1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __LINUX_BITMAP_H 3 #define __LINUX_BITMAP_H 4 5 #ifndef __ASSEMBLY__ 6 7 #include <linux/align.h> 8 #include <linux/bitops.h> 9 #include <linux/limits.h> 10 #include <linux/string.h> 11 #include <linux/types.h> 12 13 struct device; 14 15 /* 16 * bitmaps provide bit arrays that consume one or more unsigned 17 * longs. The bitmap interface and available operations are listed 18 * here, in bitmap.h 19 * 20 * Function implementations generic to all architectures are in 21 * lib/bitmap.c. Functions implementations that are architecture 22 * specific are in various include/asm-<arch>/bitops.h headers 23 * and other arch/<arch> specific files. 24 * 25 * See lib/bitmap.c for more details. 26 */ 27 28 /** 29 * DOC: bitmap overview 30 * 31 * The available bitmap operations and their rough meaning in the 32 * case that the bitmap is a single unsigned long are thus: 33 * 34 * The generated code is more efficient when nbits is known at 35 * compile-time and at most BITS_PER_LONG. 36 * 37 * :: 38 * 39 * bitmap_zero(dst, nbits) *dst = 0UL 40 * bitmap_fill(dst, nbits) *dst = ~0UL 41 * bitmap_copy(dst, src, nbits) *dst = *src 42 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 43 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 44 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 45 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 46 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 47 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 48 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 49 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? 50 * bitmap_empty(src, nbits) Are all bits zero in *src? 51 * bitmap_full(src, nbits) Are all bits set in *src? 52 * bitmap_weight(src, nbits) Hamming Weight: number set bits 53 * bitmap_set(dst, pos, nbits) Set specified bit area 54 * bitmap_clear(dst, pos, nbits) Clear specified bit area 55 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 56 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above 57 * bitmap_next_clear_region(map, &start, &end, nbits) Find next clear region 58 * bitmap_next_set_region(map, &start, &end, nbits) Find next set region 59 * bitmap_for_each_clear_region(map, rs, re, start, end) 60 * Iterate over all clear regions 61 * bitmap_for_each_set_region(map, rs, re, start, end) 62 * Iterate over all set regions 63 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n 64 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n 65 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest 66 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask) 67 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 68 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 69 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 70 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 71 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 72 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 73 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 74 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 75 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 76 * bitmap_release_region(bitmap, pos, order) Free specified bit region 77 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 78 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst 79 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst 80 * bitmap_get_value8(map, start) Get 8bit value from map at start 81 * bitmap_set_value8(map, value, start) Set 8bit value to map at start 82 * 83 * Note, bitmap_zero() and bitmap_fill() operate over the region of 84 * unsigned longs, that is, bits behind bitmap till the unsigned long 85 * boundary will be zeroed or filled as well. Consider to use 86 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling 87 * respectively. 88 */ 89 90 /** 91 * DOC: bitmap bitops 92 * 93 * Also the following operations in asm/bitops.h apply to bitmaps.:: 94 * 95 * set_bit(bit, addr) *addr |= bit 96 * clear_bit(bit, addr) *addr &= ~bit 97 * change_bit(bit, addr) *addr ^= bit 98 * test_bit(bit, addr) Is bit set in *addr? 99 * test_and_set_bit(bit, addr) Set bit and return old value 100 * test_and_clear_bit(bit, addr) Clear bit and return old value 101 * test_and_change_bit(bit, addr) Change bit and return old value 102 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 103 * find_first_bit(addr, nbits) Position first set bit in *addr 104 * find_next_zero_bit(addr, nbits, bit) 105 * Position next zero bit in *addr >= bit 106 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 107 * find_next_and_bit(addr1, addr2, nbits, bit) 108 * Same as find_next_bit, but in 109 * (*addr1 & *addr2) 110 * 111 */ 112 113 /** 114 * DOC: declare bitmap 115 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 116 * to declare an array named 'name' of just enough unsigned longs to 117 * contain all bit positions from 0 to 'bits' - 1. 118 */ 119 120 /* 121 * Allocation and deallocation of bitmap. 122 * Provided in lib/bitmap.c to avoid circular dependency. 