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/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 : */
121 : extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
122 : extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
123 : extern void bitmap_free(const unsigned long *bitmap);
124 :
125 : /*
126 : * lib/bitmap.c provides these functions:
127 : */
128 :
129 : extern int __bitmap_equal(const unsigned long *bitmap1,
130 : const unsigned long *bitmap2, unsigned int nbits);
131 : extern bool __pure __bitmap_or_equal(const unsigned long *src1,
132 : const unsigned long *src2,
133 : const unsigned long *src3,
134 : unsigned int nbits);
135 : extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
136 : unsigned int nbits);
137 : extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
138 : unsigned int shift, unsigned int nbits);
139 : extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
140 : unsigned int shift, unsigned int nbits);
141 : extern void bitmap_cut(unsigned long *dst, const unsigned long *src,
142 : unsigned int first, unsigned int cut,
143 : unsigned int nbits);
144 : extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
145 : const unsigned long *bitmap2, unsigned int nbits);
146 : extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
147 : const unsigned long *bitmap2, unsigned int nbits);
148 : extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
149 : const unsigned long *bitmap2, unsigned int nbits);
150 : extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
151 : const unsigned long *bitmap2, unsigned int nbits);
152 : extern void __bitmap_replace(unsigned long *dst,
153 : const unsigned long *old, const unsigned long *new,
154 : const unsigned long *mask, unsigned int nbits);
155 : extern int __bitmap_intersects(const unsigned long *bitmap1,
156 : const unsigned long *bitmap2, unsigned int nbits);
157 : extern int __bitmap_subset(const unsigned long *bitmap1,
158 : const unsigned long *bitmap2, unsigned int nbits);
159 : extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
160 : extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
161 : extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
162 :
163 : extern 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 : */
182 : static inline unsigned long
183 3 : bitmap_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 3 : return bitmap_find_next_zero_area_off(map, size, start, nr,
190 : align_mask, 0);
191 : }
192 :
193 : extern int bitmap_parse(const char *buf, unsigned int buflen,
194 : unsigned long *dst, int nbits);
195 : extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
196 : unsigned long *dst, int nbits);
197 : extern int bitmap_parselist(const char *buf, unsigned long *maskp,
198 : int nmaskbits);
199 : extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
200 : unsigned long *dst, int nbits);
201 : extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
202 : const unsigned long *old, const unsigned long *new, unsigned int nbits);
203 : extern int bitmap_bitremap(int oldbit,
204 : const unsigned long *old, const unsigned long *new, int bits);
205 : extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
206 : const unsigned long *relmap, unsigned int bits);
207 : extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
208 : unsigned int sz, unsigned int nbits);
209 : extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
210 : extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
211 : extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
212 :
213 : #ifdef __BIG_ENDIAN
214 : extern 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
218 : extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
219 : extern 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 :
233 3022 : static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
234 : {
235 3022 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
236 2738 : memset(dst, 0, len);
237 4 : }
238 :
239 1129 : static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
240 : {
241 1129 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
242 1129 : memset(dst, 0xff, len);
243 1 : }
244 :
245 3439 : static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
246 : unsigned int nbits)
247 : {
248 3439 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
249 3418 : memcpy(dst, src, len);
250 0 : }
251 :
252 : /*
253 : * Copy bitmap and clear tail bits in last word.
