Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * lib/bitmap.c |
| 3 | * Helper functions for bitmap.h. |
| 4 | * |
| 5 | * This source code is licensed under the GNU General Public License, |
| 6 | * Version 2. See the file COPYING for more details. |
| 7 | */ |
| 8 | #include <linux/module.h> |
| 9 | #include <linux/ctype.h> |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/bitmap.h> |
| 12 | #include <linux/bitops.h> |
| 13 | #include <asm/uaccess.h> |
| 14 | |
| 15 | /* |
| 16 | * bitmaps provide an array of bits, implemented using an an |
| 17 | * array of unsigned longs. The number of valid bits in a |
| 18 | * given bitmap does _not_ need to be an exact multiple of |
| 19 | * BITS_PER_LONG. |
| 20 | * |
| 21 | * The possible unused bits in the last, partially used word |
| 22 | * of a bitmap are 'don't care'. The implementation makes |
| 23 | * no particular effort to keep them zero. It ensures that |
| 24 | * their value will not affect the results of any operation. |
| 25 | * The bitmap operations that return Boolean (bitmap_empty, |
| 26 | * for example) or scalar (bitmap_weight, for example) results |
| 27 | * carefully filter out these unused bits from impacting their |
| 28 | * results. |
| 29 | * |
| 30 | * These operations actually hold to a slightly stronger rule: |
| 31 | * if you don't input any bitmaps to these ops that have some |
| 32 | * unused bits set, then they won't output any set unused bits |
| 33 | * in output bitmaps. |
| 34 | * |
| 35 | * The byte ordering of bitmaps is more natural on little |
| 36 | * endian architectures. See the big-endian headers |
| 37 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h |
| 38 | * for the best explanations of this ordering. |
| 39 | */ |
| 40 | |
| 41 | int __bitmap_empty(const unsigned long *bitmap, int bits) |
| 42 | { |
| 43 | int k, lim = bits/BITS_PER_LONG; |
| 44 | for (k = 0; k < lim; ++k) |
| 45 | if (bitmap[k]) |
| 46 | return 0; |
| 47 | |
| 48 | if (bits % BITS_PER_LONG) |
| 49 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
| 50 | return 0; |
| 51 | |
| 52 | return 1; |
| 53 | } |
| 54 | EXPORT_SYMBOL(__bitmap_empty); |
| 55 | |
| 56 | int __bitmap_full(const unsigned long *bitmap, int bits) |
| 57 | { |
| 58 | int k, lim = bits/BITS_PER_LONG; |
| 59 | for (k = 0; k < lim; ++k) |
| 60 | if (~bitmap[k]) |
| 61 | return 0; |
| 62 | |
| 63 | if (bits % BITS_PER_LONG) |
| 64 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
| 65 | return 0; |
| 66 | |
| 67 | return 1; |
| 68 | } |
| 69 | EXPORT_SYMBOL(__bitmap_full); |
| 70 | |
| 71 | int __bitmap_equal(const unsigned long *bitmap1, |
| 72 | const unsigned long *bitmap2, int bits) |
| 73 | { |
| 74 | int k, lim = bits/BITS_PER_LONG; |
| 75 | for (k = 0; k < lim; ++k) |
| 76 | if (bitmap1[k] != bitmap2[k]) |
| 77 | return 0; |
| 78 | |
| 79 | if (bits % BITS_PER_LONG) |
| 80 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
| 81 | return 0; |
| 82 | |
| 83 | return 1; |
| 84 | } |
| 85 | EXPORT_SYMBOL(__bitmap_equal); |
| 86 | |
| 87 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits) |
| 88 | { |
| 89 | int k, lim = bits/BITS_PER_LONG; |
| 90 | for (k = 0; k < lim; ++k) |
| 91 | dst[k] = ~src[k]; |
| 92 | |
| 93 | if (bits % BITS_PER_LONG) |
| 94 | dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits); |
| 95 | } |
| 96 | EXPORT_SYMBOL(__bitmap_complement); |
| 97 | |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 98 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
Randy Dunlap | 05fb6bf | 2007-02-28 20:12:13 -0800 | [diff] [blame] | 100 | * @dst : destination bitmap |
| 101 | * @src : source bitmap |
| 102 | * @shift : shift by this many bits |
| 103 | * @bits : bitmap size, in bits |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | * |
| 105 | * Shifting right (dividing) means moving bits in the MS -> LS bit |
| 106 | * direction. Zeros are fed into the vacated MS positions and the |
| 107 | * LS bits shifted off the bottom are lost. |
| 108 | */ |
| 109 | void __bitmap_shift_right(unsigned long *dst, |
| 110 | const unsigned long *src, int shift, int bits) |
| 111 | { |
| 112 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
| 113 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
| 114 | unsigned long mask = (1UL << left) - 1; |
| 115 | for (k = 0; off + k < lim; ++k) { |
| 116 | unsigned long upper, lower; |
| 117 | |
| 118 | /* |
| 119 | * If shift is not word aligned, take lower rem bits of |
| 120 | * word above and make them the top rem bits of result. |
| 121 | */ |
| 122 | if (!rem || off + k + 1 >= lim) |
| 123 | upper = 0; |
| 124 | else { |
| 125 | upper = src[off + k + 1]; |
| 126 | if (off + k + 1 == lim - 1 && left) |
| 127 | upper &= mask; |
| 128 | } |
| 129 | lower = src[off + k]; |
| 130 | if (left && off + k == lim - 1) |
| 131 | lower &= mask; |
| 132 | dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem; |
| 133 | if (left && k == lim - 1) |
| 134 | dst[k] &= mask; |
| 135 | } |
| 136 | if (off) |
| 137 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); |
| 138 | } |
| 139 | EXPORT_SYMBOL(__bitmap_shift_right); |
| 140 | |
| 141 | |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 142 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
Randy Dunlap | 05fb6bf | 2007-02-28 20:12:13 -0800 | [diff] [blame] | 144 | * @dst : destination bitmap |
| 145 | * @src : source bitmap |
| 146 | * @shift : shift by this many bits |
| 147 | * @bits : bitmap size, in bits |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | * |
| 149 | * Shifting left (multiplying) means moving bits in the LS -> MS |
| 150 | * direction. Zeros are fed into the vacated LS bit positions |
| 151 | * and those MS bits shifted off the top are lost. |
| 152 | */ |
| 153 | |
| 154 | void __bitmap_shift_left(unsigned long *dst, |
| 155 | const unsigned long *src, int shift, int bits) |
| 156 | { |
| 157 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
| 158 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
| 159 | for (k = lim - off - 1; k >= 0; --k) { |
| 160 | unsigned long upper, lower; |
| 161 | |
| 162 | /* |
| 163 | * If shift is not word aligned, take upper rem bits of |
| 164 | * word below and make them the bottom rem bits of result. |
| 165 | */ |
| 166 | if (rem && k > 0) |
| 167 | lower = src[k - 1]; |
| 168 | else |
| 169 | lower = 0; |
| 170 | upper = src[k]; |
| 171 | if (left && k == lim - 1) |
| 172 | upper &= (1UL << left) - 1; |
| 173 | dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; |
| 174 | if (left && k + off == lim - 1) |
| 175 | dst[k + off] &= (1UL << left) - 1; |
| 176 | } |
