[go: up one dir, main page]
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_FIND_H_
3#define __LINUX_FIND_H_
4
5#ifndef __LINUX_BITMAP_H
6#error only <linux/bitmap.h> can be included directly
7#endif
8
9#include <linux/bitops.h>
10
11unsigned long _find_next_bit(const unsigned long *addr1, unsigned long nbits,
12 unsigned long start);
13unsigned long _find_next_and_bit(const unsigned long *addr1, const unsigned long *addr2,
14 unsigned long nbits, unsigned long start);
15unsigned long _find_next_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
16 unsigned long nbits, unsigned long start);
17unsigned long _find_next_or_bit(const unsigned long *addr1, const unsigned long *addr2,
18 unsigned long nbits, unsigned long start);
19unsigned long _find_next_zero_bit(const unsigned long *addr, unsigned long nbits,
20 unsigned long start);
21extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
22unsigned long __find_nth_bit(const unsigned long *addr, unsigned long size, unsigned long n);
23unsigned long __find_nth_and_bit(const unsigned long *addr1, const unsigned long *addr2,
24 unsigned long size, unsigned long n);
25unsigned long __find_nth_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
26 unsigned long size, unsigned long n);
27unsigned long __find_nth_and_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
28 const unsigned long *addr3, unsigned long size,
29 unsigned long n);
30extern unsigned long _find_first_and_bit(const unsigned long *addr1,
31 const unsigned long *addr2, unsigned long size);
32unsigned long _find_first_andnot_bit(const unsigned long *addr1, const unsigned long *addr2,
33 unsigned long size);
34unsigned long _find_first_and_and_bit(const unsigned long *addr1, const unsigned long *addr2,
35 const unsigned long *addr3, unsigned long size);
36extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size);
37extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size);
38
39#ifdef __BIG_ENDIAN
40unsigned long _find_first_zero_bit_le(const unsigned long *addr, unsigned long size);
41unsigned long _find_next_zero_bit_le(const unsigned long *addr, unsigned
42 long size, unsigned long offset);
43unsigned long _find_next_bit_le(const unsigned long *addr, unsigned
44 long size, unsigned long offset);
45#endif
46
47unsigned long find_random_bit(const unsigned long *addr, unsigned long size);
48
49#ifndef find_next_bit
50/**
51 * find_next_bit - find the next set bit in a memory region
52 * @addr: The address to base the search on
53 * @size: The bitmap size in bits
54 * @offset: The bitnumber to start searching at
55 *
56 * Returns the bit number for the next set bit
57 * If no bits are set, returns @size.
58 */
59static __always_inline
60unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
61 unsigned long offset)
62{
63 if (small_const_nbits(size)) {
64 unsigned long val;
65
66 if (unlikely(offset >= size))
67 return size;
68
69 val = *addr & GENMASK(size - 1, offset);
70 return val ? __ffs(val) : size;
71 }
72
73 return _find_next_bit(addr1: addr, nbits: size, start: offset);
74}
75#endif
76
77#ifndef find_next_and_bit
78/**
79 * find_next_and_bit - find the next set bit in both memory regions
80 * @addr1: The first address to base the search on
81 * @addr2: The second address to base the search on
82 * @size: The bitmap size in bits
83 * @offset: The bitnumber to start searching at
84 *
85 * Returns the bit number for the next set bit
86 * If no bits are set, returns @size.
87 */
88static __always_inline
89unsigned long find_next_and_bit(const unsigned long *addr1,
90 const unsigned long *addr2, unsigned long size,
91 unsigned long offset)
92{
93 if (small_const_nbits(size)) {
94 unsigned long val;
95
96 if (unlikely(offset >= size))
97 return size;
98
99 val = *addr1 & *addr2 & GENMASK(size - 1, offset);
100 return val ? __ffs(val) : size;
101 }
102
103 return _find_next_and_bit(addr1, addr2, nbits: size, start: offset);
104}
105#endif
106
107#ifndef find_next_andnot_bit
108/**
109 * find_next_andnot_bit - find the next set bit in *addr1 excluding all the bits
110 * in *addr2
111 * @addr1: The first address to base the search on
112 * @addr2: The second address to base the search on
113 * @size: The bitmap size in bits
114 * @offset: The bitnumber to start searching at
115 *
116 * Returns the bit number for the next set bit
117 * If no bits are set, returns @size.
