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/find.h> 10 #include <linux/limits.h> 11 #include <linux/string.h> 12 #include <linux/types.h> 13 #include <linux/bitmap-str.h> 14 15 struct device; 16 17 /* 18 * bitmaps provide bit arrays that consume one or more unsigned 19 * longs. The bitmap interface and available operations are listed 20 * here, in bitmap.h 21 * 22 * Function implementations generic to all architectures are in 23 * lib/bitmap.c. Functions implementations that are architecture 24 * specific are in various include/asm-<arch>/bitops.h headers 25 * and other arch/<arch> specific files. 26 * 27 * See lib/bitmap.c for more details. 28 */ 29 30 /** 31 * DOC: bitmap overview 32 * 33 * The available bitmap operations and their rough meaning in the 34 * case that the bitmap is a single unsigned long are thus: 35 * 36 * The generated code is more efficient when nbits is known at 37 * compile-time and at most BITS_PER_LONG. 38 * 39 * :: 40 * 41 * bitmap_zero(dst, nbits) *dst = 0UL 42 * bitmap_fill(dst, nbits) *dst = ~0UL 43 * bitmap_copy(dst, src, nbits) *dst = *src 44 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 45 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 46 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 47 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 48 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 49 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 50 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 51 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? 52 * bitmap_empty(src, nbits) Are all bits zero in *src? 53 * bitmap_full(src, nbits) Are all bits set in *src? 54 * bitmap_weight(src, nbits) Hamming Weight: number set bits 55 * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap 56 * bitmap_set(dst, pos, nbits) Set specified bit area 57 * bitmap_clear(dst, pos, nbits) Clear specified bit area 58 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 59 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above 60 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n 61 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n 62 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest 63 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask) 64 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 65 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 66 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 67 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 68 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 69 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 70 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 71 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 72 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 73 * bitmap_release_region(bitmap, pos, order) Free specified bit region 74 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 75 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst 76 * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst 77 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst 78 * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst 79 * bitmap_get_value8(map, start) Get 8bit value from map at start 80 * bitmap_set_value8(map, value, start) Set 8bit value to map at start 81 * 82 * Note, bitmap_zero() and bitmap_fill() operate over the region of 83 * unsigned longs, that is, bits behind bitmap till the unsigned long 84 * boundary will be zeroed or filled as well. Consider to use 85 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling 86 * respectively. 87 */ 88 89 /** 90 * DOC: bitmap bitops 91 * 92 * Also the following operations in asm/bitops.h apply to bitmaps.:: 93 * 94 * set_bit(bit, addr) *addr |= bit 95 * clear_bit(bit, addr) *addr &= ~bit 96 * change_bit(bit, addr) *addr ^= bit 97 * test_bit(bit, addr) Is bit set in *addr? 98 * test_and_set_bit(bit, addr) Set bit and return old value 99 * test_and_clear_bit(bit, addr) Clear bit and return old value 100 * test_and_change_bit(bit, addr) Change bit and return old value 101 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 102 * find_first_bit(addr, nbits) Position first set bit in *addr 103 * find_next_zero_bit(addr, nbits, bit) 104 * Position next zero bit in *addr >= bit 105 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 106 * find_next_and_bit(addr1, addr2, nbits, bit) 107 * Same as find_next_bit, but in 108 * (*addr1 & *addr2) 109 * 110 */ 111 112 /** 113 * DOC: declare bitmap 114 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 115 * to declare an array named 'name' of just enough unsigned longs to 116 * contain all bit positions from 0 to 'bits' - 1. 117 */ 118 119 /* 120 * Allocation and deallocation of bitmap. 121 * Provided in lib/bitmap.c to avoid circular dependency. 