| 177 | if (off) |
| 178 | memset(dst, 0, off*sizeof(unsigned long)); |
| 179 | } |
| 180 | EXPORT_SYMBOL(__bitmap_shift_left); |
| 181 | |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 182 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | const unsigned long *bitmap2, int bits) |
| 184 | { |
| 185 | int k; |
| 186 | int nr = BITS_TO_LONGS(bits); |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 187 | unsigned long result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
| 189 | for (k = 0; k < nr; k++) |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 190 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
| 191 | return result != 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | } |
| 193 | EXPORT_SYMBOL(__bitmap_and); |
| 194 | |
| 195 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
| 196 | const unsigned long *bitmap2, int bits) |
| 197 | { |
| 198 | int k; |
| 199 | int nr = BITS_TO_LONGS(bits); |
| 200 | |
| 201 | for (k = 0; k < nr; k++) |
| 202 | dst[k] = bitmap1[k] | bitmap2[k]; |
| 203 | } |
| 204 | EXPORT_SYMBOL(__bitmap_or); |
| 205 | |
| 206 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
| 207 | const unsigned long *bitmap2, int bits) |
| 208 | { |
| 209 | int k; |
| 210 | int nr = BITS_TO_LONGS(bits); |
| 211 | |
| 212 | for (k = 0; k < nr; k++) |
| 213 | dst[k] = bitmap1[k] ^ bitmap2[k]; |
| 214 | } |
| 215 | EXPORT_SYMBOL(__bitmap_xor); |
| 216 | |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 217 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | const unsigned long *bitmap2, int bits) |
| 219 | { |
| 220 | int k; |
| 221 | int nr = BITS_TO_LONGS(bits); |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 222 | unsigned long result = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | |
| 224 | for (k = 0; k < nr; k++) |
Linus Torvalds | f4b0373 | 2009-08-21 09:26:15 -0700 | [diff] [blame] | 225 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
| 226 | return result != 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | } |
| 228 | EXPORT_SYMBOL(__bitmap_andnot); |
| 229 | |
| 230 | int __bitmap_intersects(const unsigned long *bitmap1, |
| 231 | const unsigned long *bitmap2, int bits) |
| 232 | { |
| 233 | int k, lim = bits/BITS_PER_LONG; |
| 234 | for (k = 0; k < lim; ++k) |
| 235 | if (bitmap1[k] & bitmap2[k]) |
| 236 | return 1; |
| 237 | |
| 238 | if (bits % BITS_PER_LONG) |
| 239 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
| 240 | return 1; |
| 241 | return 0; |
| 242 | } |
| 243 | EXPORT_SYMBOL(__bitmap_intersects); |
| 244 | |
| 245 | int __bitmap_subset(const unsigned long *bitmap1, |
| 246 | const unsigned long *bitmap2, int bits) |
| 247 | { |
| 248 | int k, lim = bits/BITS_PER_LONG; |
| 249 | for (k = 0; k < lim; ++k) |
| 250 | if (bitmap1[k] & ~bitmap2[k]) |
| 251 | return 0; |
| 252 | |
| 253 | if (bits % BITS_PER_LONG) |
| 254 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
| 255 | return 0; |
| 256 | return 1; |
| 257 | } |
| 258 | EXPORT_SYMBOL(__bitmap_subset); |
| 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | int __bitmap_weight(const unsigned long *bitmap, int bits) |
| 261 | { |
| 262 | int k, w = 0, lim = bits/BITS_PER_LONG; |
| 263 | |
| 264 | for (k = 0; k < lim; k++) |
Akinobu Mita | 37d5411 | 2006-03-26 01:39:56 -0800 | [diff] [blame] | 265 | w += hweight_long(bitmap[k]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | |
| 267 | if (bits % BITS_PER_LONG) |
Akinobu Mita | 37d5411 | 2006-03-26 01:39:56 -0800 | [diff] [blame] | 268 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | |
| 270 | return w; |
| 271 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | EXPORT_SYMBOL(__bitmap_weight); |
| 273 | |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 274 | #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) |
| 275 | |
| 276 | void bitmap_set(unsigned long *map, int start, int nr) |
| 277 | { |
| 278 | unsigned long *p = map + BIT_WORD(start); |
| 279 | const int size = start + nr; |
| 280 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
| 281 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); |
| 282 | |
| 283 | while (nr - bits_to_set >= 0) { |
| 284 | *p |= mask_to_set; |
| 285 | nr -= bits_to_set; |
| 286 | bits_to_set = BITS_PER_LONG; |
| 287 | mask_to_set = ~0UL; |
| 288 | p++; |
| 289 | } |
| 290 | if (nr) { |
| 291 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
| 292 | *p |= mask_to_set; |
| 293 | } |
| 294 | } |
| 295 | EXPORT_SYMBOL(bitmap_set); |
| 296 | |
| 297 | void bitmap_clear(unsigned long *map, int start, int nr) |
| 298 | { |
| 299 | unsigned long *p = map + BIT_WORD(start); |
| 300 | const int size = start + nr; |
| 301 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
| 302 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
| 303 | |
| 304 | while (nr - bits_to_clear >= 0) { |
| 305 | *p &= ~mask_to_clear; |
| 306 | nr -= bits_to_clear; |
| 307 | bits_to_clear = BITS_PER_LONG; |
| 308 | mask_to_clear = ~0UL; |
| 309 | p++; |
| 310 | } |
| 311 | if (nr) { |
| 312 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
| 313 | *p &= ~mask_to_clear; |
| 314 | } |
| 315 | } |
| 316 | EXPORT_SYMBOL(bitmap_clear); |
| 317 | |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 318 | /** |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 319 | * bitmap_find_next_zero_area - find a contiguous aligned zero area |
| 320 | * @map: The address to base the search on |
| 321 | * @size: The bitmap size in bits |
| 322 | * @start: The bitnumber to start searching at |
| 323 | * @nr: The number of zeroed bits we're looking for |
| 324 | * @align_mask: Alignment mask for zero area |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 325 | * @align_offset: Alignment offset for zero area. |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 326 | * |
| 327 | * The @align_mask should be one less than a power of 2; the effect is that |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 328 | * the bit offset of all zero areas this function finds plus @align_offset |
| 329 | * is multiple of that power of 2. |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 330 | */ |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 331 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
| 332 | unsigned long size, |
| 333 | unsigned long start, |
| 334 | unsigned int nr, |
| 335 | unsigned long align_mask, |
| 336 | unsigned long align_offset) |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 337 | { |
| 338 | unsigned long index, end, i; |
| 339 | again: |
| 340 | index = find_next_zero_bit(map, size, start); |
| 341 | |
