|
| 390 |
|
| 391 | |
| 392 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
|
| 393 | * @map: The address to base the search on
|
| 394 | * @size: The bitmap size in bits
|
| 395 | * @start: The bitnumber to start searching at
|
| 396 | * @nr: The number of zeroed bits we're looking for
|
| 397 | * @align_mask: Alignment mask for zero area
|
| 398 | * @align_offset: Alignment offset for zero area.
|
| 399 | *
|
| 400 | * The @align_mask should be one less than a power of 2; the effect is that
|
| 401 | * the bit offset of all zero areas this function finds plus @align_offset
|
| 402 | * is multiple of that power of 2.
|
| 403 |
|
| 404 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
|
| 405 | unsigned long size,
|
| 406 | unsigned long start,
|
| 407 | unsigned int nr,
|
| 408 | unsigned long align_mask,
|
| 409 | unsigned long align_offset)
|
| 410 | {
|
| 411 | unsigned long index, end, i;
|
| 412 | again:
|
| 413 | index = find_next_zero_bit(map, size, start);
|
| 414 |
|
| 415 |
|
| 416 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
|
| 417 |
|
| 418 | end = index + nr;
|
| 419 | if (end > size)
|
| 420 | return end;
|
| 421 | i = find_next_bit(map, end, index);
|
| 422 | if (i < end) {
|
| 423 | start = i + 1;
|
| 424 | goto again;
|
| 425 | }
|
| 426 | return index;
|
| 427 | }
|
| 428 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
|
| 429 |
|
| 430 | |
| 431 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
|
| 432 | * second version by Paul Jackson, third by Joe Korty.
|
| 433 |
|
| 434 |
|
| 435 | |
| 436 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
|
| 437 | *
|
| 438 | * @ubuf: pointer to user buffer containing string.
|
| 439 | * @ulen: buffer size in bytes. If string is smaller than this
|
| 440 | * then it must be terminated with a \0.
|
| 441 | * @maskp: pointer to bitmap array that will contain result.
|
| 442 | * @nmaskbits: size of bitmap, in bits.
|
| 443 |
|
| 444 | int bitmap_parse_user(const char __user *ubuf,
|
| 445 | unsigned int ulen, unsigned long *maskp,
|
| 446 | int nmaskbits)
|
| 447 | {
|
| 448 | char *buf;
|
| 449 | int ret;
|
| 450 |
|
| 451 | buf = memdup_user_nul(ubuf, ulen);
|
| 452 | if (IS_ERR(buf))
|
| 453 | return PTR_ERR(buf);
|
| 454 |
|
| 455 | ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits);
|
| 456 |
|
| 457 | kfree(buf);
|
| 458 | return ret;
|
| 459 | }
|
| 460 | EXPORT_SYMBOL(bitmap_parse_user);
|
| 461 |
|
| 462 | |
| 463 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
|
| 464 | * @list: indicates whether the bitmap must be list
|
| 465 | * @buf: page aligned buffer into which string is placed
|
| 466 | * @maskp: pointer to bitmap to convert
|
| 467 | * @nmaskbits: size of bitmap, in bits
|
| 468 | *
|
| 469 | * Output format is a comma-separated list of decimal numbers and
|
| 470 | * ranges if list is specified or hex digits grouped into comma-separated
|
| 471 | * sets of 8 digits/set. Returns the number of characters written to buf.
|
| 472 | *
|
| 473 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
|
| 474 | * area and that sufficient storage remains at @buf to accommodate the
|
| 475 | * bitmap_print_to_pagebuf() output. Returns the number of characters
|
| 476 | * actually printed to @buf, excluding terminating '\0'.
|
| 477 |
|
| 478 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
|
| 479 | int nmaskbits)
|
| 480 | {
|
| 481 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
|
| 482 |
|
| 483 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
|
| 484 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
|
| 485 | }
|
| 486 | EXPORT_SYMBOL(bitmap_print_to_pagebuf);
|
| 487 |
|
| 488 | |
| 489 | * Region 9-38:4/10 describes the following bitmap structure:
|
| 490 | * 0 9 12 18 38
|
| 491 | * .........****......****......****......
