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) 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_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
57 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
58 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
59 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
60 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
61 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
62 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
63 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
64 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
65 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
66 * bitmap_release_region(bitmap, pos, order) Free specified bit region
67 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
68 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
69 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
70 * bitmap_get_value8(map, start) Get 8bit value from map at start
71 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
73 * Note, bitmap_zero() and bitmap_fill() operate over the region of
74 * unsigned longs, that is, bits behind bitmap till the unsigned long
75 * boundary will be zeroed or filled as well. Consider to use
76 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
83 * Also the following operations in asm/bitops.h apply to bitmaps.::
85 * set_bit(bit, addr) *addr |= bit
86 * clear_bit(bit, addr) *addr &= ~bit
87 * change_bit(bit, addr) *addr ^= bit
88 * test_bit(bit, addr) Is bit set in *addr?
89 * test_and_set_bit(bit, addr) Set bit and return old value
90 * test_and_clear_bit(bit, addr) Clear bit and return old value
91 * test_and_change_bit(bit, addr) Change bit and return old value
92 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
93 * find_first_bit(addr, nbits) Position first set bit in *addr
94 * find_next_zero_bit(addr, nbits, bit)
95 * Position next zero bit in *addr >= bit
96 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
97 * find_next_and_bit(addr1, addr2, nbits, bit)
98 * Same as find_next_bit, but in
104 * DOC: declare bitmap
105 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
106 * to declare an array named 'name' of just enough unsigned longs to
107 * contain all bit positions from 0 to 'bits' - 1.
111 * Allocation and deallocation of bitmap.
112 * Provided in lib/bitmap.c to avoid circular dependency.
114 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
115 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
116 extern void bitmap_free(const unsigned long *bitmap);
119 * lib/bitmap.c provides these functions:
122 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
123 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
124 extern int __bitmap_equal(const unsigned long *bitmap1,
125 const unsigned long *bitmap2, unsigned int nbits);
126 extern bool __pure __bitmap_or_equal(const unsigned long *src1,
127 const unsigned long *src2,
128 const unsigned long *src3,
130 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
132 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
133 unsigned int shift, unsigned int nbits);
134 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
135 unsigned int shift, unsigned int nbits);
136 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
137 const unsigned long *bitmap2, unsigned int nbits);
138 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
139 const unsigned long *bitmap2, unsigned int nbits);
140 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
141 const unsigned long *bitmap2, unsigned int nbits);
142 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
143 const unsigned long *bitmap2, unsigned int nbits);
144 extern void __bitmap_replace(unsigned long *dst,
145 const unsigned long *old, const unsigned long *new,
146 const unsigned long *mask, unsigned int nbits);
147 extern int __bitmap_intersects(const unsigned long *bitmap1,
148 const unsigned long *bitmap2, unsigned int nbits);
149 extern int __bitmap_subset(const unsigned long *bitmap1,
150 const unsigned long *bitmap2, unsigned int nbits);
151 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
152 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
153 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
155 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
159 unsigned long align_mask,
160 unsigned long align_offset);
163 * bitmap_find_next_zero_area - find a contiguous aligned zero area
164 * @map: The address to base the search on
165 * @size: The bitmap size in bits
166 * @start: The bitnumber to start searching at
167 * @nr: The number of zeroed bits we're looking for
168 * @align_mask: Alignment mask for zero area
170 * The @align_mask should be one less than a power of 2; the effect is that
171 * the bit offset of all zero areas this function finds is multiples of that
172 * power of 2. A @align_mask of 0 means no alignment is required.