| 342 | /* Align allocation */ |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 343 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 344 | |
| 345 | end = index + nr; |
| 346 | if (end > size) |
| 347 | return end; |
| 348 | i = find_next_bit(map, end, index); |
| 349 | if (i < end) { |
| 350 | start = i + 1; |
| 351 | goto again; |
| 352 | } |
| 353 | return index; |
| 354 | } |
Bryan Huntsman | 3f2bc4d | 2011-08-16 17:27:22 -0700 | [diff] [blame] | 355 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
Akinobu Mita | c1a2a96 | 2009-12-15 16:48:25 -0800 | [diff] [blame] | 356 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | /* |
| 358 | * Bitmap printing & parsing functions: first version by Bill Irwin, |
| 359 | * second version by Paul Jackson, third by Joe Korty. |
| 360 | */ |
| 361 | |
| 362 | #define CHUNKSZ 32 |
| 363 | #define nbits_to_hold_value(val) fls(val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
| 365 | |
| 366 | /** |
| 367 | * bitmap_scnprintf - convert bitmap to an ASCII hex string. |
| 368 | * @buf: byte buffer into which string is placed |
| 369 | * @buflen: reserved size of @buf, in bytes |
| 370 | * @maskp: pointer to bitmap to convert |
| 371 | * @nmaskbits: size of bitmap, in bits |
| 372 | * |
| 373 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into |
| 374 | * comma-separated sets of eight digits per set. |
| 375 | */ |
| 376 | int bitmap_scnprintf(char *buf, unsigned int buflen, |
| 377 | const unsigned long *maskp, int nmaskbits) |
| 378 | { |
| 379 | int i, word, bit, len = 0; |
| 380 | unsigned long val; |
| 381 | const char *sep = ""; |
| 382 | int chunksz; |
| 383 | u32 chunkmask; |
| 384 | |
| 385 | chunksz = nmaskbits & (CHUNKSZ - 1); |
| 386 | if (chunksz == 0) |
| 387 | chunksz = CHUNKSZ; |
| 388 | |
Nick Wilson | 8c0e33c | 2005-06-25 14:59:00 -0700 | [diff] [blame] | 389 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | for (; i >= 0; i -= CHUNKSZ) { |
| 391 | chunkmask = ((1ULL << chunksz) - 1); |
| 392 | word = i / BITS_PER_LONG; |
| 393 | bit = i % BITS_PER_LONG; |
| 394 | val = (maskp[word] >> bit) & chunkmask; |
| 395 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep, |
| 396 | (chunksz+3)/4, val); |
| 397 | chunksz = CHUNKSZ; |
| 398 | sep = ","; |
| 399 | } |
| 400 | return len; |
| 401 | } |
| 402 | EXPORT_SYMBOL(bitmap_scnprintf); |
| 403 | |
| 404 | /** |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 405 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
| 406 | * @buf: pointer to buffer containing string. |
| 407 | * @buflen: buffer size in bytes. If string is smaller than this |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | * then it must be terminated with a \0. |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 409 | * @is_user: location of buffer, 0 indicates kernel space |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | * @maskp: pointer to bitmap array that will contain result. |
| 411 | * @nmaskbits: size of bitmap, in bits. |
| 412 | * |
| 413 | * Commas group hex digits into chunks. Each chunk defines exactly 32 |
| 414 | * bits of the resultant bitmask. No chunk may specify a value larger |
Randy Dunlap | 6e1907ff | 2006-06-25 05:48:57 -0700 | [diff] [blame] | 415 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
| 416 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
| 418 | * Leading and trailing whitespace accepted, but not embedded whitespace. |
| 419 | */ |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 420 | int __bitmap_parse(const char *buf, unsigned int buflen, |
| 421 | int is_user, unsigned long *maskp, |
| 422 | int nmaskbits) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | { |
| 424 | int c, old_c, totaldigits, ndigits, nchunks, nbits; |
| 425 | u32 chunk; |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 426 | const char __user *ubuf = buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | |
| 428 | bitmap_zero(maskp, nmaskbits); |
| 429 | |
| 430 | nchunks = nbits = totaldigits = c = 0; |
| 431 | do { |
| 432 | chunk = ndigits = 0; |
| 433 | |
| 434 | /* Get the next chunk of the bitmap */ |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 435 | while (buflen) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | old_c = c; |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 437 | if (is_user) { |
| 438 | if (__get_user(c, ubuf++)) |
| 439 | return -EFAULT; |
| 440 | } |
| 441 | else |
| 442 | c = *buf++; |
| 443 | buflen--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 444 | if (isspace(c)) |
| 445 | continue; |
| 446 | |
| 447 | /* |
| 448 | * If the last character was a space and the current |
| 449 | * character isn't '\0', we've got embedded whitespace. |
| 450 | * This is a no-no, so throw an error. |
| 451 | */ |
| 452 | if (totaldigits && c && isspace(old_c)) |
| 453 | return -EINVAL; |
| 454 | |
| 455 | /* A '\0' or a ',' signal the end of the chunk */ |
| 456 | if (c == '\0' || c == ',') |
| 457 | break; |
| 458 | |
| 459 | if (!isxdigit(c)) |
| 460 | return -EINVAL; |
| 461 | |
| 462 | /* |
| 463 | * Make sure there are at least 4 free bits in 'chunk'. |
| 464 | * If not, this hexdigit will overflow 'chunk', so |
| 465 | * throw an error. |
| 466 | */ |
| 467 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) |
| 468 | return -EOVERFLOW; |
| 469 | |
Andy Shevchenko | 66f1991 | 2010-10-26 14:23:03 -0700 | [diff] [blame] | 470 | chunk = (chunk << 4) | hex_to_bin(c); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | ndigits++; totaldigits++; |
| 472 | } |
| 473 | if (ndigits == 0) |
| 474 | return -EINVAL; |
| 475 | if (nchunks == 0 && chunk == 0) |
| 476 | continue; |
| 477 | |
| 478 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); |
| 479 | *maskp |= chunk; |
| 480 | nchunks++; |
| 481 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; |
| 482 | if (nbits > nmaskbits) |
| 483 | return -EOVERFLOW; |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 484 | } while (buflen && c == ','); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
| 486 | return 0; |
| 487 | } |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 488 | EXPORT_SYMBOL(__bitmap_parse); |
| 489 | |
| 490 | /** |
Ben Hutchings | 9a86e2b | 2010-03-05 13:43:17 -0800 | [diff] [blame] | 491 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
Reinette Chatre | 01a3ee2 | 2006-10-11 01:21:55 -0700 | [diff] [blame] | 492 | * |
| 493 | * @ubuf: pointer to user buffer containing string. |
| 494 | * @ulen: buffer size in bytes. If string is smaller than this |
| 495 | * then it must be terminated with a \0. |
| 496 | * @maskp: pointer to bitmap array that will contain result. |