|
| 492 | * ^ ^ ^ ^
|
| 493 | * start off group_len end
|
| 494 |
|
| 495 | struct region {
|
| 496 | unsigned int start;
|
| 497 | unsigned int off;
|
| 498 | unsigned int group_len;
|
| 499 | unsigned int end;
|
| 500 | };
|
| 501 |
|
| 502 | static int bitmap_set_region(const struct region *r,
|
| 503 | unsigned long *bitmap, int nbits)
|
| 504 | {
|
| 505 | unsigned int start;
|
| 506 |
|
| 507 | if (r->end >= nbits)
|
| 508 | return -ERANGE;
|
| 509 |
|
| 510 | for (start = r->start; start <= r->end; start += r->group_len)
|
| 511 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
|
| 512 |
|
| 513 | return 0;
|
| 514 | }
|
| 515 |
|
| 516 | static int bitmap_check_region(const struct region *r)
|
| 517 | {
|
| 518 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
|
| 519 | return -EINVAL;
|
| 520 |
|
| 521 | return 0;
|
| 522 | }
|
| 523 |
|
| 524 | static const char *bitmap_getnum(const char *str, unsigned int *num)
|
| 525 | {
|
| 526 | unsigned long long n;
|
| 527 | unsigned int len;
|
| 528 |
|
| 529 | len = _parse_integer(str, 10, &n);
|
| 530 | if (!len)
|
| 531 | return ERR_PTR(-EINVAL);
|
| 532 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
|
| 533 | return ERR_PTR(-EOVERFLOW);
|
| 534 |
|
| 535 | *num = n;
|
| 536 | return str + len;
|
| 537 | }
|
| 538 |
|
| 539 | static inline bool end_of_str(char c)
|
| 540 | {
|
| 541 | return c == '\0' || c == '\n';
|
| 542 | }
|
| 543 |
|
| 544 | static inline bool __end_of_region(char c)
|
| 545 | {
|
| 546 | return isspace(c) || c == ',';
|
| 547 | }
|
| 548 |
|
| 549 | static inline bool end_of_region(char c)
|
| 550 | {
|
| 551 | return __end_of_region(c) || end_of_str(c);
|
| 552 | }
|
| 553 |
|
| 554 | |
| 555 | * The format allows commas and whitespaces at the beginning
|
| 556 | * of the region.
|
| 557 |
|
| 558 | static const char *bitmap_find_region(const char *str)
|
| 559 | {
|
| 560 | while (__end_of_region(*str))
|
| 561 | str++;
|
| 562 |
|
| 563 | return end_of_str(*str) ? NULL : str;
|
| 564 | }
|
| 565 |
|
| 566 | static const char *bitmap_find_region_reverse(const char *start, const char *end)
|
| 567 | {
|
| 568 | while (start <= end && __end_of_region(*end))
|
| 569 | end--;
|
| 570 |
|
| 571 | return end;
|
| 572 | }
|
| 573 |
|
| 574 | static const char *bitmap_parse_region(const char *str, struct region *r)
|
| 575 | {
|
| 576 | str = bitmap_getnum(str, &r->start);
|
| 577 | if (IS_ERR(str))
|
| 578 | return str;
|
| 579 |
|
| 580 | if (end_of_region(*str))
|
| 581 | goto no_end;
|
| 582 |
|
| 583 | if (*str != '-')
|
| 584 | return ERR_PTR(-EINVAL);
|
| 585 |
|
| 586 | str = bitmap_getnum(str + 1, &r->end);
|
| 587 | if (IS_ERR(str))
|
| 588 | return str;
|
| 589 |
|
| 590 | if (end_of_region(*str))
|
| 591 | goto no_pattern;
|
| 592 |
|
| 593 | if (*str != ':')
|
| 594 | return ERR_PTR(-EINVAL);
|
| 595 |
|
| 596 | str = bitmap_getnum(str + 1, &r->off);
|
| 597 | if (IS_ERR(str))
|
| 598 | return str;
|
| 599 |
|
| 600 | if (*str != '/')
|
| 601 | return ERR_PTR(-EINVAL);
|
| 602 |
|
| 603 | return bitmap_getnum(str + 1, &r->group_len);
|
| 604 |
|
| 605 | no_end:
|
| 606 | r->end = r->start;
|
| 607 | no_pattern:
|
| 608 | r->off = r->end + 1;
|
| 609 | r->group_len = r->end + 1;
|
| 610 |
|
| 611 | return end_of_str(*str) ? NULL : str;
|
| 612 | }
|
| 613 |
|
| 614 | |
| 615 | * bitmap_parselist - convert list format ASCII string to bitmap
|
| 616 | * @buf: read user string from this buffer; must be terminated
|
| 617 | * with a \0 or \n.
|
| 618 | * @maskp: write resulting mask here
|
| 619 | * @nmaskbits: number of bits in mask to be written
|
| 620 | *
|
| 621 | * Input format is a comma-separated list of decimal numbers and
|
| 622 | * ranges. Consecutively set bits are shown as two hyphen-separated
|
| 623 | * decimal numbers, the smallest and largest bit numbers set in
|
| 624 | * the range.
|
| 625 | * Optionally each range can be postfixed to denote that only parts of it
|
| 626 | * should be set. The range will divided to groups of specific size.
|
| 627 | * From each group will be used only defined amount of bits.
