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bitmap.h
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linux-6.19.14/include/linux/bitmap.h
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/cleanup.h> 10#include <linux/errno.h> 11#include <linux/find.h> 12#include <linux/limits.h> 13#include <linux/string.h> 14#include <linux/types.h> 15#include <linux/bitmap-str.h> 16 17struct device; 18 19/* 20 * bitmaps provide bit arrays that consume one or more unsigned 21 * longs. The bitmap interface and available operations are listed 22 * here, in bitmap.h 23 * 24 * Function implementations generic to all architectures are in 25 * lib/bitmap.c. Functions implementations that are architecture 26 * specific are in various arch/<arch>/include/asm/bitops.h headers 27 * and other arch/<arch> specific files. 28 * 29 * See lib/bitmap.c for more details. 30 */ 31 32/** 33 * DOC: bitmap overview 34 * 35 * The available bitmap operations and their rough meaning in the 36 * case that the bitmap is a single unsigned long are thus: 37 * 38 * The generated code is more efficient when nbits is known at 39 * compile-time and at most BITS_PER_LONG. 40 * 41 * :: 42 * 43 * bitmap_zero(dst, nbits) *dst = 0UL 44 * bitmap_fill(dst, nbits) *dst = ~0UL 45 * bitmap_copy(dst, src, nbits) *dst = *src 46 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 47 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 48 * bitmap_weighted_or(dst, src1, src2, nbits) *dst = *src1 | *src2. Returns Hamming Weight of dst 49 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 50 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 51 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 52 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 53 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 54 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? 55 * bitmap_empty(src, nbits) Are all bits zero in *src? 56 * bitmap_full(src, nbits) Are all bits set in *src? 57 * bitmap_weight(src, nbits) Hamming Weight: number set bits 58 * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap 59 * bitmap_weight_andnot(src1, src2, nbits) Hamming Weight of andnot'ed bitmap 60 * bitmap_set(dst, pos, nbits) Set specified bit area 61 * bitmap_clear(dst, pos, nbits) Clear specified bit area 62 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 63 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above 64 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n 65 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n 66 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest 67 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask) 68 * bitmap_scatter(dst, src, mask, nbits) *dst = map(dense, sparse)(src) 69 * bitmap_gather(dst, src, mask, nbits) *dst = map(sparse, dense)(src) 70 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 71 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 72 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 73 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 74 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 75 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 76 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 77 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 78 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 79 * bitmap_release_region(bitmap, pos, order) Free specified bit region 80 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 81 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst 82 * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst 83 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst 84 * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst 85 * bitmap_get_value8(map, start) Get 8bit value from map at start 86 * bitmap_set_value8(map, value, start) Set 8bit value to map at start 87 * bitmap_read(map, start, nbits) Read an nbits-sized value from 88 * map at start 89 * bitmap_write(map, value, start, nbits) Write an nbits-sized value to 90 * map at start 91 * 92 * Note, bitmap_zero() and bitmap_fill() operate over the region of 93 * unsigned longs, that is, bits behind bitmap till the unsigned long 94 * boundary will be zeroed or filled as well. Consider to use 95 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling 96 * respectively. 