123 */ 124 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags); 125 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags); 126 void bitmap_free(const unsigned long *bitmap); 127 128 /* Managed variants of the above. */ 129 unsigned long *devm_bitmap_alloc(struct device *dev, 130 unsigned int nbits, gfp_t flags); 131 unsigned long *devm_bitmap_zalloc(struct device *dev, 132 unsigned int nbits, gfp_t flags); 133 134 /* 135 * lib/bitmap.c provides these functions: 136 */ 137 138 int __bitmap_equal(const unsigned long *bitmap1, 139 const unsigned long *bitmap2, unsigned int nbits); 140 bool __pure __bitmap_or_equal(const unsigned long *src1, 141 const unsigned long *src2, 142 const unsigned long *src3, 143 unsigned int nbits); 144 void __bitmap_complement(unsigned long *dst, const unsigned long *src, 145 unsigned int nbits); 146 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 147 unsigned int shift, unsigned int nbits); 148 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 149 unsigned int shift, unsigned int nbits); 150 void bitmap_cut(unsigned long *dst, const unsigned long *src, 151 unsigned int first, unsigned int cut, unsigned int nbits); 152 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 153 const unsigned long *bitmap2, unsigned int nbits); 154 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 155 const unsigned long *bitmap2, unsigned int nbits); 156 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 157 const unsigned long *bitmap2, unsigned int nbits); 158 int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 159 const unsigned long *bitmap2, unsigned int nbits); 160 void __bitmap_replace(unsigned long *dst, 161 const unsigned long *old, const unsigned long *new, 162 const unsigned long *mask, unsigned int nbits); 163 int __bitmap_intersects(const unsigned long *bitmap1, 164 const unsigned long *bitmap2, unsigned int nbits); 165 int __bitmap_subset(const unsigned long *bitmap1, 166 const unsigned long *bitmap2, unsigned int nbits); 167 int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 168 void __bitmap_set(unsigned long *map, unsigned int start, int len); 169 void __bitmap_clear(unsigned long *map, unsigned int start, int len); 170 171 unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 172 unsigned long size, 173 unsigned long start, 174 unsigned int nr, 175 unsigned long align_mask, 176 unsigned long align_offset); 177 178 /** 179 * bitmap_find_next_zero_area - find a contiguous aligned zero area 180 * @map: The address to base the search on 181 * @size: The bitmap size in bits 182 * @start: The bitnumber to start searching at 183 * @nr: The number of zeroed bits we're looking for 184 * @align_mask: Alignment mask for zero area 185 * 186 * The @align_mask should be one less than a power of 2; the effect is that 187 * the bit offset of all zero areas this function finds is multiples of that 188 * power of 2. A @align_mask of 0 means no alignment is required. 189 */ 190 static inline unsigned long 191 bitmap_find_next_zero_area(unsigned long *map, 192 unsigned long size, 193 unsigned long start, 194 unsigned int nr, 195 unsigned long align_mask) 196 { 197 return bitmap_find_next_zero_area_off(map, size, start, nr, 198 align_mask, 0); 199 } 200 201 int bitmap_parse(const char *buf, unsigned int buflen, 202 unsigned long *dst, int nbits); 203 int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, 204 unsigned long *dst, int nbits); 205 int bitmap_parselist(const char *buf, unsigned long *maskp, 206 int nmaskbits); 207 int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, 208 unsigned long *dst, int nbits); 209 void bitmap_remap(unsigned long *dst, const unsigned long *src, 210 const unsigned long *old, const unsigned long *new, unsigned int nbits); 211 int bitmap_bitremap(int oldbit, 212 const unsigned long *old, const unsigned long *new, int bits); 213 void bitmap_onto(unsigned long *dst, const unsigned long *orig, 214 const unsigned long *relmap, unsigned int bits); 215 void bitmap_fold(unsigned long *dst, const unsigned long *orig, 216 unsigned int sz, unsigned int nbits); 217 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 218 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 219 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 220 221 #ifdef __BIG_ENDIAN 222 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); 223 #else 224 #define bitmap_copy_le bitmap_copy 225 #endif 226 unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); 227 int bitmap_print_to_pagebuf(bool list, char *buf, 228 const unsigned long *maskp, int nmaskbits); 229 230 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 231 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 232 233 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 234 { 235 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 236 memset(dst, 0, len); 237 } 238 239 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 240 { 241 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 242 memset(dst, 0xff, len); 243 } 244 245 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 246 unsigned int nbits) 247 { 248 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 249 memcpy(dst, src, len); 250 } 251 252 /* 253 * Copy bitmap and clear tail bits in last word. 254 */ 255 static inline void bitmap_copy_clear_tail(unsigned long *dst, 256 const unsigned long *src, unsigned int nbits) 257 { 258 bitmap_copy(dst, src, nbits); 259 if (nbits % BITS_PER_LONG) 260 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); 261 } 262 263 /* 264 * On 32-bit systems bitmaps are represented as u32 arrays internally, and 265 * therefore conversion is not needed when copying data from/to arrays of u32. 