118 */
119static __always_inline
120unsigned long find_next_andnot_bit(const unsigned long *addr1,
121 const unsigned long *addr2, unsigned long size,
122 unsigned long offset)
123{
124 if (small_const_nbits(size)) {
125 unsigned long val;
126
127 if (unlikely(offset >= size))
128 return size;
129
130 val = *addr1 & ~*addr2 & GENMASK(size - 1, offset);
131 return val ? __ffs(val) : size;
132 }
133
134 return _find_next_andnot_bit(addr1, addr2, nbits: size, start: offset);
135}
136#endif
137
138#ifndef find_next_or_bit
139/**
140 * find_next_or_bit - find the next set bit in either memory regions
141 * @addr1: The first address to base the search on
142 * @addr2: The second address to base the search on
143 * @size: The bitmap size in bits
144 * @offset: The bitnumber to start searching at
145 *
146 * Returns the bit number for the next set bit
147 * If no bits are set, returns @size.
148 */
149static __always_inline
150unsigned long find_next_or_bit(const unsigned long *addr1,
151 const unsigned long *addr2, unsigned long size,
152 unsigned long offset)
153{
154 if (small_const_nbits(size)) {
155 unsigned long val;
156
157 if (unlikely(offset >= size))
158 return size;
159
160 val = (*addr1 | *addr2) & GENMASK(size - 1, offset);
161 return val ? __ffs(val) : size;
162 }
163
164 return _find_next_or_bit(addr1, addr2, nbits: size, start: offset);
165}
166#endif
167
168#ifndef find_next_zero_bit
169/**
170 * find_next_zero_bit - find the next cleared bit in a memory region
171 * @addr: The address to base the search on
172 * @size: The bitmap size in bits
173 * @offset: The bitnumber to start searching at
174 *
175 * Returns the bit number of the next zero bit
176 * If no bits are zero, returns @size.
177 */
178static __always_inline
179unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
180 unsigned long offset)
181{
182 if (small_const_nbits(size)) {
183 unsigned long val;
184
185 if (unlikely(offset >= size))
186 return size;
187
188 val = *addr | ~GENMASK(size - 1, offset);
189 return val == ~0UL ? size : ffz(val);
190 }
191
192 return _find_next_zero_bit(addr, nbits: size, start: offset);
193}
194#endif
195
196#ifndef find_first_bit
197/**
198 * find_first_bit - find the first set bit in a memory region
199 * @addr: The address to start the search at
200 * @size: The maximum number of bits to search
201 *
202 * Returns the bit number of the first set bit.
203 * If no bits are set, returns @size.
204 */
205static __always_inline
206unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
207{
208 if (small_const_nbits(size)) {
209 unsigned long val = *addr & GENMASK(size - 1, 0);
210
211 return val ? __ffs(val) : size;
212 }
213
214 return _find_first_bit(addr, size);
215}
216#endif
217
218/**
219 * find_nth_bit - find N'th set bit in a memory region
220 * @addr: The address to start the search at
221 * @size: The maximum number of bits to search
222 * @n: The number of set bit, which position is needed, counting from 0
223 *
224 * The following is semantically equivalent:
225 * idx = find_nth_bit(addr, size, 0);
226 * idx = find_first_bit(addr, size);
227 *
228 * Returns the bit number of the N'th set bit.
229 * If no such, returns >= @size.