| 497 | * @nmaskbits: size of bitmap, in bits. |
| 498 | * |
| 499 | * Wrapper for __bitmap_parse(), providing it with user buffer. |
| 500 | * |
| 501 | * We cannot have this as an inline function in bitmap.h because it needs |
| 502 | * linux/uaccess.h to get the access_ok() declaration and this causes |
| 503 | * cyclic dependencies. |
| 504 | */ |
| 505 | int bitmap_parse_user(const char __user *ubuf, |
| 506 | unsigned int ulen, unsigned long *maskp, |
| 507 | int nmaskbits) |
| 508 | { |
| 509 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
| 510 | return -EFAULT; |
| 511 | return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits); |
| 512 | } |
| 513 | EXPORT_SYMBOL(bitmap_parse_user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | |
| 515 | /* |
| 516 | * bscnl_emit(buf, buflen, rbot, rtop, bp) |
| 517 | * |
| 518 | * Helper routine for bitmap_scnlistprintf(). Write decimal number |
| 519 | * or range to buf, suppressing output past buf+buflen, with optional |
| 520 | * comma-prefix. Return len of what would be written to buf, if it |
| 521 | * all fit. |
| 522 | */ |
| 523 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) |
| 524 | { |
| 525 | if (len > 0) |
| 526 | len += scnprintf(buf + len, buflen - len, ","); |
| 527 | if (rbot == rtop) |
| 528 | len += scnprintf(buf + len, buflen - len, "%d", rbot); |
| 529 | else |
| 530 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop); |
| 531 | return len; |
| 532 | } |
| 533 | |
| 534 | /** |
| 535 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string |
| 536 | * @buf: byte buffer into which string is placed |
| 537 | * @buflen: reserved size of @buf, in bytes |
| 538 | * @maskp: pointer to bitmap to convert |
| 539 | * @nmaskbits: size of bitmap, in bits |
| 540 | * |
| 541 | * Output format is a comma-separated list of decimal numbers and |
| 542 | * ranges. Consecutively set bits are shown as two hyphen-separated |
| 543 | * decimal numbers, the smallest and largest bit numbers set in |
| 544 | * the range. Output format is compatible with the format |
| 545 | * accepted as input by bitmap_parselist(). |
| 546 | * |
| 547 | * The return value is the number of characters which would be |
| 548 | * generated for the given input, excluding the trailing '\0', as |
| 549 | * per ISO C99. |
| 550 | */ |
| 551 | int bitmap_scnlistprintf(char *buf, unsigned int buflen, |
| 552 | const unsigned long *maskp, int nmaskbits) |
| 553 | { |
| 554 | int len = 0; |
| 555 | /* current bit is 'cur', most recently seen range is [rbot, rtop] */ |
| 556 | int cur, rbot, rtop; |
| 557 | |
Andi Kleen | 0b030c2 | 2007-11-05 14:50:56 -0800 | [diff] [blame] | 558 | if (buflen == 0) |
| 559 | return 0; |
| 560 | buf[0] = 0; |
| 561 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | rbot = cur = find_first_bit(maskp, nmaskbits); |
| 563 | while (cur < nmaskbits) { |
| 564 | rtop = cur; |
| 565 | cur = find_next_bit(maskp, nmaskbits, cur+1); |
| 566 | if (cur >= nmaskbits || cur > rtop + 1) { |
| 567 | len = bscnl_emit(buf, buflen, rbot, rtop, len); |
| 568 | rbot = cur; |
| 569 | } |
| 570 | } |
| 571 | return len; |
| 572 | } |
| 573 | EXPORT_SYMBOL(bitmap_scnlistprintf); |
| 574 | |
| 575 | /** |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 576 | * __bitmap_parselist - convert list format ASCII string to bitmap |
Randy Dunlap | b0825ee | 2011-06-15 15:08:10 -0700 | [diff] [blame] | 577 | * @buf: read nul-terminated user string from this buffer |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 578 | * @buflen: buffer size in bytes. If string is smaller than this |
| 579 | * then it must be terminated with a \0. |
| 580 | * @is_user: location of buffer, 0 indicates kernel space |
Randy Dunlap | 6e1907ff | 2006-06-25 05:48:57 -0700 | [diff] [blame] | 581 | * @maskp: write resulting mask here |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | * @nmaskbits: number of bits in mask to be written |
| 583 | * |
| 584 | * Input format is a comma-separated list of decimal numbers and |
| 585 | * ranges. Consecutively set bits are shown as two hyphen-separated |
| 586 | * decimal numbers, the smallest and largest bit numbers set in |
| 587 | * the range. |
| 588 | * |
Randy Dunlap | 6e1907ff | 2006-06-25 05:48:57 -0700 | [diff] [blame] | 589 | * Returns 0 on success, -errno on invalid input strings. |
| 590 | * Error values: |
| 591 | * %-EINVAL: second number in range smaller than first |
| 592 | * %-EINVAL: invalid character in string |
| 593 | * %-ERANGE: bit number specified too large for mask |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | */ |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 595 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
| 596 | int is_user, unsigned long *maskp, |
| 597 | int nmaskbits) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | { |
| 599 | unsigned a, b; |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 600 | int c, old_c, totaldigits; |
| 601 | const char __user *ubuf = buf; |
| 602 | int exp_digit, in_range; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 604 | totaldigits = c = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | bitmap_zero(maskp, nmaskbits); |
| 606 | do { |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 607 | exp_digit = 1; |
| 608 | in_range = 0; |
| 609 | a = b = 0; |
| 610 | |
| 611 | /* Get the next cpu# or a range of cpu#'s */ |
| 612 | while (buflen) { |
| 613 | old_c = c; |
| 614 | if (is_user) { |
| 615 | if (__get_user(c, ubuf++)) |
| 616 | return -EFAULT; |
| 617 | } else |
| 618 | c = *buf++; |
| 619 | buflen--; |
| 620 | if (isspace(c)) |
| 621 | continue; |
| 622 | |
| 623 | /* |
| 624 | * If the last character was a space and the current |
| 625 | * character isn't '\0', we've got embedded whitespace. |
| 626 | * This is a no-no, so throw an error. |
| 627 | */ |
| 628 | if (totaldigits && c && isspace(old_c)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | return -EINVAL; |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 630 | |
| 631 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
| 632 | if (c == '\0' || c == ',') |
| 633 | break; |
| 634 | |
| 635 | if (c == '-') { |
| 636 | if (exp_digit || in_range) |
| 637 | return -EINVAL; |
| 638 | b = 0; |
| 639 | in_range = 1; |
| 640 | exp_digit = 1; |
| 641 | continue; |
| 642 | } |
| 643 | |
| 644 | if (!isdigit(c)) |
| 645 | return -EINVAL; |
| 646 | |
| 647 | b = b * 10 + (c - '0'); |
| 648 | if (!in_range) |
| 649 | a = b; |
| 650 | exp_digit = 0; |
| 651 | totaldigits++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | } |
