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_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 57 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 58 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 59 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 60 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 61 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 62 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 63 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 64 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 65 * bitmap_release_region(bitmap, pos, order) Free specified bit region 66 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 67 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst 68 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst 69 * 70 * Note, bitmap_zero() and bitmap_fill() operate over the region of 71 * unsigned longs, that is, bits behind bitmap till the unsigned long 72 * boundary will be zeroed or filled as well. Consider to use 73 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling 74 * respectively. 75 */ 76 77 /** 78 * DOC: bitmap bitops 79 * 80 * Also the following operations in asm/bitops.h apply to bitmaps.:: 81 * 82 * set_bit(bit, addr) *addr |= bit 83 * clear_bit(bit, addr) *addr &= ~bit 84 * change_bit(bit, addr) *addr ^= bit 85 * test_bit(bit, addr) Is bit set in *addr? 86 * test_and_set_bit(bit, addr) Set bit and return old value 87 * test_and_clear_bit(bit, addr) Clear bit and return old value 88 * test_and_change_bit(bit, addr) Change bit and return old value 89 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 90 * find_first_bit(addr, nbits) Position first set bit in *addr 91 * find_next_zero_bit(addr, nbits, bit) 92 * Position next zero bit in *addr >= bit 93 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 94 * find_next_and_bit(addr1, addr2, nbits, bit) 95 * Same as find_next_bit, but in 96 * (*addr1 & *addr2) 97 * 98 */ 99 100 /** 101 * DOC: declare bitmap 102 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 103 * to declare an array named 'name' of just enough unsigned longs to 104 * contain all bit positions from 0 to 'bits' - 1. 105 */ 106 107 /* 108 * Allocation and deallocation of bitmap. 109 * Provided in lib/bitmap.c to avoid circular dependency. 110 */ 111 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags); 112 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags); 113 extern void bitmap_free(const unsigned long *bitmap); 114 115 /* 116 * lib/bitmap.c provides these functions: 117 */ 118 119 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); 120 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); 121 extern int __bitmap_equal(const unsigned long *bitmap1, 122 const unsigned long *bitmap2, unsigned int nbits); 123 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, 124 unsigned int nbits); 125 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 126 unsigned int shift, unsigned int nbits); 127 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 128 unsigned int shift, unsigned int nbits); 129 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 130 const unsigned long *bitmap2, unsigned int nbits); 131 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 132 const unsigned long *bitmap2, unsigned int nbits); 133 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 134 const unsigned long *bitmap2, unsigned int nbits); 135 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 136 const unsigned long *bitmap2, unsigned int nbits); 137 extern int __bitmap_intersects(const unsigned long *bitmap1, 138 const unsigned long *bitmap2, unsigned int nbits); 139 extern int __bitmap_subset(const unsigned long *bitmap1, 140 const unsigned long *bitmap2, unsigned int nbits); 141 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 142 extern void __bitmap_set(unsigned long *map, unsigned int start, int len); 143 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len); 144 145 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 146 unsigned long size, 147 unsigned long start, 148 unsigned int nr, 149 unsigned long align_mask, 150 unsigned long align_offset); 151 152 /** 153 * bitmap_find_next_zero_area - find a contiguous aligned zero area 154 * @map: The address to base the search on 155 * @size: The bitmap size in bits 156 * @start: The bitnumber to start searching at 157 * @nr: The number of zeroed bits we're looking for 158 * @align_mask: Alignment mask for zero area 159 * 160 * The @align_mask should be one less than a power of 2; the effect is that 161 * the bit offset of all zero areas this function finds is multiples of that 162 * power of 2. A @align_mask of 0 means no alignment is required. 