1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BITMAP_H
3 #define __LINUX_BITMAP_H
7 #include <linux/align.h>
8 #include <linux/types.h>
9 #include <linux/bitops.h>
10 #include <linux/limits.h>
11 #include <linux/string.h>
14 * bitmaps provide bit arrays that consume one or more unsigned
15 * longs. The bitmap interface and available operations are listed
18 * Function implementations generic to all architectures are in
19 * lib/bitmap.c. Functions implementations that are architecture
20 * specific are in various include/asm-<arch>/bitops.h headers
21 * and other arch/<arch> specific files.
23 * See lib/bitmap.c for more details.
27 * DOC: bitmap overview
29 * The available bitmap operations and their rough meaning in the
30 * case that the bitmap is a single unsigned long are thus:
32 * The generated code is more efficient when nbits is known at
33 * compile-time and at most BITS_PER_LONG.
37 * bitmap_zero(dst, nbits) *dst = 0UL
38 * bitmap_fill(dst, nbits) *dst = ~0UL
39 * bitmap_copy(dst, src, nbits) *dst = *src
40 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
41 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
42 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
43 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
44 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
45 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
46 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
47 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
48 * bitmap_empty(src, nbits) Are all bits zero in *src?
49 * bitmap_full(src, nbits) Are all bits set in *src?
50 * bitmap_weight(src, nbits) Hamming Weight: number set bits
51 * bitmap_set(dst, pos, nbits) Set specified bit area
52 * bitmap_clear(dst, pos, nbits) Clear specified bit area
53 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
54 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
55 * bitmap_next_clear_region(map, &start, &end, nbits) Find next clear region
56 * bitmap_next_set_region(map, &start, &end, nbits) Find next set region
57 * bitmap_for_each_clear_region(map, rs, re, start, end)
58 * Iterate over all clear regions
59 * bitmap_for_each_set_region(map, rs, re, start, end)
60 * Iterate over all set regions
61 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
62 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
63 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
64 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
65 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
66 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
67 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
68 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
69 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
70 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
71 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
72 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
73 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
74 * bitmap_release_region(bitmap, pos, order) Free specified bit region
75 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
76 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
77 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
78 * bitmap_get_value8(map, start) Get 8bit value from map at start
79 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
81 * Note, bitmap_zero() and bitmap_fill() operate over the region of
82 * unsigned longs, that is, bits behind bitmap till the unsigned long
83 * boundary will be zeroed or filled as well. Consider to use
84 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
91 * Also the following operations in asm/bitops.h apply to bitmaps.::
93 * set_bit(bit, addr) *addr |= bit
94 * clear_bit(bit, addr) *addr &= ~bit
95 * change_bit(bit, addr) *addr ^= bit
96 * test_bit(bit, addr) Is bit set in *addr?
97 * test_and_set_bit(bit, addr) Set bit and return old value
98 * test_and_clear_bit(bit, addr) Clear bit and return old value
99 * test_and_change_bit(bit, addr) Change bit and return old value
100 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
101 * find_first_bit(addr, nbits) Position first set bit in *addr
102 * find_next_zero_bit(addr, nbits, bit)
103 * Position next zero bit in *addr >= bit
104 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
105 * find_next_and_bit(addr1, addr2, nbits, bit)
106 * Same as find_next_bit, but in
112 * DOC: declare bitmap
113 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
114 * to declare an array named 'name' of just enough unsigned longs to
115 * contain all bit positions from 0 to 'bits' - 1.
119 * Allocation and deallocation of bitmap.
120 * Provided in lib/bitmap.c to avoid circular dependency.
122 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
123 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
124 extern void bitmap_free(const unsigned long *bitmap);
127 * lib/bitmap.c provides these functions:
130 extern int __bitmap_equal(const unsigned long *bitmap1,
131 const unsigned long *bitmap2, unsigned int nbits);
132 extern bool __pure __bitmap_or_equal(const unsigned long *src1,
133 const unsigned long *src2,
134 const unsigned long *src3,
136 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
138 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
139 unsigned int shift, unsigned int nbits);
140 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
141 unsigned int shift, unsigned int nbits);
142 extern void bitmap_cut(unsigned long *dst, const unsigned long *src,
143 unsigned int first, unsigned int cut,
145 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
146 const unsigned long *bitmap2, unsigned int nbits);
147 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
148 const unsigned long *bitmap2, unsigned int nbits);
149 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
150 const unsigned long *bitmap2, unsigned int nbits);
151 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
152 const unsigned long *bitmap2, unsigned int nbits);
153 extern void __bitmap_replace(unsigned long *dst,
154 const unsigned long *old, const unsigned long *new,
155 const unsigned long *mask, unsigned int nbits);
156 extern int __bitmap_intersects(const unsigned long *bitmap1,
157 const unsigned long *bitmap2, unsigned int nbits);
158 extern int __bitmap_subset(const unsigned long *bitmap1,
159 const unsigned long *bitmap2, unsigned int nbits);
160 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
161 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
162 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
164 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
168 unsigned long align_mask,
169 unsigned long align_offset);
172 * bitmap_find_next_zero_area - find a contiguous aligned zero area
173 * @map: The address to base the search on
174 * @size: The bitmap size in bits
175 * @start: The bitnumber to start searching at
176 * @nr: The number of zeroed bits we're looking for
177 * @align_mask: Alignment mask for zero area
179 * The @align_mask should be one less than a power of 2; the effect is that
180 * the bit offset of all zero areas this function finds is multiples of that
181 * power of 2. A @align_mask of 0 means no alignment is required.
