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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BITMAP_H
3 #define __LINUX_BITMAP_H
7 #include <linux/align.h>
8 #include <linux/bitops.h>
9 #include <linux/limits.h>
10 #include <linux/string.h>
11 #include <linux/types.h>
16 * bitmaps provide bit arrays that consume one or more unsigned
17 * longs. The bitmap interface and available operations are listed
20 * Function implementations generic to all architectures are in
21 * lib/bitmap.c. Functions implementations that are architecture
22 * specific are in various include/asm-<arch>/bitops.h headers
23 * and other arch/<arch> specific files.
25 * See lib/bitmap.c for more details.
29 * DOC: bitmap overview
31 * The available bitmap operations and their rough meaning in the
32 * case that the bitmap is a single unsigned long are thus:
34 * The generated code is more efficient when nbits is known at
35 * compile-time and at most BITS_PER_LONG.
39 * bitmap_zero(dst, nbits) *dst = 0UL
40 * bitmap_fill(dst, nbits) *dst = ~0UL
41 * bitmap_copy(dst, src, nbits) *dst = *src
42 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
43 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
44 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
45 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
46 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
47 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
48 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
49 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
50 * bitmap_empty(src, nbits) Are all bits zero in *src?
51 * bitmap_full(src, nbits) Are all bits set in *src?
52 * bitmap_weight(src, nbits) Hamming Weight: number set bits
53 * bitmap_set(dst, pos, nbits) Set specified bit area
54 * bitmap_clear(dst, pos, nbits) Clear specified bit area
55 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
56 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
57 * bitmap_next_clear_region(map, &start, &end, nbits) Find next clear region
58 * bitmap_next_set_region(map, &start, &end, nbits) Find next set region
59 * bitmap_for_each_clear_region(map, rs, re, start, end)
60 * Iterate over all clear regions
61 * bitmap_for_each_set_region(map, rs, re, start, end)
62 * Iterate over all set regions
63 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
64 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
65 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
66 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
67 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
68 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
69 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
70 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
71 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
72 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
73 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
74 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
75 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
76 * bitmap_release_region(bitmap, pos, order) Free specified bit region
77 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
78 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
79 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
80 * bitmap_get_value8(map, start) Get 8bit value from map at start
81 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
83 * Note, bitmap_zero() and bitmap_fill() operate over the region of
84 * unsigned longs, that is, bits behind bitmap till the unsigned long
85 * boundary will be zeroed or filled as well. Consider to use
86 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
93 * Also the following operations in asm/bitops.h apply to bitmaps.::
95 * set_bit(bit, addr) *addr |= bit
96 * clear_bit(bit, addr) *addr &= ~bit
97 * change_bit(bit, addr) *addr ^= bit
98 * test_bit(bit, addr) Is bit set in *addr?
99 * test_and_set_bit(bit, addr) Set bit and return old value
100 * test_and_clear_bit(bit, addr) Clear bit and return old value
101 * test_and_change_bit(bit, addr) Change bit and return old value
102 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
103 * find_first_bit(addr, nbits) Position first set bit in *addr
104 * find_next_zero_bit(addr, nbits, bit)
105 * Position next zero bit in *addr >= bit
106 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
107 * find_next_and_bit(addr1, addr2, nbits, bit)
108 * Same as find_next_bit, but in
114 * DOC: declare bitmap
115 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
116 * to declare an array named 'name' of just enough unsigned longs to
117 * contain all bit positions from 0 to 'bits' - 1.
121 * Allocation and deallocation of bitmap.
122 * Provided in lib/bitmap.c to avoid circular dependency.
