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_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
69 * bitmap_get_value8(map, start) Get 8bit value from map at start
70 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
72 * Note, bitmap_zero() and bitmap_fill() operate over the region of
73 * unsigned longs, that is, bits behind bitmap till the unsigned long
74 * boundary will be zeroed or filled as well. Consider to use
75 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
82 * Also the following operations in asm/bitops.h apply to bitmaps.::
84 * set_bit(bit, addr) *addr |= bit
85 * clear_bit(bit, addr) *addr &= ~bit
86 * change_bit(bit, addr) *addr ^= bit
87 * test_bit(bit, addr) Is bit set in *addr?
88 * test_and_set_bit(bit, addr) Set bit and return old value
89 * test_and_clear_bit(bit, addr) Clear bit and return old value
90 * test_and_change_bit(bit, addr) Change bit and return old value
91 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
92 * find_first_bit(addr, nbits) Position first set bit in *addr
93 * find_next_zero_bit(addr, nbits, bit)
94 * Position next zero bit in *addr >= bit
95 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
96 * find_next_and_bit(addr1, addr2, nbits, bit)
97 * Same as find_next_bit, but in
103 * DOC: declare bitmap
104 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
105 * to declare an array named 'name' of just enough unsigned longs to
106 * contain all bit positions from 0 to 'bits' - 1.
110 * Allocation and deallocation of bitmap.
111 * Provided in lib/bitmap.c to avoid circular dependency.
113 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
114 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
115 extern void bitmap_free(const unsigned long *bitmap);
118 * lib/bitmap.c provides these functions:
121 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
122 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
123 extern int __bitmap_equal(const unsigned long *bitmap1,
124 const unsigned long *bitmap2, unsigned int nbits);
125 extern bool __pure __bitmap_or_equal(const unsigned long *src1,
126 const unsigned long *src2,
127 const unsigned long *src3,
129 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
131 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
132 unsigned int shift, unsigned int nbits);
133 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
134 unsigned int shift, unsigned int nbits);
135 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
136 const unsigned long *bitmap2, unsigned int nbits);
137 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
138 const unsigned long *bitmap2, unsigned int nbits);
139 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
140 const unsigned long *bitmap2, unsigned int nbits);
141 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
142 const unsigned long *bitmap2, unsigned int nbits);
143 extern int __bitmap_intersects(const unsigned long *bitmap1,
144 const unsigned long *bitmap2, unsigned int nbits);
145 extern int __bitmap_subset(const unsigned long *bitmap1,
146 const unsigned long *bitmap2, unsigned int nbits);
147 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
148 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
149 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
151 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
155 unsigned long align_mask,
156 unsigned long align_offset);
159 * bitmap_find_next_zero_area - find a contiguous aligned zero area
160 * @map: The address to base the search on
161 * @size: The bitmap size in bits
162 * @start: The bitnumber to start searching at
163 * @nr: The number of zeroed bits we're looking for
164 * @align_mask: Alignment mask for zero area
166 * The @align_mask should be one less than a power of 2; the effect is that
167 * the bit offset of all zero areas this function finds is multiples of that
168 * power of 2. A @align_mask of 0 means no alignment is required.
170 static inline unsigned long
171 bitmap_find_next_zero_area(unsigned long *map,
175 unsigned long align_mask)
177 return bitmap_find_next_zero_area_off(map, size, start, nr,
181 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
182 unsigned long *dst, int nbits);
183 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
184 unsigned long *dst, int nbits);
185 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
187 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
188 unsigned long *dst, int nbits);
189 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
190 const unsigned long *old, const unsigned long *new, unsigned int nbits);
191 extern int bitmap_bitremap(int oldbit,
192 const unsigned long *old, const unsigned long *new, int bits);
193 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
194 const unsigned long *relmap, unsigned int bits);
195 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
196 unsigned int sz, unsigned int nbits);
197 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
198 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
199 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
202 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
204 #define bitmap_copy_le bitmap_copy
206 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
207 extern int bitmap_print_to_pagebuf(bool list, char *buf,
208 const unsigned long *maskp, int nmaskbits);
210 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
211 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
214 * The static inlines below do not handle constant nbits==0 correctly,
215 * so make such users (should any ever turn up) call the out-of-line
218 #define small_const_nbits(nbits) \
219 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
221 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
223 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
227 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
229 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
230 memset(dst, 0xff, len);
233 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
236 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
237 memcpy(dst, src, len);
241 * Copy bitmap and clear tail bits in last word.
243 static inline void bitmap_copy_clear_tail(unsigned long *dst,
244 const unsigned long *src, unsigned int nbits)
246 bitmap_copy(dst, src, nbits);
247 if (nbits % BITS_PER_LONG)
248 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
252 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
253 * therefore conversion is not needed when copying data from/to arrays of u32.
