Line data Source code
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/align.h>
8 : #include <linux/bitops.h>
9 : #include <linux/find.h>
10 : #include <linux/limits.h>
11 : #include <linux/string.h>
12 : #include <linux/types.h>
13 :
14 : struct device;
15 :
16 : /*
17 : * bitmaps provide bit arrays that consume one or more unsigned
18 : * longs. The bitmap interface and available operations are listed
19 : * here, in bitmap.h
20 : *
21 : * Function implementations generic to all architectures are in
22 : * lib/bitmap.c. Functions implementations that are architecture
23 : * specific are in various include/asm-<arch>/bitops.h headers
24 : * and other arch/<arch> specific files.
25 : *
26 : * See lib/bitmap.c for more details.
27 : */
28 :
29 : /**
30 : * DOC: bitmap overview
31 : *
32 : * The available bitmap operations and their rough meaning in the
33 : * case that the bitmap is a single unsigned long are thus:
34 : *
35 : * The generated code is more efficient when nbits is known at
36 : * compile-time and at most BITS_PER_LONG.
37 : *
38 : * ::
39 : *
40 : * bitmap_zero(dst, nbits) *dst = 0UL
41 : * bitmap_fill(dst, nbits) *dst = ~0UL
42 : * bitmap_copy(dst, src, nbits) *dst = *src
43 : * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
44 : * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
45 : * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
46 : * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
47 : * bitmap_complement(dst, src, nbits) *dst = ~(*src)
48 : * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
49 : * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
50 : * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
51 : * bitmap_empty(src, nbits) Are all bits zero in *src?
52 : * bitmap_full(src, nbits) Are all bits set in *src?
53 : * bitmap_weight(src, nbits) Hamming Weight: number set bits
54 : * bitmap_set(dst, pos, nbits) Set specified bit area
55 : * bitmap_clear(dst, pos, nbits) Clear specified bit area
56 : * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
57 : * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
58 : * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
59 : * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
60 : * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
61 : * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
62 : * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
63 : * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
64 : * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
65 : * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
66 : * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
67 : * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
68 : * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
69 : * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
70 : * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
71 : * bitmap_release_region(bitmap, pos, order) Free specified bit region
72 : * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
73 : * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
74 : * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
75 : * bitmap_get_value8(map, start) Get 8bit value from map at start
76 : * bitmap_set_value8(map, value, start) Set 8bit value to map at start
77 : *
78 : * Note, bitmap_zero() and bitmap_fill() operate over the region of
79 : * unsigned longs, that is, bits behind bitmap till the unsigned long
80 : * boundary will be zeroed or filled as well. Consider to use
81 : * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
82 : * respectively.
83 : */
84 :
85 : /**
86 : * DOC: bitmap bitops
87 : *
88 : * Also the following operations in asm/bitops.h apply to bitmaps.::
89 : *
90 : * set_bit(bit, addr) *addr |= bit
91 : * clear_bit(bit, addr) *addr &= ~bit
92 : * change_bit(bit, addr) *addr ^= bit
93 : * test_bit(bit, addr) Is bit set in *addr?
94 : * test_and_set_bit(bit, addr) Set bit and return old value
95 : * test_and_clear_bit(bit, addr) Clear bit and return old value
96 : * test_and_change_bit(bit, addr) Change bit and return old value
97 : * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
98 : * find_first_bit(addr, nbits) Position first set bit in *addr
99 : * find_next_zero_bit(addr, nbits, bit)
100 : * Position next zero bit in *addr >= bit
101 : * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
102 : * find_next_and_bit(addr1, addr2, nbits, bit)
103 : * Same as find_next_bit, but in
104 : * (*addr1 & *addr2)
105 : *
106 : */
107 :
108 : /**
109 : * DOC: declare bitmap
110 : * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
111 : * to declare an array named 'name' of just enough unsigned longs to
112 : * contain all bit positions from 0 to 'bits' - 1.
113 : */
114 :
115 : /*
116 : * Allocation and deallocation of bitmap.
117 : * Provided in lib/bitmap.c to avoid circular dependency.