124 unsigned long *bitmap_alloc(unsigned int nbits
, gfp_t flags
);
125 unsigned long *bitmap_zalloc(unsigned int nbits
, gfp_t flags
);
126 void bitmap_free(const unsigned long *bitmap
);
128 /* Managed variants of the above. */
129 unsigned long *devm_bitmap_alloc(struct device
*dev
,
130 unsigned int nbits
, gfp_t flags
);
131 unsigned long *devm_bitmap_zalloc(struct device
*dev
,
132 unsigned int nbits
, gfp_t flags
);
135 * lib/bitmap.c provides these functions:
138 int __bitmap_equal(const unsigned long *bitmap1
,
139 const unsigned long *bitmap2
, unsigned int nbits
);
140 bool __pure
__bitmap_or_equal(const unsigned long *src1
,
141 const unsigned long *src2
,
142 const unsigned long *src3
,
144 void __bitmap_complement(unsigned long *dst
, const unsigned long *src
,
146 void __bitmap_shift_right(unsigned long *dst
, const unsigned long *src
,
147 unsigned int shift
, unsigned int nbits
);
148 void __bitmap_shift_left(unsigned long *dst
, const unsigned long *src
,
149 unsigned int shift
, unsigned int nbits
);
150 void bitmap_cut(unsigned long *dst
, const unsigned long *src
,
151 unsigned int first
, unsigned int cut
, unsigned int nbits
);
152 int __bitmap_and(unsigned long *dst
, const unsigned long *bitmap1
,
153 const unsigned long *bitmap2
, unsigned int nbits
);
154 void __bitmap_or(unsigned long *dst
, const unsigned long *bitmap1
,
155 const unsigned long *bitmap2
, unsigned int nbits
);
156 void __bitmap_xor(unsigned long *dst
, const unsigned long *bitmap1
,
157 const unsigned long *bitmap2
, unsigned int nbits
);
158 int __bitmap_andnot(unsigned long *dst
, const unsigned long *bitmap1
,
159 const unsigned long *bitmap2
, unsigned int nbits
);
160 void __bitmap_replace(unsigned long *dst
,
161 const unsigned long *old
, const unsigned long *new,
162 const unsigned long *mask
, unsigned int nbits
);
163 int __bitmap_intersects(const unsigned long *bitmap1
,
164 const unsigned long *bitmap2
, unsigned int nbits
);
165 int __bitmap_subset(const unsigned long *bitmap1
,
166 const unsigned long *bitmap2
, unsigned int nbits
);
167 int __bitmap_weight(const unsigned long *bitmap
, unsigned int nbits
);
168 void __bitmap_set(unsigned long *map
, unsigned int start
, int len
);
169 void __bitmap_clear(unsigned long *map
, unsigned int start
, int len
);
171 unsigned long bitmap_find_next_zero_area_off(unsigned long *map
,
175 unsigned long align_mask
,
176 unsigned long align_offset
);
179 * bitmap_find_next_zero_area - find a contiguous aligned zero area
180 * @map: The address to base the search on
181 * @size: The bitmap size in bits
182 * @start: The bitnumber to start searching at
183 * @nr: The number of zeroed bits we're looking for
184 * @align_mask: Alignment mask for zero area
186 * The @align_mask should be one less than a power of 2; the effect is that
187 * the bit offset of all zero areas this function finds is multiples of that
188 * power of 2. A @align_mask of 0 means no alignment is required.
190 static inline unsigned long
191 bitmap_find_next_zero_area(unsigned long *map
,
195 unsigned long align_mask
)
197 return bitmap_find_next_zero_area_off(map
, size
, start
, nr
,
201 int bitmap_parse(const char *buf
, unsigned int buflen
,
202 unsigned long *dst
, int nbits
);
203 int bitmap_parse_user(const char __user
*ubuf
, unsigned int ulen
,
204 unsigned long *dst
, int nbits
);
205 int bitmap_parselist(const char *buf
, unsigned long *maskp
,
207 int bitmap_parselist_user(const char __user
*ubuf
, unsigned int ulen
,
208 unsigned long *dst
, int nbits
);
209 void bitmap_remap(unsigned long *dst
, const unsigned long *src
,
210 const unsigned long *old
, const unsigned long *new, unsigned int nbits
);
211 int bitmap_bitremap(int oldbit
,
212 const unsigned long *old
, const unsigned long *new, int bits
);
213 void bitmap_onto(unsigned long *dst
, const unsigned long *orig
,