122 */ 123 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags); 124 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags); 125 unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node); 126 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node); 127 void bitmap_free(const unsigned long *bitmap); 128 129 /* Managed variants of the above. */ 130 unsigned long *devm_bitmap_alloc(struct device *dev, 131 unsigned int nbits, gfp_t flags); 132 unsigned long *devm_bitmap_zalloc(struct device *dev, 133 unsigned int nbits, gfp_t flags); 134 135 /* 136 * lib/bitmap.c provides these functions: 137 */ 138 139 bool __bitmap_equal(const unsigned long *bitmap1, 140 const unsigned long *bitmap2, unsigned int nbits); 141 bool __pure __bitmap_or_equal(const unsigned long *src1, 142 const unsigned long *src2, 143 const unsigned long *src3, 144 unsigned int nbits); 145 void __bitmap_complement(unsigned long *dst, const unsigned long *src, 146 unsigned int nbits); 147 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 148 unsigned int shift, unsigned int nbits); 149 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 150 unsigned int shift, unsigned int nbits); 151 void bitmap_cut(unsigned long *dst, const unsigned long *src, 152 unsigned int first, unsigned int cut, unsigned int nbits); 153 bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 154 const unsigned long *bitmap2, unsigned int nbits); 155 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 156 const unsigned long *bitmap2, unsigned int nbits); 157 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 158 const unsigned long *bitmap2, unsigned int nbits); 159 bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 160 const unsigned long *bitmap2, unsigned int nbits); 161 void __bitmap_replace(unsigned long *dst, 162 const unsigned long *old, const unsigned long *new, 163 const unsigned long *mask, unsigned int nbits); 164 bool __bitmap_intersects(const unsigned long *bitmap1, 165 const unsigned long *bitmap2, unsigned int nbits); 166 bool __bitmap_subset(const unsigned long *bitmap1, 167 const unsigned long *bitmap2, unsigned int nbits); 168 unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 169 unsigned int __bitmap_weight_and(const unsigned long *bitmap1, 170 const unsigned long *bitmap2, unsigned int nbits); 171 void __bitmap_set(unsigned long *map, unsigned int start, int len); 172 void __bitmap_clear(unsigned long *map, unsigned int start, int len); 173 174 unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 175 unsigned long size, 176 unsigned long start, 177 unsigned int nr, 178 unsigned long align_mask, 179 unsigned long align_offset); 180 181 /** 182 * bitmap_find_next_zero_area - find a contiguous aligned zero area 183 * @map: The address to base the search on 184 * @size: The bitmap size in bits 185 * @start: The bitnumber to start searching at 186 * @nr: The number of zeroed bits we're looking for 187 * @align_mask: Alignment mask for zero area 188 * 189 * The @align_mask should be one less than a power of 2; the effect is that 190 * the bit offset of all zero areas this function finds is multiples of that 191 * power of 2. A @align_mask of 0 means no alignment is required. 192 */ 193 static inline unsigned long 194 bitmap_find_next_zero_area(unsigned long *map, 195 unsigned long size, 196 unsigned long start, 197 unsigned int nr, 198 unsigned long align_mask) 199 { 200 return bitmap_find_next_zero_area_off(map, size, start, nr, 201 align_mask, 0); 202 } 203 204 void bitmap_remap(unsigned long *dst, const unsigned long *src, 205 const unsigned long *old, const unsigned long *new, unsigned int nbits); 206 int bitmap_bitremap(int oldbit, 207 const unsigned long *old, const unsigned long *new, int bits); 208 void bitmap_onto(unsigned long *dst, const unsigned long *orig, 209 const unsigned long *relmap, unsigned int bits); 210 void bitmap_fold(unsigned long *dst, const unsigned long *orig, 211 unsigned int sz, unsigned int nbits); 212 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 213 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 214 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 215 216 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 217 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 218 219 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 220 { 221 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 222 223 if (small_const_nbits(nbits)) 224 *dst = 0; 225 else 226 memset(dst, 0, len); 227 } 228 229 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 230 { 231 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 232 233 if (small_const_nbits(nbits)) 234 *dst = ~0UL; 235 else 236 memset(dst, 0xff, len); 237 } 238 239 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 240 unsigned int nbits) 241 { 242 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 243 244 if (small_const_nbits(nbits)) 245 *dst = *src; 246 else 247 memcpy(dst, src, len); 248 } 249 250 /* 251 * Copy bitmap and clear tail bits in last word. 252 */ 253 static inline void bitmap_copy_clear_tail(unsigned long *dst, 254 const unsigned long *src, unsigned int nbits) 255 { 256 bitmap_copy(dst, src, nbits); 257 if (nbits % BITS_PER_LONG) 258 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); 259 } 260 261 /* 262 * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64 263 * machines the order of hi and lo parts of numbers match the bitmap structure. 264 * In both cases conversion is not needed when copying data from/to arrays of 265 * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead 266 * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit 267 * architectures are not using bitmap_copy_clear_tail(). 