97 */ 98 99/** 100 * DOC: bitmap bitops 101 * 102 * Also the following operations in asm/bitops.h apply to bitmaps.:: 103 * 104 * set_bit(bit, addr) *addr |= bit 105 * clear_bit(bit, addr) *addr &= ~bit 106 * change_bit(bit, addr) *addr ^= bit 107 * test_bit(bit, addr) Is bit set in *addr? 108 * test_and_set_bit(bit, addr) Set bit and return old value 109 * test_and_clear_bit(bit, addr) Clear bit and return old value 110 * test_and_change_bit(bit, addr) Change bit and return old value 111 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 112 * find_first_bit(addr, nbits) Position first set bit in *addr 113 * find_next_zero_bit(addr, nbits, bit) 114 * Position next zero bit in *addr >= bit 115 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 116 * find_next_and_bit(addr1, addr2, nbits, bit) 117 * Same as find_next_bit, but in 118 * (*addr1 & *addr2) 119 * 120 */ 121 122/** 123 * DOC: declare bitmap 124 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 125 * to declare an array named 'name' of just enough unsigned longs to 126 * contain all bit positions from 0 to 'bits' - 1. 127 */ 128 129/* 130 * Allocation and deallocation of bitmap. 131 * Provided in lib/bitmap.c to avoid circular dependency. 132 */ 133unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags); 134unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags); 135unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node); 136unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node); 137void bitmap_free(const unsigned long *bitmap); 138 139DEFINE_FREE(bitmap, unsigned long *, if (_T) bitmap_free(_T)) 140 141/* Managed variants of the above. */ 142unsigned long *devm_bitmap_alloc(struct device *dev, 143 unsigned int nbits, gfp_t flags); 144unsigned long *devm_bitmap_zalloc(struct device *dev, 145 unsigned int nbits, gfp_t flags); 146 147/* 148 * lib/bitmap.c provides these functions: 149 */ 150 151bool __bitmap_equal(const unsigned long *bitmap1, 152 const unsigned long *bitmap2, unsigned int nbits); 153bool __pure __bitmap_or_equal(const unsigned long *src1, 154 const unsigned long *src2, 155 const unsigned long *src3, 156 unsigned int nbits); 157void __bitmap_complement(unsigned long *dst, const unsigned long *src, 158 unsigned int nbits); 159void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 160 unsigned int shift, unsigned int nbits); 161void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 162 unsigned int shift, unsigned int nbits); 163void bitmap_cut(unsigned long *dst, const unsigned long *src, 164 unsigned int first, unsigned int cut, unsigned int nbits); 165bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 166 const unsigned long *bitmap2, unsigned int nbits); 167void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 168 const unsigned long *bitmap2, unsigned int nbits); 169unsigned int __bitmap_weighted_or(unsigned long *dst, const unsigned long *bitmap1, 170 const unsigned long *bitmap2, unsigned int nbits); 171void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 172 const unsigned long *bitmap2, unsigned int nbits); 173bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 174 const unsigned long *bitmap2, unsigned int nbits); 175void __bitmap_replace(unsigned long *dst, 176 const unsigned long *old, const unsigned long *new, 177 const unsigned long *mask, unsigned int nbits); 178bool __bitmap_intersects(const unsigned long *bitmap1, 179 const unsigned long *bitmap2, unsigned int nbits); 180bool __bitmap_subset(const unsigned long *bitmap1, 181 const unsigned long *bitmap2, unsigned int nbits); 182unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 183unsigned int __bitmap_weight_and(const unsigned long *bitmap1, 184 const unsigned long *bitmap2, unsigned int nbits); 185unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1, 186 const unsigned long *bitmap2, unsigned int nbits); 187void __bitmap_set(unsigned long *map, unsigned int start, int len); 188void __bitmap_clear(unsigned long *map, unsigned int start, int len); 189 190unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 191 unsigned long size, 192 unsigned long start, 193 unsigned int nr, 194 unsigned long align_mask, 195 unsigned long align_offset); 196 197/** 198 * bitmap_find_next_zero_area - find a contiguous aligned zero area 199 * @map: The address to base the search on 200 * @size: The bitmap size in bits 201 * @start: The bitnumber to start searching at 202 * @nr: The number of zeroed bits we're looking for 203 * @align_mask: Alignment mask for zero area 204 * 205 * The @align_mask should be one less than a power of 2; the effect is that 206 * the bit offset of all zero areas this function finds is multiples of that 207 * power of 2. A @align_mask of 0 means no alignment is required. 