214 const unsigned long *relmap
, unsigned int bits
);
215 void bitmap_fold(unsigned long *dst
, const unsigned long *orig
,
216 unsigned int sz
, unsigned int nbits
);
217 int bitmap_find_free_region(unsigned long *bitmap
, unsigned int bits
, int order
);
218 void bitmap_release_region(unsigned long *bitmap
, unsigned int pos
, int order
);
219 int bitmap_allocate_region(unsigned long *bitmap
, unsigned int pos
, int order
);
222 void bitmap_copy_le(unsigned long *dst
, const unsigned long *src
, unsigned int nbits
);
224 #define bitmap_copy_le bitmap_copy
226 unsigned int bitmap_ord_to_pos(const unsigned long *bitmap
, unsigned int ord
, unsigned int nbits
);
227 int bitmap_print_to_pagebuf(bool list
, char *buf
,
228 const unsigned long *maskp
, int nmaskbits
);
230 extern int bitmap_print_bitmask_to_buf(char *buf
, const unsigned long *maskp
,
231 int nmaskbits
, loff_t off
, size_t count
);
233 extern int bitmap_print_list_to_buf(char *buf
, const unsigned long *maskp
,
234 int nmaskbits
, loff_t off
, size_t count
);
236 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
237 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
239 static inline void bitmap_zero(unsigned long *dst
, unsigned int nbits
)
241 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
245 static inline void bitmap_fill(unsigned long *dst
, unsigned int nbits
)
247 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
248 memset(dst
, 0xff, len
);
251 static inline void bitmap_copy(unsigned long *dst
, const unsigned long *src
,
254 unsigned int len
= BITS_TO_LONGS(nbits
) * sizeof(unsigned long);
255 memcpy(dst
, src
, len
);
259 * Copy bitmap and clear tail bits in last word.
261 static inline void bitmap_copy_clear_tail(unsigned long *dst
,
262 const unsigned long *src
, unsigned int nbits
)
264 bitmap_copy(dst
, src
, nbits
);
265 if (nbits
% BITS_PER_LONG
)
266 dst
[nbits
/ BITS_PER_LONG
] &= BITMAP_LAST_WORD_MASK(nbits
);
270 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
271 * therefore conversion is not needed when copying data from/to arrays of u32.
273 #if BITS_PER_LONG == 64
274 void bitmap_from_arr32(unsigned long *bitmap
, const u32
*buf
,
276 void bitmap_to_arr32(u32
*buf
, const unsigned long *bitmap
,
279 #define bitmap_from_arr32(bitmap, buf, nbits) \
280 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
281 (const unsigned long *) (buf), (nbits))
282 #define bitmap_to_arr32(buf, bitmap, nbits) \
283 bitmap_copy_clear_tail((unsigned long *) (buf), \
284 (const unsigned long *) (bitmap), (nbits))
287 static inline int bitmap_and(unsigned long *dst
, const unsigned long *src1
,
288 const unsigned long *src2
, unsigned int nbits
)
290 if (small_const_nbits(nbits
))
291 return (*dst
= *src1
& *src2
& BITMAP_LAST_WORD_MASK(nbits
)) != 0;
292 return __bitmap_and(dst
, src1
, src2
, nbits
);
295 static inline void bitmap_or(unsigned long *dst
, const unsigned long *src1
,
296 const unsigned long *src2
, unsigned int nbits
)
298 if (small_const_nbits(nbits
))
299 *dst
= *src1
| *src2
;
301 __bitmap_or(dst
, src1
, src2
, nbits
);
304 static inline void bitmap_xor(unsigned long *dst
, const unsigned long *src1
,
305 const unsigned long *src2
, unsigned int nbits
)
307 if (small_const_nbits(nbits
))
308 *dst
= *src1
^ *src2
;
310 __bitmap_xor(dst
, src1
, src2
, nbits
);
313 static inline int bitmap_andnot(unsigned long *dst
, const unsigned long *src1
,
314 const unsigned long *src2
, unsigned int nbits
)
316 if (small_const_nbits(nbits
))
317 return (*dst
= *src1
& ~(*src2
) & BITMAP_LAST_WORD_MASK(nbits
)) != 0;
318 return __bitmap_andnot(dst
, src1
, src2
, nbits
);
321 static inline void bitmap_complement(unsigned long *dst
, const unsigned long *src
,
324 if (small_const_nbits(nbits
))
327 __bitmap_complement(dst
, src
, nbits
);
330 #ifdef __LITTLE_ENDIAN
331 #define BITMAP_MEM_ALIGNMENT 8
