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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, mask_off) as above
54 * bitmap_next_clear_region(map, &start, &end, nbits) Find next clear region
55 * bitmap_next_set_region(map, &start, &end, nbits) Find next set region
56 * bitmap_for_each_clear_region(map, rs, re, start, end)
57 * Iterate over all clear regions
58 * bitmap_for_each_set_region(map, rs, re, start, end)
59 * Iterate over all set regions
60 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
61 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
62 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
63 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
64 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
65 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
66 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
67 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
68 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
69 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
70 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
71 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
72 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
73 * bitmap_release_region(bitmap, pos, order) Free specified bit region
74 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
75 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
76 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
77 * bitmap_get_value8(map, start) Get 8bit value from map at start
78 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
79 *
80 * Note, bitmap_zero() and bitmap_fill() operate over the region of
81 * unsigned longs, that is, bits behind bitmap till the unsigned long
82 * boundary will be zeroed or filled as well. Consider to use
83 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
84 * respectively.
85 */
86
87/**
88 * DOC: bitmap bitops
89 *
90 * Also the following operations in asm/bitops.h apply to bitmaps.::
91 *
92 * set_bit(bit, addr) *addr |= bit
93 * clear_bit(bit, addr) *addr &= ~bit
94 * change_bit(bit, addr) *addr ^= bit
95 * test_bit(bit, addr) Is bit set in *addr?
96 * test_and_set_bit(bit, addr) Set bit and return old value
97 * test_and_clear_bit(bit, addr) Clear bit and return old value
98 * test_and_change_bit(bit, addr) Change bit and return old value
99 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
100 * find_first_bit(addr, nbits) Position first set bit in *addr
101 * find_next_zero_bit(addr, nbits, bit)
102 * Position next zero bit in *addr >= bit
103 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
104 * find_next_and_bit(addr1, addr2, nbits, bit)
105 * Same as find_next_bit, but in
106 * (*addr1 & *addr2)
107 *
108 */
109
110/**
111 * DOC: declare bitmap
112 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
113 * to declare an array named 'name' of just enough unsigned longs to
114 * contain all bit positions from 0 to 'bits' - 1.
115 */
116
117/*
118 * Allocation and deallocation of bitmap.
119 * Provided in lib/bitmap.c to avoid circular dependency.
120 */
121extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
122extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
123extern void bitmap_free(const unsigned long *bitmap);
124
125/*
126 * lib/bitmap.c provides these functions:
127 */
128
129extern int __bitmap_equal(const unsigned long *bitmap1,
130 const unsigned long *bitmap2, unsigned int nbits);
131extern bool __pure __bitmap_or_equal(const unsigned long *src1,
132 const unsigned long *src2,
133 const unsigned long *src3,
134 unsigned int nbits);
135extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
136 unsigned int nbits);
137extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
138 unsigned int shift, unsigned int nbits);
139extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
140 unsigned int shift, unsigned int nbits);
141extern void bitmap_cut(unsigned long *dst, const unsigned long *src,
142 unsigned int first, unsigned int cut,
143 unsigned int nbits);
144extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
145 const unsigned long *bitmap2, unsigned int nbits);
146extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
147 const unsigned long *bitmap2, unsigned int nbits);
148extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
149 const unsigned long *bitmap2, unsigned int nbits);
150extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
151 const unsigned long *bitmap2, unsigned int nbits);
152extern void __bitmap_replace(unsigned long *dst,
153 const unsigned long *old, const unsigned long *new,
154 const unsigned long *mask, unsigned int nbits);
155extern int __bitmap_intersects(const unsigned long *bitmap1,
156 const unsigned long *bitmap2, unsigned int nbits);
157extern int __bitmap_subset(const unsigned long *bitmap1,
158 const unsigned long *bitmap2, unsigned int nbits);
159extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
160extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
161extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
162
163extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
164 unsigned long size,
165 unsigned long start,
166 unsigned int nr,
167 unsigned long align_mask,
168 unsigned long align_offset);
169
170/**
171 * bitmap_find_next_zero_area - find a contiguous aligned zero area
172 * @map: The address to base the search on
173 * @size: The bitmap size in bits
174 * @start: The bitnumber to start searching at
175 * @nr: The number of zeroed bits we're looking for
176 * @align_mask: Alignment mask for zero area
177 *
178 * The @align_mask should be one less than a power of 2; the effect is that
179 * the bit offset of all zero areas this function finds is multiples of that
180 * power of 2. A @align_mask of 0 means no alignment is required.
