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 * Note that nbits should be always a compile time evaluable constant.
32 * Otherwise many inlines will generate horrible code.
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_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
57 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
58 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
59 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
60 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
61 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
62 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
63 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
64 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
65 * bitmap_release_region(bitmap, pos, order) Free specified bit region
66 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
67 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
68 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
70 * Note, bitmap_zero() and bitmap_fill() operate over the region of
71 * unsigned longs, that is, bits behind bitmap till the unsigned long
72 * boundary will be zeroed or filled as well. Consider to use
73 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
80 * Also the following operations in asm/bitops.h apply to bitmaps.::
82 * set_bit(bit, addr) *addr |= bit
83 * clear_bit(bit, addr) *addr &= ~bit
84 * change_bit(bit, addr) *addr ^= bit
85 * test_bit(bit, addr) Is bit set in *addr?
86 * test_and_set_bit(bit, addr) Set bit and return old value
87 * test_and_clear_bit(bit, addr) Clear bit and return old value
88 * test_and_change_bit(bit, addr) Change bit and return old value
89 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
90 * find_first_bit(addr, nbits) Position first set bit in *addr
91 * find_next_zero_bit(addr, nbits, bit)
92 * Position next zero bit in *addr >= bit
93 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
94 * find_next_and_bit(addr1, addr2, nbits, bit)
95 * Same as find_next_bit, but in
101 * DOC: declare bitmap
102 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
103 * to declare an array named 'name' of just enough unsigned longs to
104 * contain all bit positions from 0 to 'bits' - 1.
108 * Allocation and deallocation of bitmap.
109 * Provided in lib/bitmap.c to avoid circular dependency.
111 extern unsigned long *bitmap_alloc(unsigned int nbits
, gfp_t flags
);
112 extern unsigned long *bitmap_zalloc(unsigned int nbits
, gfp_t flags
);
113 extern void bitmap_free(const unsigned long *bitmap
);
116 * lib/bitmap.c provides these functions:
119 extern int __bitmap_empty(const unsigned long *bitmap
, unsigned int nbits
);
120 extern int __bitmap_full(const unsigned long *bitmap
, unsigned int nbits
);
121 extern int __bitmap_equal(const unsigned long *bitmap1
,
122 const unsigned long *bitmap2
, unsigned int nbits
);
123 extern void __bitmap_complement(unsigned long *dst
, const unsigned long *src
,
125 extern void __bitmap_shift_right(unsigned long *dst
, const unsigned long *src
,
126 unsigned int shift
, unsigned int nbits
);
127 extern void __bitmap_shift_left(unsigned long *dst
, const unsigned long *src
,
128 unsigned int shift
, unsigned int nbits
);
129 extern int __bitmap_and(unsigned long *dst
, const unsigned long *bitmap1
,
130 const unsigned long *bitmap2
, unsigned int nbits
);
131 extern void __bitmap_or(unsigned long *dst
, const unsigned long *bitmap1
,
132 const unsigned long *bitmap2
, unsigned int nbits
);
133 extern void __bitmap_xor(unsigned long *dst
, const unsigned long *bitmap1
,
134 const unsigned long *bitmap2
, unsigned int nbits
);
135 extern int __bitmap_andnot(unsigned long *dst
, const unsigned long *bitmap1
,
136 const unsigned long *bitmap2
, unsigned int nbits
);
137 extern int __bitmap_intersects(const unsigned long *bitmap1
,
138 const unsigned long *bitmap2
, unsigned int nbits
);
139 extern int __bitmap_subset(const unsigned long *bitmap1
,
140 const unsigned long *bitmap2
, unsigned int nbits
);
141 extern int __bitmap_weight(const unsigned long *bitmap
, unsigned int nbits
);
142 extern void __bitmap_set(unsigned long *map
, unsigned int start
, int len
);
143 extern void __bitmap_clear(unsigned long *map
, unsigned int start
, int len
);
145 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map
,
149 unsigned long align_mask
,
150 unsigned long align_offset
);
153 * bitmap_find_next_zero_area - find a contiguous aligned zero area
154 * @map: The address to base the search on
155 * @size: The bitmap size in bits
156 * @start: The bitnumber to start searching at
157 * @nr: The number of zeroed bits we're looking for
158 * @align_mask: Alignment mask for zero area
160 * The @align_mask should be one less than a power of 2; the effect is that
161 * the bit offset of all zero areas this function finds is multiples of that
162 * power of 2. A @align_mask of 0 means no alignment is required.