|
| 628 | * Syntax: range:used_size/group_size
|
| 629 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
|
| 630 | *
|
| 631 | * Returns: 0 on success, -errno on invalid input strings. Error values:
|
| 632 | *
|
| 633 | * - ``-EINVAL``: wrong region format
|
| 634 | * - ``-EINVAL``: invalid character in string
|
| 635 | * - ``-ERANGE``: bit number specified too large for mask
|
| 636 | * - ``-EOVERFLOW``: integer overflow in the input parameters
|
| 637 |
|
| 638 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
|
| 639 | {
|
| 640 | struct region r;
|
| 641 | long ret;
|
| 642 |
|
| 643 | bitmap_zero(maskp, nmaskbits);
|
| 644 |
|
| 645 | while (buf) {
|
| 646 | buf = bitmap_find_region(buf);
|
| 647 | if (buf == NULL)
|
| 648 | return 0;
|
| 649 |
|
| 650 | buf = bitmap_parse_region(buf, &r);
|
| 651 | if (IS_ERR(buf))
|
| 652 | return PTR_ERR(buf);
|
| 653 |
|
| 654 | ret = bitmap_check_region(&r);
|
| 655 | if (ret)
|
| 656 | return ret;
|
| 657 |
|
| 658 | ret = bitmap_set_region(&r, maskp, nmaskbits);
|
| 659 | if (ret)
|
| 660 | return ret;
|
| 661 | }
|
| 662 |
|
| 663 | return 0;
|
| 664 | }
|
| 665 | EXPORT_SYMBOL(bitmap_parselist);
|
| 666 |
|
| 667 |
|
| 668 | |
| 669 | * bitmap_parselist_user()
|
| 670 | *
|
| 671 | * @ubuf: pointer to user buffer containing string.
|
| 672 | * @ulen: buffer size in bytes. If string is smaller than this
|
| 673 | * then it must be terminated with a \0.
|
| 674 | * @maskp: pointer to bitmap array that will contain result.
|
| 675 | * @nmaskbits: size of bitmap, in bits.
|
| 676 | *
|
| 677 | * Wrapper for bitmap_parselist(), providing it with user buffer.
|
| 678 |
|
| 679 | int bitmap_parselist_user(const char __user *ubuf,
|
| 680 | unsigned int ulen, unsigned long *maskp,
|
| 681 | int nmaskbits)
|
| 682 | {
|
| 683 | char *buf;
|
| 684 | int ret;
|
| 685 |
|
| 686 | buf = memdup_user_nul(ubuf, ulen);
|
| 687 | if (IS_ERR(buf))
|
| 688 | return PTR_ERR(buf);
|
| 689 |
|
| 690 | ret = bitmap_parselist(buf, maskp, nmaskbits);
|
| 691 |
|
| 692 | kfree(buf);
|
| 693 | return ret;
|
| 694 | }
|
| 695 | EXPORT_SYMBOL(bitmap_parselist_user);
|
| 696 |
|
| 697 | static const char *bitmap_get_x32_reverse(const char *start,
|
| 698 | const char *end, u32 *num)
|
| 699 | {
|
| 700 | u32 ret = 0;
|
| 701 | int c, i;
|
| 702 |
|
| 703 | for (i = 0; i < 32; i += 4) {
|
| 704 | c = hex_to_bin(*end--);
|
| 705 | if (c < 0)
|
| 706 | return ERR_PTR(-EINVAL);
|
| 707 |
|
| 708 | ret |= c << i;
|
| 709 |
|
| 710 | if (start > end || __end_of_region(*end))
|
| 711 | goto out;
|
| 712 | }
|
| 713 |
|
| 714 | if (hex_to_bin(*end--) >= 0)
|
| 715 | return ERR_PTR(-EOVERFLOW);
|
| 716 | out:
|
| 717 | *num = ret;
|
| 718 | return end;
|
| 719 | }
|
| 720 |
|
| 721 | |
| 722 | * bitmap_parse - convert an ASCII hex string into a bitmap.
|
| 723 | * @start: pointer to buffer containing string.
|
| 724 | * @buflen: buffer size in bytes. If string is smaller than this
|
| 725 | * then it must be terminated with a \0 or \n. In that case,
|
| 726 | * UINT_MAX may be provided instead of string length.
|
| 727 | * @maskp: pointer to bitmap array that will contain result.
|
| 728 | * @nmaskbits: size of bitmap, in bits.
|
| 729 | *
|
| 730 | * Commas group hex digits into chunks. Each chunk defines exactly 32
|
| 731 | * bits of the resultant bitmask. No chunk may specify a value larger
|
| 732 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
|
| 733 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal
|
| 734 | * characters. Grouping such as "1,,5", ",44", "," or "" is allowed.
|
| 735 | * Leading, embedded and trailing whitespace accepted.
|
| 736 |
|
| 737 | int bitmap_parse(const char *start, unsigned int buflen,
|
| 738 | unsigned long *maskp, int nmaskbits)
|
| 739 | {
|
| 740 | const char *end = strnchrnul(start, buflen, '\n') - 1;
|
| 741 | int chunks = BITS_TO_U32(nmaskbits);
|
| 742 | u32 *bitmap = (u32 *)maskp;
|
| 743 | int unset_bit;
|
| 744 | int chunk;
|
| 745 |
|
| 746 | for (chunk = 0; ; chunk++) {
|
| 747 | end = bitmap_find_region_reverse(start, end);
|
| 748 | if (start > end)
|
| 749 | break;
|
| 750 |
|
| 751 | if (!chunks--)
|
| 752 | return -EOVERFLOW;
|
| 753 |
|
| 754 | #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
|
| 755 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]);
|
| 756 | #else
|
| 757 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]);
|
| 758 | #endif
|
| 759 | if (IS_ERR(end))
|
| 760 | return PTR_ERR(end);
|
| 761 | }
|
| 762 |
|
| 763 | unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
|
| 764 | if (unset_bit < nmaskbits) {
|
| 765 | bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit);
|
| 766 | return 0;
|
| 767 | }
|
| 768 |
|
| 769 | if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit)
|
| 770 | return -EOVERFLOW;
|
| 771 |
|
| 772 | return 0;
|
| 773 | }
|
| 774 | EXPORT_SYMBOL(bitmap_parse);
|
| 775 |
|
| 776 |
|
| 777 | #ifdef CONFIG_NUMA
|
| 778 | |
| 779 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
|
| 780 | * @buf: pointer to a bitmap
|
| 781 | * @pos: a bit position in @buf (0 <= @pos < @nbits)
|
| 782 | * @nbits: number of valid bit positions in @buf
|
| 783 | *
|
| 784 | * Map the bit at position @pos in @buf (of length @nbits) to the
|
| 785 | * ordinal of which set bit it is. If it is not set or if @pos
|
| 786 | * is not a valid bit position, map to -1.