174 static inline unsigned long
175 bitmap_find_next_zero_area(unsigned long *map,
179 unsigned long align_mask)
181 return bitmap_find_next_zero_area_off(map, size, start, nr,
185 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
186 unsigned long *dst, int nbits);
187 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
188 unsigned long *dst, int nbits);
189 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
191 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
192 unsigned long *dst, int nbits);
193 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
194 const unsigned long *old, const unsigned long *new, unsigned int nbits);
195 extern int bitmap_bitremap(int oldbit,
196 const unsigned long *old, const unsigned long *new, int bits);
197 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
198 const unsigned long *relmap, unsigned int bits);
199 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
200 unsigned int sz, unsigned int nbits);
201 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
202 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
203 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
206 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
208 #define bitmap_copy_le bitmap_copy
210 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
211 extern int bitmap_print_to_pagebuf(bool list, char *buf,
212 const unsigned long *maskp, int nmaskbits);
214 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
215 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
218 * The static inlines below do not handle constant nbits==0 correctly,
219 * so make such users (should any ever turn up) call the out-of-line
222 #define small_const_nbits(nbits) \
223 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
225 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
227 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
231 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
233 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
234 memset(dst, 0xff, len);
237 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
240 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
241 memcpy(dst, src, len);
245 * Copy bitmap and clear tail bits in last word.
247 static inline void bitmap_copy_clear_tail(unsigned long *dst,
248 const unsigned long *src, unsigned int nbits)
250 bitmap_copy(dst, src, nbits);
251 if (nbits % BITS_PER_LONG)
252 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
256 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
257 * therefore conversion is not needed when copying data from/to arrays of u32.
259 #if BITS_PER_LONG == 64
260 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
262 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
265 #define bitmap_from_arr32(bitmap, buf, nbits) \
266 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
267 (const unsigned long *) (buf), (nbits))
268 #define bitmap_to_arr32(buf, bitmap, nbits) \
269 bitmap_copy_clear_tail((unsigned long *) (buf), \
270 (const unsigned long *) (bitmap), (nbits))
273 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
274 const unsigned long *src2, unsigned int nbits)
276 if (small_const_nbits(nbits))
277 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
278 return __bitmap_and(dst, src1, src2, nbits);
281 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
282 const unsigned long *src2, unsigned int nbits)
284 if (small_const_nbits(nbits))
285 *dst = *src1 | *src2;
287 __bitmap_or(dst, src1, src2, nbits);
290 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
291 const unsigned long *src2, unsigned int nbits)
293 if (small_const_nbits(nbits))
294 *dst = *src1 ^ *src2;
296 __bitmap_xor(dst, src1, src2, nbits);
299 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
300 const unsigned long *src2, unsigned int nbits)
302 if (small_const_nbits(nbits))
303 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
304 return __bitmap_andnot(dst, src1, src2, nbits);
307 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
310 if (small_const_nbits(nbits))
313 __bitmap_complement(dst, src, nbits);
316 #ifdef __LITTLE_ENDIAN
317 #define BITMAP_MEM_ALIGNMENT 8
319 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
321 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
323 static inline int bitmap_equal(const unsigned long *src1,
324 const unsigned long *src2, unsigned int nbits)
326 if (small_const_nbits(nbits))
327 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
328 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
329 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
330 return !memcmp(src1, src2, nbits / 8);
331 return __bitmap_equal(src1, src2, nbits);
335 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
336 * @src1: Pointer to bitmap 1
337 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
338 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
339 * @nbits: number of bits in each of these bitmaps
341 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
343 static inline bool bitmap_or_equal(const unsigned long *src1,
344 const unsigned long *src2,
345 const unsigned long *src3,
348 if (!small_const_nbits(nbits))
349 return __bitmap_or_equal(src1, src2, src3, nbits);
351 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
354 static inline int bitmap_intersects(const unsigned long *src1,
355 const unsigned long *src2, unsigned int nbits)
357 if (small_const_nbits(nbits))
358 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