333 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
335 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
337 static inline int bitmap_equal(const unsigned long *src1
,
338 const unsigned long *src2
, unsigned int nbits
)
340 if (small_const_nbits(nbits
))
341 return !((*src1
^ *src2
) & BITMAP_LAST_WORD_MASK(nbits
));
342 if (__builtin_constant_p(nbits
& BITMAP_MEM_MASK
) &&
343 IS_ALIGNED(nbits
, BITMAP_MEM_ALIGNMENT
))
344 return !memcmp(src1
, src2
, nbits
/ 8);
345 return __bitmap_equal(src1
, src2
, nbits
);
349 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
350 * @src1: Pointer to bitmap 1
351 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
352 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
353 * @nbits: number of bits in each of these bitmaps
355 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
357 static inline bool bitmap_or_equal(const unsigned long *src1
,
358 const unsigned long *src2
,
359 const unsigned long *src3
,
362 if (!small_const_nbits(nbits
))
363 return __bitmap_or_equal(src1
, src2
, src3
, nbits
);
365 return !(((*src1
| *src2
) ^ *src3
) & BITMAP_LAST_WORD_MASK(nbits
));
368 static inline int bitmap_intersects(const unsigned long *src1
,
369 const unsigned long *src2
, unsigned int nbits
)
371 if (small_const_nbits(nbits
))
372 return ((*src1
& *src2
) & BITMAP_LAST_WORD_MASK(nbits
)) != 0;
374 return __bitmap_intersects(src1
, src2
, nbits
);
377 static inline int bitmap_subset(const unsigned long *src1
,
378 const unsigned long *src2
, unsigned int nbits
)
380 if (small_const_nbits(nbits
))
381 return ! ((*src1
& ~(*src2
)) & BITMAP_LAST_WORD_MASK(nbits
));
383 return __bitmap_subset(src1
, src2
, nbits
);
386 static inline bool bitmap_empty(const unsigned long *src
, unsigned nbits
)
388 if (small_const_nbits(nbits
))
389 return ! (*src
& BITMAP_LAST_WORD_MASK(nbits
));
391 return find_first_bit(src
, nbits
) == nbits
;
394 static inline bool bitmap_full(const unsigned long *src
, unsigned int nbits
)
396 if (small_const_nbits(nbits
))
397 return ! (~(*src
) & BITMAP_LAST_WORD_MASK(nbits
));
399 return find_first_zero_bit(src
, nbits
) == nbits
;
402 static __always_inline
int bitmap_weight(const unsigned long *src
, unsigned int nbits
)
404 if (small_const_nbits(nbits
))
405 return hweight_long(*src
& BITMAP_LAST_WORD_MASK(nbits
));
406 return __bitmap_weight(src
, nbits
);
409 static __always_inline
void bitmap_set(unsigned long *map
, unsigned int start
,
412 if (__builtin_constant_p(nbits
) && nbits
== 1)
413 __set_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, 0xff, nbits
/ 8);
420 __bitmap_set(map
, start
, nbits
);
423 static __always_inline
void bitmap_clear(unsigned long *map
, unsigned int start
,
426 if (__builtin_constant_p(nbits
) && nbits
== 1)
427 __clear_bit(start
, map
);
428 else if (__builtin_constant_p(start
& BITMAP_MEM_MASK
) &&
429 IS_ALIGNED(start
, BITMAP_MEM_ALIGNMENT
) &&
430 __builtin_constant_p(nbits
& BITMAP_MEM_MASK
) &&
431 IS_ALIGNED(nbits
, BITMAP_MEM_ALIGNMENT
))
432 memset((char *)map
+ start
/ 8, 0, nbits
/ 8);
434 __bitmap_clear(map
, start
, nbits
);
437 static inline void bitmap_shift_right(unsigned long *dst
, const unsigned long *src
,
438 unsigned int shift
, unsigned int nbits
)
440 if (small_const_nbits(nbits
))
441 *dst
= (*src
& BITMAP_LAST_WORD_MASK(nbits
)) >> shift
;
443 __bitmap_shift_right(dst
, src
, shift
, nbits
);
446 static inline void bitmap_shift_left(unsigned long *dst
, const unsigned long *src
,
447 unsigned int shift
, unsigned int nbits
)
449 if (small_const_nbits(nbits
))
450 *dst
= (*src
<< shift
) & BITMAP_LAST_WORD_MASK(nbits
);
452 __bitmap_shift_left(dst
, src
, shift
, nbits
);
455 static inline void bitmap_replace(unsigned long *dst
,
456 const unsigned long *old
,
457 const unsigned long *new,
458 const unsigned long *mask
,
461 if (small_const_nbits(nbits
))
462 *dst
= (*old
& ~(*mask