|
| 787 | *
|
| 788 | * If for example, just bits 4 through 7 are set in @buf, then @pos
|
| 789 | * values 4 through 7 will get mapped to 0 through 3, respectively,
|
| 790 | * and other @pos values will get mapped to -1. When @pos value 7
|
| 791 | * gets mapped to (returns) @ord value 3 in this example, that means
|
| 792 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
|
| 793 | *
|
| 794 | * The bit positions 0 through @bits are valid positions in @buf.
|
| 795 |
|
| 796 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
|
| 797 | {
|
| 798 | if (pos >= nbits || !test_bit(pos, buf))
|
| 799 | return -1;
|
| 800 |
|
| 801 | return __bitmap_weight(buf, pos);
|
| 802 | }
|
| 803 |
|
| 804 | |
| 805 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap
|
| 806 | * @buf: pointer to bitmap
|
| 807 | * @ord: ordinal bit position (n-th set bit, n >= 0)
|
| 808 | * @nbits: number of valid bit positions in @buf
|
| 809 | *
|
| 810 | * Map the ordinal offset of bit @ord in @buf to its position in @buf.
|
| 811 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
|
| 812 | * >= weight(buf), returns @nbits.
|
| 813 | *
|
| 814 | * If for example, just bits 4 through 7 are set in @buf, then @ord
|
| 815 | * values 0 through 3 will get mapped to 4 through 7, respectively,
|
| 816 | * and all other @ord values returns @nbits. When @ord value 3
|
| 817 | * gets mapped to (returns) @pos value 7 in this example, that means
|
| 818 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
|
| 819 | *
|
| 820 | * The bit positions 0 through @nbits-1 are valid positions in @buf.
|
| 821 |
|
| 822 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
|
| 823 | {
|
| 824 | unsigned int pos;
|
| 825 |
|
| 826 | for (pos = find_first_bit(buf, nbits);
|
| 827 | pos < nbits && ord;
|
| 828 | pos = find_next_bit(buf, nbits, pos + 1))
|
| 829 | ord--;
|
| 830 |
|
| 831 | return pos;
|
| 832 | }
|
| 833 |
|
| 834 | |
| 835 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
|
| 836 | * @dst: remapped result
|
| 837 | * @src: subset to be remapped
|
| 838 | * @old: defines domain of map
|
| 839 | * @new: defines range of map
|
| 840 | * @nbits: number of bits in each of these bitmaps
|
| 841 | *
|
| 842 | * Let @old and @new define a mapping of bit positions, such that
|
| 843 | * whatever position is held by the n-th set bit in @old is mapped
|
| 844 | * to the n-th set bit in @new. In the more general case, allowing
|
| 845 | * for the possibility that the weight 'w' of @new is less than the
|
| 846 | * weight of @old, map the position of the n-th set bit in @old to
|
| 847 | * the position of the m-th set bit in @new, where m == n % w.
|
| 848 | *
|
| 849 | * If either of the @old and @new bitmaps are empty, or if @src and
|
| 850 | * @dst point to the same location, then this routine copies @src
|
| 851 | * to @dst.
|
| 852 | *
|
| 853 | * The positions of unset bits in @old are mapped to themselves
|
| 854 | * (the identify map).
|
| 855 | *
|
| 856 | * Apply the above specified mapping to @src, placing the result in
|
| 857 | * @dst, clearing any bits previously set in @dst.
|
| 858 | *
|
| 859 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 860 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 861 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 862 | * bit positions unchanged. So if say @src comes into this routine
|
| 863 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
|
| 864 | * 13 and 15 set.