163 */ 164 static inline unsigned long 165 bitmap_find_next_zero_area(unsigned long *map, 166 unsigned long size, 167 unsigned long start, 168 unsigned int nr, 169 unsigned long align_mask) 170 { 171 return bitmap_find_next_zero_area_off(map, size, start, nr, 172 align_mask, 0); 173 } 174 175 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, 176 unsigned long *dst, int nbits); 177 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, 178 unsigned long *dst, int nbits); 179 extern int bitmap_parselist(const char *buf, unsigned long *maskp, 180 int nmaskbits); 181 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, 182 unsigned long *dst, int nbits); 183 extern void bitmap_remap(unsigned long *dst, const unsigned long *src, 184 const unsigned long *old, const unsigned long *new, unsigned int nbits); 185 extern int bitmap_bitremap(int oldbit, 186 const unsigned long *old, const unsigned long *new, int bits); 187 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig, 188 const unsigned long *relmap, unsigned int bits); 189 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, 190 unsigned int sz, unsigned int nbits); 191 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 192 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 193 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 194 195 #ifdef __BIG_ENDIAN 196 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); 197 #else 198 #define bitmap_copy_le bitmap_copy 199 #endif 200 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); 201 extern int bitmap_print_to_pagebuf(bool list, char *buf, 202 const unsigned long *maskp, int nmaskbits); 203 204 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 205 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 206 207 /* 208 * The static inlines below do not handle constant nbits==0 correctly, 209 * so make such users (should any ever turn up) call the out-of-line 210 * versions. 211 */ 212 #define small_const_nbits(nbits) \ 213 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0) 214 215 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 216 { 217 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 218 memset(dst, 0, len); 219 } 220 221 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 222 { 223 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 224 memset(dst, 0xff, len); 225 } 226 227 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 228 unsigned int nbits) 229 { 230 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 231 memcpy(dst, src, len); 232 } 233 234 /* 235 * Copy bitmap and clear tail bits in last word. 236 */ 237 static inline void bitmap_copy_clear_tail(unsigned long *dst, 238 const unsigned long *src, unsigned int nbits) 239 { 240 bitmap_copy(dst, src, nbits); 241 if (nbits % BITS_PER_LONG) 242 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); 243 } 244 245 /* 246 * On 32-bit systems bitmaps are represented as u32 arrays internally, and 247 * therefore conversion is not needed when copying data from/to arrays of u32. 248 */ 249 #if BITS_PER_LONG == 64 250 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, 251 unsigned int nbits); 252 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, 253 unsigned int nbits); 254 #else 255 #define bitmap_from_arr32(bitmap, buf, nbits) \ 256 bitmap_copy_clear_tail((unsigned long *) (bitmap), \ 257 (const unsigned long *) (buf), (nbits)) 258 #define bitmap_to_arr32(buf, bitmap, nbits) \ 259 bitmap_copy_clear_tail((unsigned long *) (buf), \ 260 (const unsigned long *) (bitmap), (nbits)) 261 #endif 262 263 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 264 const unsigned long *src2, unsigned int nbits) 265 { 266 if (small_const_nbits(nbits)) 267 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 268 return __bitmap_and(dst, src1, src2, nbits); 269 } 270 271 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 272 const unsigned long *src2, unsigned int nbits) 273 { 274 if (small_const_nbits(nbits)) 275 *dst = *src1 | *src2; 276 else 277 __bitmap_or(dst, src1, src2, nbits); 278 } 279 280 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 281 const unsigned long *src2, unsigned int nbits) 282 { 283 if (small_const_nbits(nbits)) 284 *dst = *src1 ^ *src2; 285 else 286 __bitmap_xor(dst, src1, src2, nbits); 287 } 288 289 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 290 const unsigned long *src2, unsigned int nbits) 291 { 292 if (small_const_nbits(nbits)) 293 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 294 return __bitmap_andnot(dst, src1, src2, nbits); 295 } 296 297 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 298 unsigned int nbits) 299 { 300 if (small_const_nbits(nbits)) 301 *dst = ~(*src); 302 else 303 __bitmap_complement(dst, src, nbits); 304 } 305 306 #ifdef __LITTLE_ENDIAN 307 #define BITMAP_MEM_ALIGNMENT 8 308 #else 309 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) 310 #endif 311 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) 312 313 static inline int bitmap_equal(const unsigned long *src1, 314 const unsigned long *src2, unsigned int nbits) 315 { 316 if (small_const_nbits(nbits)) 317 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 318 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && 319 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 