1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BITMAP_H
3 #define __LINUX_BITMAP_H
7 #include <linux/types.h>
8 #include <linux/bitops.h>
9 #include <linux/string.h>
10 #include <linux/kernel.h>
13 * bitmaps provide bit arrays that consume one or more unsigned
14 * longs. The bitmap interface and available operations are listed
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.
22 * See lib/bitmap.c for more details.
26 * DOC: bitmap overview
28 * The available bitmap operations and their rough meaning in the
29 * case that the bitmap is a single unsigned long are thus:
31 * The generated code is more efficient when nbits is known at
32 * compile-time and at most BITS_PER_LONG.
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, mask_off) as above
54 * bitmap_next_clear_region(map, &start, &end, nbits) Find next clear region
55 * bitmap_next_set_region(map, &start, &end, nbits) Find next set region
56 * bitmap_for_each_clear_region(map, rs, re, start, end)
57 * Iterate over all clear regions
58 * bitmap_for_each_set_region(map, rs, re, start, end)
59 * Iterate over all set regions
60 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
61 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
62 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
63 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
64 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
65 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
66 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
67 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
68 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
69 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
70 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
71 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
72 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
73 * bitmap_release_region(bitmap, pos, order) Free specified bit region
74 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
75 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
76 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
77 * bitmap_get_value8(map, start) Get 8bit value from map at start
78 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
80 * Note, bitmap_zero() and bitmap_fill() operate over the region of
81 * unsigned longs, that is, bits behind bitmap till the unsigned long
82 * boundary will be zeroed or filled as well. Consider to use
83 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
90 * Also the following operations in asm/bitops.h apply to bitmaps.::
92 * set_bit(bit, addr) *addr |= bit
93 * clear_bit(bit, addr) *addr &= ~bit
94 * change_bit(bit, addr) *addr ^= bit
95 * test_bit(bit, addr) Is bit set in *addr?
96 * test_and_set_bit(bit, addr) Set bit and return old value
97 * test_and_clear_bit(bit, addr) Clear bit and return old value
98 * test_and_change_bit(bit, addr) Change bit and return old value
99 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
100 * find_first_bit(addr, nbits) Position first set bit in *addr
101 * find_next_zero_bit(addr, nbits, bit)
102 * Position next zero bit in *addr >= bit
103 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
104 * find_next_and_bit(addr1, addr2, nbits, bit)
105 * Same as find_next_bit, but in
111 * DOC: declare bitmap
112 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
113 * to declare an array named 'name' of just enough unsigned longs to
114 * contain all bit positions from 0 to 'bits' - 1.
118 * Allocation and deallocation of bitmap.
119 * Provided in lib/bitmap.c to avoid circular dependency.
121 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
122 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
123 void bitmap_free(const unsigned long *bitmap);
126 * lib/bitmap.c provides these functions:
129 int __bitmap_equal(const unsigned long *bitmap1,
130 const unsigned long *bitmap2, unsigned int nbits);
131 bool __pure __bitmap_or_equal(const unsigned long *src1,
132 const unsigned long *src2,
133 const unsigned long *src3,
135 void __bitmap_complement(unsigned long *dst, const unsigned long *src,
137 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
138 unsigned int shift, unsigned int nbits);
139 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
140 unsigned int shift, unsigned int nbits);
141 void bitmap_cut(unsigned long *dst, const unsigned long *src,
142 unsigned int first, unsigned int cut, unsigned int nbits);
143 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
144 const unsigned long *bitmap2, unsigned int nbits);
145 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
146 const unsigned long *bitmap2, unsigned int nbits);
147 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
148 const unsigned long *bitmap2, unsigned int nbits);
149 int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
150 const unsigned long *bitmap2, unsigned int nbits);
151 void __bitmap_replace(unsigned long *dst,
152 const unsigned long *old, const unsigned long *new,
153 const unsigned long *mask, unsigned int nbits);
154 int __bitmap_intersects(const unsigned long *bitmap1,
155 const unsigned long *bitmap2, unsigned int nbits);
156 int __bitmap_subset(const unsigned long *bitmap1,
157 const unsigned long *bitmap2, unsigned int nbits);
158 int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
159 void __bitmap_set(unsigned long *map, unsigned int start, int len);
160 void __bitmap_clear(unsigned long *map, unsigned int start, int len);
162 unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
166 unsigned long align_mask,
167 unsigned long align_offset);
170 * bitmap_find_next_zero_area - find a contiguous aligned zero area
171 * @map: The address to base the search on
172 * @size: The bitmap size in bits
173 * @start: The bitnumber to start searching at
174 * @nr: The number of zeroed bits we're looking for
175 * @align_mask: Alignment mask for zero area
177 * The @align_mask should be one less than a power of 2; the effect is that
178 * the bit offset of all zero areas this function finds is multiples of that
179 * power of 2. A @align_mask of 0 means no alignment is required.
