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