|
| 865 |
|
| 866 | void bitmap_remap(unsigned long *dst, const unsigned long *src,
|
| 867 | const unsigned long *old, const unsigned long *new,
|
| 868 | unsigned int nbits)
|
| 869 | {
|
| 870 | unsigned int oldbit, w;
|
| 871 |
|
| 872 | if (dst == src)
|
| 873 | return;
|
| 874 | bitmap_zero(dst, nbits);
|
| 875 |
|
| 876 | w = bitmap_weight(new, nbits);
|
| 877 | for_each_set_bit(oldbit, src, nbits) {
|
| 878 | int n = bitmap_pos_to_ord(old, oldbit, nbits);
|
| 879 |
|
| 880 | if (n < 0 || w == 0)
|
| 881 | set_bit(oldbit, dst);
|
| 882 | else
|
| 883 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
|
| 884 | }
|
| 885 | }
|
| 886 |
|
| 887 | |
| 888 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
|
| 889 | * @oldbit: bit position to be mapped
|
| 890 | * @old: defines domain of map
|
| 891 | * @new: defines range of map
|
| 892 | * @bits: number of bits in each of these bitmaps
|
| 893 | *
|
| 894 | * Let @old and @new define a mapping of bit positions, such that
|
| 895 | * whatever position is held by the n-th set bit in @old is mapped
|
| 896 | * to the n-th set bit in @new. In the more general case, allowing
|
| 897 | * for the possibility that the weight 'w' of @new is less than the
|
| 898 | * weight of @old, map the position of the n-th set bit in @old to
|
| 899 | * the position of the m-th set bit in @new, where m == n % w.
|
| 900 | *
|
| 901 | * The positions of unset bits in @old are mapped to themselves
|
| 902 | * (the identify map).
|
| 903 | *
|
| 904 | * Apply the above specified mapping to bit position @oldbit, returning
|
| 905 | * the new bit position.
|
| 906 | *
|
| 907 | * For example, lets say that @old has bits 4 through 7 set, and
|
| 908 | * @new has bits 12 through 15 set. This defines the mapping of bit
|
| 909 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
|
| 910 | * bit positions unchanged. So if say @oldbit is 5, then this routine
|
| 911 | * returns 13.
|
| 912 |
|
| 913 | int bitmap_bitremap(int oldbit, const unsigned long *old,
|
| 914 | const unsigned long *new, int bits)
|
| 915 | {
|
| 916 | int w = bitmap_weight(new, bits);
|
| 917 | int n = bitmap_pos_to_ord(old, oldbit, bits);
|
| 918 | if (n < 0 || w == 0)
|
| 919 | return oldbit;
|
| 920 | else
|
| 921 | return bitmap_ord_to_pos(new, n % w, bits);
|
| 922 | }
|
| 923 |
|
| 924 | |
| 925 | * bitmap_onto - translate one bitmap relative to another
|
| 926 | * @dst: resulting translated bitmap
|
| 927 | * @orig: original untranslated bitmap
|
| 928 | * @relmap: bitmap relative to which translated
|
| 929 | * @bits: number of bits in each of these bitmaps
|
| 930 | *
|
| 931 | * Set the n-th bit of @dst iff there exists some m such that the
|
| 932 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and
|
| 933 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
|
| 934 | * (If you understood the previous sentence the first time your
|
| 935 | * read it, you're overqualified for your current job.)
|
| 936 | *
|
| 937 | * In other words, @orig is mapped onto (surjectively) @dst,
|
| 938 | * using the map { <n, m> | the n-th bit of @relmap is the
|
| 939 | * m-th set bit of @relmap }.
|
| 940 | *
|
| 941 | * Any set bits in @orig above bit number W, where W is the
|
| 942 | * weight of (number of set bits in) @relmap are mapped nowhere.
|
| 943 | * In particular, if for all bits m set in @orig, m >= W, then
|
| 944 | * @dst will end up empty. In situations where the possibility
|
| 945 | * of such an empty result is not desired, one way to avoid it is
|
| 946 | * to use the bitmap_fold() operator, below, to first fold the
|
| 947 | * @orig bitmap over itself so that all its set bits x are in the
|
| 948 | * range 0 <= x < W. The bitmap_fold() operator does this by
|
| 949 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
|
| 950 | *
|
| 951 | * Example [1] for bitmap_onto():
|
| 952 | * Let's say @relmap has bits 30-39 set, and @orig has bits
|
| 953 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
|
| 954 | * @dst will have bits 31, 33, 35, 37 and 39 set.
|
| 955 | *
|
| 956 | * When bit 0 is set in @orig, it means turn on the bit in
|
| 957 | * @dst corresponding to whatever is the first bit (if any)
|
| 958 | * that is turned on in @relmap. Since bit 0 was off in the
|
| 959 | * above example, we leave off that bit (bit 30) in @dst.
|
| 960 | *
|
| 961 | * When bit 1 is set in @orig (as in the above example), it
|
| 962 | * means turn on the bit in @dst corresponding to whatever
|
| 963 | * is the second bit that is turned on in @relmap. The second
|
| 964 | * bit in @relmap that was turned on in the above example was
|
| 965 | * bit 31, so we turned on bit 31 in @dst.
|
| 966 | *
|
| 967 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
|
| 968 | * because they were the 4th, 6th, 8th and 10th set bits
|
| 969 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of
|
| 970 | * @orig (i.e. bits 3, 5, 7 and 9) were also set.
|
| 971 | *
|
| 972 | * When bit 11 is set in @orig, it means turn on the bit in
|
| 973 | * @dst corresponding to whatever is the twelfth bit that is
|
| 974 | * turned on in @relmap. In the above example, there were
|
| 975 | * only ten bits turned on in @relmap (30..39), so that bit
|
| 976 | * 11 was set in @orig had no affect on @dst.
