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_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
55 : * bitmap_set(dst, pos, nbits) Set specified bit area
56 : * bitmap_clear(dst, pos, nbits) Clear specified bit area
57 : * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
58 : * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
59 : * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
60 : * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
61 : * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
62 : * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
63 : * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
64 : * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
65 : * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
66 : * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
67 : * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
68 : * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
69 : * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
70 : * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
71 : * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
72 : * bitmap_release_region(bitmap, pos, order) Free specified bit region
73 : * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
74 : * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
75 : * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst
76 : * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
77 : * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
78 : * bitmap_get_value8(map, start) Get 8bit value from map at start
79 : * bitmap_set_value8(map, value, start) Set 8bit value to map at start
80 : *
81 : * Note, bitmap_zero() and bitmap_fill() operate over the region of
82 : * unsigned longs, that is, bits behind bitmap till the unsigned long
83 : * boundary will be zeroed or filled as well. Consider to use
84 : * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
85 : * respectively.
86 : */
87 :
88 : /**
89 : * DOC: bitmap bitops
90 : *
91 : * Also the following operations in asm/bitops.h apply to bitmaps.::
92 : *
93 : * set_bit(bit, addr) *addr |= bit
94 : * clear_bit(bit, addr) *addr &= ~bit
95 : * change_bit(bit, addr) *addr ^= bit
96 : * test_bit(bit, addr) Is bit set in *addr?
97 : * test_and_set_bit(bit, addr) Set bit and return old value
98 : * test_and_clear_bit(bit, addr) Clear bit and return old value
99 : * test_and_change_bit(bit, addr) Change bit and return old value
100 : * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
101 : * find_first_bit(addr, nbits) Position first set bit in *addr
102 : * find_next_zero_bit(addr, nbits, bit)
103 : * Position next zero bit in *addr >= bit
104 : * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
105 : * find_next_and_bit(addr1, addr2, nbits, bit)
106 : * Same as find_next_bit, but in
107 : * (*addr1 & *addr2)
108 : *
109 : */
110 :
111 : /**
112 : * DOC: declare bitmap
113 : * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
114 : * to declare an array named 'name' of just enough unsigned longs to
115 : * contain all bit positions from 0 to 'bits' - 1.
116 : */
117 :
118 : /*
119 : * Allocation and deallocation of bitmap.
120 : * Provided in lib/bitmap.c to avoid circular dependency.
121 : */
122 : unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
123 : unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
124 : unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
125 : unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
126 : void bitmap_free(const unsigned long *bitmap);
127 :
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);
133 :
134 : /*
135 : * lib/bitmap.c provides these functions:
136 : */
137 :
138 : bool __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,
143 : unsigned int nbits);
144 : void __bitmap_complement(unsigned long *dst, const unsigned long *src,
145 : unsigned int nbits);
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 : bool __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 : bool __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 : bool __bitmap_intersects(const unsigned long *bitmap1,
164 : const unsigned long *bitmap2, unsigned int nbits);
165 : bool __bitmap_subset(const unsigned long *bitmap1,
166 : const unsigned long *bitmap2, unsigned int nbits);
167 : unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
168 : unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
169 : const unsigned long *bitmap2, unsigned int nbits);
170 : void __bitmap_set(unsigned long *map, unsigned int start, int len);
171 : void __bitmap_clear(unsigned long *map, unsigned int start, int len);
172 :
173 : unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
174 : unsigned long size,
175 : unsigned long start,
176 : unsigned int nr,
177 : unsigned long align_mask,
178 : unsigned long align_offset);
179 :
180 : /**
181 : * bitmap_find_next_zero_area - find a contiguous aligned zero area
182 : * @map: The address to base the search on
183 : * @size: The bitmap size in bits
184 : * @start: The bitnumber to start searching at
185 : * @nr: The number of zeroed bits we're looking for
186 : * @align_mask: Alignment mask for zero area
187 : *
188 : * The @align_mask should be one less than a power of 2; the effect is that
189 : * the bit offset of all zero areas this function finds is multiples of that
190 : * power of 2. A @align_mask of 0 means no alignment is required.