230 */
231static __always_inline
232unsigned long find_nth_bit(const unsigned long *addr, unsigned long size, unsigned long n)
233{
234 if (n >= size)
235 return size;
236
237 if (small_const_nbits(size)) {
238 unsigned long val = *addr & GENMASK(size - 1, 0);
239
240 return val ? fns(word: val, n) : size;
241 }
242
243 return __find_nth_bit(addr, size, n);
244}
245
246/**
247 * find_nth_and_bit - find N'th set bit in 2 memory regions
248 * @addr1: The 1st address to start the search at
249 * @addr2: The 2nd address to start the search at
250 * @size: The maximum number of bits to search
251 * @n: The number of set bit, which position is needed, counting from 0
252 *
253 * Returns the bit number of the N'th set bit.
254 * If no such, returns @size.
255 */
256static __always_inline
257unsigned long find_nth_and_bit(const unsigned long *addr1, const unsigned long *addr2,
258 unsigned long size, unsigned long n)
259{
260 if (n >= size)
261 return size;
262
263 if (small_const_nbits(size)) {
264 unsigned long val = *addr1 & *addr2 & GENMASK(size - 1, 0);
265
266 return val ? fns(word: val, n) : size;
267 }
268
269 return __find_nth_and_bit(addr1, addr2, size, n);
270}
271
272/**
273 * find_nth_and_andnot_bit - find N'th set bit in 2 memory regions,
274 * excluding those set in 3rd region
275 * @addr1: The 1st address to start the search at
276 * @addr2: The 2nd address to start the search at
277 * @addr3: The 3rd address to start the search at
278 * @size: The maximum number of bits to search
279 * @n: The number of set bit, which position is needed, counting from 0
280 *
281 * Returns the bit number of the N'th set bit.
282 * If no such, returns @size.
283 */
284static __always_inline
285unsigned long find_nth_and_andnot_bit(const unsigned long *addr1,
286 const unsigned long *addr2,
287 const unsigned long *addr3,
288 unsigned long size, unsigned long n)
289{
290 if (n >= size)
291 return size;
292
293 if (small_const_nbits(size)) {
294 unsigned long val = *addr1 & *addr2 & (~*addr3) & GENMASK(size - 1, 0);
295
296 return val ? fns(word: val, n) : size;
297 }
298
299 return __find_nth_and_andnot_bit(addr1, addr2, addr3, size, n);
300}
301
302#ifndef find_first_and_bit
303/**
304 * find_first_and_bit - find the first set bit in both memory regions
305 * @addr1: The first address to base the search on
306 * @addr2: The second address to base the search on
307 * @size: The bitmap size in bits
308 *
309 * Returns the bit number for the next set bit
310 * If no bits are set, returns @size.
311 */
312static __always_inline
313unsigned long find_first_and_bit(const unsigned long *addr1,
314 const unsigned long *addr2,
315 unsigned long size)
316{
317 if (small_const_nbits(size)) {
318 unsigned long val = *addr1 & *addr2 & GENMASK(size - 1, 0);
319
320 return val ? __ffs(val) : size;
321 }
322
323 return _find_first_and_bit(addr1, addr2, size);
324}
325#endif
326
327/**
328 * find_first_andnot_bit - find the first bit set in 1st memory region and unset in 2nd
329 * @addr1: The first address to base the search on
330 * @addr2: The second address to base the search on
331 * @size: The bitmap size in bits
332 *
333 * Returns the bit number for the first set bit
334 * If no bits are set, returns >= @size.
335 */
336static __always_inline
337unsigned long find_first_andnot_bit(const unsigned long *addr1,
338 const unsigned long *addr2,
339 unsigned long size)
340{
341 if (small_const_nbits(size)) {
342 unsigned long val = *addr1 & (~*addr2) & GENMASK(size - 1, 0);
343
344 return val ? __ffs(val) : size;
345 }
346
347 return _find_first_andnot_bit(addr1, addr2, size);
348}
349
350/**
351 * find_first_and_and_bit - find the first set bit in 3 memory regions
352 * @addr1: The first address to base the search on
353 * @addr2: The second address to base the search on
354 * @addr3: The third address to base the search on
355 * @size: The bitmap size in bits
356 *
357 * Returns the bit number for the first set bit
358 * If no bits are set, returns @size.
