1 #ifndef __LINUX_BITMAP_H 2 #define __LINUX_BITMAP_H 3 4 #ifndef __ASSEMBLY__ 5 6 #include <linux/types.h> 7 #include <linux/bitops.h> 8 #include <linux/string.h> 9 #include <linux/kernel.h> 10 11 /* 12 * bitmaps provide bit arrays that consume one or more unsigned 13 * longs. The bitmap interface and available operations are listed 14 * here, in bitmap.h 15 * 16 * Function implementations generic to all architectures are in 17 * lib/bitmap.c. Functions implementations that are architecture 18 * specific are in various include/asm-<arch>/bitops.h headers 19 * and other arch/<arch> specific files. 20 * 21 * See lib/bitmap.c for more details. 22 */ 23 24 /** 25 * DOC: bitmap overview 26 * 27 * The available bitmap operations and their rough meaning in the 28 * case that the bitmap is a single unsigned long are thus: 29 * 30 * Note that nbits should be always a compile time evaluable constant. 31 * Otherwise many inlines will generate horrible code. 32 * 33 * :: 34 * 35 * bitmap_zero(dst, nbits) *dst = 0UL 36 * bitmap_fill(dst, nbits) *dst = ~0UL 37 * bitmap_copy(dst, src, nbits) *dst = *src 38 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 39 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 40 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 41 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) 42 * bitmap_complement(dst, src, nbits) *dst = ~(*src) 43 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? 44 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? 45 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? 46 * bitmap_empty(src, nbits) Are all bits zero in *src? 47 * bitmap_full(src, nbits) Are all bits set in *src? 48 * bitmap_weight(src, nbits) Hamming Weight: number set bits 49 * bitmap_set(dst, pos, nbits) Set specified bit area 50 * bitmap_clear(dst, pos, nbits) Clear specified bit area 51 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area 52 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above 53 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n 54 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n 55 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) 56 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) 57 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap 58 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz 59 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf 60 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf 61 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf 62 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf 63 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region 64 * bitmap_release_region(bitmap, pos, order) Free specified bit region 65 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region 66 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) 67 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) 68 * 69 */ 70 71 /** 72 * DOC: bitmap bitops 73 * 74 * Also the following operations in asm/bitops.h apply to bitmaps.:: 75 * 76 * set_bit(bit, addr) *addr |= bit 77 * clear_bit(bit, addr) *addr &= ~bit 78 * change_bit(bit, addr) *addr ^= bit 79 * test_bit(bit, addr) Is bit set in *addr? 80 * test_and_set_bit(bit, addr) Set bit and return old value 81 * test_and_clear_bit(bit, addr) Clear bit and return old value 82 * test_and_change_bit(bit, addr) Change bit and return old value 83 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr 84 * find_first_bit(addr, nbits) Position first set bit in *addr 85 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit 86 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit 87 * 88 */ 89 90 /** 91 * DOC: declare bitmap 92 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used 93 * to declare an array named 'name' of just enough unsigned longs to 94 * contain all bit positions from 0 to 'bits' - 1. 95 */ 96 97 /* 98 * lib/bitmap.c provides these functions: 99 */ 100 101 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); 102 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); 103 extern int __bitmap_equal(const unsigned long *bitmap1, 104 const unsigned long *bitmap2, unsigned int nbits); 105 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, 106 unsigned int nbits); 107 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, 108 unsigned int shift, unsigned int nbits); 109 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, 110 unsigned int shift, unsigned int nbits); 111 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, 112 const unsigned long *bitmap2, unsigned int nbits); 113 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, 114 const unsigned long *bitmap2, unsigned int nbits); 115 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, 116 const unsigned long *bitmap2, unsigned int nbits); 117 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, 118 const unsigned long *bitmap2, unsigned int nbits); 119 extern int __bitmap_intersects(const unsigned long *bitmap1, 120 const unsigned long *bitmap2, unsigned int nbits); 121 extern int __bitmap_subset(const unsigned long *bitmap1, 122 const unsigned long *bitmap2, unsigned int nbits); 