191 : */
192 : static inline unsigned long
193 : bitmap_find_next_zero_area(unsigned long *map,
194 : unsigned long size,
195 : unsigned long start,
196 : unsigned int nr,
197 : unsigned long align_mask)
198 : {
199 : return bitmap_find_next_zero_area_off(map, size, start, nr,
200 : align_mask, 0);
201 : }
202 :
203 : int bitmap_parse(const char *buf, unsigned int buflen,
204 : unsigned long *dst, int nbits);
205 : int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
206 : unsigned long *dst, int nbits);
207 : int bitmap_parselist(const char *buf, unsigned long *maskp,
208 : int nmaskbits);
209 : int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
210 : unsigned long *dst, int nbits);
211 : void bitmap_remap(unsigned long *dst, const unsigned long *src,
212 : const unsigned long *old, const unsigned long *new, unsigned int nbits);
213 : int bitmap_bitremap(int oldbit,
214 : const unsigned long *old, const unsigned long *new, int bits);
215 : void bitmap_onto(unsigned long *dst, const unsigned long *orig,
216 : const unsigned long *relmap, unsigned int bits);
217 : void bitmap_fold(unsigned long *dst, const unsigned long *orig,
218 : unsigned int sz, unsigned int nbits);
219 : int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
220 : void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
221 : int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
222 :
223 : #ifdef __BIG_ENDIAN
224 : void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
225 : #else
226 : #define bitmap_copy_le bitmap_copy
227 : #endif
228 : int bitmap_print_to_pagebuf(bool list, char *buf,
229 : const unsigned long *maskp, int nmaskbits);
230 :
231 : extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
232 : int nmaskbits, loff_t off, size_t count);
233 :
234 : extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
235 : int nmaskbits, loff_t off, size_t count);
236 :
237 : #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
238 : #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
239 :
240 1 : static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
241 : {
242 1 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
243 :
244 1 : if (small_const_nbits(nbits))
245 1 : *dst = 0;
246 : else
247 0 : memset(dst, 0, len);
248 1 : }
249 :
250 377 : static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
251 : {
252 377 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
253 :
254 377 : if (small_const_nbits(nbits))
255 376 : *dst = ~0UL;
256 : else
257 2 : memset(dst, 0xff, len);
258 377 : }
259 :
260 35 : static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
261 : unsigned int nbits)
262 : {
263 35 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
264 :
265 35 : if (small_const_nbits(nbits))
266 35 : *dst = *src;
267 : else
268 0 : memcpy(dst, src, len);
269 35 : }
270 :
271 : /*
272 : * Copy bitmap and clear tail bits in last word.
273 : */
274 : static inline void bitmap_copy_clear_tail(unsigned long *dst,
275 : const unsigned long *src, unsigned int nbits)
276 : {
277 : bitmap_copy(dst, src, nbits);
278 : if (nbits % BITS_PER_LONG)
279 : dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
280 : }
281 :
282 : /*
283 : * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
284 : * machines the order of hi and lo parts of numbers match the bitmap structure.
285 : * In both cases conversion is not needed when copying data from/to arrays of
286 : * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead
287 : * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit
288 : * architectures are not using bitmap_copy_clear_tail().
289 : */
290 : #if BITS_PER_LONG == 64
291 : void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
292 : unsigned int nbits);
293 : void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
294 : unsigned int nbits);
295 : #else
296 : #define bitmap_from_arr32(bitmap, buf, nbits) \
297 : bitmap_copy_clear_tail((unsigned long *) (bitmap), \
298 : (const unsigned long *) (buf), (nbits))
299 : #define bitmap_to_arr32(buf, bitmap, nbits) \
300 : bitmap_copy_clear_tail((unsigned long *) (buf), \
301 : (const unsigned long *) (bitmap), (nbits))
302 : #endif
303 :
304 : /*
305 : * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
306 : * the conversion is not needed when copying data from/to arrays of u64.