183 static inline unsigned long
184 bitmap_find_next_zero_area(unsigned long *map,
188 unsigned long align_mask)
190 return bitmap_find_next_zero_area_off(map, size, start, nr,
194 extern int bitmap_parse(const char *buf, unsigned int buflen,
195 unsigned long *dst, int nbits);
196 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
197 unsigned long *dst, int nbits);
198 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
200 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
201 unsigned long *dst, int nbits);
202 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
203 const unsigned long *old, const unsigned long *new, unsigned int nbits);
204 extern int bitmap_bitremap(int oldbit,
205 const unsigned long *old, const unsigned long *new, int bits);
206 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
207 const unsigned long *relmap, unsigned int bits);
208 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
209 unsigned int sz, unsigned int nbits);
210 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
211 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
212 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
215 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
217 #define bitmap_copy_le bitmap_copy
219 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
220 extern int bitmap_print_to_pagebuf(bool list, char *buf,
221 const unsigned long *maskp, int nmaskbits);
223 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
224 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
226 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
228 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
232 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
234 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
235 memset(dst, 0xff, len);
238 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
241 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
242 memcpy(dst, src, len);
246 * Copy bitmap and clear tail bits in last word.
248 static inline void bitmap_copy_clear_tail(unsigned long *dst,
249 const unsigned long *src, unsigned int nbits)
251 bitmap_copy(dst, src, nbits);
252 if (nbits % BITS_PER_LONG)
253 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
257 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
258 * therefore conversion is not needed when copying data from/to arrays of u32.
260 #if BITS_PER_LONG == 64
261 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
263 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
266 #define bitmap_from_arr32(bitmap, buf, nbits) \
267 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
268 (const unsigned long *) (buf), (nbits))
269 #define bitmap_to_arr32(buf, bitmap, nbits) \
270 bitmap_copy_clear_tail((unsigned long *) (buf), \
271 (const unsigned long *) (bitmap), (nbits))
274 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
275 const unsigned long *src2, unsigned int nbits)
277 if (small_const_nbits(nbits))
278 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
279 return __bitmap_and(dst, src1, src2, nbits);
282 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
283 const unsigned long *src2, unsigned int nbits)
285 if (small_const_nbits(nbits))
286 *dst = *src1 | *src2;
288 __bitmap_or(dst, src1, src2, nbits);
291 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
292 const unsigned long *src2, unsigned int nbits)
294 if (small_const_nbits(nbits))
295 *dst = *src1 ^ *src2;
297 __bitmap_xor(dst, src1, src2, nbits);
300 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
301 const unsigned long *src2, unsigned int nbits)
303 if (small_const_nbits(nbits))
304 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
305 return __bitmap_andnot(dst, src1, src2, nbits);
308 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
311 if (small_const_nbits(nbits))
314 __bitmap_complement(dst, src, nbits);
317 #ifdef __LITTLE_ENDIAN
318 #define BITMAP_MEM_ALIGNMENT 8
320 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
322 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
324 static inline int bitmap_equal(const unsigned long *src1,
325 const unsigned long *src2, unsigned int nbits)
327 if (small_const_nbits(nbits))
328 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
329 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
330 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
331 return !memcmp(src1, src2, nbits / 8);
332 return __bitmap_equal(src1, src2, nbits);
336 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
337 * @src1: Pointer to bitmap 1
338 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
339 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
340 * @nbits: number of bits in each of these bitmaps
342 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
344 static inline bool bitmap_or_equal(const unsigned long *src1,
345 const unsigned long *src2,
346 const unsigned long *src3,
349 if (!small_const_nbits(nbits))
350 return __bitmap_or_equal(src1, src2, src3, nbits);
352 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
355 static inline int bitmap_intersects(const unsigned long *src1,
356 const unsigned long *src2, unsigned int nbits)
358 if (small_const_nbits(nbits))
359 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
361 return __bitmap_intersects(src1, src2, nbits);
364 static inline int bitmap_subset(const unsigned long *src1,
365 const unsigned long *src2, unsigned int nbits)
367 if (small_const_nbits(nbits))
368 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
370 return __bitmap_subset(src1, src2, nbits);
373 static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
375 if (small_const_nbits(nbits))
376 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
378 return find_first_bit(src, nbits) == nbits;