181 static inline unsigned long
182 bitmap_find_next_zero_area(unsigned long *map,
186 unsigned long align_mask)
188 return bitmap_find_next_zero_area_off(map, size, start, nr,
192 int bitmap_parse(const char *buf, unsigned int buflen,
193 unsigned long *dst, int nbits);
194 int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
195 unsigned long *dst, int nbits);
196 int bitmap_parselist(const char *buf, unsigned long *maskp,
198 int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
199 unsigned long *dst, int nbits);
200 void bitmap_remap(unsigned long *dst, const unsigned long *src,
201 const unsigned long *old, const unsigned long *new, unsigned int nbits);
202 int bitmap_bitremap(int oldbit,
203 const unsigned long *old, const unsigned long *new, int bits);
204 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
205 const unsigned long *relmap, unsigned int bits);
206 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
207 unsigned int sz, unsigned int nbits);
208 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
209 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
210 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
213 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
215 #define bitmap_copy_le bitmap_copy
217 unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
218 int bitmap_print_to_pagebuf(bool list, char *buf,
219 const unsigned long *maskp, int nmaskbits);
221 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
222 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
225 * The static inlines below do not handle constant nbits==0 correctly,
226 * so make such users (should any ever turn up) call the out-of-line
229 #define small_const_nbits(nbits) \
230 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
232 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
234 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
238 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
240 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
241 memset(dst, 0xff, len);
244 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
247 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
248 memcpy(dst, src, len);
252 * Copy bitmap and clear tail bits in last word.
254 static inline void bitmap_copy_clear_tail(unsigned long *dst,
255 const unsigned long *src, unsigned int nbits)
257 bitmap_copy(dst, src, nbits);
258 if (nbits % BITS_PER_LONG)
259 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
263 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
264 * therefore conversion is not needed when copying data from/to arrays of u32.
266 #if BITS_PER_LONG == 64
267 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
269 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
272 #define bitmap_from_arr32(bitmap, buf, nbits) \
273 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
274 (const unsigned long *) (buf), (nbits))
275 #define bitmap_to_arr32(buf, bitmap, nbits) \
276 bitmap_copy_clear_tail((unsigned long *) (buf), \
277 (const unsigned long *) (bitmap), (nbits))
280 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
281 const unsigned long *src2, unsigned int nbits)
283 if (small_const_nbits(nbits))
284 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
285 return __bitmap_and(dst, src1, src2, nbits);
288 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
289 const unsigned long *src2, unsigned int nbits)
291 if (small_const_nbits(nbits))
292 *dst = *src1 | *src2;
294 __bitmap_or(dst, src1, src2, nbits);
297 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
298 const unsigned long *src2, unsigned int nbits)
300 if (small_const_nbits(nbits))
301 *dst = *src1 ^ *src2;
303 __bitmap_xor(dst, src1, src2, nbits);
306 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
307 const unsigned long *src2, unsigned int nbits)
309 if (small_const_nbits(nbits))
310 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
311 return __bitmap_andnot(dst, src1, src2, nbits);
314 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
317 if (small_const_nbits(nbits))
320 __bitmap_complement(dst, src, nbits);
323 #ifdef __LITTLE_ENDIAN
324 #define BITMAP_MEM_ALIGNMENT 8
326 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
328 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
330 static inline int bitmap_equal(const unsigned long *src1,
331 const unsigned long *src2, unsigned int nbits)
333 if (small_const_nbits(nbits))
334 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
335 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
336 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
337 return !memcmp(src1, src2, nbits / 8);
338 return __bitmap_equal(src1, src2, nbits);
342 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
343 * @src1: Pointer to bitmap 1
344 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
345 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
346 * @nbits: number of bits in each of these bitmaps
348 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
350 static inline bool bitmap_or_equal(const unsigned long *src1,
351 const unsigned long *src2,
352 const unsigned long *src3,
355 if (!small_const_nbits(nbits))
356 return __bitmap_or_equal(src1, src2, src3, nbits);
358 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
361 static inline int bitmap_intersects(const unsigned long *src1,
362 const unsigned long *src2, unsigned int nbits)
364 if (small_const_nbits(nbits))
365 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
367 return __bitmap_intersects(src1, src2, nbits);
370 static inline int bitmap_subset(const unsigned long *src1,
371 const unsigned long *src2, unsigned int nbits)
373 if (small_const_nbits(nbits))
374 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
376 return __bitmap_subset(src1, src2, nbits);
379 static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
381 if (small_const_nbits(nbits))