320 return !memcmp(src1, src2, nbits / 8); 321 return __bitmap_equal(src1, src2, nbits); 322 } 323 324 static inline int bitmap_intersects(const unsigned long *src1, 325 const unsigned long *src2, unsigned int nbits) 326 { 327 if (small_const_nbits(nbits)) 328 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 329 else 330 return __bitmap_intersects(src1, src2, nbits); 331 } 332 333 static inline int bitmap_subset(const unsigned long *src1, 334 const unsigned long *src2, unsigned int nbits) 335 { 336 if (small_const_nbits(nbits)) 337 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 338 else 339 return __bitmap_subset(src1, src2, nbits); 340 } 341 342 static inline int bitmap_empty(const unsigned long *src, unsigned nbits) 343 { 344 if (small_const_nbits(nbits)) 345 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 346 347 return find_first_bit(src, nbits) == nbits; 348 } 349 350 static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 351 { 352 if (small_const_nbits(nbits)) 353 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 354 355 return find_first_zero_bit(src, nbits) == nbits; 356 } 357 358 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 359 { 360 if (small_const_nbits(nbits)) 361 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 362 return __bitmap_weight(src, nbits); 363 } 364 365 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 366 unsigned int nbits) 367 { 368 if (__builtin_constant_p(nbits) && nbits == 1) 369 __set_bit(start, map); 370 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 371 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 372 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 373 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 374 memset((char *)map + start / 8, 0xff, nbits / 8); 375 else 376 __bitmap_set(map, start, nbits); 377 } 378 379 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 380 unsigned int nbits) 381 { 382 if (__builtin_constant_p(nbits) && nbits == 1) 383 __clear_bit(start, map); 384 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 385 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 386 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 387 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 388 memset((char *)map + start / 8, 0, nbits / 8); 389 else 390 __bitmap_clear(map, start, nbits); 391 } 392 393 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 394 unsigned int shift, unsigned int nbits) 395 { 396 if (small_const_nbits(nbits)) 397 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 398 else 399 __bitmap_shift_right(dst, src, shift, nbits); 400 } 401 402 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 403 unsigned int shift, unsigned int nbits) 404 { 405 if (small_const_nbits(nbits)) 406 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 407 else 408 __bitmap_shift_left(dst, src, shift, nbits); 409 } 410 411 static inline int bitmap_parse(const char *buf, unsigned int buflen, 412 unsigned long *maskp, int nmaskbits) 413 { 414 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); 415 } 416 417 /** 418 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 419 * @n: u64 value 420 * 421 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 422 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 423 * 424 * There are four combinations of endianness and length of the word in linux 425 * ABIs: LE64, BE64, LE32 and BE32. 426 * 427 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 428 * bitmaps and therefore don't require any special handling. 429 * 430 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 431 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 432 * other hand is represented as an array of 32-bit words and the position of 433 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 434 * word. For example, bit #42 is located at 10th position of 2nd word. 435 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 436 * values in memory as it usually does. But for BE we need to swap hi and lo 437 * words manually. 438 * 439 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 440 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 441 * hi and lo words, as is expected by bitmap. 442 */ 443 #if __BITS_PER_LONG == 64 444 #define BITMAP_FROM_U64(n) (n) 445 #else 446 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 447 ((unsigned long) ((u64)(n) >> 32)) 448 #endif 449 450 /** 451 * bitmap_from_u64 - Check and swap words within u64. 452 * @mask: source bitmap 453 * @dst: destination bitmap 454 * 455 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 456 * to read u64 mask, we will get the wrong word. 457 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 458 * but we expect the lower 32-bits of u64. 459 */ 460 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 461 { 462 dst[0] = mask & ULONG_MAX; 463 464 if (sizeof(mask) > sizeof(unsigned long)) 465 dst[1] = mask >> 32; 466 } 467 468 #endif /* __ASSEMBLY__ */ 469 470 #endif /* __LINUX_BITMAP_H */ 471