360 return __bitmap_intersects(src1, src2, nbits);
363 static inline int bitmap_subset(const unsigned long *src1,
364 const unsigned long *src2, unsigned int nbits)
366 if (small_const_nbits(nbits))
367 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
369 return __bitmap_subset(src1, src2, nbits);
372 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
374 if (small_const_nbits(nbits))
375 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
377 return find_first_bit(src, nbits) == nbits;
380 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
382 if (small_const_nbits(nbits))
383 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
385 return find_first_zero_bit(src, nbits) == nbits;
388 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
390 if (small_const_nbits(nbits))
391 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
392 return __bitmap_weight(src, nbits);
395 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
398 if (__builtin_constant_p(nbits) && nbits == 1)
399 __set_bit(start, map);
400 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
401 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
402 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
403 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
404 memset((char *)map + start / 8, 0xff, nbits / 8);
406 __bitmap_set(map, start, nbits);
409 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
412 if (__builtin_constant_p(nbits) && nbits == 1)
413 __clear_bit(start, map);
414 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
415 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
416 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
417 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
418 memset((char *)map + start / 8, 0, nbits / 8);
420 __bitmap_clear(map, start, nbits);
423 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
424 unsigned int shift, unsigned int nbits)
426 if (small_const_nbits(nbits))
427 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
429 __bitmap_shift_right(dst, src, shift, nbits);
432 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
433 unsigned int shift, unsigned int nbits)
435 if (small_const_nbits(nbits))
436 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
438 __bitmap_shift_left(dst, src, shift, nbits);
441 static inline void bitmap_replace(unsigned long *dst,
442 const unsigned long *old,
443 const unsigned long *new,
444 const unsigned long *mask,
447 if (small_const_nbits(nbits))
448 *dst = (*old & ~(*mask)) | (*new & *mask);
450 __bitmap_replace(dst, old, new, mask, nbits);
453 static inline int bitmap_parse(const char *buf, unsigned int buflen,
454 unsigned long *maskp, int nmaskbits)
456 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
460 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
463 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
464 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
466 * There are four combinations of endianness and length of the word in linux
467 * ABIs: LE64, BE64, LE32 and BE32.
469 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
470 * bitmaps and therefore don't require any special handling.
472 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
473 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
474 * other hand is represented as an array of 32-bit words and the position of
475 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
476 * word. For example, bit #42 is located at 10th position of 2nd word.
477 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
478 * values in memory as it usually does. But for BE we need to swap hi and lo
481 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
482 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
483 * hi and lo words, as is expected by bitmap.
485 #if __BITS_PER_LONG == 64
486 #define BITMAP_FROM_U64(n) (n)
488 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
489 ((unsigned long) ((u64)(n) >> 32))
493 * bitmap_from_u64 - Check and swap words within u64.
494 * @mask: source bitmap
495 * @dst: destination bitmap
497 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
498 * to read u64 mask, we will get the wrong word.
499 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
500 * but we expect the lower 32-bits of u64.
502 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
504 dst[0] = mask & ULONG_MAX;
506 if (sizeof(mask) > sizeof(unsigned long))
511 * bitmap_get_value8 - get an 8-bit value within a memory region
512 * @map: address to the bitmap memory region
513 * @start: bit offset of the 8-bit value; must be a multiple of 8
515 * Returns the 8-bit value located at the @start bit offset within the @src
518 static inline unsigned long bitmap_get_value8(const unsigned long *map,
521 const size_t index = BIT_WORD(start);
522 const unsigned long offset = start % BITS_PER_LONG;
524 return (map[index] >> offset) & 0xFF;
528 * bitmap_set_value8 - set an 8-bit value within a memory region
529 * @map: address to the bitmap memory region
530 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
531 * @start: bit offset of the 8-bit value; must be a multiple of 8
533 static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
536 const size_t index = BIT_WORD(start);
537 const unsigned long offset = start % BITS_PER_LONG;
539 map[index] &= ~(0xFFUL << offset);
540 map[index] |= value << offset;
543 #endif /* __ASSEMBLY__ */
545 #endif /* __LINUX_BITMAP_H */