208 */ 209static __always_inline 210unsigned long bitmap_find_next_zero_area(unsigned long *map, 211 unsigned long size, 212 unsigned long start, 213 unsigned int nr, 214 unsigned long align_mask) 215{ 216 return bitmap_find_next_zero_area_off(map, size, start, nr, 217 align_mask, 0); 218} 219 220void bitmap_remap(unsigned long *dst, const unsigned long *src, 221 const unsigned long *old, const unsigned long *new, unsigned int nbits); 222int bitmap_bitremap(int oldbit, 223 const unsigned long *old, const unsigned long *new, int bits); 224void bitmap_onto(unsigned long *dst, const unsigned long *orig, 225 const unsigned long *relmap, unsigned int bits); 226void bitmap_fold(unsigned long *dst, const unsigned long *orig, 227 unsigned int sz, unsigned int nbits); 228 229#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 230#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 231 232#define bitmap_size(nbits) (ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE) 233 234static __always_inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 235{ 236 unsigned int len = bitmap_size(nbits); 237 238 if (small_const_nbits(nbits)) 239 *dst = 0; 240 else 241 memset(dst, 0, len); 242} 243 244static __always_inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 245{ 246 unsigned int len = bitmap_size(nbits); 247 248 if (small_const_nbits(nbits)) 249 *dst = ~0UL; 250 else 251 memset(dst, 0xff, len); 252} 253 254static __always_inline 255void bitmap_copy(unsigned long *dst, const unsigned long *src, unsigned int nbits) 256{ 257 unsigned int len = bitmap_size(nbits); 258 259 if (small_const_nbits(nbits)) 260 *dst = *src; 261 else 262 memcpy(dst, src, len); 263} 264 265/* 266 * Copy bitmap and clear tail bits in last word. 267 */ 268static __always_inline 269void bitmap_copy_clear_tail(unsigned long *dst, const unsigned long *src, unsigned int nbits) 270{ 271 bitmap_copy(dst, src, nbits); 272 if (nbits % BITS_PER_LONG) 273 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); 274} 275 276static inline void bitmap_copy_and_extend(unsigned long *to, 277 const unsigned long *from, 278 unsigned int count, unsigned int size) 279{ 280 unsigned int copy = BITS_TO_LONGS(count); 281 282 memcpy(to, from, copy * sizeof(long)); 283 if (count % BITS_PER_LONG) 284 to[copy - 1] &= BITMAP_LAST_WORD_MASK(count); 285 memset(to + copy, 0, bitmap_size(size) - copy * sizeof(long)); 286} 287 288/* 289 * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64 290 * machines the order of hi and lo parts of numbers match the bitmap structure. 291 * In both cases conversion is not needed when copying data from/to arrays of 292 * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead 293 * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit 294 * architectures are not using bitmap_copy_clear_tail(). 295 */ 296#if BITS_PER_LONG == 64 297void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, 298 unsigned int nbits); 299void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, 300 unsigned int nbits); 301#else 302#define bitmap_from_arr32(bitmap, buf, nbits) \ 303 bitmap_copy_clear_tail((unsigned long *) (bitmap), \ 304 (const unsigned long *) (buf), (nbits)) 305#define bitmap_to_arr32(buf, bitmap, nbits) \ 306 bitmap_copy_clear_tail((unsigned long *) (buf), \ 307 (const unsigned long *) (bitmap), (nbits)) 308#endif 309 310/* 311 * On 64-bit systems bitmaps are represented as u64 arrays internally. So, 312 * the conversion is not needed when copying data from/to arrays of u64. 