268 */ 269 #if BITS_PER_LONG == 64 270 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, 271 unsigned int nbits); 272 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, 273 unsigned int nbits); 274 #else 275 #define bitmap_from_arr32(bitmap, buf, nbits) \ 276 bitmap_copy_clear_tail((unsigned long *) (bitmap), \ 277 (const unsigned long *) (buf), (nbits)) 278 #define bitmap_to_arr32(buf, bitmap, nbits) \ 279 bitmap_copy_clear_tail((unsigned long *) (buf), \ 280 (const unsigned long *) (bitmap), (nbits)) 281 #endif 282 283 /* 284 * On 64-bit systems bitmaps are represented as u64 arrays internally. So, 285 * the conversion is not needed when copying data from/to arrays of u64. 286 */ 287 #if BITS_PER_LONG == 32 288 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits); 289 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits); 290 #else 291 #define bitmap_from_arr64(bitmap, buf, nbits) \ 292 bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits)) 293 #define bitmap_to_arr64(buf, bitmap, nbits) \ 294 bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits)) 295 #endif 296 297 static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1, 298 const unsigned long *src2, unsigned int nbits) 299 { 300 if (small_const_nbits(nbits)) 301 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 302 return __bitmap_and(dst, src1, src2, nbits); 303 } 304 305 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 306 const unsigned long *src2, unsigned int nbits) 307 { 308 if (small_const_nbits(nbits)) 309 *dst = *src1 | *src2; 310 else 311 __bitmap_or(dst, src1, src2, nbits); 312 } 313 314 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 315 const unsigned long *src2, unsigned int nbits) 316 { 317 if (small_const_nbits(nbits)) 318 *dst = *src1 ^ *src2; 319 else 320 __bitmap_xor(dst, src1, src2, nbits); 321 } 322 323 static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1, 324 const unsigned long *src2, unsigned int nbits) 325 { 326 if (small_const_nbits(nbits)) 327 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 328 return __bitmap_andnot(dst, src1, src2, nbits); 329 } 330 331 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 332 unsigned int nbits) 333 { 334 if (small_const_nbits(nbits)) 335 *dst = ~(*src); 336 else 337 __bitmap_complement(dst, src, nbits); 338 } 339 340 #ifdef __LITTLE_ENDIAN 341 #define BITMAP_MEM_ALIGNMENT 8 342 #else 343 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) 344 #endif 345 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) 346 347 static inline bool bitmap_equal(const unsigned long *src1, 348 const unsigned long *src2, unsigned int nbits) 349 { 350 if (small_const_nbits(nbits)) 351 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 352 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && 353 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 354 return !memcmp(src1, src2, nbits / 8); 355 return __bitmap_equal(src1, src2, nbits); 356 } 357 358 /** 359 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third 360 * @src1: Pointer to bitmap 1 361 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1 362 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2 363 * @nbits: number of bits in each of these bitmaps 364 * 365 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise 366 */ 367 static inline bool bitmap_or_equal(const unsigned long *src1, 368 const unsigned long *src2, 369 const unsigned long *src3, 370 unsigned int nbits) 371 { 372 if (!small_const_nbits(nbits)) 373 return __bitmap_or_equal(src1, src2, src3, nbits); 374 375 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits)); 376 } 377 378 static inline bool bitmap_intersects(const unsigned long *src1, 379 const unsigned long *src2, 380 unsigned int nbits) 381 { 382 if (small_const_nbits(nbits)) 383 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 384 else 385 return __bitmap_intersects(src1, src2, nbits); 386 } 387 388 static inline bool bitmap_subset(const unsigned long *src1, 389 const unsigned long *src2, unsigned int nbits) 390 { 391 if (small_const_nbits(nbits)) 392 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 393 else 394 return __bitmap_subset(src1, src2, nbits); 395 } 396 397 static inline bool bitmap_empty(const unsigned long *src, unsigned nbits) 398 { 399 if (small_const_nbits(nbits)) 400 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 401 402 return find_first_bit(src, nbits) == nbits; 403 } 404 405 static inline bool bitmap_full(const unsigned long *src, unsigned int nbits) 406 { 407 if (small_const_nbits(nbits)) 408 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 409 410 return find_first_zero_bit(src, nbits) == nbits; 411 } 412 413 static __always_inline 414 unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits) 415 { 416 if (small_const_nbits(nbits)) 417 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 418 return __bitmap_weight(src, nbits); 419 } 420 421 static __always_inline 422 unsigned long bitmap_weight_and(const unsigned long *src1, 423 const unsigned long *src2, unsigned int nbits) 424 { 425 if (small_const_nbits(nbits)) 426 return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)); 427 return __bitmap_weight_and(src1, src2, nbits); 428 } 429 430 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 