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