307 : */
308 : #if BITS_PER_LONG == 32
309 : void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
310 : void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
311 : #else
312 : #define bitmap_from_arr64(bitmap, buf, nbits) \
313 : bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
314 : #define bitmap_to_arr64(buf, bitmap, nbits) \
315 : bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
316 : #endif
317 :
318 : static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1,
319 : const unsigned long *src2, unsigned int nbits)
320 : {
321 : if (small_const_nbits(nbits))
322 7 : return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
323 : return __bitmap_and(dst, src1, src2, nbits);
324 : }
325 :
326 0 : static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
327 : const unsigned long *src2, unsigned int nbits)
328 : {
329 0 : if (small_const_nbits(nbits))
330 0 : *dst = *src1 | *src2;
331 : else
332 0 : __bitmap_or(dst, src1, src2, nbits);
333 0 : }
334 :
335 : static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
336 : const unsigned long *src2, unsigned int nbits)
337 : {
338 : if (small_const_nbits(nbits))
339 : *dst = *src1 ^ *src2;
340 : else
341 : __bitmap_xor(dst, src1, src2, nbits);
342 : }
343 :
344 : static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
345 : const unsigned long *src2, unsigned int nbits)
346 : {
347 : if (small_const_nbits(nbits))
348 0 : return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
349 : return __bitmap_andnot(dst, src1, src2, nbits);
350 : }
351 :
352 : static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
353 : unsigned int nbits)
354 : {
355 : if (small_const_nbits(nbits))
356 : *dst = ~(*src);
357 : else
358 0 : __bitmap_complement(dst, src, nbits);
359 : }
360 :
361 : #ifdef __LITTLE_ENDIAN
362 : #define BITMAP_MEM_ALIGNMENT 8
363 : #else
364 : #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
365 : #endif
366 : #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
367 :
368 4 : static inline bool bitmap_equal(const unsigned long *src1,
369 : const unsigned long *src2, unsigned int nbits)
370 : {
371 4 : if (small_const_nbits(nbits))
372 4 : return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
373 0 : if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
374 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
375 0 : return !memcmp(src1, src2, nbits / 8);
376 0 : return __bitmap_equal(src1, src2, nbits);
377 : }
378 :
379 : /**
380 : * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
381 : * @src1: Pointer to bitmap 1
382 : * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
383 : * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
384 : * @nbits: number of bits in each of these bitmaps
385 : *
386 : * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
387 : */
388 : static inline bool bitmap_or_equal(const unsigned long *src1,
389 : const unsigned long *src2,
390 : const unsigned long *src3,
391 : unsigned int nbits)
392 : {
393 : if (!small_const_nbits(nbits))
394 : return __bitmap_or_equal(src1, src2, src3, nbits);
395 :
396 : return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
397 : }
398 :
399 : static inline bool bitmap_intersects(const unsigned long *src1,
400 : const unsigned long *src2,
401 : unsigned int nbits)
402 : {
403 : if (small_const_nbits(nbits))
404 0 : return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
405 : else
406 : return __bitmap_intersects(src1, src2, nbits);
407 : }
408 :
409 : static inline bool bitmap_subset(const unsigned long *src1,
410 : const unsigned long *src2, unsigned int nbits)
411 : {
412 : if (small_const_nbits(nbits))
413 0 : return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
414 : else
415 0 : return __bitmap_subset(src1, src2, nbits);
416 : }
417 :
418 53 : static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
419 : {
420 53 : if (small_const_nbits(nbits))
421 58 : return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
422 :
423 0 : return find_first_bit(src, nbits) == nbits;
424 : }
425 :
426 : static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
427 : {
428 : if (small_const_nbits(nbits))
429 : return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
430 :
431 120 : return find_first_zero_bit(src, nbits) == nbits;
432 : }
433 :
434 : static __always_inline
435 : unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
436 : {
437 1 : if (small_const_nbits(nbits))
438 8 : return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
439 0 : return __bitmap_weight(src, nbits);
440 : }
441 :
442 : static __always_inline
443 : unsigned long bitmap_weight_and(const unsigned long *src1,
444 : const unsigned long *src2, unsigned int nbits)
445 : {
446 : if (small_const_nbits(nbits))
447 : return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits));
448 : return __bitmap_weight_and(src1, src2, nbits);
449 : }
450 :
451 : static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
452 : unsigned int nbits)
453 : {
454 242 : if (__builtin_constant_p(nbits) && nbits == 1)
455 0 : __set_bit(start, map);
456 242 : else if (small_const_nbits(start + nbits))
457 0 : *map |= GENMASK(start + nbits - 1, start);
458 242 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
459 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