254 : */
255 : static 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
268 : extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
269 : unsigned int nbits);
270 : extern 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 :
281 9360 : static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
282 : const unsigned long *src2, unsigned int nbits)
283 : {
284 9360 : if (small_const_nbits(nbits))
285 9360 : return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
286 0 : return __bitmap_and(dst, src1, src2, nbits);
287 : }
288 :
289 31 : static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
290 : const unsigned long *src2, unsigned int nbits)
291 : {
292 31 : if (small_const_nbits(nbits))
293 25 : *dst = *src1 | *src2;
294 : else
295 6 : __bitmap_or(dst, src1, src2, nbits);
296 6 : }
297 :
298 : static 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 :
307 1 : static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
308 : const unsigned long *src2, unsigned int nbits)
309 : {
310 1 : if (small_const_nbits(nbits))
311 0 : return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
312 1 : return __bitmap_andnot(dst, src1, src2, nbits);
313 : }
314 :
315 0 : static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
316 : unsigned int nbits)
317 : {
318 0 : if (small_const_nbits(nbits))
319 : *dst = ~(*src);
320 : else
321 0 : __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 :
331 129 : static inline int bitmap_equal(const unsigned long *src1,
332 : const unsigned long *src2, unsigned int nbits)
333 : {
334 129 : if (small_const_nbits(nbits))
335 129 : return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
336 0 : if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
337 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
338 0 : return !memcmp(src1, src2, nbits / 8);
339 0 : 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 : */
351 62 : static 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 62 : if (!small_const_nbits(nbits))
357 0 : return __bitmap_or_equal(src1, src2, src3, nbits);
358 :
359 62 : return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
360 : }
361 :
362 7947 : static inline int bitmap_intersects(const unsigned long *src1,
363 : const unsigned long *src2, unsigned int nbits)
364 : {
365 7947 : if (small_const_nbits(nbits))
366 7947 : return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
367 : else
368 0 : return __bitmap_intersects(src1, src2, nbits);
369 : }
370 :
371 512 : static inline int bitmap_subset(const unsigned long *src1,
372 : const unsigned long *src2, unsigned int nbits)
373 : {
374 512 : if (small_const_nbits(nbits))
375 512 : return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
376 : else
377 0 : return __bitmap_subset(src1, src2, nbits);
378 : }
379 :
380 21252 : static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
381 : {
382 21252 : if (small_const_nbits(nbits))
383 19969 : return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
384 :
385 1283 : return find_first_bit(src, nbits) == nbits;
386 : }
387 :
388 1477 : static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
389 : {
390 1477 : if (small_const_nbits(nbits))
391 0 : return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
392 :
393 1477 : return find_first_zero_bit(src, nbits) == nbits;
394 : }
395 :
396 387 : static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
397 : {
398 340 : if (small_const_nbits(nbits))
399 394 : return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
400 1 : return __bitmap_weight(src, nbits);
401 : }
402 :
403 2178 : static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
404 : unsigned int nbits)
405 : {
406 2178 : if (__builtin_constant_p(nbits) && nbits == 1)
407 4 : __set_bit(start, map);
408 2173 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
409 1 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
410 1 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
411 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
412 0 : memset((char *)map + start / 8, 0xff, nbits / 8);
413 : else
414 2174 : __bitmap_set(map, start, nbits);
415 : }
416 :
417 3731 : static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
418 : unsigned int nbits)
419 : {
420 3731 : if (__builtin_constant_p(nbits) && nbits == 1)
421 0 : __clear_bit(start, map);
422 3731 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
423 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
424 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
425 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
426 1 : memset((char *)map + start / 8, 0, nbits / 8);
427 : else
428 3730 : __bitmap_clear(map, start, nbits);
429 : }
430 :
431 : static 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 :
440 : static 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 :
449 : static 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 :
461 4204 : static inline void bitmap_next_clear_region(unsigned long *bitmap,
462 : unsigned int *rs, unsigned int *re,
463 : unsigned int end)
464 : {
465 4204 : *rs = find_next_zero_bit(bitmap, end, *rs);
466 4204 : *re = find_next_bit(bitmap, end, *rs + 1);
467 4204 : }
468 :
469 0 : static inline void bitmap_next_set_region(unsigned long *bitmap,
470 : unsigned int *rs, unsigned int *re,
471 : unsigned int end)
472 : {
473 0 : *rs = find_next_bit(bitmap, end, *rs);
474 0 : *re = find_next_zero_bit(bitmap, end, *rs + 1);
475 0 : }
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 : */
539 0 : static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
540 : {
541 0 : dst[0] = mask & ULONG_MAX;
542 :
543 0 : 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 : */
555 0 : static inline unsigned long bitmap_get_value8(const unsigned long *map,
556 : unsigned long start)
557 : {
558 0 : const size_t index = BIT_WORD(start);
559 0 : const unsigned long offset = start % BITS_PER_LONG;
560 :
561 0 : 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 : */
570 : static 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 */
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