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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_BITMAP_H
3#define __LINUX_BITMAP_H
4
5#ifndef __ASSEMBLY__
6
7#include <linux/types.h>
8#include <linux/bitops.h>
9#include <linux/string.h>
10#include <linux/kernel.h>
11
12/*
13 * bitmaps provide bit arrays that consume one or more unsigned
14 * longs. The bitmap interface and available operations are listed
15 * here, in bitmap.h
16 *
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.
21 *
22 * See lib/bitmap.c for more details.
23 */
24
25/**
26 * DOC: bitmap overview
27 *
28 * The available bitmap operations and their rough meaning in the
29 * case that the bitmap is a single unsigned long are thus:
30 *
31 * The generated code is more efficient when nbits is known at
32 * compile-time and at most BITS_PER_LONG.
33 *
34 * ::
35 *
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_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
57 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
58 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
59 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
60 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
61 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
62 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
63 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
64 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
65 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
66 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
67 * bitmap_release_region(bitmap, pos, order) Free specified bit region
68 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
69 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
70 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
71 * bitmap_get_value8(map, start) Get 8bit value from map at start
72 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
73 *
74 * Note, bitmap_zero() and bitmap_fill() operate over the region of
75 * unsigned longs, that is, bits behind bitmap till the unsigned long
76 * boundary will be zeroed or filled as well. Consider to use
77 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
78 * respectively.
79 */
80
81/**
82 * DOC: bitmap bitops
83 *
84 * Also the following operations in asm/bitops.h apply to bitmaps.::
85 *
86 * set_bit(bit, addr) *addr |= bit
87 * clear_bit(bit, addr) *addr &= ~bit
88 * change_bit(bit, addr) *addr ^= bit
89 * test_bit(bit, addr) Is bit set in *addr?
90 * test_and_set_bit(bit, addr) Set bit and return old value
91 * test_and_clear_bit(bit, addr) Clear bit and return old value
92 * test_and_change_bit(bit, addr) Change bit and return old value
93 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
94 * find_first_bit(addr, nbits) Position first set bit in *addr
95 * find_next_zero_bit(addr, nbits, bit)
96 * Position next zero bit in *addr >= bit
97 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
98 * find_next_and_bit(addr1, addr2, nbits, bit)
99 * Same as find_next_bit, but in
100 * (*addr1 & *addr2)
101 *
102 */
103
104/**
105 * DOC: declare bitmap
106 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
107 * to declare an array named 'name' of just enough unsigned longs to
108 * contain all bit positions from 0 to 'bits' - 1.
109 */
110
111/*
112 * Allocation and deallocation of bitmap.
113 * Provided in lib/bitmap.c to avoid circular dependency.
114 */
115extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
116extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
117extern void bitmap_free(const unsigned long *bitmap);
118
119/*
120 * lib/bitmap.c provides these functions:
121 */
122
123extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
124extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
125extern int __bitmap_equal(const unsigned long *bitmap1,
126 const unsigned long *bitmap2, unsigned int nbits);
127extern bool __pure __bitmap_or_equal(const unsigned long *src1,
128 const unsigned long *src2,
129 const unsigned long *src3,
130 unsigned int nbits);
131extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
132 unsigned int nbits);
133extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
134 unsigned int shift, unsigned int nbits);
135extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
136 unsigned int shift, unsigned int nbits);
137extern void bitmap_cut(unsigned long *dst, const unsigned long *src,
138 unsigned int first, unsigned int cut,
139 unsigned int nbits);
140extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
141 const unsigned long *bitmap2, unsigned int nbits);
142extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
143 const unsigned long *bitmap2, unsigned int nbits);
144extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
145 const unsigned long *bitmap2, unsigned int nbits);
146extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
147 const unsigned long *bitmap2, unsigned int nbits);
148extern void __bitmap_replace(unsigned long *dst,
149 const unsigned long *old, const unsigned long *new,
150 const unsigned long *mask, unsigned int nbits);
151extern int __bitmap_intersects(const unsigned long *bitmap1,
152 const unsigned long *bitmap2, unsigned int nbits);
153extern int __bitmap_subset(const unsigned long *bitmap1,
154 const unsigned long *bitmap2, unsigned int nbits);
155extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
156extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
157extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
158
159extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
160 unsigned long size,
161 unsigned long start,
162 unsigned int nr,
163 unsigned long align_mask,
164 unsigned long align_offset);
165
166/**
167 * bitmap_find_next_zero_area - find a contiguous aligned zero area
168 * @map: The address to base the search on
169 * @size: The bitmap size in bits
170 * @start: The bitnumber to start searching at
171 * @nr: The number of zeroed bits we're looking for
172 * @align_mask: Alignment mask for zero area
173 *
174 * The @align_mask should be one less than a power of 2; the effect is that
175 * the bit offset of all zero areas this function finds is multiples of that
176 * power of 2. A @align_mask of 0 means no alignment is required.