359 */
360static __always_inline
361unsigned long find_first_and_and_bit(const unsigned long *addr1,
362 const unsigned long *addr2,
363 const unsigned long *addr3,
364 unsigned long size)
365{
366 if (small_const_nbits(size)) {
367 unsigned long val = *addr1 & *addr2 & *addr3 & GENMASK(size - 1, 0);
368
369 return val ? __ffs(val) : size;
370 }
371
372 return _find_first_and_and_bit(addr1, addr2, addr3, size);
373}
374
375#ifndef find_first_zero_bit
376/**
377 * find_first_zero_bit - find the first cleared bit in a memory region
378 * @addr: The address to start the search at
379 * @size: The maximum number of bits to search
380 *
381 * Returns the bit number of the first cleared bit.
382 * If no bits are zero, returns @size.
383 */
384static __always_inline
385unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
386{
387 if (small_const_nbits(size)) {
388 unsigned long val = *addr | ~GENMASK(size - 1, 0);
389
390 return val == ~0UL ? size : ffz(val);
391 }
392
393 return _find_first_zero_bit(addr, size);
394}
395#endif
396
397#ifndef find_last_bit
398/**
399 * find_last_bit - find the last set bit in a memory region
400 * @addr: The address to start the search at
401 * @size: The number of bits to search
402 *
403 * Returns the bit number of the last set bit, or size.
404 */
405static __always_inline
406unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
407{
408 if (small_const_nbits(size)) {
409 unsigned long val = *addr & GENMASK(size - 1, 0);
410
411 return val ? __fls(word: val) : size;
412 }
413
414 return _find_last_bit(addr, size);
415}
416#endif
417
418/**
419 * find_next_and_bit_wrap - find the next set bit in both memory regions
420 * @addr1: The first address to base the search on
421 * @addr2: The second address to base the search on
422 * @size: The bitmap size in bits
423 * @offset: The bitnumber to start searching at
424 *
425 * Returns the bit number for the next set bit, or first set bit up to @offset
426 * If no bits are set, returns @size.
427 */
428static __always_inline
429unsigned long find_next_and_bit_wrap(const unsigned long *addr1,
430 const unsigned long *addr2,
431 unsigned long size, unsigned long offset)
432{
433 unsigned long bit = find_next_and_bit(addr1, addr2, size, offset);
434
435 if (bit < size || offset == 0)
436 return bit;
437
438 bit = find_first_and_bit(addr1, addr2, size: offset);
439 return bit < offset ? bit : size;
440}
441
442/**
443 * find_next_bit_wrap - find the next set bit in a memory region
444 * @addr: The address to base the search on
445 * @size: The bitmap size in bits
446 * @offset: The bitnumber to start searching at
447 *
448 * Returns the bit number for the next set bit, or first set bit up to @offset
449 * If no bits are set, returns @size.
450 */
451static __always_inline
452unsigned long find_next_bit_wrap(const unsigned long *addr,
453 unsigned long size, unsigned long offset)
454{
455 unsigned long bit = find_next_bit(addr, size, offset);
456
457 if (bit < size || offset == 0)
458 return bit;
459
460 bit = find_first_bit(addr, size: offset);
461 return bit < offset ? bit : size;
462}
463
464/*
465 * Helper for for_each_set_bit_wrap(). Make sure you're doing right thing
466 * before using it alone.
467 */
468static __always_inline
469unsigned long __for_each_wrap(const unsigned long *bitmap, unsigned long size,
470 unsigned long start, unsigned long n)
471{
472 unsigned long bit;
473
474 /* If not wrapped around */
475 if (n > start) {
476 /* and have a bit, just return it. */
477 bit = find_next_bit(addr: bitmap, size, offset: n);
478 if (bit < size)
479 return bit;
480
481 /* Otherwise, wrap around and ... */
482 n = 0;
483 }
484
485 /* Search the other part. */
486 bit = find_next_bit(addr: bitmap, size: start, offset: n);
487 return bit < start ? bit : size;
488}
489
490/**
491 * find_next_clump8 - find next 8-bit clump with set bits in a memory region
492 * @clump: location to store copy of found clump
493 * @addr: address to base the search on
494 * @size: bitmap size in number of bits
495 * @offset: bit offset at which to start searching
496 *
497 * Returns the bit offset for the next set clump; the found clump value is
498 * copied to the location pointed by @clump. If no bits are set, returns @size.