118 : */
119 : unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
120 : unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
121 : unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
122 : unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
123 : void bitmap_free(const unsigned long *bitmap);
124 :
125 : /* Managed variants of the above. */
126 : unsigned long *devm_bitmap_alloc(struct device *dev,
127 : unsigned int nbits, gfp_t flags);
128 : unsigned long *devm_bitmap_zalloc(struct device *dev,
129 : unsigned int nbits, gfp_t flags);
130 :
131 : /*
132 : * lib/bitmap.c provides these functions:
133 : */
134 :
135 : int __bitmap_equal(const unsigned long *bitmap1,
136 : const unsigned long *bitmap2, unsigned int nbits);
137 : bool __pure __bitmap_or_equal(const unsigned long *src1,
138 : const unsigned long *src2,
139 : const unsigned long *src3,
140 : unsigned int nbits);
141 : void __bitmap_complement(unsigned long *dst, const unsigned long *src,
142 : unsigned int nbits);
143 : void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
144 : unsigned int shift, unsigned int nbits);
145 : void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
146 : unsigned int shift, unsigned int nbits);
147 : void bitmap_cut(unsigned long *dst, const unsigned long *src,
148 : unsigned int first, unsigned int cut, unsigned int nbits);
149 : int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
150 : const unsigned long *bitmap2, unsigned int nbits);
151 : void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
152 : const unsigned long *bitmap2, unsigned int nbits);
153 : void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
154 : const unsigned long *bitmap2, unsigned int nbits);
155 : int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
156 : const unsigned long *bitmap2, unsigned int nbits);
157 : void __bitmap_replace(unsigned long *dst,
158 : const unsigned long *old, const unsigned long *new,
159 : const unsigned long *mask, unsigned int nbits);
160 : int __bitmap_intersects(const unsigned long *bitmap1,
161 : const unsigned long *bitmap2, unsigned int nbits);
162 : int __bitmap_subset(const unsigned long *bitmap1,
163 : const unsigned long *bitmap2, unsigned int nbits);
164 : int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
165 : void __bitmap_set(unsigned long *map, unsigned int start, int len);
166 : void __bitmap_clear(unsigned long *map, unsigned int start, int len);
167 :
168 : unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
169 : unsigned long size,
170 : unsigned long start,
171 : unsigned int nr,
172 : unsigned long align_mask,
173 : unsigned long align_offset);
174 :
175 : /**
176 : * bitmap_find_next_zero_area - find a contiguous aligned zero area
177 : * @map: The address to base the search on
178 : * @size: The bitmap size in bits
179 : * @start: The bitnumber to start searching at
180 : * @nr: The number of zeroed bits we're looking for
181 : * @align_mask: Alignment mask for zero area
182 : *
183 : * The @align_mask should be one less than a power of 2; the effect is that
184 : * the bit offset of all zero areas this function finds is multiples of that
185 : * power of 2. A @align_mask of 0 means no alignment is required.
186 : */
187 : static inline unsigned long
188 : bitmap_find_next_zero_area(unsigned long *map,
189 : unsigned long size,
190 : unsigned long start,
191 : unsigned int nr,
192 : unsigned long align_mask)
193 : {
194 0 : return bitmap_find_next_zero_area_off(map, size, start, nr,
195 : align_mask, 0);
196 : }
197 :
198 : int bitmap_parse(const char *buf, unsigned int buflen,
199 : unsigned long *dst, int nbits);
200 : int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
201 : unsigned long *dst, int nbits);
202 : int bitmap_parselist(const char *buf, unsigned long *maskp,
203 : int nmaskbits);
204 : int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
205 : unsigned long *dst, int nbits);
206 : void bitmap_remap(unsigned long *dst, const unsigned long *src,
207 : const unsigned long *old, const unsigned long *new, unsigned int nbits);
208 : int bitmap_bitremap(int oldbit,
209 : const unsigned long *old, const unsigned long *new, int bits);
210 : void bitmap_onto(unsigned long *dst, const unsigned long *orig,
211 : const unsigned long *relmap, unsigned int bits);
212 : void bitmap_fold(unsigned long *dst, const unsigned long *orig,
213 : unsigned int sz, unsigned int nbits);
214 : int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
215 : void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
216 : int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
217 :
218 : #ifdef __BIG_ENDIAN
219 : void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
220 : #else
221 : #define bitmap_copy_le bitmap_copy
222 : #endif
223 : unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
224 : int bitmap_print_to_pagebuf(bool list, char *buf,
225 : const unsigned long *maskp, int nmaskbits);
226 :
227 : extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
228 : int nmaskbits, loff_t off, size_t count);
229 :
230 : extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
231 : int nmaskbits, loff_t off, size_t count);
232 :
233 : #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
234 : #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
235 :
236 : static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
237 : {
238 0 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
239 0 : memset(dst, 0, len);
240 : }
241 :
242 : static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
243 : {
244 329 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
245 329 : memset(dst, 0xff, len);
246 : }
247 :
248 : static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
249 : unsigned int nbits)
250 : {
251 35 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
252 35 : memcpy(dst, src, len);
253 : }
254 :
255 : /*
256 : * Copy bitmap and clear tail bits in last word.