313 */ 314#if BITS_PER_LONG == 32 315void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits); 316void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits); 317#else 318#define bitmap_from_arr64(bitmap, buf, nbits) \ 319 bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits)) 320#define bitmap_to_arr64(buf, bitmap, nbits) \ 321 bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits)) 322#endif 323 324static __always_inline 325bool bitmap_and(unsigned long *dst, const unsigned long *src1, 326 const unsigned long *src2, unsigned int nbits) 327{ 328 if (small_const_nbits(nbits)) 329 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 330 return __bitmap_and(dst, src1, src2, nbits); 331} 332 333static __always_inline 334void bitmap_or(unsigned long *dst, const unsigned long *src1, 335 const unsigned long *src2, unsigned int nbits) 336{ 337 if (small_const_nbits(nbits)) 338 *dst = *src1 | *src2; 339 else 340 __bitmap_or(dst, src1, src2, nbits); 341} 342 343static __always_inline 344unsigned int bitmap_weighted_or(unsigned long *dst, const unsigned long *src1, 345 const unsigned long *src2, unsigned int nbits) 346{ 347 if (small_const_nbits(nbits)) { 348 *dst = *src1 | *src2; 349 return hweight_long(*dst & BITMAP_LAST_WORD_MASK(nbits)); 350 } else { 351 return __bitmap_weighted_or(dst, src1, src2, nbits); 352 } 353} 354 355static __always_inline 356void bitmap_xor(unsigned long *dst, const unsigned long *src1, 357 const unsigned long *src2, unsigned int nbits) 358{ 359 if (small_const_nbits(nbits)) 360 *dst = *src1 ^ *src2; 361 else 362 __bitmap_xor(dst, src1, src2, nbits); 363} 364 365static __always_inline 366bool bitmap_andnot(unsigned long *dst, const unsigned long *src1, 367 const unsigned long *src2, unsigned int nbits) 368{ 369 if (small_const_nbits(nbits)) 370 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 371 return __bitmap_andnot(dst, src1, src2, nbits); 372} 373 374static __always_inline 375void bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int nbits) 376{ 377 if (small_const_nbits(nbits)) 378 *dst = ~(*src); 379 else 380 __bitmap_complement(dst, src, nbits); 381} 382 383#ifdef __LITTLE_ENDIAN 384#define BITMAP_MEM_ALIGNMENT 8 385#else 386#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) 387#endif 388#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) 389 390static __always_inline 391bool bitmap_equal(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) 392{ 393 if (small_const_nbits(nbits)) 394 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 395 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && 396 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 397 return !memcmp(src1, src2, nbits / 8); 398 return __bitmap_equal(src1, src2, nbits); 399} 400 401/** 402 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third 403 * @src1: Pointer to bitmap 1 404 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1 405 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2 406 * @nbits: number of bits in each of these bitmaps 407 * 408 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise 409 */ 410static __always_inline 411bool bitmap_or_equal(const unsigned long *src1, const unsigned long *src2, 412 const unsigned long *src3, unsigned int nbits) 413{ 414 if (!small_const_nbits(nbits)) 415 return __bitmap_or_equal(src1, src2, src3, nbits); 416 417 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits)); 418} 419 420static __always_inline 421bool bitmap_intersects(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) 422{ 423 if (small_const_nbits(nbits)) 424 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 425 else 426 return __bitmap_intersects(src1, src2, nbits); 427} 428 429static __always_inline 430bool bitmap_subset(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) 431{ 432 if (small_const_nbits(nbits)) 433 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 434 else 435 return __bitmap_subset(src1, src2, nbits); 436} 437 438static __always_inline 439bool bitmap_empty(const unsigned long *src, unsigned nbits) 440{ 441 if (small_const_nbits(nbits)) 442 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 443 444 return find_first_bit(src, nbits) == nbits; 445} 446 447static __always_inline 448bool bitmap_full(const unsigned long *src, unsigned int nbits) 449{ 450 if (small_const_nbits(nbits)) 451 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 452 453 return find_first_zero_bit(src, nbits) == nbits; 454} 455 456static __always_inline 457unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits) 458{ 459 if (small_const_nbits(nbits)) 460 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 461 return __bitmap_weight(src, nbits); 462} 463 464static __always_inline 465unsigned long bitmap_weight_and(const unsigned long *src1, 466 const unsigned long *src2, unsigned int nbits) 467{ 468 if (small_const_nbits(nbits)) 469 return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)); 470 return __bitmap_weight_and(src1, src2, nbits); 471} 472 473static __always_inline 474unsigned long bitmap_weight_andnot(const unsigned long *src1, 475 const unsigned long *src2, unsigned int nbits) 476{ 477 if (small_const_nbits(nbits)) 478 return hweight_long(*src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)); 479 return __bitmap_weight_andnot(src1, src2, nbits); 480} 481 482static __always_inline 483void bitmap_set(unsigned long *map, unsigned int start, unsigned int nbits) 484{ 485 if (__builtin_constant_p(nbits) && nbits == 1) 486 __set_bit(start, map); 487 else if (small_const_nbits(start + nbits)) 488 *map |= GENMASK(start + nbits - 1, start); 489 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 490 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 491 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 492 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 493 memset((char *)map + start / 8, 0xff, nbits / 8); 494 else 495 __bitmap_set(map, start, nbits); 496} 497 498static __always_inline 499void bitmap_clear(unsigned long *map, unsigned int start, unsigned int nbits) 500{ 501 if (__builtin_constant_p(nbits) && nbits == 1) 502 __clear_bit(start, map); 503 else if (small_const_nbits(start + nbits)) 504 *map &= ~GENMASK(start + nbits - 1, start); 505 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 506 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 507 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 508 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 509 memset((char *)map + start / 8, 0, nbits / 8); 510 else 511 __bitmap_clear(map, start, nbits); 512} 513 514static __always_inline 515void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 516 unsigned int shift, unsigned int nbits) 517{ 518 if (small_const_nbits(nbits)) 519 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 520 else 521 __bitmap_shift_right(dst, src, shift, nbits); 522} 523 524static __always_inline 525void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 526 unsigned int shift, unsigned int nbits) 527{ 528 if (small_const_nbits(nbits)) 529 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 530 else 531 __bitmap_shift_left(dst, src, shift, nbits); 532} 533 534static __always_inline 535void bitmap_replace(unsigned long *dst, 536 const unsigned long *old, 537 const unsigned long *new, 538 const unsigned long *mask, 539 unsigned int nbits) 540{ 541 if (small_const_nbits(nbits)) 542 *dst = (*old & ~(*mask)) | (*new & *mask); 543 else 544 __bitmap_replace(dst, old, new, mask, nbits); 545} 546 547/** 548 * bitmap_scatter - Scatter a bitmap according to the given mask 549 * @dst: scattered bitmap 550 * @src: gathered bitmap 551 * @mask: mask representing bits to assign to in the scattered bitmap 552 * @nbits: number of bits in each of these bitmaps 553 * 554 * Scatters bitmap with sequential bits according to the given @mask. 555 * 556 * Example: 557 * If @src bitmap = 0x005a, with @mask = 0x1313, @dst will be 0x0302. 558 * 559 * Or in binary form 560 * @src @mask @dst 561 * 0000000001011010 0001001100010011 0000001100000010 562 * 563 * (Bits 0, 1, 2, 3, 4, 5 are copied to the bits 0, 1, 4, 8, 9, 12) 564 * 565 * A more 'visual' description of the operation:: 566 * 567 * src: 0000000001011010 568 * |||||| 569 * +------+||||| 570 * | +----+|||| 571 * | |+----+||| 572 * | || +-+|| 573 * | || | || 574 * mask: ...v..vv...v..vv 575 * ...0..11...0..10 576 * dst: 0000001100000010 577 * 578 * A relationship exists between bitmap_scatter() and bitmap_gather(). See 579 * bitmap_gather() for the bitmap gather detailed operations. TL;DR: 580 * bitmap_gather() can be seen as the 'reverse' bitmap_scatter() operation. 