|
| 977 | *
|
| 978 | * Example [2] for bitmap_fold() + bitmap_onto():
|
| 979 | * Let's say @relmap has these ten bits set::
|
| 980 | *
|
| 981 | * 40 41 42 43 45 48 53 61 74 95
|
| 982 | *
|
| 983 | * (for the curious, that's 40 plus the first ten terms of the
|
| 984 | * Fibonacci sequence.)
|
| 985 | *
|
| 986 | * Further lets say we use the following code, invoking
|
| 987 | * bitmap_fold() then bitmap_onto, as suggested above to
|
| 988 | * avoid the possibility of an empty @dst result::
|
| 989 | *
|
| 990 | * unsigned long *tmp; // a temporary bitmap's bits
|
| 991 | *
|
| 992 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
|
| 993 | * bitmap_onto(dst, tmp, relmap, bits);
|
| 994 | *
|
| 995 | * Then this table shows what various values of @dst would be, for
|
| 996 | * various @orig's. I list the zero-based positions of each set bit.
|
| 997 | * The tmp column shows the intermediate result, as computed by
|
| 998 | * using bitmap_fold() to fold the @orig bitmap modulo ten
|
| 999 | * (the weight of @relmap):
|
| 1000 | *
|
| 1001 | * =============== ============== =================
|
| 1002 | * @orig tmp @dst
|
| 1003 | * 0 0 40
|
| 1004 | * 1 1 41
|
| 1005 | * 9 9 95
|
| 1006 | * 10 0 40 [#f1]_
|
| 1007 | * 1 3 5 7 1 3 5 7 41 43 48 61
|
| 1008 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
|
| 1009 | * 0 9 18 27 0 9 8 7 40 61 74 95
|
| 1010 | * 0 10 20 30 0 40
|
| 1011 | * 0 11 22 33 0 1 2 3 40 41 42 43
|
| 1012 | * 0 12 24 36 0 2 4 6 40 42 45 53
|
| 1013 | * 78 102 211 1 2 8 41 42 74 [#f1]_
|
| 1014 | * =============== ============== =================
|
| 1015 | *
|
| 1016 | * .. [#f1]
|
| 1017 | *
|
| 1018 | * For these marked lines, if we hadn't first done bitmap_fold()
|
| 1019 | * into tmp, then the @dst result would have been empty.
|
| 1020 | *
|
| 1021 | * If either of @orig or @relmap is empty (no set bits), then @dst
|
| 1022 | * will be returned empty.
|
| 1023 | *
|
| 1024 | * If (as explained above) the only set bits in @orig are in positions
|
| 1025 | * m where m >= W, (where W is the weight of @relmap) then @dst will
|
| 1026 | * once again be returned empty.
|
| 1027 | *
|
| 1028 | * All bits in @dst not set by the above rule are cleared.
|
| 1029 |
|
| 1030 | void bitmap_onto(unsigned long *dst, const unsigned long *orig,
|
| 1031 | const unsigned long *relmap, unsigned int bits)
|
| 1032 | {
|
| 1033 | unsigned int n, m;
|
| 1034 |
|
| 1035 | if (dst == orig)
|
| 1036 | return;
|
| 1037 | bitmap_zero(dst, bits);
|
| 1038 |
|
| 1039 | |
| 1040 | * The following code is a more efficient, but less
|
| 1041 | * obvious, equivalent to the loop:
|
| 1042 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
|
| 1043 | * n = bitmap_ord_to_pos(orig, m, bits);
|
| 1044 | * if (test_bit(m, orig))
|
| 1045 | * set_bit(n, dst);
|
| 1046 | * }
|
| 1047 |
|
| 1048 |
|
| 1049 | m = 0;
|
| 1050 | for_each_set_bit(n, relmap, bits) {
|
| 1051 |
|
| 1052 | if (test_bit(m, orig))
|
| 1053 | set_bit(n, dst);
|
| 1054 | m++;
|
| 1055 | }
|
| 1056 | }
|
| 1057 |
|
| 1058 | |
| 1059 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size
|
| 1060 | * @dst: resulting smaller bitmap
|
| 1061 | * @orig: original larger bitmap
|
| 1062 | * @sz: specified size
|
| 1063 | * @nbits: number of bits in each of these bitmaps
|
| 1064 | *
|
| 1065 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
|
| 1066 | * Clear all other bits in @dst. See further the comment and
|
| 1067 | * Example [2] for bitmap_onto() for why and how to use this.
|
| 1068 |
|
| 1069 | void bitmap_fold(unsigned long *dst, const unsigned long *orig,
|
| 1070 | unsigned int sz, unsigned int nbits)
|
| 1071 | {
|
| 1072 | unsigned int oldbit;
|
| 1073 |
|
| 1074 | if (dst == orig)
|
| 1075 | return;
|
| 1076 | bitmap_zero(dst, nbits);
|
| 1077 |
|
| 1078 | for_each_set_bit(oldbit, orig, nbits)
|
| 1079 | set_bit(oldbit % sz, dst);
|
| 1080 | }
|
| 1081 | #endif
|
| 1082 |
|
| 1083 | |
| 1084 | * Common code for bitmap_*_region() routines.