| 653 | if (!(a <= b)) |
| 654 | return -EINVAL; |
| 655 | if (b >= nmaskbits) |
| 656 | return -ERANGE; |
| 657 | while (a <= b) { |
| 658 | set_bit(a, maskp); |
| 659 | a++; |
| 660 | } |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 661 | } while (buflen && c == ','); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | return 0; |
| 663 | } |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 664 | |
| 665 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) |
| 666 | { |
| 667 | char *nl = strchr(bp, '\n'); |
| 668 | int len; |
| 669 | |
| 670 | if (nl) |
| 671 | len = nl - bp; |
| 672 | else |
| 673 | len = strlen(bp); |
| 674 | |
| 675 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); |
| 676 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 677 | EXPORT_SYMBOL(bitmap_parselist); |
| 678 | |
Mike Travis | 4b06042 | 2011-05-24 17:13:12 -0700 | [diff] [blame] | 679 | |
| 680 | /** |
| 681 | * bitmap_parselist_user() |
| 682 | * |
| 683 | * @ubuf: pointer to user buffer containing string. |
| 684 | * @ulen: buffer size in bytes. If string is smaller than this |
| 685 | * then it must be terminated with a \0. |
| 686 | * @maskp: pointer to bitmap array that will contain result. |
| 687 | * @nmaskbits: size of bitmap, in bits. |
| 688 | * |
| 689 | * Wrapper for bitmap_parselist(), providing it with user buffer. |
| 690 | * |
| 691 | * We cannot have this as an inline function in bitmap.h because it needs |
| 692 | * linux/uaccess.h to get the access_ok() declaration and this causes |
| 693 | * cyclic dependencies. |
| 694 | */ |
| 695 | int bitmap_parselist_user(const char __user *ubuf, |
| 696 | unsigned int ulen, unsigned long *maskp, |
| 697 | int nmaskbits) |
| 698 | { |
| 699 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
| 700 | return -EFAULT; |
| 701 | return __bitmap_parselist((const char *)ubuf, |
| 702 | ulen, 1, maskp, nmaskbits); |
| 703 | } |
| 704 | EXPORT_SYMBOL(bitmap_parselist_user); |
| 705 | |
| 706 | |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 707 | /** |
Ben Hutchings | 9a86e2b | 2010-03-05 13:43:17 -0800 | [diff] [blame] | 708 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 709 | * @buf: pointer to a bitmap |
| 710 | * @pos: a bit position in @buf (0 <= @pos < @bits) |
| 711 | * @bits: number of valid bit positions in @buf |
| 712 | * |
| 713 | * Map the bit at position @pos in @buf (of length @bits) to the |
| 714 | * ordinal of which set bit it is. If it is not set or if @pos |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 715 | * is not a valid bit position, map to -1. |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 716 | * |
| 717 | * If for example, just bits 4 through 7 are set in @buf, then @pos |
| 718 | * values 4 through 7 will get mapped to 0 through 3, respectively, |
| 719 | * and other @pos values will get mapped to 0. When @pos value 7 |
| 720 | * gets mapped to (returns) @ord value 3 in this example, that means |
| 721 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. |
| 722 | * |
| 723 | * The bit positions 0 through @bits are valid positions in @buf. |
| 724 | */ |
| 725 | static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) |
| 726 | { |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 727 | int i, ord; |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 728 | |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 729 | if (pos < 0 || pos >= bits || !test_bit(pos, buf)) |
| 730 | return -1; |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 731 | |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 732 | i = find_first_bit(buf, bits); |
| 733 | ord = 0; |
| 734 | while (i < pos) { |
| 735 | i = find_next_bit(buf, bits, i + 1); |
| 736 | ord++; |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 737 | } |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 738 | BUG_ON(i != pos); |
| 739 | |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 740 | return ord; |
| 741 | } |
| 742 | |
| 743 | /** |
Ben Hutchings | 9a86e2b | 2010-03-05 13:43:17 -0800 | [diff] [blame] | 744 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 745 | * @buf: pointer to bitmap |
| 746 | * @ord: ordinal bit position (n-th set bit, n >= 0) |
| 747 | * @bits: number of valid bit positions in @buf |
| 748 | * |
| 749 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 750 | * Value of @ord should be in range 0 <= @ord < weight(buf), else |
| 751 | * results are undefined. |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 752 | * |
| 753 | * If for example, just bits 4 through 7 are set in @buf, then @ord |
| 754 | * values 0 through 3 will get mapped to 4 through 7, respectively, |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 755 | * and all other @ord values return undefined values. When @ord value 3 |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 756 | * gets mapped to (returns) @pos value 7 in this example, that means |
| 757 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. |
| 758 | * |
| 759 | * The bit positions 0 through @bits are valid positions in @buf. |
| 760 | */ |
Linus Torvalds | 35926ff | 2010-05-30 09:00:03 -0700 | [diff] [blame] | 761 | static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 762 | { |
| 763 | int pos = 0; |
| 764 | |
| 765 | if (ord >= 0 && ord < bits) { |
| 766 | int i; |
| 767 | |
| 768 | for (i = find_first_bit(buf, bits); |
| 769 | i < bits && ord > 0; |
| 770 | i = find_next_bit(buf, bits, i + 1)) |
| 771 | ord--; |
| 772 | if (i < bits && ord == 0) |
| 773 | pos = i; |
| 774 | } |
| 775 | |
| 776 | return pos; |
| 777 | } |
| 778 | |
| 779 | /** |
| 780 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 781 | * @dst: remapped result |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 782 | * @src: subset to be remapped |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 783 | * @old: defines domain of map |
| 784 | * @new: defines range of map |
| 785 | * @bits: number of bits in each of these bitmaps |
| 786 | * |
| 787 | * Let @old and @new define a mapping of bit positions, such that |
| 788 | * whatever position is held by the n-th set bit in @old is mapped |
| 789 | * to the n-th set bit in @new. In the more general case, allowing |
| 790 | * for the possibility that the weight 'w' of @new is less than the |
| 791 | * weight of @old, map the position of the n-th set bit in @old to |
| 792 | * the position of the m-th set bit in @new, where m == n % w. |
| 793 | * |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 794 | * If either of the @old and @new bitmaps are empty, or if @src and |