266 */ 267 #if BITS_PER_LONG == 64 268 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, 269 unsigned int nbits); 270 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, 271 unsigned int nbits); 272 #else 273 #define bitmap_from_arr32(bitmap, buf, nbits) \ 274 bitmap_copy_clear_tail((unsigned long *) (bitmap), \ 275 (const unsigned long *) (buf), (nbits)) 276 #define bitmap_to_arr32(buf, bitmap, nbits) \ 277 bitmap_copy_clear_tail((unsigned long *) (buf), \ 278 (const unsigned long *) (bitmap), (nbits)) 279 #endif 280 281 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 282 const unsigned long *src2, unsigned int nbits) 283 { 284 if (small_const_nbits(nbits)) 285 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 286 return __bitmap_and(dst, src1, src2, nbits); 287 } 288 289 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 290 const unsigned long *src2, unsigned int nbits) 291 { 292 if (small_const_nbits(nbits)) 293 *dst = *src1 | *src2; 294 else 295 __bitmap_or(dst, src1, src2, nbits); 296 } 297 298 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 299 const unsigned long *src2, unsigned int nbits) 300 { 301 if (small_const_nbits(nbits)) 302 *dst = *src1 ^ *src2; 303 else 304 __bitmap_xor(dst, src1, src2, nbits); 305 } 306 307 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 308 const unsigned long *src2, unsigned int nbits) 309 { 310 if (small_const_nbits(nbits)) 311 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 312 return __bitmap_andnot(dst, src1, src2, nbits); 313 } 314 315 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 316 unsigned int nbits) 317 { 318 if (small_const_nbits(nbits)) 319 *dst = ~(*src); 320 else 321 __bitmap_complement(dst, src, nbits); 322 } 323 324 #ifdef __LITTLE_ENDIAN 325 #define BITMAP_MEM_ALIGNMENT 8 326 #else 327 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) 328 #endif 329 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) 330 331 static inline int bitmap_equal(const unsigned long *src1, 332 const unsigned long *src2, unsigned int nbits) 333 { 334 if (small_const_nbits(nbits)) 335 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 336 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && 337 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 338 return !memcmp(src1, src2, nbits / 8); 339 return __bitmap_equal(src1, src2, nbits); 340 } 341 342 /** 343 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third 344 * @src1: Pointer to bitmap 1 345 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1 346 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2 347 * @nbits: number of bits in each of these bitmaps 348 * 349 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise 350 */ 351 static inline bool bitmap_or_equal(const unsigned long *src1, 352 const unsigned long *src2, 353 const unsigned long *src3, 354 unsigned int nbits) 355 { 356 if (!small_const_nbits(nbits)) 357 return __bitmap_or_equal(src1, src2, src3, nbits); 358 359 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits)); 360 } 361 362 static inline int bitmap_intersects(const unsigned long *src1, 363 const unsigned long *src2, unsigned int nbits) 364 { 365 if (small_const_nbits(nbits)) 366 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 367 else 368 return __bitmap_intersects(src1, src2, nbits); 369 } 370 371 static inline int bitmap_subset(const unsigned long *src1, 372 const unsigned long *src2, unsigned int nbits) 373 { 374 if (small_const_nbits(nbits)) 375 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 376 else 377 return __bitmap_subset(src1, src2, nbits); 378 } 379 380 static inline bool bitmap_empty(const unsigned long *src, unsigned nbits) 381 { 382 if (small_const_nbits(nbits)) 383 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 384 385 return find_first_bit(src, nbits) == nbits; 386 } 387 388 static inline bool bitmap_full(const unsigned long *src, unsigned int nbits) 389 { 390 if (small_const_nbits(nbits)) 391 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 392 393 return find_first_zero_bit(src, nbits) == nbits; 394 } 395 396 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 397 { 398 if (small_const_nbits(nbits)) 399 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 400 return __bitmap_weight(src, nbits); 401 } 402 403 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 404 unsigned int nbits) 405 { 406 if (__builtin_constant_p(nbits) && nbits == 1) 407 __set_bit(start, map); 408 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 409 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 410 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 411 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 412 memset((char *)map + start / 8, 0xff, nbits / 8); 413 else 414 __bitmap_set(map, start, nbits); 415 } 416 417 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 418 unsigned int nbits) 419 { 420 if (__builtin_constant_p(nbits) && nbits == 1) 421 __clear_bit(start, map); 422 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 423 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 424 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 425 