164 static inline unsigned long
165 bitmap_find_next_zero_area(unsigned long *map
,
169 unsigned long align_mask
)
171 return bitmap_find_next_zero_area_off(map
, size
, start
, nr
,
175 extern int __bitmap_parse(const char *buf
, unsigned int buflen
, int is_user
,
176 unsigned long *dst
, int nbits
);
177 extern int bitmap_parse_user(const char __user
*ubuf
, unsigned int ulen
,
178 unsigned long *dst
, int nbits
);
179 extern int bitmap_parselist(const char *buf
, unsigned long *maskp
,
181 extern int bitmap_parselist_user(const char __user
*ubuf
, unsigned int ulen
,
182 unsigned long *dst
, int nbits
);
183 extern void bitmap_remap(unsigned long *dst
, const unsigned long *src
,
184 const unsigned long *old
, const unsigned long *new, unsigned int nbits
);
185 extern int bitmap_bitremap(int oldbit
,
186 const unsigned long *old
, const unsigned long *new, int bits
);
187 extern void bitmap_onto(unsigned long *dst
, const unsigned long *orig
,
188 const unsigned long *relmap
, unsigned int bits
);
189 extern void bitmap_fold(unsigned long *dst
, const unsigned long *orig
,
190 unsigned int sz
, unsigned int nbits
);
191 extern int bitmap_find_free_region(unsigned long *bitmap
, unsigned int bits
, int order
);
192 extern void bitmap_release_region(unsigned long *bitmap
, unsigned int pos
, int order
);
193 extern int bitmap_allocate_region(unsigned long *bitmap
, unsigned int pos
, int order
);
196 extern void bitmap_copy_le(unsigned long *dst
, const unsigned long *src
, unsigned int nbits
);
198 #define bitmap_copy_le bitmap_copy
200 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap
, unsigned int ord
, unsigned int nbits
);
201 extern int bitmap_print_to_pagebuf(bool list
, char *buf
,
202 const unsigned long *maskp
, int nmaskbits
);
204 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
205 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
207 #define small_const_nbits(nbits) \
208 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
210 static inline void bitmap_zero(unsigned long *dst
, unsigned int nbits
)
212 if (small_const_nbits(nbits
))
215 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
220 static inline void bitmap_fill(unsigned long *dst
, unsigned int nbits
)
222 if (small_const_nbits(nbits
))
225 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
226 memset(dst
, 0xff, len
);
230 static inline void bitmap_copy(unsigned long *dst
, const unsigned long *src
,
233 if (small_const_nbits(nbits
))
236 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
237 memcpy(dst
, src
, len
);
242 * Copy bitmap and clear tail bits in last word.
244 static inline void bitmap_copy_clear_tail(unsigned long *dst
,
245 const unsigned long *src
, unsigned int nbits
)
247 bitmap_copy(dst
, src
, nbits
);
248 if (nbits
% BITS_PER_LONG
)
249 dst
[nbits
/ BITS_PER_LONG
] &= BITMAP_LAST_WORD_MASK(nbits
);
253 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
254 * therefore conversion is not needed when copying data from/to arrays of u32.