| 795 | * @dst point to the same location, then this routine copies @src |
| 796 | * to @dst. |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 797 | * |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 798 | * The positions of unset bits in @old are mapped to themselves |
| 799 | * (the identify map). |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 800 | * |
| 801 | * Apply the above specified mapping to @src, placing the result in |
| 802 | * @dst, clearing any bits previously set in @dst. |
| 803 | * |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 804 | * For example, lets say that @old has bits 4 through 7 set, and |
| 805 | * @new has bits 12 through 15 set. This defines the mapping of bit |
| 806 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 807 | * bit positions unchanged. So if say @src comes into this routine |
| 808 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, |
| 809 | * 13 and 15 set. |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 810 | */ |
| 811 | void bitmap_remap(unsigned long *dst, const unsigned long *src, |
| 812 | const unsigned long *old, const unsigned long *new, |
| 813 | int bits) |
| 814 | { |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 815 | int oldbit, w; |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 816 | |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 817 | if (dst == src) /* following doesn't handle inplace remaps */ |
| 818 | return; |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 819 | bitmap_zero(dst, bits); |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 820 | |
| 821 | w = bitmap_weight(new, bits); |
Akinobu Mita | 08564fb | 2010-03-05 13:43:18 -0800 | [diff] [blame] | 822 | for_each_set_bit(oldbit, src, bits) { |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 823 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
Akinobu Mita | 08564fb | 2010-03-05 13:43:18 -0800 | [diff] [blame] | 824 | |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 825 | if (n < 0 || w == 0) |
| 826 | set_bit(oldbit, dst); /* identity map */ |
| 827 | else |
| 828 | set_bit(bitmap_ord_to_pos(new, n % w, bits), dst); |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 829 | } |
| 830 | } |
| 831 | EXPORT_SYMBOL(bitmap_remap); |
| 832 | |
| 833 | /** |
| 834 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit |
Randy Dunlap | 6e1907ff | 2006-06-25 05:48:57 -0700 | [diff] [blame] | 835 | * @oldbit: bit position to be mapped |
| 836 | * @old: defines domain of map |
| 837 | * @new: defines range of map |
| 838 | * @bits: number of bits in each of these bitmaps |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 839 | * |
| 840 | * Let @old and @new define a mapping of bit positions, such that |
| 841 | * whatever position is held by the n-th set bit in @old is mapped |
| 842 | * to the n-th set bit in @new. In the more general case, allowing |
| 843 | * for the possibility that the weight 'w' of @new is less than the |
| 844 | * weight of @old, map the position of the n-th set bit in @old to |
| 845 | * the position of the m-th set bit in @new, where m == n % w. |
| 846 | * |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 847 | * The positions of unset bits in @old are mapped to themselves |
| 848 | * (the identify map). |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 849 | * |
| 850 | * Apply the above specified mapping to bit position @oldbit, returning |
| 851 | * the new bit position. |
| 852 | * |
| 853 | * For example, lets say that @old has bits 4 through 7 set, and |
| 854 | * @new has bits 12 through 15 set. This defines the mapping of bit |
| 855 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 856 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
| 857 | * returns 13. |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 858 | */ |
| 859 | int bitmap_bitremap(int oldbit, const unsigned long *old, |
| 860 | const unsigned long *new, int bits) |
| 861 | { |
Paul Jackson | 96b7f34 | 2006-01-08 01:01:46 -0800 | [diff] [blame] | 862 | int w = bitmap_weight(new, bits); |
| 863 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
| 864 | if (n < 0 || w == 0) |
| 865 | return oldbit; |
| 866 | else |
| 867 | return bitmap_ord_to_pos(new, n % w, bits); |
Paul Jackson | fb5eeee | 2005-10-30 15:02:33 -0800 | [diff] [blame] | 868 | } |
| 869 | EXPORT_SYMBOL(bitmap_bitremap); |
| 870 | |
Paul Jackson | 7ea931c | 2008-04-28 02:12:29 -0700 | [diff] [blame] | 871 | /** |
| 872 | * bitmap_onto - translate one bitmap relative to another |
| 873 | * @dst: resulting translated bitmap |
| 874 | * @orig: original untranslated bitmap |
| 875 | * @relmap: bitmap relative to which translated |
| 876 | * @bits: number of bits in each of these bitmaps |
| 877 | * |
| 878 | * Set the n-th bit of @dst iff there exists some m such that the |
| 879 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and |
| 880 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. |
| 881 | * (If you understood the previous sentence the first time your |
| 882 | * read it, you're overqualified for your current job.) |
| 883 | * |
| 884 | * In other words, @orig is mapped onto (surjectively) @dst, |
| 885 | * using the the map { <n, m> | the n-th bit of @relmap is the |
| 886 | * m-th set bit of @relmap }. |
| 887 | * |
| 888 | * Any set bits in @orig above bit number W, where W is the |
| 889 | * weight of (number of set bits in) @relmap are mapped nowhere. |
| 890 | * In particular, if for all bits m set in @orig, m >= W, then |
| 891 | * @dst will end up empty. In situations where the possibility |
| 892 | * of such an empty result is not desired, one way to avoid it is |
| 893 | * to use the bitmap_fold() operator, below, to first fold the |
| 894 | * @orig bitmap over itself so that all its set bits x are in the |
| 895 | * range 0 <= x < W. The bitmap_fold() operator does this by |
| 896 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. |
| 897 | * |
| 898 | * Example [1] for bitmap_onto(): |
| 899 | * Let's say @relmap has bits 30-39 set, and @orig has bits |
| 900 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, |
| 901 | * @dst will have bits 31, 33, 35, 37 and 39 set. |
| 902 | * |
| 903 | * When bit 0 is set in @orig, it means turn on the bit in |
| 904 | * @dst corresponding to whatever is the first bit (if any) |
| 905 | * that is turned on in @relmap. Since bit 0 was off in the |
| 906 | * above example, we leave off that bit (bit 30) in @dst. |
| 907 | * |
| 908 | * When bit 1 is set in @orig (as in the above example), it |
| 909 | * means turn on the bit in @dst corresponding to whatever |
