Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_BITMAP_H
3#define __LINUX_BITMAP_H
4
5#ifndef __ASSEMBLY__
6
7#include <linux/align.h>
8#include <linux/bitops.h>
9#include <linux/cleanup.h>
10#include <linux/errno.h>
11#include <linux/find.h>
12#include <linux/limits.h>
13#include <linux/string.h>
14#include <linux/types.h>
15#include <linux/bitmap-str.h>
16
17struct device;
18
19/*
20 * bitmaps provide bit arrays that consume one or more unsigned
21 * longs. The bitmap interface and available operations are listed
22 * here, in bitmap.h
23 *
24 * Function implementations generic to all architectures are in
25 * lib/bitmap.c. Functions implementations that are architecture
26 * specific are in various arch/<arch>/include/asm/bitops.h headers
27 * and other arch/<arch> specific files.
28 *
29 * See lib/bitmap.c for more details.
30 */
31
32/**
33 * DOC: bitmap overview
34 *
35 * The available bitmap operations and their rough meaning in the
36 * case that the bitmap is a single unsigned long are thus:
37 *
38 * The generated code is more efficient when nbits is known at
39 * compile-time and at most BITS_PER_LONG.
40 *
41 * ::
42 *
43 * bitmap_zero(dst, nbits) *dst = 0UL
44 * bitmap_fill(dst, nbits) *dst = ~0UL
45 * bitmap_copy(dst, src, nbits) *dst = *src
46 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
47 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
48 * bitmap_weighted_or(dst, src1, src2, nbits) *dst = *src1 | *src2. Returns Hamming Weight of dst
49 * bitmap_weighted_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2. Returns Hamming Weight of dst
50 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
51 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
52 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
53 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
54 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
55 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
56 * bitmap_empty(src, nbits) Are all bits zero in *src?
57 * bitmap_full(src, nbits) Are all bits set in *src?
58 * bitmap_weight(src, nbits) Hamming Weight: number set bits
59 * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
60 * bitmap_weight_andnot(src1, src2, nbits) Hamming Weight of andnot'ed bitmap
61 * bitmap_weight_from(src, start, end) Hamming Weight starting from @start
62 * bitmap_set(dst, pos, nbits) Set specified bit area
63 * bitmap_clear(dst, pos, nbits) Clear specified bit area
64 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
65 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
66 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
67 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
68 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
69 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
70 * bitmap_scatter(dst, src, mask, nbits) *dst = map(dense, sparse)(src)
71 * bitmap_gather(dst, src, mask, nbits) *dst = map(sparse, dense)(src)
72 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
73 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
74 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
75 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
76 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
77 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
78 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
79 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
80 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
81 * bitmap_release_region(bitmap, pos, order) Free specified bit region
82 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
83 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
84 * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst
85 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
86 * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
87 * bitmap_get_value8(map, start) Get 8bit value from map at start
88 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
89 * bitmap_read(map, start, nbits) Read an nbits-sized value from
90 * map at start
91 * bitmap_write(map, value, start, nbits) Write an nbits-sized value to
92 * map at start
93 *
94 * Note, bitmap_zero() and bitmap_fill() operate over the region of
95 * unsigned longs, that is, bits behind bitmap till the unsigned long
96 * boundary will be zeroed or filled as well. Consider to use
97 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
98 * respectively.
99 */
100
101/**
102 * DOC: bitmap bitops
103 *
104 * Also the following operations in asm/bitops.h apply to bitmaps.::
105 *
106 * set_bit(bit, addr) *addr |= bit
107 * clear_bit(bit, addr) *addr &= ~bit
108 * change_bit(bit, addr) *addr ^= bit
109 * test_bit(bit, addr) Is bit set in *addr?
110 * test_and_set_bit(bit, addr) Set bit and return old value
111 * test_and_clear_bit(bit, addr) Clear bit and return old value
112 * test_and_change_bit(bit, addr) Change bit and return old value
113 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
114 * find_first_bit(addr, nbits) Position first set bit in *addr
115 * find_next_zero_bit(addr, nbits, bit)
116 * Position next zero bit in *addr >= bit
117 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
118 * find_next_and_bit(addr1, addr2, nbits, bit)
119 * Same as find_next_bit, but in
120 * (*addr1 & *addr2)
121 *
122 */
123
124/**
125 * DOC: declare bitmap
126 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
127 * to declare an array named 'name' of just enough unsigned longs to
128 * contain all bit positions from 0 to 'bits' - 1.
129 */
130
131/*
132 * Allocation and deallocation of bitmap.
133 * Provided in lib/bitmap.c to avoid circular dependency.