|
| 1085 | * bitmap: array of unsigned longs corresponding to the bitmap
|
| 1086 | * pos: the beginning of the region
|
| 1087 | * order: region size (log base 2 of number of bits)
|
| 1088 | * reg_op: operation(s) to perform on that region of bitmap
|
| 1089 | *
|
| 1090 | * Can set, verify and/or release a region of bits in a bitmap,
|
| 1091 | * depending on which combination of REG_OP_* flag bits is set.
|
| 1092 | *
|
| 1093 | * A region of a bitmap is a sequence of bits in the bitmap, of
|
| 1094 | * some size '1 << order' (a power of two), aligned to that same
|
| 1095 | * '1 << order' power of two.
|
| 1096 | *
|
| 1097 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
|
| 1098 | * Returns 0 in all other cases and reg_ops.
|
| 1099 |
|
| 1100 |
|
| 1101 | enum {
|
| 1102 | REG_OP_ISFREE,
|
| 1103 | REG_OP_ALLOC,
|
| 1104 | REG_OP_RELEASE,
|
| 1105 | };
|
| 1106 |
|
| 1107 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
|
| 1108 | {
|
| 1109 | int nbits_reg;
|
| 1110 | int index;
|
| 1111 | int offset;
|
| 1112 | int nlongs_reg;
|
| 1113 | int nbitsinlong;
|
| 1114 | unsigned long mask;
|
| 1115 | int i;
|
| 1116 | int ret = 0;
|
| 1117 |
|
| 1118 | |
| 1119 | * Either nlongs_reg == 1 (for small orders that fit in one long)
|
| 1120 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
|
| 1121 |
|
| 1122 | nbits_reg = 1 << order;
|
| 1123 | index = pos / BITS_PER_LONG;
|
| 1124 | offset = pos - (index * BITS_PER_LONG);
|
| 1125 | nlongs_reg = BITS_TO_LONGS(nbits_reg);
|
| 1126 | nbitsinlong = min(nbits_reg, BITS_PER_LONG);
|
| 1127 |
|
| 1128 | |
| 1129 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that
|
| 1130 | * overflows if nbitsinlong == BITS_PER_LONG.
|
| 1131 |
|
| 1132 | mask = (1UL << (nbitsinlong - 1));
|
| 1133 | mask += mask - 1;
|
| 1134 | mask <<= offset;
|
| 1135 |
|
| 1136 | switch (reg_op) {
|
| 1137 | case REG_OP_ISFREE:
|
| 1138 | for (i = 0; i < nlongs_reg; i++) {
|
| 1139 | if (bitmap[index + i] & mask)
|
| 1140 | goto done;
|
| 1141 | }
|
| 1142 | ret = 1;
|
| 1143 | break;
|
| 1144 |
|
| 1145 | case REG_OP_ALLOC:
|
| 1146 | for (i = 0; i < nlongs_reg; i++)
|
| 1147 | bitmap[index + i] |= mask;
|
| 1148 | break;
|
| 1149 |
|
| 1150 | case REG_OP_RELEASE:
|
| 1151 | for (i = 0; i < nlongs_reg; i++)
|
| 1152 | bitmap[index + i] &= ~mask;
|
| 1153 | break;
|
| 1154 | }
|
| 1155 | done:
|
| 1156 | return ret;
|
| 1157 | }
|
| 1158 |
|
| 1159 | |
| 1160 | * bitmap_find_free_region - find a contiguous aligned mem region
|
| 1161 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1162 | * @bits: number of bits in the bitmap
|
| 1163 | * @order: region size (log base 2 of number of bits) to find
|
| 1164 | *
|
| 1165 | * Find a region of free (zero) bits in a @bitmap of @bits bits and
|
| 1166 | * allocate them (set them to one). Only consider regions of length
|
| 1167 | * a power (@order) of two, aligned to that power of two, which
|
| 1168 | * makes the search algorithm much faster.
|
| 1169 | *
|
| 1170 | * Return the bit offset in bitmap of the allocated region,
|
| 1171 | * or -errno on failure.
|
| 1172 |
|
| 1173 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
|
| 1174 | {
|
| 1175 | unsigned int pos, end;
|
| 1176 |
|
| 1177 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
|
| 1178 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1179 | continue;
|
| 1180 | __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1181 | return pos;
|
| 1182 | }
|
| 1183 | return -ENOMEM;
|
| 1184 | }
|
| 1185 | EXPORT_SYMBOL(bitmap_find_free_region);
|
| 1186 |
|
| 1187 | |
| 1188 | * bitmap_release_region - release allocated bitmap region
|
| 1189 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1190 | * @pos: beginning of bit region to release
|
| 1191 | * @order: region size (log base 2 of number of bits) to release
|
| 1192 | *
|
| 1193 | * This is the complement to __bitmap_find_free_region() and releases
|
| 1194 | * the found region (by clearing it in the bitmap).