| 910 | * is the second bit that is turned on in @relmap. The second |
| 911 | * bit in @relmap that was turned on in the above example was |
| 912 | * bit 31, so we turned on bit 31 in @dst. |
| 913 | * |
| 914 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, |
| 915 | * because they were the 4th, 6th, 8th and 10th set bits |
| 916 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of |
| 917 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. |
| 918 | * |
| 919 | * When bit 11 is set in @orig, it means turn on the bit in |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 920 | * @dst corresponding to whatever is the twelfth bit that is |
Paul Jackson | 7ea931c | 2008-04-28 02:12:29 -0700 | [diff] [blame] | 921 | * turned on in @relmap. In the above example, there were |
| 922 | * only ten bits turned on in @relmap (30..39), so that bit |
| 923 | * 11 was set in @orig had no affect on @dst. |
| 924 | * |
| 925 | * Example [2] for bitmap_fold() + bitmap_onto(): |
| 926 | * Let's say @relmap has these ten bits set: |
| 927 | * 40 41 42 43 45 48 53 61 74 95 |
| 928 | * (for the curious, that's 40 plus the first ten terms of the |
| 929 | * Fibonacci sequence.) |
| 930 | * |
| 931 | * Further lets say we use the following code, invoking |
| 932 | * bitmap_fold() then bitmap_onto, as suggested above to |
| 933 | * avoid the possitility of an empty @dst result: |
| 934 | * |
| 935 | * unsigned long *tmp; // a temporary bitmap's bits |
| 936 | * |
| 937 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); |
| 938 | * bitmap_onto(dst, tmp, relmap, bits); |
| 939 | * |
| 940 | * Then this table shows what various values of @dst would be, for |
| 941 | * various @orig's. I list the zero-based positions of each set bit. |
| 942 | * The tmp column shows the intermediate result, as computed by |
| 943 | * using bitmap_fold() to fold the @orig bitmap modulo ten |
| 944 | * (the weight of @relmap). |
| 945 | * |
| 946 | * @orig tmp @dst |
| 947 | * 0 0 40 |
| 948 | * 1 1 41 |
| 949 | * 9 9 95 |
| 950 | * 10 0 40 (*) |
| 951 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
| 952 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 |
| 953 | * 0 9 18 27 0 9 8 7 40 61 74 95 |
| 954 | * 0 10 20 30 0 40 |
| 955 | * 0 11 22 33 0 1 2 3 40 41 42 43 |
| 956 | * 0 12 24 36 0 2 4 6 40 42 45 53 |
| 957 | * 78 102 211 1 2 8 41 42 74 (*) |
| 958 | * |
| 959 | * (*) For these marked lines, if we hadn't first done bitmap_fold() |
| 960 | * into tmp, then the @dst result would have been empty. |
| 961 | * |
| 962 | * If either of @orig or @relmap is empty (no set bits), then @dst |
| 963 | * will be returned empty. |
| 964 | * |
| 965 | * If (as explained above) the only set bits in @orig are in positions |
| 966 | * m where m >= W, (where W is the weight of @relmap) then @dst will |
| 967 | * once again be returned empty. |
| 968 | * |
| 969 | * All bits in @dst not set by the above rule are cleared. |
| 970 | */ |
| 971 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, |
| 972 | const unsigned long *relmap, int bits) |
| 973 | { |
| 974 | int n, m; /* same meaning as in above comment */ |
| 975 | |
| 976 | if (dst == orig) /* following doesn't handle inplace mappings */ |
| 977 | return; |
| 978 | bitmap_zero(dst, bits); |
| 979 | |
| 980 | /* |
| 981 | * The following code is a more efficient, but less |
| 982 | * obvious, equivalent to the loop: |
| 983 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { |
| 984 | * n = bitmap_ord_to_pos(orig, m, bits); |
| 985 | * if (test_bit(m, orig)) |
| 986 | * set_bit(n, dst); |
| 987 | * } |
| 988 | */ |
| 989 | |
| 990 | m = 0; |
Akinobu Mita | 08564fb | 2010-03-05 13:43:18 -0800 | [diff] [blame] | 991 | for_each_set_bit(n, relmap, bits) { |
Paul Jackson | 7ea931c | 2008-04-28 02:12:29 -0700 | [diff] [blame] | 992 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
| 993 | if (test_bit(m, orig)) |
| 994 | set_bit(n, dst); |
| 995 | m++; |
| 996 | } |
| 997 | } |
| 998 | EXPORT_SYMBOL(bitmap_onto); |
| 999 | |
| 1000 | /** |
| 1001 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size |
| 1002 | * @dst: resulting smaller bitmap |
| 1003 | * @orig: original larger bitmap |
| 1004 | * @sz: specified size |
| 1005 | * @bits: number of bits in each of these bitmaps |
| 1006 | * |
| 1007 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. |
| 1008 | * Clear all other bits in @dst. See further the comment and |
| 1009 | * Example [2] for bitmap_onto() for why and how to use this. |
| 1010 | */ |
| 1011 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, |
| 1012 | int sz, int bits) |
| 1013 | { |
| 1014 | int oldbit; |
| 1015 | |
| 1016 | if (dst == orig) /* following doesn't handle inplace mappings */ |
| 1017 | return; |
| 1018 | bitmap_zero(dst, bits); |
| 1019 | |
Akinobu Mita | 08564fb | 2010-03-05 13:43:18 -0800 | [diff] [blame] | 1020 | for_each_set_bit(oldbit, orig, bits) |
Paul Jackson | 7ea931c | 2008-04-28 02:12:29 -0700 | [diff] [blame] | 1021 | set_bit(oldbit % sz, dst); |
| 1022 | } |
| 1023 | EXPORT_SYMBOL(bitmap_fold); |
| 1024 | |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1025 | /* |
| 1026 | * Common code for bitmap_*_region() routines. |
| 1027 | * bitmap: array of unsigned longs corresponding to the bitmap |
| 1028 | * pos: the beginning of the region |
| 1029 | * order: region size (log base 2 of number of bits) |
| 1030 | * reg_op: operation(s) to perform on that region of bitmap |
| 1031 | * |
| 1032 | * Can set, verify and/or release a region of bits in a bitmap, |
| 1033 | * depending on which combination of REG_OP_* flag bits is set. |
| 1034 | * |
| 1035 | * A region of a bitmap is a sequence of bits in the bitmap, of |
| 1036 | * some size '1 << order' (a power of two), aligned to that same |
| 1037 | * '1 << order' power of two. |
| 1038 | * |
| 1039 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). |
| 1040 | * Returns 0 in all other cases and reg_ops. |
| 1041 | */ |
| 1042 | |
| 1043 | enum { |
| 1044 | REG_OP_ISFREE, /* true if region is all zero bits */ |
| 1045 | REG_OP_ALLOC, /* set all bits in region */ |
| 1046 | REG_OP_RELEASE, /* clear all bits in region */ |
| 1047 | }; |
| 1048 | |
| 1049 | static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) |
| 1050 | { |
| 1051 | int nbits_reg; /* number of bits in region */ |
| 1052 | int index; /* index first long of region in bitmap */ |
| 1053 | int offset; /* bit offset region in bitmap[index] */ |
| 1054 | int nlongs_reg; /* num longs spanned by region in bitmap */ |
| 1055 | int nbitsinlong; /* num bits of region in each spanned long */ |
| 1056 | unsigned long mask; /* bitmask for one long of region */ |
