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 * The available bitmap operations and their rough meaning in the 27 * case that the bitmap is a single unsigned long are thus: 28 * 29 * Note that nbits should be always a compile time evaluable constant. 30 * Otherwise many inlines will generate horrible code. 31 * 32 * bitmap_zero(dst, nbits) *dst = 0UL 33 * bitmap_fill(dst, nbits) *dst = ~0UL 34 * bitmap_copy(dst, src, nbits) *dst = *src 35 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 36 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 37 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 38 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 39 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 40 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 41 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 42 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? 43 * bitmap_empty(src, nbits) Are all bits zero in *src? 44 * bitmap_full(src, nbits) Are all bits set in *src? 45 * bitmap_weight(src, nbits) Hamming Weight: number set bits 46 * bitmap_set(dst, pos, nbits) Set specified bit area 47 * bitmap_clear(dst, pos, nbits) Clear specified bit area 48 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 49 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above 50 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n 51 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n 52 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 53 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 54 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 55 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 56 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 57 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 58 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 59 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 60 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 61 * bitmap_release_region(bitmap, pos, order) Free specified bit region 62 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 63 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) 64 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) 65 */ 66 67 /* 68 * Also the following operations in asm/bitops.h apply to bitmaps. 69 * 70 * set_bit(bit, addr) *addr |= bit 71 * clear_bit(bit, addr) *addr &= ~bit 72 * change_bit(bit, addr) *addr ^= bit 73 * test_bit(bit, addr) Is bit set in *addr? 74 * test_and_set_bit(bit, addr) Set bit and return old value 75 * test_and_clear_bit(bit, addr) Clear bit and return old value 76 * test_and_change_bit(bit, addr) Change bit and return old value 77 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 78 * find_first_bit(addr, nbits) Position first set bit in *addr 79 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit 80 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 81 */ 82 83 /* 84 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 85 * to declare an array named 'name' of just enough unsigned longs to 86 * contain all bit positions from 0 to 'bits' - 1. 87 */ 88 89 /* 90 * lib/bitmap.c provides these functions: 91 */ 92 93 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); 94 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); 95 extern int __bitmap_equal(const unsigned long *bitmap1, 96 const unsigned long *bitmap2, unsigned int nbits); 97 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, 98 unsigned int nbits); 99 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 100 unsigned int shift, unsigned int nbits); 101 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 102 unsigned int shift, unsigned int nbits); 103 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 104 const unsigned long *bitmap2, unsigned int nbits); 105 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 106 const unsigned long *bitmap2, unsigned int nbits); 107 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 108 const unsigned long *bitmap2, unsigned int nbits); 109 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 110 const unsigned long *bitmap2, unsigned int nbits); 111 extern int __bitmap_intersects(const unsigned long *bitmap1, 112 const unsigned long *bitmap2, unsigned int nbits); 113 extern int __bitmap_subset(const unsigned long *bitmap1, 114 const unsigned long *bitmap2, unsigned int nbits); 115 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 116 extern void __bitmap_set(unsigned long *map, unsigned int start, int len); 117 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len); 118 119 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 120 unsigned long size, 121 unsigned long start, 122 unsigned int nr, 123 unsigned long align_mask, 124 unsigned long align_offset); 125 126 /** 127 * bitmap_find_next_zero_area - find a contiguous aligned zero area 128 * @map: The address to base the search on 129 * @size: The bitmap size in bits 130 * @start: The bitnumber to start searching at 131 * @nr: The number of zeroed bits we're looking for 132 * @align_mask: Alignment mask for zero area 133 * 134 * The @align_mask should be one less than a power of 2; the effect is that 135 * the bit offset of all zero areas this function finds is multiples of that 136 * power of 2. A @align_mask of 0 means no alignment is required. 137 */ 138 static inline unsigned long 139 bitmap_find_next_zero_area(unsigned long *map, 140 unsigned long size, 141 unsigned long start, 142 unsigned int nr, 143 unsigned long align_mask) 144 { 145 return bitmap_find_next_zero_area_off(map, size, start, nr, 146 align_mask, 0); 147 } 148 149 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, 150 unsigned long *dst, int nbits); 151 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, 152 unsigned long *dst, int nbits); 153 extern int bitmap_parselist(const char *buf, unsigned long *maskp, 154 int nmaskbits); 155 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, 156 unsigned long *dst, int nbits); 157 extern void bitmap_remap(unsigned long *dst, const unsigned long *src, 158 const unsigned long *old, const unsigned long *new, unsigned int nbits); 159 extern int bitmap_bitremap(int oldbit, 160 const unsigned long *old, const unsigned long *new, int bits); 161 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig, 162 const unsigned long *relmap, unsigned int bits); 163 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, 164 unsigned int sz, unsigned int nbits); 165 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 166 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 167 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 168 extern unsigned int bitmap_from_u32array(unsigned long *bitmap, 169 unsigned int nbits, 170 const u32 *buf, 171 unsigned int nwords); 172 extern unsigned int bitmap_to_u32array(u32 *buf, 173 unsigned int nwords, 174 const unsigned long *bitmap, 175 unsigned int nbits); 176 #ifdef __BIG_ENDIAN 177 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); 178 #else 179 #define bitmap_copy_le bitmap_copy 180 #endif 181 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); 182 extern