256 #if BITS_PER_LONG == 64
257 extern void bitmap_from_arr32(unsigned long *bitmap
, const u32
*buf
,
259 extern void bitmap_to_arr32(u32
*buf
, const unsigned long *bitmap
,
262 #define bitmap_from_arr32(bitmap, buf, nbits) \
263 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
264 (const unsigned long *) (buf), (nbits))
265 #define bitmap_to_arr32(buf, bitmap, nbits) \
266 bitmap_copy_clear_tail((unsigned long *) (buf), \
267 (const unsigned long *) (bitmap), (nbits))
270 static inline int bitmap_and(unsigned long *dst
, const unsigned long *src1
,
271 const unsigned long *src2
, unsigned int nbits
)
273 if (small_const_nbits(nbits
))
274 return (*dst
= *src1
& *src2
& BITMAP_LAST_WORD_MASK(nbits
)) != 0;
275 return __bitmap_and(dst
, src1
, src2
, nbits
);
278 static inline void bitmap_or(unsigned long *dst
, const unsigned long *src1
,
279 const unsigned long *src2
, unsigned int nbits
)
281 if (small_const_nbits(nbits
))
282 *dst
= *src1
| *src2
;
284 __bitmap_or(dst
, src1
, src2
, nbits
);
287 static inline void bitmap_xor(unsigned long *dst
, const unsigned long *src1
,
288 const unsigned long *src2
, unsigned int nbits
)
290 if (small_const_nbits(nbits
))
291 *dst
= *src1
^ *src2
;
293 __bitmap_xor(dst
, src1
, src2
, nbits
);
296 static inline int bitmap_andnot(unsigned long *dst
, const unsigned long *src1
,
297 const unsigned long *src2
, unsigned int nbits
)
299 if (small_const_nbits(nbits
))
300 return (*dst
= *src1
& ~(*src2
) & BITMAP_LAST_WORD_MASK(nbits
)) != 0;
301 return __bitmap_andnot(dst
, src1
, src2
, nbits
);
304 static inline void bitmap_complement(unsigned long *dst
, const unsigned long *src
,
307 if (small_const_nbits(nbits
))
310 __bitmap_complement(dst
, src
, nbits
);
313 #ifdef __LITTLE_ENDIAN
314 #define BITMAP_MEM_ALIGNMENT 8
316 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
318 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
320 static inline int bitmap_equal(const unsigned long *src1
,
321 const unsigned long *src2
, unsigned int nbits
)
323 if (small_const_nbits(nbits
))
324 return !((*src1
^ *src2
) & BITMAP_LAST_WORD_MASK(nbits
));
325 if (__builtin_constant_p(nbits
& BITMAP_MEM_MASK
) &&
326 IS_ALIGNED(nbits
, BITMAP_MEM_ALIGNMENT
))
327 return !memcmp(src1
, src2
, nbits
/ 8);
328 return __bitmap_equal(src1
, src2
, nbits
);
331 static inline int bitmap_intersects(const unsigned long *src1
,
332 const unsigned long *src2
, unsigned int nbits
)
334 if (small_const_nbits(nbits
))
335 return ((*src1
& *src2
) & BITMAP_LAST_WORD_MASK(nbits
)) != 0;
337 return __bitmap_intersects(src1
, src2
, nbits
);
340 static inline int bitmap_subset(const unsigned long *src1
,
341 const unsigned long *src2
, unsigned int nbits
)
343 if (small_const_nbits(nbits
))
344 return ! ((*src1
& ~(*src2
)) & BITMAP_LAST_WORD_MASK(nbits
));
346 return __bitmap_subset(src1
, src2
, nbits
);
349 static inline int bitmap_empty(const unsigned long *src
, unsigned nbits
)
351 if (small_const_nbits(nbits
))
352 return ! (*src
& BITMAP_LAST_WORD_MASK(nbits
));
354 return find_first_bit(src
, nbits
) == nbits
;
357 static inline int bitmap_full(const unsigned long *src
, unsigned int nbits
)
359 if (small_const_nbits(nbits
))
360 return ! (~(*src
) & BITMAP_LAST_WORD_MASK(nbits
));
362 return find_first_zero_bit(src
, nbits
) == nbits
;
365 static __always_inline
int bitmap_weight(const unsigned long *src
, unsigned int nbits
)
367 if (small_const_nbits(nbits
))
368 return hweight_long(*src
& BITMAP_LAST_WORD_MASK(nbits
