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_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) 68 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) 69 * 70 */ 71 72 /** 73 * DOC: bitmap bitops 74 * 75 * Also the following operations in asm/bitops.h apply to bitmaps.:: 76 * 77 * set_bit(bit, addr) *addr |= bit 78 * clear_bit(bit, addr) *addr &= ~bit 79 * change_bit(bit, addr) *addr ^= bit 80 * test_bit(bit, addr) Is bit set in *addr? 81 * test_and_set_bit(bit, addr) Set bit and return old value 82 * test_and_clear_bit(bit, addr) Clear bit and return old value 83 * test_and_change_bit(bit, addr) Change bit and return old value 84 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 85 * find_first_bit(addr, nbits) Position first set bit in *addr 86 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit 87 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 88 * 89 */ 90 91 /** 92 * DOC: declare bitmap 93 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 94 * to declare an array named 'name' of just enough unsigned longs to 95 * contain all bit positions from 0 to 'bits' - 1. 96 */ 97 98 /* 99 * lib/bitmap.c provides these functions: 100 */ 101 102 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); 103 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); 104 extern int __bitmap_equal(const unsigned long *bitmap1, 105 const unsigned long *bitmap2, unsigned int nbits); 106 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, 107 unsigned int nbits); 108 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 109 unsigned int shift, unsigned int nbits); 110 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 111 unsigned int shift, unsigned int nbits); 112 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 113 const unsigned long *bitmap2, unsigned int nbits); 114 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 115 const unsigned long *bitmap2, unsigned int nbits); 116 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 117 const unsigned long *bitmap2, unsigned int nbits); 118 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 119 const unsigned long *bitmap2, unsigned int nbits); 120 extern int __bitmap_intersects(const unsigned long *bitmap1, 121 const unsigned long *bitmap2, unsigned int nbits); 122 extern int __bitmap_subset(const unsigned long *bitmap1, 123 const unsigned long *bitmap2, unsigned int nbits); 124 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 125 extern void __bitmap_set(unsigned long *map, unsigned int start, int len); 126 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len); 127 128 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 129 unsigned long size, 130 unsigned long start, 131 unsigned int nr, 132 unsigned long align_mask, 133 unsigned long align_offset); 134 135 /** 136 * bitmap_find_next_zero_area - find a contiguous aligned zero area 137 * @map: The address to base the search on 138 * @size: The bitmap size in bits 139 * @start: The bitnumber to start searching at 140 * @nr: The number of zeroed bits we're looking for 141 * @align_mask: Alignment mask for zero area 142 * 143 * The @align_mask should be one less than a power of 2; the effect is that 144 * the bit offset of all zero areas this function finds is multiples of that 145 * power of 2. A @align_mask of 0 means no alignment is required. 146 */ 147 static inline unsigned long 148 bitmap_find_next_zero_area(unsigned long *map, 149 unsigned long size, 150 unsigned long start, 151 unsigned int nr, 152 unsigned long align_mask) 153 { 154 return bitmap_find_next_zero_area_off(map, size, start, nr, 155 align_mask, 0); 156 } 157 158 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, 159 unsigned long *dst, int nbits); 160 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, 161 unsigned long *dst, int nbits); 162 extern int bitmap_parselist(const char *buf, unsigned long *maskp, 163 int nmaskbits); 164 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, 165 unsigned long *dst, int nbits); 166 extern void bitmap_remap(unsigned long *dst, const unsigned long *src, 167 const unsigned long *old, const unsigned long *new, unsigned int nbits); 168 extern int bitmap_bitremap(int oldbit, 169 const unsigned long *old, const unsigned long *new, int bits); 170 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig, 171 const unsigned long *relmap, unsigned int bits); 172 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, 173 unsigned int sz, unsigned int nbits); 174 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 175 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 176 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 177 extern unsigned int bitmap_from_u32array(unsigned long *bitmap, 178 unsigned int nbits, 179 const u32 *buf, 180 unsigned int nwords); 181 extern unsigned int bitmap_to_u32array(u32 *buf, 182 unsigned int nwords, 183 const unsigned long *bitmap, 184 unsigned int nbits); 185 #ifdef __BIG_ENDIAN 186 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); 187 #else 188 #define bitmap_copy_le bitmap_copy 189 #endif 190 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); 191 extern int bitmap_print_to_pagebuf(bool list, char *buf, 192 const unsigned long *maskp, int nmaskbits); 193 194 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 195 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 196 197 #define small_const_nbits(nbits) \ 198 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) 199 200 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 201 { 202 if (small_const_nbits(nbits)) 203 *dst = 0UL; 204 else { 205 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 206 memset(dst, 0, len); 207 } 208 } 209 210 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 211 { 212 unsigned int nlongs = BITS_TO_LONGS(nbits); 213 if (!small_const_nbits(nbits)) { 214 unsigned int len = (nlongs - 1) * sizeof(unsigned long); 215 memset(dst, 0xff, len); 216 } 217 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); 218 } 219 220 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 221 unsigned int nbits) 222 { 223 if (small_const_nbits(nbits)) 224 *dst = *src; 225 else { 226 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 227 memcpy(dst, src, len); 