382 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
384 return find_first_bit(src, nbits) == nbits;
387 static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
389 if (small_const_nbits(nbits))
390 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
392 return find_first_zero_bit(src, nbits) == nbits;
395 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
397 if (small_const_nbits(nbits))
398 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
399 return __bitmap_weight(src, nbits);
402 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
405 if (__builtin_constant_p(nbits) && nbits == 1)
406 __set_bit(start, map);
407 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
408 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
409 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
410 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
411 memset((char *)map + start / 8, 0xff, nbits / 8);
413 __bitmap_set(map, start, nbits);
416 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
419 if (__builtin_constant_p(nbits) && nbits == 1)
420 __clear_bit(start, map);
421 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
422 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
423 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
424 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
425 memset((char *)map + start / 8, 0, nbits / 8);
427 __bitmap_clear(map, start, nbits);
430 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
431 unsigned int shift, unsigned int nbits)
433 if (small_const_nbits(nbits))
434 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
436 __bitmap_shift_right(dst, src, shift, nbits);
439 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
440 unsigned int shift, unsigned int nbits)
442 if (small_const_nbits(nbits))
443 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
445 __bitmap_shift_left(dst, src, shift, nbits);
448 static inline void bitmap_replace(unsigned long *dst,
449 const unsigned long *old,
450 const unsigned long *new,
451 const unsigned long *mask,
454 if (small_const_nbits(nbits))
455 *dst = (*old & ~(*mask)) | (*new & *mask);
457 __bitmap_replace(dst, old, new, mask, nbits);
460 static inline void bitmap_next_clear_region(unsigned long *bitmap,
461 unsigned int *rs, unsigned int *re,
464 *rs = find_next_zero_bit(bitmap, end, *rs);
465 *re = find_next_bit(bitmap, end, *rs + 1);
468 static inline void bitmap_next_set_region(unsigned long *bitmap,
469 unsigned int *rs, unsigned int *re,
472 *rs = find_next_bit(bitmap, end, *rs);
473 *re = find_next_zero_bit(bitmap, end, *rs + 1);
477 * Bitmap region iterators. Iterates over the bitmap between [@start, @end).
478 * @rs and @re should be integer variables and will be set to start and end
479 * index of the current clear or set region.
481 #define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \
482 for ((rs) = (start), \
483 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \
486 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)))
488 #define bitmap_for_each_set_region(bitmap, rs, re, start, end) \
489 for ((rs) = (start), \
490 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \
493 bitmap_next_set_region((bitmap), &(rs), &(re), (end)))
496 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
499 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
500 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
502 * There are four combinations of endianness and length of the word in linux
503 * ABIs: LE64, BE64, LE32 and BE32.
505 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
506 * bitmaps and therefore don't require any special handling.
508 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
509 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
510 * other hand is represented as an array of 32-bit words and the position of
511 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
512 * word. For example, bit #42 is located at 10th position of 2nd word.
513 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
514 * values in memory as it usually does. But for BE we need to swap hi and lo
517 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
518 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
519 * hi and lo words, as is expected by bitmap.
521 #if __BITS_PER_LONG == 64
522 #define BITMAP_FROM_U64(n) (n)
524 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
525 ((unsigned long) ((u64)(n) >> 32))
529 * bitmap_from_u64 - Check and swap words within u64.
530 * @mask: source bitmap
531 * @dst: destination bitmap
533 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
534 * to read u64 mask, we will get the wrong word.
535 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
536 * but we expect the lower 32-bits of u64.
538 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
540 dst[0] = mask & ULONG_MAX;
542 if (sizeof(mask) > sizeof(unsigned long))
547 * bitmap_get_value8 - get an 8-bit value within a memory region
548 * @map: address to the bitmap memory region
549 * @start: bit offset of the 8-bit value; must be a multiple of 8
551 * Returns the 8-bit value located at the @start bit offset within the @src
554 static inline unsigned long bitmap_get_value8(const unsigned long *map,
557 const size_t index = BIT_WORD(start);
558 const unsigned long offset = start % BITS_PER_LONG;
560 return (map[index] >> offset) & 0xFF;
564 * bitmap_set_value8 - set an 8-bit value within a memory region
565 * @map: address to the bitmap memory region
566 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
567 * @start: bit offset of the 8-bit value; must be a multiple of 8
569 static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
572 const size_t index = BIT_WORD(start);
573 const unsigned long offset = start % BITS_PER_LONG;
575 map[index] &= ~(0xFFUL << offset);
576 map[index] |= value << offset;
579 #endif /* __ASSEMBLY__ */
581 #endif /* __LINUX_BITMAP_H */