177 */
178static inline unsigned long
179bitmap_find_next_zero_area(unsigned long *map,
180 unsigned long size,
181 unsigned long start,
182 unsigned int nr,
183 unsigned long align_mask)
184{
185 return bitmap_find_next_zero_area_off(map, size, start, nr,
186 align_mask, 0);
187}
188
189extern int bitmap_parse(const char *buf, unsigned int buflen,
190 unsigned long *dst, int nbits);
191extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
192 unsigned long *dst, int nbits);
193extern int bitmap_parselist(const char *buf, unsigned long *maskp,
194 int nmaskbits);
195extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
196 unsigned long *dst, int nbits);
197extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
198 const unsigned long *old, const unsigned long *new, unsigned int nbits);
199extern int bitmap_bitremap(int oldbit,
200 const unsigned long *old, const unsigned long *new, int bits);
201extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
202 const unsigned long *relmap, unsigned int bits);
203extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
204 unsigned int sz, unsigned int nbits);
205extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
206extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
207extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
208
209#ifdef __BIG_ENDIAN
210extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
211#else
212#define bitmap_copy_le bitmap_copy
213#endif
214extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
215extern int bitmap_print_to_pagebuf(bool list, char *buf,
216 const unsigned long *maskp, int nmaskbits);
217
218#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
219#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
220
221/*
222 * The static inlines below do not handle constant nbits==0 correctly,
223 * so make such users (should any ever turn up) call the out-of-line
224 * versions.
225 */
226#define small_const_nbits(nbits) \
227 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
228
229static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
230{
231 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
232 memset(dst, 0, len);
233}
234
235static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
236{
237 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
238 memset(dst, 0xff, len);
239}
240
241static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
242 unsigned int nbits)
243{
244 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
245 memcpy(dst, src, len);
246}
247
248/*
249 * Copy bitmap and clear tail bits in last word.
250 */
251static inline void bitmap_copy_clear_tail(unsigned long *dst,
252 const unsigned long *src, unsigned int nbits)
253{
254 bitmap_copy(dst, src, nbits);
255 if (nbits % BITS_PER_LONG)
256 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
257}
258
259/*
260 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
261 * therefore conversion is not needed when copying data from/to arrays of u32.