581 */ 582static __always_inline 583void bitmap_scatter(unsigned long *dst, const unsigned long *src, 584 const unsigned long *mask, unsigned int nbits) 585{ 586 unsigned int n = 0; 587 unsigned int bit; 588 589 bitmap_zero(dst, nbits); 590 591 for_each_set_bit(bit, mask, nbits) 592 __assign_bit(bit, dst, test_bit(n++, src)); 593} 594 595/** 596 * bitmap_gather - Gather a bitmap according to given mask 597 * @dst: gathered bitmap 598 * @src: scattered bitmap 599 * @mask: mask representing bits to extract from in the scattered bitmap 600 * @nbits: number of bits in each of these bitmaps 601 * 602 * Gathers bitmap with sparse bits according to the given @mask. 603 * 604 * Example: 605 * If @src bitmap = 0x0302, with @mask = 0x1313, @dst will be 0x001a. 606 * 607 * Or in binary form 608 * @src @mask @dst 609 * 0000001100000010 0001001100010011 0000000000011010 610 * 611 * (Bits 0, 1, 4, 8, 9, 12 are copied to the bits 0, 1, 2, 3, 4, 5) 612 * 613 * A more 'visual' description of the operation:: 614 * 615 * mask: ...v..vv...v..vv 616 * src: 0000001100000010 617 * ^ ^^ ^ 0 618 * | || | 10 619 * | || > 010 620 * | |+--> 1010 621 * | +--> 11010 622 * +----> 011010 623 * dst: 0000000000011010 624 * 625 * A relationship exists between bitmap_gather() and bitmap_scatter(). See 626 * bitmap_scatter() for the bitmap scatter detailed operations. TL;DR: 627 * bitmap_scatter() can be seen as the 'reverse' bitmap_gather() operation. 628 * 629 * Suppose scattered computed using bitmap_scatter(scattered, src, mask, n). 630 * The operation bitmap_gather(result, scattered, mask, n) leads to a result 631 * equal or equivalent to src. 632 * 633 * The result can be 'equivalent' because bitmap_scatter() and bitmap_gather() 634 * are not bijective. 635 * The result and src values are equivalent in that sense that a call to 636 * bitmap_scatter(res, src, mask, n) and a call to 637 * bitmap_scatter(res, result, mask, n) will lead to the same res value. 638 */ 639static __always_inline 640void bitmap_gather(unsigned long *dst, const unsigned long *src, 641 const unsigned long *mask, unsigned int nbits) 642{ 643 unsigned int n = 0; 644 unsigned int bit; 645 646 bitmap_zero(dst, nbits); 647 648 for_each_set_bit(bit, mask, nbits) 649 __assign_bit(n++, dst, test_bit(bit, src)); 650} 651 652static __always_inline 653void bitmap_next_set_region(unsigned long *bitmap, unsigned int *rs, 654 unsigned int *re, unsigned int end) 655{ 656 *rs = find_next_bit(bitmap, end, *rs); 657 *re = find_next_zero_bit(bitmap, end, *rs + 1); 658} 659 660/** 661 * bitmap_release_region - release allocated bitmap region 662 * @bitmap: array of unsigned longs corresponding to the bitmap 663 * @pos: beginning of bit region to release 664 * @order: region size (log base 2 of number of bits) to release 665 * 666 * This is the complement to __bitmap_find_free_region() and releases 667 * the found region (by clearing it in the bitmap). 668 */ 669static __always_inline 670void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) 671{ 672 bitmap_clear(bitmap, pos, BIT(order)); 673} 674 675/** 676 * bitmap_allocate_region - allocate bitmap region 677 * @bitmap: array of unsigned longs corresponding to the bitmap 678 * @pos: beginning of bit region to allocate 679 * @order: region size (log base 2 of number of bits) to allocate 680 * 681 * Allocate (set bits in) a specified region of a bitmap. 682 * 683 * Returns: 0 on success, or %-EBUSY if specified region wasn't 684 * free (not all bits were zero). 685 */ 686static __always_inline 687int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) 688{ 689 unsigned int len = BIT(order); 690 691 if (find_next_bit(bitmap, pos + len, pos) < pos + len) 692 return -EBUSY; 693 bitmap_set(bitmap, pos, len); 694 return 0; 695} 696 697/** 698 * bitmap_find_free_region - find a contiguous aligned mem region 699 * @bitmap: array of unsigned longs corresponding to the bitmap 700 * @bits: number of bits in the bitmap 701 * @order: region size (log base 2 of number of bits) to find 702 * 703 * Find a region of free (zero) bits in a @bitmap of @bits bits and 704 * allocate them (set them to one). Only consider regions of length 705 * a power (@order) of two, aligned to that power of two, which 706 * makes the search algorithm much faster. 707 * 708 * Returns: the bit offset in bitmap of the allocated region, 709 * or -errno on failure. 710 */ 711static __always_inline 712int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) 713{ 714 unsigned int pos, end; /* scans bitmap by regions of size order */ 715 716 for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) { 717 if (!bitmap_allocate_region(bitmap, pos, order)) 718 return pos; 719 } 720 return -ENOMEM; 721} 722 723/** 724 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 725 * @n: u64 value 726 * 727 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 728 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 729 * 730 * There are four combinations of endianness and length of the word in linux 731 * ABIs: LE64, BE64, LE32 and BE32. 