|
| 1195 | *
|
| 1196 | * No return value.
|
| 1197 |
|
| 1198 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
|
| 1199 | {
|
| 1200 | __reg_op(bitmap, pos, order, REG_OP_RELEASE);
|
| 1201 | }
|
| 1202 | EXPORT_SYMBOL(bitmap_release_region);
|
| 1203 |
|
| 1204 | |
| 1205 | * bitmap_allocate_region - allocate bitmap region
|
| 1206 | * @bitmap: array of unsigned longs corresponding to the bitmap
|
| 1207 | * @pos: beginning of bit region to allocate
|
| 1208 | * @order: region size (log base 2 of number of bits) to allocate
|
| 1209 | *
|
| 1210 | * Allocate (set bits in) a specified region of a bitmap.
|
| 1211 | *
|
| 1212 | * Return 0 on success, or %-EBUSY if specified region wasn't
|
| 1213 | * free (not all bits were zero).
|
| 1214 |
|
| 1215 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
|
| 1216 | {
|
| 1217 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
|
| 1218 | return -EBUSY;
|
| 1219 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
|
| 1220 | }
|
| 1221 | EXPORT_SYMBOL(bitmap_allocate_region);
|
| 1222 |
|
| 1223 | |
| 1224 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
|
| 1225 | * @dst: destination buffer
|
| 1226 | * @src: bitmap to copy
|
| 1227 | * @nbits: number of bits in the bitmap
|
| 1228 | *
|
| 1229 | * Require nbits % BITS_PER_LONG == 0.
|
| 1230 |
|
| 1231 | #ifdef __BIG_ENDIAN
|
| 1232 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
|
| 1233 | {
|
| 1234 | unsigned int i;
|
| 1235 |
|
| 1236 | for (i = 0; i < nbits/BITS_PER_LONG; i++) {
|
| 1237 | if (BITS_PER_LONG == 64)
|
| 1238 | dst[i] = cpu_to_le64(src[i]);
|
| 1239 | else
|
| 1240 | dst[i] = cpu_to_le32(src[i]);
|
| 1241 | }
|
| 1242 | }
|
| 1243 | EXPORT_SYMBOL(bitmap_copy_le);
|
| 1244 | #endif
|
| 1245 |
|
| 1246 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
|
| 1247 | {
|
| 1248 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
|
| 1249 | flags);
|
| 1250 | }
|
| 1251 | EXPORT_SYMBOL(bitmap_alloc);
|
| 1252 |
|
| 1253 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
|
| 1254 | {
|
| 1255 | return bitmap_alloc(nbits, flags | __GFP_ZERO);
|
| 1256 | }
|
| 1257 | EXPORT_SYMBOL(bitmap_zalloc);
|
| 1258 |
|
| 1259 | void bitmap_free(const unsigned long *bitmap)
|
| 1260 | {
|
| 1261 | kfree(bitmap);
|
| 1262 | }
|
| 1263 | EXPORT_SYMBOL(bitmap_free);
|
| 1264 |
|
| 1265 | #if BITS_PER_LONG == 64
|
| 1266 | |
| 1267 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
|
| 1268 | * @bitmap: array of unsigned longs, the destination bitmap
|
| 1269 | * @buf: array of u32 (in host byte order), the source bitmap
|
| 1270 | * @nbits: number of bits in @bitmap
|
| 1271 |
|
| 1272 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
|
| 1273 | {
|
| 1274 | unsigned int i, halfwords;
|
| 1275 |
|
| 1276 | halfwords = DIV_ROUND_UP(nbits, 32);
|
| 1277 | for (i = 0; i < halfwords; i++) {
|
| 1278 | bitmap[i/2] = (unsigned long) buf[i];
|
| 1279 | if (++i < halfwords)
|
| 1280 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
|
| 1281 | }
|
| 1282 |
|
| 1283 |
|
| 1284 | if (nbits % BITS_PER_LONG)
|
| 1285 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
|
| 1286 | }
|
| 1287 | EXPORT_SYMBOL(bitmap_from_arr32);
|
| 1288 |
|
| 1289 | |
| 1290 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
|
| 1291 | * @buf: array of u32 (in host byte order), the dest bitmap
|
| 1292 | * @bitmap: array of unsigned longs, the source bitmap
|
| 1293 | * @nbits: number of bits in @bitmap
|
| 1294 |
|
| 1295 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
|
| 1296 | {
|
| 1297 | unsigned int i, halfwords;
|
| 1298 |
|
| 1299 | halfwords = DIV_ROUND_UP(nbits, 32);
|
| 1300 | for (i = 0; i < halfwords; i++) {
|
| 1301 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
|
| 1302 | if (++i < halfwords)
|
| 1303 | buf[i] = (u32) (bitmap[i/2] >> 32);
|
| 1304 | }
|
| 1305 |
|
| 1306 |
|
| 1307 | if (nbits % BITS_PER_LONG)
|
| 1308 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
|
| 1309 | }
|
| 1310 | EXPORT_SYMBOL(bitmap_to_arr32);
|
| 1311 |
|
| 1312 | #endif
|