262 */
263#if BITS_PER_LONG == 64
264extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
265 unsigned int nbits);
266extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
267 unsigned int nbits);
268#else
269#define bitmap_from_arr32(bitmap, buf, nbits) \
270 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
271 (const unsigned long *) (buf), (nbits))
272#define bitmap_to_arr32(buf, bitmap, nbits) \
273 bitmap_copy_clear_tail((unsigned long *) (buf), \
274 (const unsigned long *) (bitmap), (nbits))
275#endif
276
277static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
278 const unsigned long *src2, unsigned int nbits)
279{
280 if (small_const_nbits(nbits))
281 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
282 return __bitmap_and(dst, src1, src2, nbits);
283}
284
285static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
286 const unsigned long *src2, unsigned int nbits)
287{
288 if (small_const_nbits(nbits))
289 *dst = *src1 | *src2;
290 else
291 __bitmap_or(dst, src1, src2, nbits);
292}
293
294static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
295 const unsigned long *src2, unsigned int nbits)
296{
297 if (small_const_nbits(nbits))
298 *dst = *src1 ^ *src2;
299 else
300 __bitmap_xor(dst, src1, src2, nbits);
301}
302
303static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
304 const unsigned long *src2, unsigned int nbits)
305{
306 if (small_const_nbits(nbits))
307 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
308 return __bitmap_andnot(dst, src1, src2, nbits);
309}
310
311static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
312 unsigned int nbits)
313{
314 if (small_const_nbits(nbits))
315 *dst = ~(*src);
316 else
317 __bitmap_complement(dst, src, nbits);
318}
319
320#ifdef __LITTLE_ENDIAN
321#define BITMAP_MEM_ALIGNMENT 8
322#else
323#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
324#endif
325#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
326
327static inline int bitmap_equal(const unsigned long *src1,
328 const unsigned long *src2, unsigned int nbits)
329{
330 if (small_const_nbits(nbits))
331 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
332 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
333 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
334 return !memcmp(src1, src2, nbits / 8);
335 return __bitmap_equal(src1, src2, nbits);
336}
337
338/**
339 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
340 * @src1: Pointer to bitmap 1
341 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
342 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
343 * @nbits: number of bits in each of these bitmaps
344 *
345 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
346 */
347static inline bool bitmap_or_equal(const unsigned long *src1,
348 const unsigned long *src2,
349 const unsigned long *src3,
350 unsigned int nbits)
351{
352 if (!small_const_nbits(nbits))
353 return __bitmap_or_equal(src1, src2, src3, nbits);
354
355 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
356}
357
358static inline int bitmap_intersects(const unsigned long *src1,
359 const unsigned long *src2, unsigned int nbits)
360{
361 if (small_const_nbits(nbits))
362 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
363 else
364 return __bitmap_intersects(src1, src2, nbits);
365}
366
367static inline int bitmap_subset(const unsigned long *src1,
368 const unsigned long *src2, unsigned int nbits)
369{
370 if (small_const_nbits(nbits))
371 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
372 else
373 return __bitmap_subset(src1, src2, nbits);
374}
375
376static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
377{
378 if (small_const_nbits(nbits))
379 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
380
381 return find_first_bit(src, nbits) == nbits;
382}
383
384static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
385{
386 if (small_const_nbits(nbits))
387 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
388
389 return find_first_zero_bit(src, nbits) == nbits;
390}
391
392static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
393{
394 if (small_const_nbits(nbits))
395 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
396 return __bitmap_weight(src, nbits);
397}
398
399static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
400 unsigned int nbits)
401{
402 if (__builtin_constant_p(nbits) && nbits == 1)
403 __set_bit(start, map);
404 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
405 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
406 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
407 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
408 memset((char *)map + start / 8, 0xff, nbits / 8);
409 else
410 __bitmap_set(map, start, nbits);
411}
412
413static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
414 unsigned int nbits)
415{
416 if (__builtin_constant_p(nbits) && nbits == 1)
417 __clear_bit(start, map);
418 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
419 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
420 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
421 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
422 memset((char *)map + start / 8, 0, nbits / 8);
423 else
424 __bitmap_clear(map, start, nbits);
425}
426
427static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
428 unsigned int shift, unsigned int nbits)
429{
430 if (small_const_nbits(nbits))
431 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
432 else
433 __bitmap_shift_right(dst, src, shift, nbits);
434}
435
436static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
437 unsigned int shift, unsigned int nbits)
438{
439 if (small_const_nbits(nbits))
440 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
441 else
442 __bitmap_shift_left(dst, src, shift, nbits);
443}
444
445static inline void bitmap_replace(unsigned long *dst,
446 const unsigned long *old,
447 const unsigned long *new,
448 const unsigned long *mask,
449 unsigned int nbits)
450{
451 if (small_const_nbits(nbits))
452 *dst = (*old & ~(*mask)) | (*new & *mask);
453 else
454 __bitmap_replace(dst, old, new, mask, nbits);
455}
456
457static inline void bitmap_next_clear_region(unsigned long *bitmap,
458 unsigned int *rs, unsigned int *re,
459 unsigned int end)
460{
461 *rs = find_next_zero_bit(bitmap, end, *rs);
462 *re = find_next_bit(bitmap, end, *rs + 1);
463}
464
465static inline void bitmap_next_set_region(unsigned long *bitmap,
466 unsigned int *rs, unsigned int *re,
467 unsigned int end)
468{
469 *rs = find_next_bit(bitmap, end, *rs);
470 *re = find_next_zero_bit(bitmap, end, *rs + 1);
471}
472
473/*
474 * Bitmap region iterators. Iterates over the bitmap between [@start, @end).
