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