255 #if BITS_PER_LONG == 64
256 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
258 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
261 #define bitmap_from_arr32(bitmap, buf, nbits) \
262 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
263 (const unsigned long *) (buf), (nbits))
264 #define bitmap_to_arr32(buf, bitmap, nbits) \
265 bitmap_copy_clear_tail((unsigned long *) (buf), \
266 (const unsigned long *) (bitmap), (nbits))
269 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
270 const unsigned long *src2, unsigned int nbits)
272 if (small_const_nbits(nbits))
273 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
274 return __bitmap_and(dst, src1, src2, nbits);
277 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
278 const unsigned long *src2, unsigned int nbits)
280 if (small_const_nbits(nbits))
281 *dst = *src1 | *src2;
283 __bitmap_or(dst, src1, src2, nbits);
286 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
287 const unsigned long *src2, unsigned int nbits)
289 if (small_const_nbits(nbits))
290 *dst = *src1 ^ *src2;
292 __bitmap_xor(dst, src1, src2, nbits);
295 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
296 const unsigned long *src2, unsigned int nbits)
298 if (small_const_nbits(nbits))
299 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
300 return __bitmap_andnot(dst, src1, src2, nbits);
303 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
306 if (small_const_nbits(nbits))
309 __bitmap_complement(dst, src, nbits);
312 #ifdef __LITTLE_ENDIAN
313 #define BITMAP_MEM_ALIGNMENT 8
315 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
317 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
319 static inline int bitmap_equal(const unsigned long *src1,
320 const unsigned long *src2, unsigned int nbits)
322 if (small_const_nbits(nbits))
323 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
324 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
325 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
326 return !memcmp(src1, src2, nbits / 8);
327 return __bitmap_equal(src1, src2, nbits);
331 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
332 * @src1: Pointer to bitmap 1
333 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
334 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
335 * @nbits: number of bits in each of these bitmaps
337 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
339 static inline bool bitmap_or_equal(const unsigned long *src1,
340 const unsigned long *src2,
341 const unsigned long *src3,
344 if (!small_const_nbits(nbits))
345 return __bitmap_or_equal(src1, src2, src3, nbits);
347 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
350 static inline int bitmap_intersects(const unsigned long *src1,
351 const unsigned long *src2, unsigned int nbits)
353 if (small_const_nbits(nbits))
354 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
356 return __bitmap_intersects(src1, src2, nbits);
359 static inline int bitmap_subset(const unsigned long *src1,
360 const unsigned long *src2, unsigned int nbits)
362 if (small_const_nbits(nbits))
363 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
365 return __bitmap_subset(src1, src2, nbits);
368 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
370 if (small_const_nbits(nbits))
371 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
373 return find_first_bit(src, nbits) == nbits;
376 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
378 if (small_const_nbits(nbits))
379 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
381 return find_first_zero_bit(src, nbits) == nbits;
384 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
386 if (small_const_nbits(nbits))
387 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
388 return __bitmap_weight(src, nbits);
391 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
394 if (__builtin_constant_p(nbits) && nbits == 1)
395 __set_bit(start, map);
396 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
397 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
398 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
399 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
400 memset((char *)map + start / 8, 0xff, nbits / 8);
402 __bitmap_set(map, start, nbits);
405 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
408 if (__builtin_constant_p(nbits) && nbits == 1)
409 __clear_bit(start, map);
410 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
411 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
412 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
413 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
414 memset((char *)map + start / 8, 0, nbits / 8);
416 __bitmap_clear(map, start, nbits);
419 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
420 unsigned int shift, unsigned int nbits)
422 if (small_const_nbits(nbits))
423 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
425 __bitmap_shift_right(dst, src, shift, nbits);
428 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
429 unsigned int shift, unsigned int nbits)
431 if (small_const_nbits(nbits))
432 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
434 __bitmap_shift_left(dst, src, shift, nbits);
437 static inline int bitmap_parse(const char *buf, unsigned int buflen,
438 unsigned long *maskp, int nmaskbits)
440 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
444 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
447 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
448 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
450 * There are four combinations of endianness and length of the word in linux
451 * ABIs: LE64, BE64, LE32 and BE32.
453 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
454 * bitmaps and therefore don't require any special handling.
456 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
457 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
458 * other hand is represented as an array of 32-bit words and the position of
459 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
460 * word. For example, bit #42 is located at 10th position of 2nd word.
461 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
462 * values in memory as it usually does. But for BE we need to swap hi and lo
465 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
466 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
467 * hi and lo words, as is expected by bitmap.
469 #if __BITS_PER_LONG == 64
470 #define BITMAP_FROM_U64(n) (n)
472 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
473 ((unsigned long) ((u64)(n) >> 32))
477 * bitmap_from_u64 - Check and swap words within u64.
478 * @mask: source bitmap
479 * @dst: destination bitmap
481 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
482 * to read u64 mask, we will get the wrong word.
483 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
484 * but we expect the lower 32-bits of u64.
486 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
488 dst[0] = mask & ULONG_MAX;
490 if (sizeof(mask) > sizeof(unsigned long))
495 * bitmap_get_value8 - get an 8-bit value within a memory region
496 * @map: address to the bitmap memory region
497 * @start: bit offset of the 8-bit value; must be a multiple of 8
499 * Returns the 8-bit value located at the @start bit offset within the @src
502 static inline unsigned long bitmap_get_value8(const unsigned long *map,
505 const size_t index = BIT_WORD(start);
506 const unsigned long offset = start % BITS_PER_LONG;
508 return (map[index] >> offset) & 0xFF;
512 * bitmap_set_value8 - set an 8-bit value within a memory region
513 * @map: address to the bitmap memory region
514 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
515 * @start: bit offset of the 8-bit value; must be a multiple of 8
517 static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
520 const size_t index = BIT_WORD(start);
521 const unsigned long offset = start % BITS_PER_LONG;
523 map[index] &= ~(0xFFUL << offset);
524 map[index] |= value << offset;
527 #endif /* __ASSEMBLY__ */
529 #endif /* __LINUX_BITMAP_H */