181 */
182static inline unsigned long
183bitmap_find_next_zero_area(unsigned long *map,
184 unsigned long size,
185 unsigned long start,
186 unsigned int nr,
187 unsigned long align_mask)
188{
189 return bitmap_find_next_zero_area_off(map, size, start, nr,
190 align_mask, 0);
191}
192
193extern int bitmap_parse(const char *buf, unsigned int buflen,
194 unsigned long *dst, int nbits);
195extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
196 unsigned long *dst, int nbits);
197extern int bitmap_parselist(const char *buf, unsigned long *maskp,
198 int nmaskbits);
199extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
200 unsigned long *dst, int nbits);
201extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
202 const unsigned long *old, const unsigned long *new, unsigned int nbits);
203extern int bitmap_bitremap(int oldbit,
204 const unsigned long *old, const unsigned long *new, int bits);
205extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
206 const unsigned long *relmap, unsigned int bits);
207extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
208 unsigned int sz, unsigned int nbits);
209extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
210extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
211extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
212
213#ifdef __BIG_ENDIAN
214extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
215#else
216#define bitmap_copy_le bitmap_copy
217#endif
218extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
219extern int bitmap_print_to_pagebuf(bool list, char *buf,
220 const unsigned long *maskp, int nmaskbits);
221
222#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
223#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
224
225/*
226 * The static inlines below do not handle constant nbits==0 correctly,
227 * so make such users (should any ever turn up) call the out-of-line
228 * versions.
229 */
230#define small_const_nbits(nbits) \
231 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
232
233static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
234{
235 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
236 memset(dst, 0, len);
237}
238
239static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
240{
241 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
242 memset(dst, 0xff, len);
243}
244
245static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
246 unsigned int nbits)
247{
248 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
249 memcpy(dst, src, len);
250}
251
252/*
253 * Copy bitmap and clear tail bits in last word.
254 */
255static inline void bitmap_copy_clear_tail(unsigned long *dst,
256 const unsigned long *src, unsigned int nbits)
257{
258 bitmap_copy(dst, src, nbits);
259 if (nbits % BITS_PER_LONG)
260 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
261}
262
263/*
264 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
265 * therefore conversion is not needed when copying data from/to arrays of u32.