));
369 return __bitmap_weight(src
, nbits
);
372 static __always_inline
void bitmap_set(unsigned long *map
, unsigned int start
,
375 if (__builtin_constant_p(nbits
) && nbits
== 1)
376 __set_bit(start
, map
);
377 else if (__builtin_constant_p(start
& BITMAP_MEM_MASK
) &&
378 IS_ALIGNED(start
, BITMAP_MEM_ALIGNMENT
) &&
379 __builtin_constant_p(nbits
& BITMAP_MEM_MASK
) &&
380 IS_ALIGNED(nbits
, BITMAP_MEM_ALIGNMENT
))
381 memset((char *)map
+ start
/ 8, 0xff, nbits
/ 8);
383 __bitmap_set(map
, start
, nbits
);
386 static __always_inline
void bitmap_clear(unsigned long *map
, unsigned int start
,
389 if (__builtin_constant_p(nbits
) && nbits
== 1)
390 __clear_bit(start
, map
);
391 else if (__builtin_constant_p(start
& BITMAP_MEM_MASK
) &&
392 IS_ALIGNED(start
, BITMAP_MEM_ALIGNMENT
) &&
393 __builtin_constant_p(nbits
& BITMAP_MEM_MASK
) &&
394 IS_ALIGNED(nbits
, BITMAP_MEM_ALIGNMENT
))
395 memset((char *)map
+ start
/ 8, 0, nbits
/ 8);
397 __bitmap_clear(map
, start
, nbits
);
400 static inline void bitmap_shift_right(unsigned long *dst
, const unsigned long *src
,
401 unsigned int shift
, int nbits
)
403 if (small_const_nbits(nbits
))
404 *dst
= (*src
& BITMAP_LAST_WORD_MASK(nbits
)) >> shift
;
406 __bitmap_shift_right(dst
, src
, shift
, nbits
);
409 static inline void bitmap_shift_left(unsigned long *dst
, const unsigned long *src
,
410 unsigned int shift
, unsigned int nbits
)
412 if (small_const_nbits(nbits
))
413 *dst
= (*src
<< shift
) & BITMAP_LAST_WORD_MASK(nbits
);
415 __bitmap_shift_left(dst
, src
, shift
, nbits
);
418 static inline int bitmap_parse(const char *buf
, unsigned int buflen
,
419 unsigned long *maskp
, int nmaskbits
)
421 return __bitmap_parse(buf
, buflen
, 0, maskp
, nmaskbits
);
425 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
428 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
429 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
431 * There are four combinations of endianness and length of the word in linux
432 * ABIs: LE64, BE64, LE32 and BE32.
434 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
435 * bitmaps and therefore don't require any special handling.
437 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
438 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
439 * other hand is represented as an array of 32-bit words and the position of
440 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
441 * word. For example, bit #42 is located at 10th position of 2nd word.
442 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
443 * values in memory as it usually does. But for BE we need to swap hi and lo
446 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
447 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
448 * hi and lo words, as is expected by bitmap.
450 #if __BITS_PER_LONG == 64
451 #define BITMAP_FROM_U64(n) (n)
453 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
454 ((unsigned long) ((u64)(n) >> 32))
458 * bitmap_from_u64 - Check and swap words within u64.
459 * @mask: source bitmap
460 * @dst: destination bitmap
462 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
463 * to read u64 mask, we will get the wrong word.
464 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
465 * but we expect the lower 32-bits of u64.
467 static inline void bitmap_from_u64(unsigned long *dst
, u64 mask
)
469 dst
[0] = mask
& ULONG_MAX
;
471 if (sizeof(mask
) > sizeof(unsigned long))
475 #endif /* __ASSEMBLY__ */
477 #endif /* __LINUX_BITMAP_H */