228 } 229 } 230 231 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 232 const unsigned long *src2, unsigned int nbits) 233 { 234 if (small_const_nbits(nbits)) 235 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 236 return __bitmap_and(dst, src1, src2, nbits); 237 } 238 239 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 240 const unsigned long *src2, unsigned int nbits) 241 { 242 if (small_const_nbits(nbits)) 243 *dst = *src1 | *src2; 244 else 245 __bitmap_or(dst, src1, src2, nbits); 246 } 247 248 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 249 const unsigned long *src2, unsigned int nbits) 250 { 251 if (small_const_nbits(nbits)) 252 *dst = *src1 ^ *src2; 253 else 254 __bitmap_xor(dst, src1, src2, nbits); 255 } 256 257 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 258 const unsigned long *src2, unsigned int nbits) 259 { 260 if (small_const_nbits(nbits)) 261 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 262 return __bitmap_andnot(dst, src1, src2, nbits); 263 } 264 265 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 266 unsigned int nbits) 267 { 268 if (small_const_nbits(nbits)) 269 *dst = ~(*src); 270 else 271 __bitmap_complement(dst, src, nbits); 272 } 273 274 static inline int bitmap_equal(const unsigned long *src1, 275 const unsigned long *src2, unsigned int nbits) 276 { 277 if (small_const_nbits(nbits)) 278 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 279 if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 280 return !memcmp(src1, src2, nbits / 8); 281 return __bitmap_equal(src1, src2, nbits); 282 } 283 284 static inline int bitmap_intersects(const unsigned long *src1, 285 const unsigned long *src2, unsigned int nbits) 286 { 287 if (small_const_nbits(nbits)) 288 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 289 else 290 return __bitmap_intersects(src1, src2, nbits); 291 } 292 293 static inline int bitmap_subset(const unsigned long *src1, 294 const unsigned long *src2, unsigned int nbits) 295 { 296 if (small_const_nbits(nbits)) 297 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 298 else 299 return __bitmap_subset(src1, src2, nbits); 300 } 301 302 static inline int bitmap_empty(const unsigned long *src, unsigned nbits) 303 { 304 if (small_const_nbits(nbits)) 305 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 306 307 return find_first_bit(src, nbits) == nbits; 308 } 309 310 static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 311 { 312 if (small_const_nbits(nbits)) 313 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 314 315 return find_first_zero_bit(src, nbits) == nbits; 316 } 317 318 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 319 { 320 if (small_const_nbits(nbits)) 321 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 322 return __bitmap_weight(src, nbits); 323 } 324 325 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 326 unsigned int nbits) 327 { 328 if (__builtin_constant_p(nbits) && nbits == 1) 329 __set_bit(start, map); 330 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 331 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 332 memset((char *)map + start / 8, 0xff, nbits / 8); 333 else 334 __bitmap_set(map, start, nbits); 335 } 336 337 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 338 unsigned int nbits) 339 { 340 if (__builtin_constant_p(nbits) && nbits == 1) 341 __clear_bit(start, map); 342 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 343 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 344 memset((char *)map + start / 8, 0, nbits / 8); 345 else 346 __bitmap_clear(map, start, nbits); 347 } 348 349 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 350 unsigned int shift, int nbits) 351 { 352 if (small_const_nbits(nbits)) 353 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 354 else 355 __bitmap_shift_right(dst, src, shift, nbits); 356 } 357 358 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 359 unsigned int shift, unsigned int nbits) 360 { 361 if (small_const_nbits(nbits)) 362 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 363 else 364 __bitmap_shift_left(dst, src, shift, nbits); 365 } 366 367 static inline int bitmap_parse(const char *buf, unsigned int buflen, 368 unsigned long *maskp, int nmaskbits) 369 { 370 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); 371 } 372 373 /** 374 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 375 * @n: u64 value 376 * 377 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 378 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 379 * 380 * There are four combinations of endianness and length of the word in linux 381 * ABIs: LE64, BE64, LE32 and BE32. 382 * 383 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 384 * bitmaps and therefore don't require any special handling. 385 * 386 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 387 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 388 * other hand is represented as an array of 32-bit words and the position of 389 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 390 * word. For example, bit #42 is located at 10th position of 2nd word. 391 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 392 * values in memory as it usually does. But for BE we need to swap hi and lo 393 * words manually. 394 * 395 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 396 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 397 * hi and lo words, as is expected by bitmap. 398 */ 399 #if __BITS_PER_LONG == 64 400 #define BITMAP_FROM_U64(n) (n) 401 #else 402 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 403 ((unsigned long) ((u64)(n) >> 32)) 404 #endif 405 406 /** 407 * bitmap_from_u64 - Check and swap words within u64. 408 * @mask: source bitmap 409 * @dst: destination bitmap 410 * 411 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 412 * to read u64 mask, we will get the wrong word. 413 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 414 * but we expect the lower 32-bits of u64. 415 */ 416 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 417 { 418 dst[0] = mask & ULONG_MAX; 419 420 if (sizeof(mask) > sizeof(unsigned long)) 421 dst[1] = mask >> 32; 422 } 423 424 #endif /* __ASSEMBLY__ */ 425 426 #endif /* __LINUX_BITMAP_H */ 427