123 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); 124 extern void __bitmap_set(unsigned long *map, unsigned int start, int len); 125 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len); 126 127 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 128 unsigned long size, 129 unsigned long start, 130 unsigned int nr, 131 unsigned long align_mask, 132 unsigned long align_offset); 133 134 /** 135 * bitmap_find_next_zero_area - find a contiguous aligned zero area 136 * @map: The address to base the search on 137 * @size: The bitmap size in bits 138 * @start: The bitnumber to start searching at 139 * @nr: The number of zeroed bits we're looking for 140 * @align_mask: Alignment mask for zero area 141 * 142 * The @align_mask should be one less than a power of 2; the effect is that 143 * the bit offset of all zero areas this function finds is multiples of that 144 * power of 2. A @align_mask of 0 means no alignment is required. 145 */ 146 static inline unsigned long 147 bitmap_find_next_zero_area(unsigned long *map, 148 unsigned long size, 149 unsigned long start, 150 unsigned int nr, 151 unsigned long align_mask) 152 { 153 return bitmap_find_next_zero_area_off(map, size, start, nr, 154 align_mask, 0); 155 } 156 157 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, 158 unsigned long *dst, int nbits); 159 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, 160 unsigned long *dst, int nbits); 161 extern int bitmap_parselist(const char *buf, unsigned long *maskp, 162 int nmaskbits); 163 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, 164 unsigned long *dst, int nbits); 165 extern void bitmap_remap(unsigned long *dst, const unsigned long *src, 166 const unsigned long *old, const unsigned long *new, unsigned int nbits); 167 extern int bitmap_bitremap(int oldbit, 168 const unsigned long *old, const unsigned long *new, int bits); 169 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig, 170 const unsigned long *relmap, unsigned int bits); 171 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, 172 unsigned int sz, unsigned int nbits); 173 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); 174 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); 175 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); 176 extern unsigned int bitmap_from_u32array(unsigned long *bitmap, 177 unsigned int nbits, 178 const u32 *buf, 179 unsigned int nwords); 180 extern unsigned int bitmap_to_u32array(u32 *buf, 181 unsigned int nwords, 182 const unsigned long *bitmap, 183 unsigned int nbits); 184 #ifdef __BIG_ENDIAN 185 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); 186 #else 187 #define bitmap_copy_le bitmap_copy 188 #endif 189 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); 190 extern int bitmap_print_to_pagebuf(bool list, char *buf, 191 const unsigned long *maskp, int nmaskbits); 192 193 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) 194 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) 195 196 #define small_const_nbits(nbits) \ 197 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) 198 199 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) 200 { 201 if (small_const_nbits(nbits)) 202 *dst = 0UL; 203 else { 204 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 205 memset(dst, 0, len); 206 } 207 } 208 209 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) 210 { 211 unsigned int nlongs = BITS_TO_LONGS(nbits); 212 if (!small_const_nbits(nbits)) { 213 unsigned int len = (nlongs - 1) * sizeof(unsigned long); 214 memset(dst, 0xff, len); 215 } 216 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); 217 } 218 219 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, 220 unsigned int nbits) 221 { 222 if (small_const_nbits(nbits)) 223 *dst = *src; 224 else { 225 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); 226 memcpy(dst, src, len); 227 } 228 } 229 230 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, 231 const unsigned long *src2, unsigned int nbits) 232 { 233 if (small_const_nbits(nbits)) 234 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; 235 return __bitmap_and(dst, src1, src2, nbits); 236 } 237 238 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, 239 const unsigned long *src2, unsigned int nbits) 240 { 241 if (small_const_nbits(nbits)) 242 *dst = *src1 | *src2; 243 else 244 __bitmap_or(dst, src1, src2, nbits); 245 } 246 247 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, 248 const unsigned long *src2, unsigned int nbits) 249 { 250 if (small_const_nbits(nbits)) 251 *dst = *src1 ^ *src2; 252 else 253 __bitmap_xor(dst, src1, src2, nbits); 254 } 255 256 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, 257 const unsigned long *src2, unsigned int nbits) 258 { 259 if (small_const_nbits(nbits)) 260 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 261 return __bitmap_andnot(dst, src1, src2, nbits); 262 } 263 264 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, 265 unsigned int nbits) 266 { 267 if (small_const_nbits(nbits)) 268 *dst = ~(*src); 269 else 270 __bitmap_complement(dst, src, nbits); 271 } 272 273 static inline int