499 */
500extern unsigned long find_next_clump8(unsigned long *clump,
501 const unsigned long *addr,
502 unsigned long size, unsigned long offset);
503
504#define find_first_clump8(clump, bits, size) \
505 find_next_clump8((clump), (bits), (size), 0)
506
507#if defined(__LITTLE_ENDIAN)
508
509static __always_inline
510unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, unsigned long offset)
511{
512 return find_next_zero_bit(addr, size, offset);
513}
514
515static __always_inline
516unsigned long find_next_bit_le(const void *addr, unsigned long size, unsigned long offset)
517{
518 return find_next_bit(addr, size, offset);
519}
520
521static __always_inline
522unsigned long find_first_zero_bit_le(const void *addr, unsigned long size)
523{
524 return find_first_zero_bit(addr, size);
525}
526
527#elif defined(__BIG_ENDIAN)
528
529#ifndef find_next_zero_bit_le
530static __always_inline
531unsigned long find_next_zero_bit_le(const void *addr, unsigned
532 long size, unsigned long offset)
533{
534 if (small_const_nbits(size)) {
535 unsigned long val = *(const unsigned long *)addr;
536
537 if (unlikely(offset >= size))
538 return size;
539
540 val = swab(val) | ~GENMASK(size - 1, offset);
541 return val == ~0UL ? size : ffz(val);
542 }
543
544 return _find_next_zero_bit_le(addr, size, offset);
545}
546#endif
547
548#ifndef find_first_zero_bit_le
549static __always_inline
550unsigned long find_first_zero_bit_le(const void *addr, unsigned long size)
551{
552 if (small_const_nbits(size)) {
553 unsigned long val = swab(*(const unsigned long *)addr) | ~GENMASK(size - 1, 0);
554
555 return val == ~0UL ? size : ffz(val);
556 }
557
558 return _find_first_zero_bit_le(addr, size);
559}
560#endif
561
562#ifndef find_next_bit_le
563static __always_inline
564unsigned long find_next_bit_le(const void *addr, unsigned
565 long size, unsigned long offset)
566{
567 if (small_const_nbits(size)) {
568 unsigned long val = *(const unsigned long *)addr;
569
570 if (unlikely(offset >= size))
571 return size;
572
573 val = swab(val) & GENMASK(size - 1, offset);
574 return val ? __ffs(val) : size;
575 }
576
577 return _find_next_bit_le(addr, size, offset);
578}
579#endif
580
581#else
582#error "Please fix <asm/byteorder.h>"
583#endif
584
585#define for_each_set_bit(bit, addr, size) \
586 for ((bit) = 0; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++)
587
588#define for_each_and_bit(bit, addr1, addr2, size) \
589 for ((bit) = 0; \
590 (bit) = find_next_and_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\
591 (bit)++)
592
593#define for_each_andnot_bit(bit, addr1, addr2, size) \
594 for ((bit) = 0; \
595 (bit) = find_next_andnot_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\
596 (bit)++)
597
598#define for_each_or_bit(bit, addr1, addr2, size) \
599 for ((bit) = 0; \
600 (bit) = find_next_or_bit((addr1), (addr2), (size), (bit)), (bit) < (size);\
601 (bit)++)
602
603/* same as for_each_set_bit() but use bit as value to start with */
604#define for_each_set_bit_from(bit, addr, size) \
605 for (; (bit) = find_next_bit((addr), (size), (bit)), (bit) < (size); (bit)++)
606
607#define for_each_clear_bit(bit, addr, size) \
608 for ((bit) = 0; \
609 (bit) = find_next_zero_bit((addr), (size), (bit)), (bit) < (size); \
610 (bit)++)
611
612/* same as for_each_clear_bit() but use bit as value to start with */
613#define for_each_clear_bit_from(bit, addr, size) \