)) | (*new & *mask
);
464 __bitmap_replace(dst
, old
, new, mask
, nbits
);
467 static inline void bitmap_next_clear_region(unsigned long *bitmap
,
468 unsigned int *rs
, unsigned int *re
,
471 *rs
= find_next_zero_bit(bitmap
, end
, *rs
);
472 *re
= find_next_bit(bitmap
, end
, *rs
+ 1);
475 static inline void bitmap_next_set_region(unsigned long *bitmap
,
476 unsigned int *rs
, unsigned int *re
,
479 *rs
= find_next_bit(bitmap
, end
, *rs
);
480 *re
= find_next_zero_bit(bitmap
, end
, *rs
+ 1);
484 * Bitmap region iterators. Iterates over the bitmap between [@start, @end).
485 * @rs and @re should be integer variables and will be set to start and end
486 * index of the current clear or set region.
488 #define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \
489 for ((rs) = (start), \
490 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \
493 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)))
495 #define bitmap_for_each_set_region(bitmap, rs, re, start, end) \
496 for ((rs) = (start), \
497 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \
500 bitmap_next_set_region((bitmap), &(rs), &(re), (end)))
503 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
506 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
507 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
509 * There are four combinations of endianness and length of the word in linux
510 * ABIs: LE64, BE64, LE32 and BE32.
512 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
513 * bitmaps and therefore don't require any special handling.
515 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
516 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
517 * other hand is represented as an array of 32-bit words and the position of
518 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
519 * word. For example, bit #42 is located at 10th position of 2nd word.
520 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
521 * values in memory as it usually does. But for BE we need to swap hi and lo
524 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
525 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
526 * hi and lo words, as is expected by bitmap.
528 #if __BITS_PER_LONG == 64
529 #define BITMAP_FROM_U64(n) (n)
531 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
532 ((unsigned long) ((u64)(n) >> 32))
536 * bitmap_from_u64 - Check and swap words within u64.
537 * @mask: source bitmap
538 * @dst: destination bitmap
540 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
541 * to read u64 mask, we will get the wrong word.
542 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
543 * but we expect the lower 32-bits of u64.
545 static inline void bitmap_from_u64(unsigned long *dst
, u64 mask
)
547 dst
[0] = mask
& ULONG_MAX
;
549 if (sizeof(mask
) > sizeof(unsigned long))
554 * bitmap_get_value8 - get an 8-bit value within a memory region
555 * @map: address to the bitmap memory region
556 * @start: bit offset of the 8-bit value; must be a multiple of 8
558 * Returns the 8-bit value located at the @start bit offset within the @src
561 static inline unsigned long bitmap_get_value8(const unsigned long *map
,
564 const size_t index
= BIT_WORD(start
);
565 const unsigned long offset
= start
% BITS_PER_LONG
;
567 return (map
[index
] >> offset
) & 0xFF;
571 * bitmap_set_value8 - set an 8-bit value within a memory region
572 * @map: address to the bitmap memory region
573 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
574 * @start: bit offset of the 8-bit value; must be a multiple of 8
576 static inline void bitmap_set_value8(unsigned long *map
, unsigned long value
,
579 const size_t index
= BIT_WORD(start
);
580 const unsigned long offset
= start
% BITS_PER_LONG
;
582 map
[index
] &= ~(0xFFUL
<< offset
);
583 map
[index
] |= value
<< offset
;
586 #endif /* __ASSEMBLY__ */
588 #endif /* __LINUX_BITMAP_H */