266 */
267#if BITS_PER_LONG == 64
268extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
269 unsigned int nbits);
270extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
271 unsigned int nbits);
272#else
273#define bitmap_from_arr32(bitmap, buf, nbits) \
274 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
275 (const unsigned long *) (buf), (nbits))
276#define bitmap_to_arr32(buf, bitmap, nbits) \
277 bitmap_copy_clear_tail((unsigned long *) (buf), \
278 (const unsigned long *) (bitmap), (nbits))
279#endif
280
281static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
282 const unsigned long *src2, unsigned int nbits)
283{
284 if (small_const_nbits(nbits))
285 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
286 return __bitmap_and(dst, src1, src2, nbits);
287}
288
289static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
290 const unsigned long *src2, unsigned int nbits)
291{
292 if (small_const_nbits(nbits))
293 *dst = *src1 | *src2;
294 else
295 __bitmap_or(dst, src1, src2, nbits);
296}
297
298static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
299 const unsigned long *src2, unsigned int nbits)
300{
301 if (small_const_nbits(nbits))
302 *dst = *src1 ^ *src2;
303 else
304 __bitmap_xor(dst, src1, src2, nbits);
305}
306
307static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
308 const unsigned long *src2, unsigned int nbits)
309{
310 if (small_const_nbits(nbits))
311 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
312 return __bitmap_andnot(dst, src1, src2, nbits);
313}
314
315static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
316 unsigned int nbits)
317{
318 if (small_const_nbits(nbits))
319 *dst = ~(*src);
320 else
321 __bitmap_complement(dst, src, nbits);
322}
323
324#ifdef __LITTLE_ENDIAN
325#define BITMAP_MEM_ALIGNMENT 8
326#else
327#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
328#endif
329#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
330
331static inline int bitmap_equal(const unsigned long *src1,
332 const unsigned long *src2, unsigned int nbits)
333{
334 if (small_const_nbits(nbits))
335 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
336 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
337 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
338 return !memcmp(src1, src2, nbits / 8);
339 return __bitmap_equal(src1, src2, nbits);
340}
341
342/**
343 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
344 * @src1: Pointer to bitmap 1
345 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
346 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
347 * @nbits: number of bits in each of these bitmaps
348 *
349 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
350 */
351static inline bool bitmap_or_equal(const unsigned long *src1,
352 const unsigned long *src2,
353 const unsigned long *src3,
354 unsigned int nbits)
355{
356 if (!small_const_nbits(nbits))
357 return __bitmap_or_equal(src1, src2, src3, nbits);
358
359 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
360}
361
362static inline int bitmap_intersects(const unsigned long *src1,
363 const unsigned long *src2, unsigned int nbits)
364{
365 if (small_const_nbits(nbits))
366 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
367 else
368 return __bitmap_intersects(src1, src2, nbits);
369}
370
371static inline int bitmap_subset(const unsigned long *src1,
372 const unsigned long *src2, unsigned int nbits)
373{
374 if (small_const_nbits(nbits))
375 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
376 else
377 return __bitmap_subset(src1, src2, nbits);
378}
379
380static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
381{
382 if (small_const_nbits(nbits))
383 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
384
385 return find_first_bit(src, nbits) == nbits;
386}
387
388static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
389{
390 if (small_const_nbits(nbits))
391 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
392
393 return find_first_zero_bit(src, nbits) == nbits;
394}
395
396static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
397{
398 if (small_const_nbits(nbits))
399 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
400 return __bitmap_weight(src, nbits);
401}
402
403static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
404 unsigned int nbits)
405{
406 if (__builtin_constant_p(nbits) && nbits == 1)
407 __set_bit(start, map);
408 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
409 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
410 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
411 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
412 memset((char *)map + start / 8, 0xff, nbits / 8);
413 else
414 __bitmap_set(map, start, nbits);
415}
416
417static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
418 unsigned int nbits)
419{
420 if (__builtin_constant_p(nbits) && nbits == 1)
421 __clear_bit(start, map);
422 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
423 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
424 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
425 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
426 memset((char *)map + start / 8, 0, nbits / 8);
427 else
428 __bitmap_clear(map, start, nbits);
429}
430
431static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
432 unsigned int shift, unsigned int nbits)
433{
434 if (small_const_nbits(nbits))
435 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
436 else
437 __bitmap_shift_right(dst, src, shift, nbits);
438}
439
440static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
441 unsigned int shift, unsigned int nbits)
442{
443 if (small_const_nbits(nbits))
444 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
445 else
446 __bitmap_shift_left(dst, src, shift, nbits);
447}
448
449static inline void bitmap_replace(unsigned long *dst,
450 const unsigned long *old,
451 const unsigned long *new,
452 const unsigned long *mask,
453 unsigned int nbits)
454{
455 if (small_const_nbits(nbits))
456 *dst = (*old & ~(*mask)) | (*new & *mask);
457 else
458 __bitmap_replace(dst, old, new, mask, nbits);
459}
460
461static inline void bitmap_next_clear_region(unsigned long *bitmap,
462 unsigned int *rs, unsigned int *re,
463 unsigned int end)
464{
465 *rs = find_next_zero_bit(bitmap, end, *rs);
466 *re = find_next_bit(bitmap, end, *rs + 1);
467}
468
469static inline void bitmap_next_set_region(unsigned long *bitmap,
470 unsigned int *rs, unsigned int *re,
471 unsigned int end)
472{
473 *rs = find_next_bit(bitmap, end, *rs);
474 *re = find_next_zero_bit(bitmap, end, *rs + 1);
475}
476
477/*
478 * Bitmap region iterators. Iterates over the bitmap between [@start, @end).