257 : */
258 : static inline void bitmap_copy_clear_tail(unsigned long *dst,
259 : const unsigned long *src, unsigned int nbits)
260 : {
261 : bitmap_copy(dst, src, nbits);
262 : if (nbits % BITS_PER_LONG)
263 : dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
264 : }
265 :
266 : /*
267 : * On 32-bit systems bitmaps are represented as u32 arrays internally, and
268 : * therefore conversion is not needed when copying data from/to arrays of u32.
269 : */
270 : #if BITS_PER_LONG == 64
271 : void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
272 : unsigned int nbits);
273 : void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
274 : unsigned int nbits);
275 : #else
276 : #define bitmap_from_arr32(bitmap, buf, nbits) \
277 : bitmap_copy_clear_tail((unsigned long *) (bitmap), \
278 : (const unsigned long *) (buf), (nbits))
279 : #define bitmap_to_arr32(buf, bitmap, nbits) \
280 : bitmap_copy_clear_tail((unsigned long *) (buf), \
281 : (const unsigned long *) (bitmap), (nbits))
282 : #endif
283 :
284 : static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
285 : const unsigned long *src2, unsigned int nbits)
286 : {
287 : if (small_const_nbits(nbits))
288 7 : return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
289 : return __bitmap_and(dst, src1, src2, nbits);
290 : }
291 :
292 0 : static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
293 : const unsigned long *src2, unsigned int nbits)
294 : {
295 0 : if (small_const_nbits(nbits))
296 0 : *dst = *src1 | *src2;
297 : else
298 0 : __bitmap_or(dst, src1, src2, nbits);
299 0 : }
300 :
301 : static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
302 : const unsigned long *src2, unsigned int nbits)
303 : {
304 : if (small_const_nbits(nbits))
305 : *dst = *src1 ^ *src2;
306 : else
307 : __bitmap_xor(dst, src1, src2, nbits);
308 : }
309 :
310 : static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
311 : const unsigned long *src2, unsigned int nbits)
312 : {
313 : if (small_const_nbits(nbits))
314 0 : return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
315 : return __bitmap_andnot(dst, src1, src2, nbits);
316 : }
317 :
318 : static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
319 : unsigned int nbits)
320 : {
321 : if (small_const_nbits(nbits))
322 : *dst = ~(*src);
323 : else
324 0 : __bitmap_complement(dst, src, nbits);
325 : }
326 :
327 : #ifdef __LITTLE_ENDIAN
328 : #define BITMAP_MEM_ALIGNMENT 8
329 : #else
330 : #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
331 : #endif
332 : #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
333 :
334 4 : static inline int bitmap_equal(const unsigned long *src1,
335 : const unsigned long *src2, unsigned int nbits)
336 : {
337 4 : if (small_const_nbits(nbits))
338 4 : return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
339 0 : if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
340 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
341 0 : return !memcmp(src1, src2, nbits / 8);
342 0 : return __bitmap_equal(src1, src2, nbits);
343 : }
344 :
345 : /**
346 : * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
347 : * @src1: Pointer to bitmap 1
348 : * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
349 : * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
350 : * @nbits: number of bits in each of these bitmaps
351 : *
352 : * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
353 : */
354 : static inline bool bitmap_or_equal(const unsigned long *src1,
355 : const unsigned long *src2,
356 : const unsigned long *src3,
357 : unsigned int nbits)
358 : {
359 : if (!small_const_nbits(nbits))
360 : return __bitmap_or_equal(src1, src2, src3, nbits);
361 :
362 : return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
363 : }
364 :
365 : static inline int bitmap_intersects(const unsigned long *src1,
366 : const unsigned long *src2, unsigned int nbits)
367 : {
368 : if (small_const_nbits(nbits))
369 : return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
370 : else
371 : return __bitmap_intersects(src1, src2, nbits);
372 : }
373 :
374 : static inline int bitmap_subset(const unsigned long *src1,
375 : const unsigned long *src2, unsigned int nbits)
376 : {
377 : if (small_const_nbits(nbits))
378 0 : return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
379 : else
380 0 : return __bitmap_subset(src1, src2, nbits);
381 : }
382 :
383 67 : static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
384 : {
385 67 : if (small_const_nbits(nbits))
386 72 : return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
387 :
388 0 : return find_first_bit(src, nbits) == nbits;
389 : }
390 :
391 : static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
392 : {
393 : if (small_const_nbits(nbits))
394 : return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
395 :
396 119 : return find_first_zero_bit(src, nbits) == nbits;
397 : }
398 :
399 : static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
400 : {
401 1 : if (small_const_nbits(nbits))
402 8 : return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
403 0 : return __bitmap_weight(src, nbits);
404 : }
405 :
406 : static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
407 : unsigned int nbits)
408 : {
409 238 : if (__builtin_constant_p(nbits) && nbits == 1)
410 64 : __set_bit(start, map);
411 238 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