732 * 733 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 734 * bitmaps and therefore don't require any special handling. 735 * 736 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 737 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 738 * other hand is represented as an array of 32-bit words and the position of 739 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 740 * word. For example, bit #42 is located at 10th position of 2nd word. 741 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 742 * values in memory as it usually does. But for BE we need to swap hi and lo 743 * words manually. 744 * 745 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 746 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 747 * hi and lo words, as is expected by bitmap. 748 */ 749#if __BITS_PER_LONG == 64 750#define BITMAP_FROM_U64(n) (n) 751#else 752#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 753 ((unsigned long) ((u64)(n) >> 32)) 754#endif 755 756/** 757 * bitmap_from_u64 - Check and swap words within u64. 758 * @mask: source bitmap 759 * @dst: destination bitmap 760 * 761 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 762 * to read u64 mask, we will get the wrong word. 763 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 764 * but we expect the lower 32-bits of u64. 765 */ 766static __always_inline void bitmap_from_u64(unsigned long *dst, u64 mask) 767{ 768 bitmap_from_arr64(dst, &mask, 64); 769} 770 771/** 772 * bitmap_read - read a value of n-bits from the memory region 773 * @map: address to the bitmap memory region 774 * @start: bit offset of the n-bit value 775 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG 776 * 777 * Returns: value of @nbits bits located at the @start bit offset within the 778 * @map memory region. For @nbits = 0 and @nbits > BITS_PER_LONG the return 779 * value is undefined. 780 */ 781static __always_inline 782unsigned long bitmap_read(const unsigned long *map, unsigned long start, unsigned long nbits) 783{ 784 size_t index = BIT_WORD(start); 785 unsigned long offset = start % BITS_PER_LONG; 786 unsigned long space = BITS_PER_LONG - offset; 787 unsigned long value_low, value_high; 788 789 if (unlikely(!nbits || nbits > BITS_PER_LONG)) 790 return 0; 791 792 if (space >= nbits) 793 return (map[index] >> offset) & BITMAP_LAST_WORD_MASK(nbits); 794 795 value_low = map[index] & BITMAP_FIRST_WORD_MASK(start); 796 value_high = map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits); 797 return (value_low >> offset) | (value_high << space); 798} 799 800/** 801 * bitmap_write - write n-bit value within a memory region 802 * @map: address to the bitmap memory region 803 * @value: value to write, clamped to nbits 804 * @start: bit offset of the n-bit value 805 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG. 806 * 807 * bitmap_write() behaves as-if implemented as @nbits calls of __assign_bit(), 808 * i.e. bits beyond @nbits are ignored: 809 * 810 * for (bit = 0; bit < nbits; bit++) 811 * __assign_bit(start + bit, bitmap, val & BIT(bit)); 812 * 813 * For @nbits == 0 and @nbits > BITS_PER_LONG no writes are performed. 814 */ 815static __always_inline 816void bitmap_write(unsigned long *map, unsigned long value, 817 unsigned long start, unsigned long nbits) 818{ 819 size_t index; 820 unsigned long offset; 821 unsigned long space; 822 unsigned long mask; 823 bool fit; 824 825 if (unlikely(!nbits || nbits > BITS_PER_LONG)) 826 return; 827 828 mask = BITMAP_LAST_WORD_MASK(nbits); 829 value &= mask; 830 offset = start % BITS_PER_LONG; 831 space = BITS_PER_LONG - offset; 832 fit = space >= nbits; 833 index = BIT_WORD(start); 834 835 map[index] &= (fit ? (~(mask << offset)) : ~BITMAP_FIRST_WORD_MASK(start)); 836 map[index] |= value << offset; 837 if (fit) 838 return; 839 840 map[index + 1] &= BITMAP_FIRST_WORD_MASK(start + nbits); 841 map[index + 1] |= (value >> space); 842} 843 844#define bitmap_get_value8(map, start) \ 845 bitmap_read(map, start, BITS_PER_BYTE) 846#define bitmap_set_value8(map, value, start) \ 847 bitmap_write(map, value, start, BITS_PER_BYTE) 848 849#endif /* __ASSEMBLY__ */ 850 851#endif /* __LINUX_BITMAP_H */
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