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 * lib/bitmap.c provides these functions:
93 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
94 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
95 extern int __bitmap_equal(const unsigned long *bitmap1,
96 const unsigned long *bitmap2, unsigned int nbits);
97 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
99 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
100 unsigned int shift, unsigned int nbits);
101 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
102 unsigned int shift, unsigned int nbits);
103 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
104 const unsigned long *bitmap2, unsigned int nbits);
105 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
106 const unsigned long *bitmap2, unsigned int nbits);
107 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
108 const unsigned long *bitmap2, unsigned int nbits);
109 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
110 const unsigned long *bitmap2, unsigned int nbits);
111 extern int __bitmap_intersects(const unsigned long *bitmap1,
112 const unsigned long *bitmap2, unsigned int nbits);
113 extern int __bitmap_subset(const unsigned long *bitmap1,
114 const unsigned long *bitmap2, unsigned int nbits);
115 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
116 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
117 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
119 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
123 unsigned long align_mask,
124 unsigned long align_offset);
127 * bitmap_find_next_zero_area - find a contiguous aligned zero area
128 * @map: The address to base the search on
129 * @size: The bitmap size in bits
130 * @start: The bitnumber to start searching at
131 * @nr: The number of zeroed bits we're looking for
132 * @align_mask: Alignment mask for zero area
134 * The @align_mask should be one less than a power of 2; the effect is that
135 * the bit offset of all zero areas this function finds is multiples of that
136 * power of 2. A @align_mask of 0 means no alignment is required.
138 static inline unsigned long
139 bitmap_find_next_zero_area(unsigned long *map,
143 unsigned long align_mask)
145 return bitmap_find_next_zero_area_off(map, size, start, nr,
149 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
150 unsigned long *dst, int nbits);
151 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
152 unsigned long *dst, int nbits);
153 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
155 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
156 unsigned long *dst, int nbits);
157 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
158 const unsigned long *old, const unsigned long *new, unsigned int nbits);
159 extern int bitmap_bitremap(int oldbit,
160 const unsigned long *old, const unsigned long *new, int bits);
161 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
162 const unsigned long *relmap, unsigned int bits);
163 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
164 unsigned int sz, unsigned int nbits);
165 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
166 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
167 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
168 extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
171 unsigned int nwords);
172 extern unsigned int bitmap_to_u32array(u32 *buf,
174 const unsigned long *bitmap,
177 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
179 #define bitmap_copy_le bitmap_copy
181 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
182 extern int bitmap_print_to_pagebuf(bool list, char *buf,
183 const unsigned long *maskp, int nmaskbits);
185 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
186 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
188 #define small_const_nbits(nbits) \
189 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
191 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
193 if (small_const_nbits(nbits))
196 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
201 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
203 unsigned int nlongs = BITS_TO_LONGS(nbits);
204 if (!small_const_nbits(nbits)) {
205 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
206 memset(dst, 0xff, len);
208 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
211 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
214 if (small_const_nbits(nbits))
217 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
218 memcpy(dst, src, len);
222 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
223 const unsigned long *src2, unsigned int nbits)
225 if (small_const_nbits(nbits))
226 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
227 return __bitmap_and(dst, src1, src2, nbits);
230 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
231 const unsigned long *src2, unsigned int nbits)
233 if (small_const_nbits(nbits))
234 *dst = *src1 | *src2;
236 __bitmap_or(dst, src1, src2, nbits);
239 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
240 const unsigned long *src2, unsigned int nbits)
242 if (small_const_nbits(nbits))
243 *dst = *src1 ^ *src2;
245 __bitmap_xor(dst, src1, src2, nbits);
248 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
249 const unsigned long *src2, unsigned int nbits)
251 if (small_const_nbits(nbits))
252 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
253 return __bitmap_andnot(dst, src1, src2, nbits);
256 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
259 if (small_const_nbits(nbits))
262 __bitmap_complement(dst, src, nbits);
265 #ifdef __LITTLE_ENDIAN
266 #define BITMAP_MEM_ALIGNMENT 8
268 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
270 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
272 static inline int bitmap_equal(const unsigned long *src1,
273 const unsigned long *src2, unsigned int nbits)
275 if (small_const_nbits(nbits))
276 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
277 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
278 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
279 return !memcmp(src1, src2, nbits / 8);
280 return __bitmap_equal(src1, src2, nbits);
283 static inline int bitmap_intersects(const unsigned long *src1,
284 const unsigned long *src2, unsigned int nbits)
286 if (small_const_nbits(nbits))
287 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
289 return __bitmap_intersects(src1, src2, nbits);
292 static inline int bitmap_subset(const unsigned long *src1,
293 const unsigned long *src2, unsigned int nbits)
295 if (small_const_nbits(nbits))
296 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
298 return __bitmap_subset(src1, src2, nbits);
301 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
303 if (small_const_nbits(nbits))
304 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
306 return find_first_bit(src, nbits) == nbits;
309 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
311 if (small_const_nbits(nbits))
312 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
314 return find_first_zero_bit(src, nbits) == nbits;
317 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
319 if (small_const_nbits(nbits))
320 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
321 return __bitmap_weight(src, nbits);
324 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
327 if (__builtin_constant_p(nbits) && nbits == 1)
328 __set_bit(start, map);
329 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
330 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
331 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
332 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
333 memset((char *)map + start / 8, 0xff, nbits / 8);
335 __bitmap_set(map, start, nbits);
338 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
341 if (__builtin_constant_p(nbits) && nbits == 1)
342 __clear_bit(start, map);
343 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
344 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
345 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
346 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
347 memset((char *)map + start / 8, 0, nbits / 8);
349 __bitmap_clear(map, start, nbits);
352 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
353 unsigned int shift, int nbits)
355 if (small_const_nbits(nbits))
356 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
358 __bitmap_shift_right(dst, src, shift, nbits);
361 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
362 unsigned int shift, unsigned int nbits)
364 if (small_const_nbits(nbits))
365 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
367 __bitmap_shift_left(dst, src, shift, nbits);
370 static inline int bitmap_parse(const char *buf, unsigned int buflen,
371 unsigned long *maskp, int nmaskbits)
373 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
377 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
379 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
380 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
382 * There are four combinations of endianness and length of the word in linux
383 * ABIs: LE64, BE64, LE32 and BE32.
385 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
386 * bitmaps and therefore don't require any special handling.
388 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
389 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
390 * other hand is represented as an array of 32-bit words and the position of
391 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
392 * word. For example, bit #42 is located at 10th position of 2nd word.
393 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
394 * values in memory as it usually does. But for BE we need to swap hi and lo
397 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
398 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
399 * hi and lo words, as is expected by bitmap.
401 #if __BITS_PER_LONG == 64
402 #define BITMAP_FROM_U64(n) (n)
404 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
405 ((unsigned long) ((u64)(n) >> 32))
409 * bitmap_from_u64 - Check and swap words within u64.
410 * @mask: source bitmap
411 * @dst: destination bitmap
413 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
414 * to read u64 mask, we will get the wrong word.
415 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
416 * but we expect the lower 32-bits of u64.
418 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
420 dst[0] = mask & ULONG_MAX;
422 if (sizeof(mask) > sizeof(unsigned long))
426 #endif /* __ASSEMBLY__ */
428 #endif /* __LINUX_BITMAP_H */