| 1057 | int i; /* scans bitmap by longs */ |
| 1058 | int ret = 0; /* return value */ |
| 1059 | |
| 1060 | /* |
| 1061 | * Either nlongs_reg == 1 (for small orders that fit in one long) |
| 1062 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) |
| 1063 | */ |
| 1064 | nbits_reg = 1 << order; |
| 1065 | index = pos / BITS_PER_LONG; |
| 1066 | offset = pos - (index * BITS_PER_LONG); |
| 1067 | nlongs_reg = BITS_TO_LONGS(nbits_reg); |
| 1068 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); |
| 1069 | |
| 1070 | /* |
| 1071 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that |
| 1072 | * overflows if nbitsinlong == BITS_PER_LONG. |
| 1073 | */ |
| 1074 | mask = (1UL << (nbitsinlong - 1)); |
| 1075 | mask += mask - 1; |
| 1076 | mask <<= offset; |
| 1077 | |
| 1078 | switch (reg_op) { |
| 1079 | case REG_OP_ISFREE: |
| 1080 | for (i = 0; i < nlongs_reg; i++) { |
| 1081 | if (bitmap[index + i] & mask) |
| 1082 | goto done; |
| 1083 | } |
| 1084 | ret = 1; /* all bits in region free (zero) */ |
| 1085 | break; |
| 1086 | |
| 1087 | case REG_OP_ALLOC: |
| 1088 | for (i = 0; i < nlongs_reg; i++) |
| 1089 | bitmap[index + i] |= mask; |
| 1090 | break; |
| 1091 | |
| 1092 | case REG_OP_RELEASE: |
| 1093 | for (i = 0; i < nlongs_reg; i++) |
| 1094 | bitmap[index + i] &= ~mask; |
| 1095 | break; |
| 1096 | } |
| 1097 | done: |
| 1098 | return ret; |
| 1099 | } |
| 1100 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | /** |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1102 | * bitmap_find_free_region - find a contiguous aligned mem region |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1103 | * @bitmap: array of unsigned longs corresponding to the bitmap |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1104 | * @bits: number of bits in the bitmap |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1105 | * @order: region size (log base 2 of number of bits) to find |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1106 | * |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1107 | * Find a region of free (zero) bits in a @bitmap of @bits bits and |
| 1108 | * allocate them (set them to one). Only consider regions of length |
| 1109 | * a power (@order) of two, aligned to that power of two, which |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1110 | * makes the search algorithm much faster. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1111 | * |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1112 | * Return the bit offset in bitmap of the allocated region, |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1113 | * or -errno on failure. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | */ |
| 1115 | int bitmap_find_free_region(unsigned long *bitmap, int bits, int order) |
| 1116 | { |
Linus Torvalds | aa8e4fc | 2009-03-12 19:32:51 -0700 | [diff] [blame] | 1117 | int pos, end; /* scans bitmap by regions of size order */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | |
Linus Torvalds | aa8e4fc | 2009-03-12 19:32:51 -0700 | [diff] [blame] | 1119 | for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) { |
| 1120 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
| 1121 | continue; |
| 1122 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
| 1123 | return pos; |
| 1124 | } |
| 1125 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | } |
| 1127 | EXPORT_SYMBOL(bitmap_find_free_region); |
| 1128 | |
| 1129 | /** |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1130 | * bitmap_release_region - release allocated bitmap region |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1131 | * @bitmap: array of unsigned longs corresponding to the bitmap |
| 1132 | * @pos: beginning of bit region to release |
| 1133 | * @order: region size (log base 2 of number of bits) to release |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1134 | * |
Robert P. J. Day | 72fd4a3 | 2007-02-10 01:45:59 -0800 | [diff] [blame] | 1135 | * This is the complement to __bitmap_find_free_region() and releases |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | * the found region (by clearing it in the bitmap). |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1137 | * |
| 1138 | * No return value. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1139 | */ |
| 1140 | void bitmap_release_region(unsigned long *bitmap, int pos, int order) |
| 1141 | { |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1142 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | } |
| 1144 | EXPORT_SYMBOL(bitmap_release_region); |
| 1145 | |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1146 | /** |
| 1147 | * bitmap_allocate_region - allocate bitmap region |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1148 | * @bitmap: array of unsigned longs corresponding to the bitmap |
| 1149 | * @pos: beginning of bit region to allocate |
| 1150 | * @order: region size (log base 2 of number of bits) to allocate |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1151 | * |
| 1152 | * Allocate (set bits in) a specified region of a bitmap. |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1153 | * |
Randy Dunlap | 6e1907ff | 2006-06-25 05:48:57 -0700 | [diff] [blame] | 1154 | * Return 0 on success, or %-EBUSY if specified region wasn't |
Paul Jackson | 87e2480 | 2006-03-24 03:15:44 -0800 | [diff] [blame] | 1155 | * free (not all bits were zero). |
| 1156 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | int bitmap_allocate_region(unsigned long *bitmap, int pos, int order) |
| 1158 | { |
Paul Jackson | 3cf64b9 | 2006-03-24 03:15:46 -0800 | [diff] [blame] | 1159 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
| 1160 | return -EBUSY; |
| 1161 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | return 0; |
| 1163 | } |
| 1164 | EXPORT_SYMBOL(bitmap_allocate_region); |
David Vrabel | ccbe329 | 2008-09-17 16:34:03 +0100 | [diff] [blame] | 1165 | |
| 1166 | /** |
| 1167 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. |
| 1168 | * @dst: destination buffer |
| 1169 | * @src: bitmap to copy |
| 1170 | * @nbits: number of bits in the bitmap |
| 1171 | * |
| 1172 | * Require nbits % BITS_PER_LONG == 0. |
| 1173 | */ |
| 1174 | void bitmap_copy_le(void *dst, const unsigned long *src, int nbits) |
| 1175 | { |
| 1176 | unsigned long *d = dst; |
| 1177 | int i; |
| 1178 | |
| 1179 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { |
| 1180 | if (BITS_PER_LONG == 64) |
| 1181 | d[i] = cpu_to_le64(src[i]); |
| 1182 | else |
| 1183 | d[i] = cpu_to_le32(src[i]); |
| 1184 | } |
| 1185 | } |
| 1186 | EXPORT_SYMBOL(bitmap_copy_le); |