614 for (; (bit) = find_next_zero_bit((addr), (size), (bit)), (bit) < (size); (bit)++)
615
616/**
617 * for_each_set_bitrange - iterate over all set bit ranges [b; e)
618 * @b: bit offset of start of current bitrange (first set bit)
619 * @e: bit offset of end of current bitrange (first unset bit)
620 * @addr: bitmap address to base the search on
621 * @size: bitmap size in number of bits
622 */
623#define for_each_set_bitrange(b, e, addr, size) \
624 for ((b) = 0; \
625 (b) = find_next_bit((addr), (size), b), \
626 (e) = find_next_zero_bit((addr), (size), (b) + 1), \
627 (b) < (size); \
628 (b) = (e) + 1)
629
630/**
631 * for_each_set_bitrange_from - iterate over all set bit ranges [b; e)
632 * @b: bit offset of start of current bitrange (first set bit); must be initialized
633 * @e: bit offset of end of current bitrange (first unset bit)
634 * @addr: bitmap address to base the search on
635 * @size: bitmap size in number of bits
636 */
637#define for_each_set_bitrange_from(b, e, addr, size) \
638 for (; \
639 (b) = find_next_bit((addr), (size), (b)), \
640 (e) = find_next_zero_bit((addr), (size), (b) + 1), \
641 (b) < (size); \
642 (b) = (e) + 1)
643
644/**
645 * for_each_clear_bitrange - iterate over all unset bit ranges [b; e)
646 * @b: bit offset of start of current bitrange (first unset bit)
647 * @e: bit offset of end of current bitrange (first set bit)
648 * @addr: bitmap address to base the search on
649 * @size: bitmap size in number of bits
650 */
651#define for_each_clear_bitrange(b, e, addr, size) \
652 for ((b) = 0; \
653 (b) = find_next_zero_bit((addr), (size), (b)), \
654 (e) = find_next_bit((addr), (size), (b) + 1), \
655 (b) < (size); \
656 (b) = (e) + 1)
657
658/**
659 * for_each_clear_bitrange_from - iterate over all unset bit ranges [b; e)
660 * @b: bit offset of start of current bitrange (first set bit); must be initialized
661 * @e: bit offset of end of current bitrange (first unset bit)
662 * @addr: bitmap address to base the search on
663 * @size: bitmap size in number of bits
664 */
665#define for_each_clear_bitrange_from(b, e, addr, size) \
666 for (; \
667 (b) = find_next_zero_bit((addr), (size), (b)), \
668 (e) = find_next_bit((addr), (size), (b) + 1), \
669 (b) < (size); \
670 (b) = (e) + 1)
671
672/**
673 * for_each_set_bit_wrap - iterate over all set bits starting from @start, and
674 * wrapping around the end of bitmap.
675 * @bit: offset for current iteration
676 * @addr: bitmap address to base the search on
677 * @size: bitmap size in number of bits
678 * @start: Starting bit for bitmap traversing, wrapping around the bitmap end
679 */
680#define for_each_set_bit_wrap(bit, addr, size, start) \
681 for ((bit) = find_next_bit_wrap((addr), (size), (start)); \
682 (bit) < (size); \
683 (bit) = __for_each_wrap((addr), (size), (start), (bit) + 1))
684
685/**
686 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
687 * @start: bit offset to start search and to store the current iteration offset
688 * @clump: location to store copy of current 8-bit clump
689 * @bits: bitmap address to base the search on
690 * @size: bitmap size in number of bits
691 */
692#define for_each_set_clump8(start, clump, bits, size) \
693 for ((start) = find_first_clump8(&(clump), (bits), (size)); \
694 (start) < (size); \
695 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
696
697#endif /*__LINUX_FIND_H_ */
698

source code of linux/include/linux/find.h