460 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
461 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
462 0 : memset((char *)map + start / 8, 0xff, nbits / 8);
463 : else
464 242 : __bitmap_set(map, start, nbits);
465 : }
466 :
467 : static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
468 : unsigned int nbits)
469 : {
470 257 : if (__builtin_constant_p(nbits) && nbits == 1)
471 0 : __clear_bit(start, map);
472 257 : else if (small_const_nbits(start + nbits))
473 0 : *map &= ~GENMASK(start + nbits - 1, start);
474 257 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
475 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
476 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
477 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
478 0 : memset((char *)map + start / 8, 0, nbits / 8);
479 : else
480 257 : __bitmap_clear(map, start, nbits);
481 : }
482 :
483 : static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
484 : unsigned int shift, unsigned int nbits)
485 : {
486 : if (small_const_nbits(nbits))
487 : *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
488 : else
489 : __bitmap_shift_right(dst, src, shift, nbits);
490 : }
491 :
492 : static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
493 : unsigned int shift, unsigned int nbits)
494 : {
495 : if (small_const_nbits(nbits))
496 : *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
497 : else
498 : __bitmap_shift_left(dst, src, shift, nbits);
499 : }
500 :
501 : static inline void bitmap_replace(unsigned long *dst,
502 : const unsigned long *old,
503 : const unsigned long *new,
504 : const unsigned long *mask,
505 : unsigned int nbits)
506 : {
507 : if (small_const_nbits(nbits))
508 : *dst = (*old & ~(*mask)) | (*new & *mask);
509 : else
510 : __bitmap_replace(dst, old, new, mask, nbits);
511 : }
512 :
513 : static inline void bitmap_next_set_region(unsigned long *bitmap,
514 : unsigned int *rs, unsigned int *re,
515 : unsigned int end)
516 : {
517 : *rs = find_next_bit(bitmap, end, *rs);
518 : *re = find_next_zero_bit(bitmap, end, *rs + 1);
519 : }
520 :
521 : /**
522 : * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
523 : * @n: u64 value
524 : *
525 : * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
526 : * integers in 32-bit environment, and 64-bit integers in 64-bit one.
527 : *
528 : * There are four combinations of endianness and length of the word in linux
529 : * ABIs: LE64, BE64, LE32 and BE32.
530 : *
531 : * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
532 : * bitmaps and therefore don't require any special handling.
533 : *
534 : * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
535 : * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
536 : * other hand is represented as an array of 32-bit words and the position of
537 : * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
538 : * word. For example, bit #42 is located at 10th position of 2nd word.
539 : * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
540 : * values in memory as it usually does. But for BE we need to swap hi and lo
541 : * words manually.
542 : *
543 : * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
544 : * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
545 : * hi and lo words, as is expected by bitmap.
546 : */
547 : #if __BITS_PER_LONG == 64
548 : #define BITMAP_FROM_U64(n) (n)
549 : #else
550 : #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
551 : ((unsigned long) ((u64)(n) >> 32))
552 : #endif
553 :
554 : /**
555 : * bitmap_from_u64 - Check and swap words within u64.
556 : * @mask: source bitmap
557 : * @dst: destination bitmap
558 : *
559 : * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
560 : * to read u64 mask, we will get the wrong word.
561 : * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
562 : * but we expect the lower 32-bits of u64.
563 : */
564 : static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
565 : {
566 : bitmap_from_arr64(dst, &mask, 64);
567 : }
568 :
569 : /**
570 : * bitmap_get_value8 - get an 8-bit value within a memory region
571 : * @map: address to the bitmap memory region
572 : * @start: bit offset of the 8-bit value; must be a multiple of 8
573 : *
574 : * Returns the 8-bit value located at the @start bit offset within the @src
575 : * memory region.
576 : */
577 : static inline unsigned long bitmap_get_value8(const unsigned long *map,
578 : unsigned long start)
579 : {
580 0 : const size_t index = BIT_WORD(start);
581 0 : const unsigned long offset = start % BITS_PER_LONG;
582 :
583 0 : return (map[index] >> offset) & 0xFF;
584 : }
585 :
586 : /**
587 : * bitmap_set_value8 - set an 8-bit value within a memory region
588 : * @map: address to the bitmap memory region
589 : * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
590 : * @start: bit offset of the 8-bit value; must be a multiple of 8
591 : */
592 : static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
593 : unsigned long start)
594 : {
595 : const size_t index = BIT_WORD(start);
596 : const unsigned long offset = start % BITS_PER_LONG;
597 :
598 : map[index] &= ~(0xFFUL << offset);
599 : map[index] |= value << offset;
600 : }
601 :
602 : #endif /* __ASSEMBLY__ */
603 :
604 : #endif /* __LINUX_BITMAP_H */
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