381 static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
383 if (small_const_nbits(nbits))
384 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
386 return find_first_zero_bit(src, nbits) == nbits;
389 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
391 if (small_const_nbits(nbits))
392 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
393 return __bitmap_weight(src, nbits);
396 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
399 if (__builtin_constant_p(nbits) && nbits == 1)
400 __set_bit(start, map);
401 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
402 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
403 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
404 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
405 memset((char *)map + start / 8, 0xff, nbits / 8);
407 __bitmap_set(map, start, nbits);
410 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
413 if (__builtin_constant_p(nbits) && nbits == 1)
414 __clear_bit(start, map);
415 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
416 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
417 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
418 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
419 memset((char *)map + start / 8, 0, nbits / 8);
421 __bitmap_clear(map, start, nbits);
424 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
425 unsigned int shift, unsigned int nbits)
427 if (small_const_nbits(nbits))
428 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
430 __bitmap_shift_right(dst, src, shift, nbits);
433 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
434 unsigned int shift, unsigned int nbits)
436 if (small_const_nbits(nbits))
437 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
439 __bitmap_shift_left(dst, src, shift, nbits);
442 static inline void bitmap_replace(unsigned long *dst,
443 const unsigned long *old,
444 const unsigned long *new,
445 const unsigned long *mask,
448 if (small_const_nbits(nbits))
449 *dst = (*old & ~(*mask)) | (*new & *mask);
451 __bitmap_replace(dst, old, new, mask, nbits);
454 static inline void bitmap_next_clear_region(unsigned long *bitmap,
455 unsigned int *rs, unsigned int *re,
458 *rs = find_next_zero_bit(bitmap, end, *rs);
459 *re = find_next_bit(bitmap, end, *rs + 1);
462 static inline void bitmap_next_set_region(unsigned long *bitmap,
463 unsigned int *rs, unsigned int *re,
466 *rs = find_next_bit(bitmap, end, *rs);
467 *re = find_next_zero_bit(bitmap, end, *rs + 1);
471 * Bitmap region iterators. Iterates over the bitmap between [@start, @end).
472 * @rs and @re should be integer variables and will be set to start and end
473 * index of the current clear or set region.
475 #define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \
476 for ((rs) = (start), \
477 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \
480 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)))
482 #define bitmap_for_each_set_region(bitmap, rs, re, start, end) \
483 for ((rs) = (start), \
484 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \
487 bitmap_next_set_region((bitmap), &(rs), &(re), (end)))
490 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
493 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
494 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
496 * There are four combinations of endianness and length of the word in linux
497 * ABIs: LE64, BE64, LE32 and BE32.
499 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
500 * bitmaps and therefore don't require any special handling.
502 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
503 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
504 * other hand is represented as an array of 32-bit words and the position of
505 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
506 * word. For example, bit #42 is located at 10th position of 2nd word.
507 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
508 * values in memory as it usually does. But for BE we need to swap hi and lo
511 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
512 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
513 * hi and lo words, as is expected by bitmap.
515 #if __BITS_PER_LONG == 64
516 #define BITMAP_FROM_U64(n) (n)
518 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
519 ((unsigned long) ((u64)(n) >> 32))
523 * bitmap_from_u64 - Check and swap words within u64.
524 * @mask: source bitmap
525 * @dst: destination bitmap
527 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
528 * to read u64 mask, we will get the wrong word.
529 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
530 * but we expect the lower 32-bits of u64.
532 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
534 dst[0] = mask & ULONG_MAX;
536 if (sizeof(mask) > sizeof(unsigned long))
541 * bitmap_get_value8 - get an 8-bit value within a memory region
542 * @map: address to the bitmap memory region
543 * @start: bit offset of the 8-bit value; must be a multiple of 8
545 * Returns the 8-bit value located at the @start bit offset within the @src
548 static inline unsigned long bitmap_get_value8(const unsigned long *map,
551 const size_t index = BIT_WORD(start);
552 const unsigned long offset = start % BITS_PER_LONG;
554 return (map[index] >> offset) & 0xFF;
558 * bitmap_set_value8 - set an 8-bit value within a memory region
559 * @map: address to the bitmap memory region
560 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
561 * @start: bit offset of the 8-bit value; must be a multiple of 8
563 static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
566 const size_t index = BIT_WORD(start);
567 const unsigned long offset = start % BITS_PER_LONG;
569 map[index] &= ~(0xFFUL << offset);
570 map[index] |= value << offset;
573 #endif /* __ASSEMBLY__ */
575 #endif /* __LINUX_BITMAP_H */