int bitmap_print_to_pagebuf(bool list, char *buf, 183 const unsigned long *maskp, int nmaskbits); 184 185 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 186 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 187 188 #define small_const_nbits(nbits) \ 189 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) 190 191 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 192 { 193 if (small_const_nbits(nbits)) 194 *dst = 0UL; 195 else { 196 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 197 memset(dst, 0, len); 198 } 199 } 200 201 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 202 { 203 unsigned int nlongs = BITS_TO_LONGS(nbits); 204 if (!small_const_nbits(nbits)) { 205 unsigned int len = (nlongs - 1) * sizeof(unsigned long); 206 memset(dst, 0xff, len); 207 } 208 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); 209 } 210 211 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 212 unsigned int nbits) 213 { 214 if (small_const_nbits(nbits)) 215 *dst = *src; 216 else { 217 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 218 memcpy(dst, src, len); 219 } 220 } 221 222 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 223 const unsigned long *src2, unsigned int nbits) 224 { 225 if (small_const_nbits(nbits)) 226 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 227 return __bitmap_and(dst, src1, src2, nbits); 228 } 229 230 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 231 const unsigned long *src2, unsigned int nbits) 232 { 233 if (small_const_nbits(nbits)) 234 *dst = *src1 | *src2; 235 else 236 __bitmap_or(dst, src1, src2, nbits); 237 } 238 239 static inline void bitmap_xor(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_xor(dst, src1, src2, nbits); 246 } 247 248 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 249 const unsigned long *src2, unsigned int nbits) 250 { 251 if (small_const_nbits(nbits)) 252 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 253 return __bitmap_andnot(dst, src1, src2, nbits); 254 } 255 256 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 257 unsigned int nbits) 258 { 259 if (small_const_nbits(nbits)) 260 *dst = ~(*src); 261 else 262 __bitmap_complement(dst, src, nbits); 263 } 264 265 static inline int bitmap_equal(const unsigned long *src1, 266 const unsigned long *src2, unsigned int nbits) 267 { 268 if (small_const_nbits(nbits)) 269 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 270 if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 271 return !memcmp(src1, src2, nbits / 8); 272 return __bitmap_equal(src1, src2, nbits); 273 } 274 275 static inline int bitmap_intersects(const unsigned long *src1, 276 const unsigned long *src2, unsigned int nbits) 277 { 278 if (small_const_nbits(nbits)) 279 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 280 else 281 return __bitmap_intersects(src1, src2, nbits); 282 } 283 284 static inline int bitmap_subset(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)); 289 else 290 return __bitmap_subset(src1, src2, nbits); 291 } 292 293 static inline int bitmap_empty(const unsigned long *src, unsigned nbits) 294 { 295 if (small_const_nbits(nbits)) 296 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 297 298 return find_first_bit(src, nbits) == nbits; 299 } 300 301 static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 302 { 303 if (small_const_nbits(nbits)) 304 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 305 306 return find_first_zero_bit(src, nbits) == nbits; 307 } 308 309 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 310 { 311 if (small_const_nbits(nbits)) 312 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 313 return __bitmap_weight(src, nbits); 314 } 315 316 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 317 unsigned int nbits) 318 { 319 if (__builtin_constant_p(nbits) && nbits == 1) 320 __set_bit(start, map); 321 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 322 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 323 memset((char *)map + start / 8, 0xff, nbits / 8); 324 else 325 __bitmap_set(map, start, nbits); 326 } 327 328 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 329 unsigned int nbits) 330 { 331 if (__builtin_constant_p(nbits) && nbits == 1) 332 __clear_bit(start, map); 333 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 334 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 335 memset((char *)map + start / 8, 0, nbits / 8); 336 else 337 __bitmap_clear(map, start, nbits); 338 } 339 340 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 341 unsigned int shift, int nbits) 342 { 343 if (small_const_nbits(nbits)) 344 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 345 else 346 __bitmap_shift_right(dst, src, shift, nbits); 347 } 348 349 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 350 unsigned int shift, unsigned int nbits) 351 { 352 if (small_const_nbits(nbits)) 353 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 354 else 355 __bitmap_shift_left(dst, src, shift, nbits); 356 } 357 358 static inline int bitmap_parse(const char *buf, unsigned int buflen, 359 unsigned long *maskp, int nmaskbits) 360 { 361 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); 362 } 363 364 /* 365 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 366 * 367 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 368 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 369 * 370 * There are four combinations of endianness and length of the word in linux 371 * ABIs: LE64, BE64, LE32 and BE32. 372 * 373 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 374 * bitmaps and therefore don't require any special handling. 375 * 376 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 377 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 378 * other hand is represented as an array of 32-bit words and the position of 379 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 380 * word. For example, bit #42 is located at 10th position of 2nd word. 381 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 382 * values in memory as it usually does. But for BE we need to swap hi and lo 383 * words manually. 384 * 385 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 386 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 387 * hi and lo words, as is expected by bitmap. 388 */ 389 #if __BITS_PER_LONG == 64 390 #define BITMAP_FROM_U64(n) (n) 391 #else 392 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 393 ((unsigned long) ((u64)(n) >> 32)) 394 #endif 395 396 /* 397 * bitmap_from_u64 - Check and swap words within u64. 398 * @mask: source bitmap 399 * @dst: destination bitmap 400 * 401 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*] 402 * to read u64 mask, we will get the wrong word. 403 * That is "(u32 *)(&val)[0]" gets the upper 32 bits, 404 * but we expect the lower 32-bits of u64. 405 */ 406 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 407 { 408 dst[0] = mask & ULONG_MAX; 409 410 if (sizeof(mask) > sizeof(unsigned long)) 411 dst[1] = mask >> 32; 412 } 413 414 #endif /* __ASSEMBLY__ */ 415 416 #endif /* __LINUX_BITMAP_H */ 417