bitmap_equal(const unsigned long *src1, 274 const unsigned long *src2, unsigned int nbits) 275 { 276 if (small_const_nbits(nbits)) 277 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); 278 if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 279 return !memcmp(src1, src2, nbits / 8); 280 return __bitmap_equal(src1, src2, nbits); 281 } 282 283 static inline int bitmap_intersects(const unsigned long *src1, 284 const unsigned long *src2, unsigned int nbits) 285 { 286 if (small_const_nbits(nbits)) 287 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; 288 else 289 return __bitmap_intersects(src1, src2, nbits); 290 } 291 292 static inline int bitmap_subset(const unsigned long *src1, 293 const unsigned long *src2, unsigned int nbits) 294 { 295 if (small_const_nbits(nbits)) 296 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); 297 else 298 return __bitmap_subset(src1, src2, nbits); 299 } 300 301 static inline int bitmap_empty(const unsigned long *src, unsigned nbits) 302 { 303 if (small_const_nbits(nbits)) 304 return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); 305 306 return find_first_bit(src, nbits) == nbits; 307 } 308 309 static inline int bitmap_full(const unsigned long *src, unsigned int nbits) 310 { 311 if (small_const_nbits(nbits)) 312 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); 313 314 return find_first_zero_bit(src, nbits) == nbits; 315 } 316 317 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) 318 { 319 if (small_const_nbits(nbits)) 320 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); 321 return __bitmap_weight(src, nbits); 322 } 323 324 static __always_inline void bitmap_set(unsigned long *map, unsigned int start, 325 unsigned int nbits) 326 { 327 if (__builtin_constant_p(nbits) && nbits == 1) 328 __set_bit(start, map); 329 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 330 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 331 memset((char *)map + start / 8, 0xff, nbits / 8); 332 else 333 __bitmap_set(map, start, nbits); 334 } 335 336 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, 337 unsigned int nbits) 338 { 339 if (__builtin_constant_p(nbits) && nbits == 1) 340 __clear_bit(start, map); 341 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && 342 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) 343 memset((char *)map + start / 8, 0, nbits / 8); 344 else 345 __bitmap_clear(map, start, nbits); 346 } 347 348 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, 349 unsigned int shift, int nbits) 350 { 351 if (small_const_nbits(nbits)) 352 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; 353 else 354 __bitmap_shift_right(dst, src, shift, nbits); 355 } 356 357 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, 358 unsigned int shift, unsigned int nbits) 359 { 360 if (small_const_nbits(nbits)) 361 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); 362 else 363 __bitmap_shift_left(dst, src, shift, nbits); 364 } 365 366 static inline int bitmap_parse(const char *buf, unsigned int buflen, 367 unsigned long *maskp, int nmaskbits) 368 { 369 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); 370 } 371 372 /** 373 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. 374 * @n: u64 value 375 * 376 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit 377 * integers in 32-bit environment, and 64-bit integers in 64-bit one. 378 * 379 * There are four combinations of endianness and length of the word in linux 380 * ABIs: LE64, BE64, LE32 and BE32. 381 * 382 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in 383 * bitmaps and therefore don't require any special handling. 384 * 385 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory 386 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the 387 * other hand is represented as an array of 32-bit words and the position of 388 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that 389 * word. For example, bit #42 is located at 10th position of 2nd word. 390 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit 391 * values in memory as it usually does. But for BE we need to swap hi and lo 392 * words manually. 393 * 394 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and 395 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps 396 * hi and lo words, as is expected by bitmap. 397 */ 398 #if __BITS_PER_LONG == 64 399 #define BITMAP_FROM_U64(n) (n) 400 #else 401 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ 402 ((unsigned long) ((u64)(n) >> 32)) 403 #endif 404 405 /** 406 * bitmap_from_u64 - Check and swap words within u64. 407 * @mask: source bitmap 408 * @dst: destination bitmap 409 * 410 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` 411 * to read u64 mask, we will get the wrong word. 412 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, 413 * but we expect the lower 32-bits of u64. 414 */ 415 static inline void bitmap_from_u64(unsigned long *dst, u64 mask) 416 { 417 dst[0] = mask & ULONG_MAX; 418 419 if (sizeof(mask) > sizeof(unsigned long)) 420 dst[1] = mask >> 32; 421 } 422 423 #endif /* __ASSEMBLY__ */ 424 425 #endif /* __LINUX_BITMAP_H */ 426