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 426 memset((char *)map + start / 8, 0, nbits / 8); 427 else 428 __bitmap_clear(map, start, nbits); 429 } 430 431 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 432 unsigned int shift, unsigned int nbits) 433 { 434 if (small_const_nbits(nbits)) 435 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 436 else 437 __bitmap_shift_right(dst, src, shift, nbits); 438 } 439 440 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 441 unsigned int shift, unsigned int nbits) 442 { 443 if (small_const_nbits(nbits)) 444 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 445 else 446 __bitmap_shift_left(dst, src, shift, nbits); 447 } 448 449 static inline void bitmap_replace(unsigned long *dst, 450 const unsigned long *old, 451 const unsigned long *new, 452 const unsigned long *mask, 453 unsigned int nbits) 454 { 455 if (small_const_nbits(nbits)) 456 *dst = (*old & ~(*mask)) | (*new & *mask); 457 else 458 __bitmap_replace(dst, old, new, mask, nbits); 459 } 460 461 static inline void bitmap_next_clear_region(unsigned long *bitmap, 462 unsigned int *rs, unsigned int *re, 463 unsigned int end) 464 { 465 *rs = find_next_zero_bit(bitmap, end, *rs); 466 *re = find_next_bit(bitmap, end, *rs + 1); 467 } 468 469 static inline void bitmap_next_set_region(unsigned long *bitmap, 470 unsigned int *rs, unsigned int *re, 471 unsigned int end) 472 { 473 *rs = find_next_bit(bitmap, end, *rs); 474 *re = find_next_zero_bit(bitmap, end, *rs + 1); 475 } 476 477 /* 478 * Bitmap region iterators. Iterates over the bitmap between [@start, @end). 479 * @rs and @re should be integer variables and will be set to start and end 480 * index of the current clear or set region. 481 */ 482 #define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \ 483 for ((rs) = (start), \ 484 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \ 485 (rs) < (re); \ 486 (rs) = (re) + 1, \ 487 bitmap_next_clear_region((bitmap), &(rs), &(re), (end))) 488 489 #define bitmap_for_each_set_region(bitmap, rs, re, start, end) \ 490 for ((rs) = (start), \ 491 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \ 492 (rs) < (re); \ 493 (rs) = (re) + 1, \ 494 bitmap_next_set_region((bitmap), &(rs), &(re), (end))) 495 496 /** 497 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 498 * @n: u64 value 499 * 500 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 501 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 502 * 503 * There are four combinations of endianness and length of the word in linux 504 * ABIs: LE64, BE64, LE32 and BE32. 505 * 506 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 507 * bitmaps and therefore don't require any special handling. 508 * 509 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 510 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 511 * other hand is represented as an array of 32-bit words and the position of 512 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 513 * word. For example, bit #42 is located at 10th position of 2nd word. 514 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 515 * values in memory as it usually does. But for BE we need to swap hi and lo 516 * words manually. 517 * 518 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 519 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 520 * hi and lo words, as is expected by bitmap. 521 */ 522 #if __BITS_PER_LONG == 64 523 #define BITMAP_FROM_U64(n) (n) 524 #else 525 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 526 ((unsigned long) ((u64)(n) >> 32)) 527 #endif 528 529 /** 530 * bitmap_from_u64 - Check and swap words within u64. 531 * @mask: source bitmap 532 * @dst: destination bitmap 533 * 534 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 535 * to read u64 mask, we will get the wrong word. 536 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 537 * but we expect the lower 32-bits of u64. 538 */ 539 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 540 { 541 dst[0] = mask & ULONG_MAX; 542 543 if (sizeof(mask) > sizeof(unsigned long)) 544 dst[1] = mask >> 32; 545 } 546 547 /** 548 * bitmap_get_value8 - get an 8-bit value within a memory region 549 * @map: address to the bitmap memory region 550 * @start: bit offset of the 8-bit value; must be a multiple of 8 551 * 552 * Returns the 8-bit value located at the @start bit offset within the @src 553 * memory region. 554 */ 555 static inline unsigned long bitmap_get_value8(const unsigned long *map, 556 unsigned long start) 557 { 558 const size_t index = BIT_WORD(start); 559 const unsigned long offset = start % BITS_PER_LONG; 560 561 return (map[index] >> offset) & 0xFF; 562 } 563 564 /** 565 * bitmap_set_value8 - set an 8-bit value within a memory region 566 * @map: address to the bitmap memory region 567 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap 568 * @start: bit offset of the 8-bit value; must be a multiple of 8 569 */ 570 static inline void bitmap_set_value8(unsigned long *map, unsigned long value, 571 unsigned long start) 572 { 573 const size_t index = BIT_WORD(start); 574 const unsigned long offset = start % BITS_PER_LONG; 575 576 map[index] &= ~(0xFFUL << offset); 577 map[index] |= value << offset; 578 } 579 580 #endif /* __ASSEMBLY__ */ 581 582 #endif /* __LINUX_BITMAP_H */ 583