412 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
413 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
414 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
415 0 : memset((char *)map + start / 8, 0xff, nbits / 8);
416 : else
417 238 : __bitmap_set(map, start, nbits);
418 : }
419 :
420 : static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
421 : unsigned int nbits)
422 : {
423 238 : if (__builtin_constant_p(nbits) && nbits == 1)
424 0 : __clear_bit(start, map);
425 238 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
426 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
427 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
428 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
429 0 : memset((char *)map + start / 8, 0, nbits / 8);
430 : else
431 238 : __bitmap_clear(map, start, nbits);
432 : }
433 :
434 : static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
435 : unsigned int shift, unsigned int nbits)
436 : {
437 : if (small_const_nbits(nbits))
438 : *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
439 : else
440 : __bitmap_shift_right(dst, src, shift, nbits);
441 : }
442 :
443 : static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
444 : unsigned int shift, unsigned int nbits)
445 : {
446 : if (small_const_nbits(nbits))
447 : *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
448 : else
449 : __bitmap_shift_left(dst, src, shift, nbits);
450 : }
451 :
452 : static inline void bitmap_replace(unsigned long *dst,
453 : const unsigned long *old,
454 : const unsigned long *new,
455 : const unsigned long *mask,
456 : unsigned int nbits)
457 : {
458 : if (small_const_nbits(nbits))
459 : *dst = (*old & ~(*mask)) | (*new & *mask);
460 : else
461 : __bitmap_replace(dst, old, new, mask, nbits);
462 : }
463 :
464 : static inline void bitmap_next_set_region(unsigned long *bitmap,
465 : unsigned int *rs, unsigned int *re,
466 : unsigned int end)
467 : {
468 : *rs = find_next_bit(bitmap, end, *rs);
469 : *re = find_next_zero_bit(bitmap, end, *rs + 1);
470 : }
471 :
472 : /**
473 : * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
474 : * @n: u64 value
475 : *
476 : * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
477 : * integers in 32-bit environment, and 64-bit integers in 64-bit one.
478 : *
479 : * There are four combinations of endianness and length of the word in linux
480 : * ABIs: LE64, BE64, LE32 and BE32.
481 : *
482 : * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
483 : * bitmaps and therefore don't require any special handling.
484 : *
485 : * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
486 : * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
487 : * other hand is represented as an array of 32-bit words and the position of
488 : * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
489 : * word. For example, bit #42 is located at 10th position of 2nd word.
490 : * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
491 : * values in memory as it usually does. But for BE we need to swap hi and lo
492 : * words manually.
493 : *
494 : * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
495 : * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
496 : * hi and lo words, as is expected by bitmap.
497 : */
498 : #if __BITS_PER_LONG == 64
499 : #define BITMAP_FROM_U64(n) (n)
500 : #else
501 : #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
502 : ((unsigned long) ((u64)(n) >> 32))
503 : #endif
504 :
505 : /**
506 : * bitmap_from_u64 - Check and swap words within u64.
507 : * @mask: source bitmap
508 : * @dst: destination bitmap
509 : *
510 : * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
511 : * to read u64 mask, we will get the wrong word.
512 : * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
513 : * but we expect the lower 32-bits of u64.
514 : */
515 : static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
516 : {
517 : dst[0] = mask & ULONG_MAX;
518 :
519 : if (sizeof(mask) > sizeof(unsigned long))
520 : dst[1] = mask >> 32;
521 : }
522 :
523 : /**
524 : * bitmap_get_value8 - get an 8-bit value within a memory region
525 : * @map: address to the bitmap memory region
526 : * @start: bit offset of the 8-bit value; must be a multiple of 8
527 : *
528 : * Returns the 8-bit value located at the @start bit offset within the @src
529 : * memory region.
530 : */
531 : static inline unsigned long bitmap_get_value8(const unsigned long *map,
532 : unsigned long start)
533 : {
534 0 : const size_t index = BIT_WORD(start);
535 0 : const unsigned long offset = start % BITS_PER_LONG;
536 :
537 0 : return (map[index] >> offset) & 0xFF;
538 : }
539 :
540 : /**
541 : * bitmap_set_value8 - set an 8-bit value within a memory region
542 : * @map: address to the bitmap memory region
543 : * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
544 : * @start: bit offset of the 8-bit value; must be a multiple of 8
545 : */
546 : static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
547 : unsigned long start)
548 : {
549 : const size_t index = BIT_WORD(start);
550 : const unsigned long offset = start % BITS_PER_LONG;
551 :
552 : map[index] &= ~(0xFFUL << offset);
553 : map[index] |= value << offset;
554 : }
555 :
556 : #endif /* __ASSEMBLY__ */
557 :
558 : #endif /* __LINUX_BITMAP_H */
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