475 * @rs and @re should be integer variables and will be set to start and end
476 * index of the current clear or set region.
477 */
478#define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \
479 for ((rs) = (start), \
480 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \
481 (rs) < (re); \
482 (rs) = (re) + 1, \
483 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)))
484
485#define bitmap_for_each_set_region(bitmap, rs, re, start, end) \
486 for ((rs) = (start), \
487 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \
488 (rs) < (re); \
489 (rs) = (re) + 1, \
490 bitmap_next_set_region((bitmap), &(rs), &(re), (end)))
491
492/**
493 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
494 * @n: u64 value
495 *
496 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
497 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
498 *
499 * There are four combinations of endianness and length of the word in linux
500 * ABIs: LE64, BE64, LE32 and BE32.
501 *
502 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
503 * bitmaps and therefore don't require any special handling.
504 *
505 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
506 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
507 * other hand is represented as an array of 32-bit words and the position of
508 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
509 * word. For example, bit #42 is located at 10th position of 2nd word.
510 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
511 * values in memory as it usually does. But for BE we need to swap hi and lo
512 * words manually.
513 *
514 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
515 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
516 * hi and lo words, as is expected by bitmap.
517 */
518#if __BITS_PER_LONG == 64
519#define BITMAP_FROM_U64(n) (n)
520#else
521#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
522 ((unsigned long) ((u64)(n) >> 32))
523#endif
524
525/**
526 * bitmap_from_u64 - Check and swap words within u64.
527 * @mask: source bitmap
528 * @dst: destination bitmap
529 *
530 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
531 * to read u64 mask, we will get the wrong word.
532 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
533 * but we expect the lower 32-bits of u64.
534 */
535static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
536{
537 dst[0] = mask & ULONG_MAX;
538
539 if (sizeof(mask) > sizeof(unsigned long))
540 dst[1] = mask >> 32;
541}
542
543/**
544 * bitmap_get_value8 - get an 8-bit value within a memory region
545 * @map: address to the bitmap memory region
546 * @start: bit offset of the 8-bit value; must be a multiple of 8
547 *
548 * Returns the 8-bit value located at the @start bit offset within the @src
549 * memory region.
550 */
551static inline unsigned long bitmap_get_value8(const unsigned long *map,
552 unsigned long start)
553{
554 const size_t index = BIT_WORD(start);
555 const unsigned long offset = start % BITS_PER_LONG;
556
557 return (map[index] >> offset) & 0xFF;
558}
559
560/**
561 * bitmap_set_value8 - set an 8-bit value within a memory region
562 * @map: address to the bitmap memory region
563 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
564 * @start: bit offset of the 8-bit value; must be a multiple of 8
565 */
566static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
567 unsigned long start)
568{
569 const size_t index = BIT_WORD(start);
570 const unsigned long offset = start % BITS_PER_LONG;
571
572 map[index] &= ~(0xFFUL << offset);
573 map[index] |= value << offset;
574}
575
576#endif /* __ASSEMBLY__ */
577
578#endif /* __LINUX_BITMAP_H */