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 * The available bitmap operations and their rough meaning in the
27 * case that the bitmap is a single unsigned long are thus:
29 * Note that nbits should be always a compile time evaluable constant.
30 * Otherwise many inlines will generate horrible code.
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)
68 * Also the following operations in asm/bitops.h apply to bitmaps.
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
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.
90 * Allocation and deallocation of bitmap.
91 * Provided in lib/bitmap.c to avoid circular dependency.
93 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
94 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
95 extern void bitmap_free(const unsigned long *bitmap);
98 * lib/bitmap.c provides these functions:
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,
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);
127 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
131 unsigned long align_mask,
132 unsigned long align_offset);
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
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.
146 static inline unsigned long
147 bitmap_find_next_zero_area(unsigned long *map,
151 unsigned long align_mask)
153 return bitmap_find_next_zero_area_off(map, size, start, nr,
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,
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,
179 unsigned int nwords);
180 extern unsigned int bitmap_to_u32array(u32 *buf,
182 const unsigned long *bitmap,
185 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
187 #define bitmap_copy_le bitmap_copy
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);
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)))
197 * The static inlines below do not handle constant nbits==0 correctly,
198 * so make such users (should any ever turn up) call the out-of-line
201 #define small_const_nbits(nbits) \
202 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
204 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
206 if (small_const_nbits(nbits))
209 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
214 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
216 unsigned int nlongs = BITS_TO_LONGS(nbits);
217 if (!small_const_nbits(nbits)) {
218 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
219 memset(dst, 0xff, len);
221 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
224 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
227 if (small_const_nbits(nbits))
230 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
231 memcpy(dst, src, len);
235 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
236 const unsigned long *src2, unsigned int nbits)
238 if (small_const_nbits(nbits))
239 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
240 return __bitmap_and(dst, src1, src2, nbits);
243 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
244 const unsigned long *src2, unsigned int nbits)
246 if (small_const_nbits(nbits))
247 *dst = *src1 | *src2;
249 __bitmap_or(dst, src1, src2, nbits);
252 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
253 const unsigned long *src2, unsigned int nbits)
255 if (small_const_nbits(nbits))
256 *dst = *src1 ^ *src2;
258 __bitmap_xor(dst, src1, src2, nbits);
261 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
262 const unsigned long *src2, unsigned int nbits)
264 if (small_const_nbits(nbits))
265 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
266 return __bitmap_andnot(dst, src1, src2, nbits);
269 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
272 if (small_const_nbits(nbits))
275 __bitmap_complement(dst, src, nbits);
278 #ifdef __LITTLE_ENDIAN
279 #define BITMAP_MEM_ALIGNMENT 8
281 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
283 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
285 static inline int bitmap_equal(const unsigned long *src1,
286 const unsigned long *src2, unsigned int nbits)
288 if (small_const_nbits(nbits))
289 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
290 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
291 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
292 return !memcmp(src1, src2, nbits / 8);
293 return __bitmap_equal(src1, src2, nbits);
296 static inline int bitmap_intersects(const unsigned long *src1,
297 const unsigned long *src2, unsigned int nbits)
299 if (small_const_nbits(nbits))
300 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
302 return __bitmap_intersects(src1, src2, nbits);
305 static inline int bitmap_subset(const unsigned long *src1,
306 const unsigned long *src2, unsigned int nbits)
308 if (small_const_nbits(nbits))
309 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
311 return __bitmap_subset(src1, src2, nbits);
314 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
316 if (small_const_nbits(nbits))
317 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
319 return find_first_bit(src, nbits) == nbits;
322 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
324 if (small_const_nbits(nbits))
325 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
327 return find_first_zero_bit(src, nbits) == nbits;
330 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
332 if (small_const_nbits(nbits))
333 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
334 return __bitmap_weight(src, nbits);
337 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
340 if (__builtin_constant_p(nbits) && nbits == 1)
341 __set_bit(start, map);
342 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
343 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
344 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
345 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
346 memset((char *)map + start / 8, 0xff, nbits / 8);
348 __bitmap_set(map, start, nbits);
351 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
354 if (__builtin_constant_p(nbits) && nbits == 1)
355 __clear_bit(start, map);
356 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
357 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
358 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
359 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
360 memset((char *)map + start / 8, 0, nbits / 8);
362 __bitmap_clear(map, start, nbits);
365 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
366 unsigned int shift, unsigned int nbits)
368 if (small_const_nbits(nbits))
369 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
371 __bitmap_shift_right(dst, src, shift, nbits);
374 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
375 unsigned int shift, unsigned int nbits)
377 if (small_const_nbits(nbits))
378 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
380 __bitmap_shift_left(dst, src, shift, nbits);
383 static inline int bitmap_parse(const char *buf, unsigned int buflen,
384 unsigned long *maskp, int nmaskbits)
386 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
390 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
392 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
393 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
395 * There are four combinations of endianness and length of the word in linux
396 * ABIs: LE64, BE64, LE32 and BE32.
398 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
399 * bitmaps and therefore don't require any special handling.
401 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
402 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
403 * other hand is represented as an array of 32-bit words and the position of
404 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
405 * word. For example, bit #42 is located at 10th position of 2nd word.
406 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
407 * values in memory as it usually does. But for BE we need to swap hi and lo
410 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
411 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
412 * hi and lo words, as is expected by bitmap.
414 #if __BITS_PER_LONG == 64
415 #define BITMAP_FROM_U64(n) (n)
417 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
418 ((unsigned long) ((u64)(n) >> 32))
422 * bitmap_from_u64 - Check and swap words within u64.
423 * @mask: source bitmap
424 * @dst: destination bitmap
426 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
427 * to read u64 mask, we will get the wrong word.
428 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
429 * but we expect the lower 32-bits of u64.
431 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
433 dst[0] = mask & ULONG_MAX;
435 if (sizeof(mask) > sizeof(unsigned long))
439 #endif /* __ASSEMBLY__ */
441 #endif /* __LINUX_BITMAP_H */