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 * Note that nbits should be always a compile time evaluable constant. 32 * Otherwise many inlines will generate horrible code. 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 #define small_const_nbits(nbits) \ 208 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) 209 210 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 211 { 212 if (small_const_nbits(nbits)) 213 *dst = 0UL; 214 else { 215 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 216 memset(dst, 0, len); 217 } 218 } 219 220 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 221 { 222 if (small_const_nbits(nbits)) 223 *dst = ~0UL; 224 else { 225 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 226 memset(dst, 0xff, len); 227 } 228 } 229 230 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 231 unsigned int nbits) 232 { 233 if (small_const_nbits(nbits)) 234 *dst = *src; 235 else { 236 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 237 memcpy(dst, src, len); 238 } 239 } 240 241 /* 242 * Copy bitmap and clear tail bits in last word. 243 */ 244 static inline void bitmap_copy_clear_tail(unsigned long *dst, 245 const unsigned long *src, unsigned int nbits) 246 { 247 bitmap_copy(dst, src, nbits); 248 if (nbits % BITS_PER_LONG) 249 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits); 250 } 251 252 /* 253 * On 32-bit systems bitmaps are represented as u32 arrays internally, and 254 * therefore conversion is not needed when copying data from/to arrays of u32. 255 */ 256 #if BITS_PER_LONG == 64 257 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, 258 unsigned int nbits); 259 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, 260 unsigned int nbits); 261 #else 262 #define bitmap_from_arr32(bitmap, buf, nbits) \ 263 bitmap_copy_clear_tail((unsigned long *) (bitmap), \ 264 (const unsigned long *) (buf), (nbits)) 265 #define bitmap_to_arr32(buf, bitmap, nbits) \ 266 bitmap_copy_clear_tail((unsigned long *) (buf), \ 267 (const unsigned long *) (bitmap), (nbits)) 268 #endif 269 270 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 271 const unsigned long *src2, unsigned int nbits) 272 { 273 if (small_const_nbits(nbits)) 274 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 275 return __bitmap_and(dst, src1, src2, nbits); 276 } 277 278 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 279 const unsigned long *src2, unsigned int nbits) 280 { 281 if (small_const_nbits(nbits)) 282 *dst = *src1 | *src2; 283 else 284 __bitmap_or(dst, src1, src2, nbits); 285 } 286 287 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 288 const unsigned long *src2, unsigned int nbits) 289 { 290 if (small_const_nbits(nbits)) 291 *dst = *src1 ^ *src2; 292 else 293 __bitmap_xor(dst, src1, src2, nbits); 294 } 295 296 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 297 const unsigned long *src2, unsigned int nbits) 298 { 299 if (small_const_nbits(nbits)) 300 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 301 return __bitmap_andnot(dst, src1, src2, nbits); 302 } 303 304 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 305 unsigned int nbits) 306 { 307 if (small_const_nbits(nbits)) 308 *dst = ~(*src); 309 else 310 __bitmap_complement(dst, src, nbits); 311 } 312 313 #ifdef __LITTLE_ENDIAN 314 #define BITMAP_MEM_ALIGNMENT 8 315 #else 316 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) 317 #endif 318 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) 319 320 static inline int bitmap_equal(const unsigned long *src1, 321 const unsigned long *src2, unsigned int nbits) 322 { 323 if (small_const_nbits(nbits)) 324 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 325 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) && 326 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 327 return !memcmp(src1, src2, nbits / 8); 328 return __bitmap_equal(src1, src2, nbits); 329 } 330 331 static inline int bitmap_intersects(const unsigned long *src1, 332 const unsigned long *src2, unsigned int nbits) 333 { 334 if (small_const_nbits(nbits)) 335 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 336 else 337 return __bitmap_intersects(src1, src2, nbits); 338 } 339 340 static inline int bitmap_subset(const unsigned long *src1, 341 const unsigned long *src2, unsigned int nbits) 342 { 343 if (small_const_nbits(nbits)) 344 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 345 else 346 return __bitmap_subset(src1, src2, nbits); 347 } 348 349 static inline int bitmap_empty(const unsigned long *src, unsigned nbits) 350 { 351 if (small_const_nbits(nbits)) 352 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 353 354 return find_first_bit(src, nbits) == nbits; 355 } 356 357 static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 358 { 359 if (small_const_nbits(nbits)) 360 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 361 362 return find_first_zero_bit(src, nbits) == nbits; 363 } 364 365 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 366 { 367 if (small_const_nbits(nbits)) 368 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 369 return __bitmap_weight(src, nbits); 370 } 371 372 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 373 unsigned int nbits) 374 { 375 if (__builtin_constant_p(nbits) && nbits == 1) 376 __set_bit(start, map); 377 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 378 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 379 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 380 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 381 memset((char *)map + start / 8, 0xff, nbits / 8); 382 else 383 __bitmap_set(map, start, nbits); 384 } 385 386 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 387 unsigned int nbits) 388 { 389 if (__builtin_constant_p(nbits) && nbits == 1) 390 __clear_bit(start, map); 391 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) && 392 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) && 393 __builtin_constant_p(nbits & BITMAP_MEM_MASK) && 394 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT)) 395 memset((char *)map + start / 8, 0, nbits / 8); 396 else 397 __bitmap_clear(map, start, nbits); 398 } 399 400 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 401 unsigned int shift, int nbits) 402 { 403 if (small_const_nbits(nbits)) 404 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 405 else 406 __bitmap_shift_right(dst, src, shift, nbits); 407 } 408 409 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 410 unsigned int shift, unsigned int nbits) 411 { 412 if (small_const_nbits(nbits)) 413 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 414 else 415 __bitmap_shift_left(dst, src, shift, nbits); 416 } 417 418 static inline int bitmap_parse(const char *buf, unsigned int buflen, 419 unsigned long *maskp, int nmaskbits) 420 { 421 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); 422 } 423 424 /** 425 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 426 * @n: u64 value 427 * 428 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 429 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 430 * 431 * There are four combinations of endianness and length of the word in linux 432 * ABIs: LE64, BE64, LE32 and BE32. 433 * 434 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 435 * bitmaps and therefore don't require any special handling. 436 * 437 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 438 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 439 * other hand is represented as an array of 32-bit words and the position of 440 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 441 * word. For example, bit #42 is located at 10th position of 2nd word. 442 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 443 * values in memory as it usually does. But for BE we need to swap hi and lo 444 * words manually. 445 * 446 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 447 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 448 * hi and lo words, as is expected by bitmap. 449 */ 450 #if __BITS_PER_LONG == 64 451 #define BITMAP_FROM_U64(n) (n) 452 #else 453 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 454 ((unsigned long) ((u64)(n) >> 32)) 455 #endif 456 457 /** 458 * bitmap_from_u64 - Check and swap words within u64. 459 * @mask: source bitmap 460 * @dst: destination bitmap 461 * 462 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 463 * to read u64 mask, we will get the wrong word. 464 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 465 * but we expect the lower 32-bits of u64. 466 */ 467 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 468 { 469 dst[0] = mask & ULONG_MAX; 470 471 if (sizeof(mask) > sizeof(unsigned long)) 472 dst[1] = mask >> 32; 473 } 474 475 #endif /* __ASSEMBLY__ */ 476 477 #endif /* __LINUX_BITMAP_H */ 478