431 unsigned int nbits) 432 { 433 if (__builtin_constant_p(nbits) && nbits == 1) 434 __set_bit(start, map); 435 else if (small_const_nbits(start + nbits)) 436 *map |= GENMASK(start + nbits - 1, start); 437 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 438 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 439 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 440 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 441 memset((char *)map + start / 8, 0xff, nbits / 8); 442 else 443 __bitmap_set(map, start, nbits); 444 } 445 446 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 447 unsigned int nbits) 448 { 449 if (__builtin_constant_p(nbits) && nbits == 1) 450 __clear_bit(start, map); 451 else if (small_const_nbits(start + nbits)) 452 *map &= ~GENMASK(start + nbits - 1, start); 453 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 454 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 455 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 456 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 457 memset((char *)map + start / 8, 0, nbits / 8); 458 else 459 __bitmap_clear(map, start, nbits); 460 } 461 462 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 463 unsigned int shift, unsigned int nbits) 464 { 465 if (small_const_nbits(nbits)) 466 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 467 else 468 __bitmap_shift_right(dst, src, shift, nbits); 469 } 470 471 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 472 unsigned int shift, unsigned int nbits) 473 { 474 if (small_const_nbits(nbits)) 475 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 476 else 477 __bitmap_shift_left(dst, src, shift, nbits); 478 } 479 480 static inline void bitmap_replace(unsigned long *dst, 481 const unsigned long *old, 482 const unsigned long *new, 483 const unsigned long *mask, 484 unsigned int nbits) 485 { 486 if (small_const_nbits(nbits)) 487 *dst = (*old & ~(*mask)) | (*new & *mask); 488 else 489 __bitmap_replace(dst, old, new, mask, nbits); 490 } 491 492 static inline void bitmap_next_set_region(unsigned long *bitmap, 493 unsigned int *rs, unsigned int *re, 494 unsigned int end) 495 { 496 *rs = find_next_bit(bitmap, end, *rs); 497 *re = find_next_zero_bit(bitmap, end, *rs + 1); 498 } 499 500 /** 501 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 502 * @n: u64 value 503 * 504 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 505 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 506 * 507 * There are four combinations of endianness and length of the word in linux 508 * ABIs: LE64, BE64, LE32 and BE32. 509 * 510 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 511 * bitmaps and therefore don't require any special handling. 512 * 513 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 514 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 515 * other hand is represented as an array of 32-bit words and the position of 516 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 517 * word. For example, bit #42 is located at 10th position of 2nd word. 518 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 519 * values in memory as it usually does. But for BE we need to swap hi and lo 520 * words manually. 521 * 522 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 523 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 524 * hi and lo words, as is expected by bitmap. 525 */ 526 #if __BITS_PER_LONG == 64 527 #define BITMAP_FROM_U64(n) (n) 528 #else 529 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 530 ((unsigned long) ((u64)(n) >> 32)) 531 #endif 532 533 /** 534 * bitmap_from_u64 - Check and swap words within u64. 535 * @mask: source bitmap 536 * @dst: destination bitmap 537 * 538 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 539 * to read u64 mask, we will get the wrong word. 540 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 541 * but we expect the lower 32-bits of u64. 542 */ 543 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 544 { 545 bitmap_from_arr64(dst, &mask, 64); 546 } 547 548 /** 549 * bitmap_get_value8 - get an 8-bit value within a memory region 550 * @map: address to the bitmap memory region 551 * @start: bit offset of the 8-bit value; must be a multiple of 8 552 * 553 * Returns the 8-bit value located at the @start bit offset within the @src 554 * memory region. 555 */ 556 static inline unsigned long bitmap_get_value8(const unsigned long *map, 557 unsigned long start) 558 { 559 const size_t index = BIT_WORD(start); 560 const unsigned long offset = start % BITS_PER_LONG; 561 562 return (map[index] >> offset) & 0xFF; 563 } 564 565 /** 566 * bitmap_set_value8 - set an 8-bit value within a memory region 567 * @map: address to the bitmap memory region 568 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap 569 * @start: bit offset of the 8-bit value; must be a multiple of 8 570 */ 571 static inline void bitmap_set_value8(unsigned long *map, unsigned long value, 572 unsigned long start) 573 { 574 const size_t index = BIT_WORD(start); 575 const unsigned long offset = start % BITS_PER_LONG; 576 577 map[index] &= ~(0xFFUL << offset); 578 map[index] |= value << offset; 579 } 580 581 #endif /* __ASSEMBLY__ */ 582 583 #endif /* __LINUX_BITMAP_H */ 584