479 * @rs and @re should be integer variables and will be set to start and end
480 * index of the current clear or set region.
481 */
482#define bitmap_for_each_clear_region(bitmap, rs, re, start, end) \
483 for ((rs) = (start), \
484 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)); \
485 (rs) < (re); \
486 (rs) = (re) + 1, \
487 bitmap_next_clear_region((bitmap), &(rs), &(re), (end)))
488
489#define bitmap_for_each_set_region(bitmap, rs, re, start, end) \
490 for ((rs) = (start), \
491 bitmap_next_set_region((bitmap), &(rs), &(re), (end)); \
492 (rs) < (re); \
493 (rs) = (re) + 1, \
494 bitmap_next_set_region((bitmap), &(rs), &(re), (end)))
495
496/**
497 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
498 * @n: u64 value
499 *
500 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
501 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
502 *
503 * There are four combinations of endianness and length of the word in linux
504 * ABIs: LE64, BE64, LE32 and BE32.
505 *
506 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
507 * bitmaps and therefore don't require any special handling.
508 *
509 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
510 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
511 * other hand is represented as an array of 32-bit words and the position of
512 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
513 * word. For example, bit #42 is located at 10th position of 2nd word.
514 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
515 * values in memory as it usually does. But for BE we need to swap hi and lo
516 * words manually.
517 *
518 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
519 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
520 * hi and lo words, as is expected by bitmap.
521 */
522#if __BITS_PER_LONG == 64
523#define BITMAP_FROM_U64(n) (n)
524#else
525#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
526 ((unsigned long) ((u64)(n) >> 32))
527#endif
528
529/**
530 * bitmap_from_u64 - Check and swap words within u64.
531 * @mask: source bitmap
532 * @dst: destination bitmap
533 *
534 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
535 * to read u64 mask, we will get the wrong word.
536 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
537 * but we expect the lower 32-bits of u64.
538 */
539static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
540{
541 dst[0] = mask & ULONG_MAX;
542
543 if (sizeof(mask) > sizeof(unsigned long))
544 dst[1] = mask >> 32;
545}
546
547/**
548 * bitmap_get_value8 - get an 8-bit value within a memory region
549 * @map: address to the bitmap memory region
550 * @start: bit offset of the 8-bit value; must be a multiple of 8
551 *
552 * Returns the 8-bit value located at the @start bit offset within the @src
553 * memory region.
554 */
555static inline unsigned long bitmap_get_value8(const unsigned long *map,
556 unsigned long start)
557{
558 const size_t index = BIT_WORD(start);
559 const unsigned long offset = start % BITS_PER_LONG;
560
561 return (map[index] >> offset) & 0xFF;
562}
563
564/**
565 * bitmap_set_value8 - set an 8-bit value within a memory region
566 * @map: address to the bitmap memory region
567 * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
568 * @start: bit offset of the 8-bit value; must be a multiple of 8
569 */
570static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
571 unsigned long start)
572{
573 const size_t index = BIT_WORD(start);
574 const unsigned long offset = start % BITS_PER_LONG;
575
576 map[index] &= ~(0xFFUL << offset);
577 map[index] |= value << offset;
578}
579
580#endif /* __ASSEMBLY__ */
581
582#endif /* __LINUX_BITMAP_H */