134 */
135unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
136unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
137unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
138unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
139void bitmap_free(const unsigned long *bitmap);
140
141DEFINE_FREE(bitmap, unsigned long *, if (_T) bitmap_free(_T))
142
143/* Managed variants of the above. */
144unsigned long *devm_bitmap_alloc(struct device *dev,
145 unsigned int nbits, gfp_t flags);
146unsigned long *devm_bitmap_zalloc(struct device *dev,
147 unsigned int nbits, gfp_t flags);
148
149/*
150 * lib/bitmap.c provides these functions:
151 */
152
153bool __bitmap_equal(const unsigned long *bitmap1,
154 const unsigned long *bitmap2, unsigned int nbits);
155bool __pure __bitmap_or_equal(const unsigned long *src1,
156 const unsigned long *src2,
157 const unsigned long *src3,
158 unsigned int nbits);
159void __bitmap_complement(unsigned long *dst, const unsigned long *src,
160 unsigned int nbits);
161void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
162 unsigned int shift, unsigned int nbits);
163void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
164 unsigned int shift, unsigned int nbits);
165void bitmap_cut(unsigned long *dst, const unsigned long *src,
166 unsigned int first, unsigned int cut, unsigned int nbits);
167bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
168 const unsigned long *bitmap2, unsigned int nbits);
169void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
170 const unsigned long *bitmap2, unsigned int nbits);
171unsigned int __bitmap_weighted_or(unsigned long *dst, const unsigned long *bitmap1,
172 const unsigned long *bitmap2, unsigned int nbits);
173unsigned int __bitmap_weighted_xor(unsigned long *dst, const unsigned long *bitmap1,
174 const unsigned long *bitmap2, unsigned int nbits);
175void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
176 const unsigned long *bitmap2, unsigned int nbits);
177bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
178 const unsigned long *bitmap2, unsigned int nbits);
179void __bitmap_replace(unsigned long *dst,
180 const unsigned long *old, const unsigned long *new,
181 const unsigned long *mask, unsigned int nbits);
182bool __bitmap_intersects(const unsigned long *bitmap1,
183 const unsigned long *bitmap2, unsigned int nbits);
184bool __bitmap_subset(const unsigned long *bitmap1,
185 const unsigned long *bitmap2, unsigned int nbits);
186unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
187unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
188 const unsigned long *bitmap2, unsigned int nbits);
189unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
190 const unsigned long *bitmap2, unsigned int nbits);
191void __bitmap_set(unsigned long *map, unsigned int start, int len);
192void __bitmap_clear(unsigned long *map, unsigned int start, int len);
193
194unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
195 unsigned long size,
196 unsigned long start,
197 unsigned int nr,
198 unsigned long align_mask,
199 unsigned long align_offset);
200
201/**
202 * bitmap_find_next_zero_area - find a contiguous aligned zero area
203 * @map: The address to base the search on
204 * @size: The bitmap size in bits
205 * @start: The bitnumber to start searching at
206 * @nr: The number of zeroed bits we're looking for
207 * @align_mask: Alignment mask for zero area
208 *
209 * The @align_mask should be one less than a power of 2; the effect is that
210 * the bit offset of all zero areas this function finds is multiples of that
211 * power of 2. A @align_mask of 0 means no alignment is required.
212 */
213static __always_inline
214unsigned long bitmap_find_next_zero_area(unsigned long *map,
215 unsigned long size,
216 unsigned long start,
217 unsigned int nr,
218 unsigned long align_mask)
219{
220 return bitmap_find_next_zero_area_off(map, size, start, nr,
221 align_mask, 0);
222}
223
224void bitmap_remap(unsigned long *dst, const unsigned long *src,
225 const unsigned long *old, const unsigned long *new, unsigned int nbits);
226int bitmap_bitremap(int oldbit,
227 const unsigned long *old, const unsigned long *new, int bits);
228void bitmap_onto(unsigned long *dst, const unsigned long *orig,
229 const unsigned long *relmap, unsigned int bits);
230void bitmap_fold(unsigned long *dst, const unsigned long *orig,
231 unsigned int sz, unsigned int nbits);
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#define bitmap_size(nbits) (ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
237
238static __always_inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
239{
240 unsigned int len = bitmap_size(nbits);
241
242 if (small_const_nbits(nbits))
243 *dst = 0;
244 else
245 memset(dst, 0, len);
246}
247
248static __always_inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
249{
250 unsigned int len = bitmap_size(nbits);
251
252 if (small_const_nbits(nbits))
253 *dst = ~0UL;
254 else
255 memset(dst, 0xff, len);
256}
257
258static __always_inline
259void bitmap_copy(unsigned long *dst, const unsigned long *src, unsigned int nbits)
260{
261 unsigned int len = bitmap_size(nbits);
262
263 if (small_const_nbits(nbits))
264 *dst = *src;
265 else
266 memcpy(dst, src, len);
267}
268
269/*
270 * Copy bitmap and clear tail bits in last word.
271 */
272static __always_inline
273void bitmap_copy_clear_tail(unsigned long *dst, const unsigned long *src, unsigned int nbits)
274{
275 bitmap_copy(dst, src, nbits);
276 if (nbits % BITS_PER_LONG)
277 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
278}
279
280static inline void bitmap_copy_and_extend(unsigned long *to,
281 const unsigned long *from,
282 unsigned int count, unsigned int size)
283{
284 unsigned int copy = BITS_TO_LONGS(count);
285
286 memcpy(to, from, copy * sizeof(long));
287 if (count % BITS_PER_LONG)
288 to[copy - 1] &= BITMAP_LAST_WORD_MASK(count);
289 memset(to + copy, 0, bitmap_size(size) - copy * sizeof(long));
290}
291
292/*
293 * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
294 * machines the order of hi and lo parts of numbers match the bitmap structure.
295 * In both cases conversion is not needed when copying data from/to arrays of
296 * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead
297 * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit
298 * architectures are not using bitmap_copy_clear_tail().
299 */
300#if BITS_PER_LONG == 64
301void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
302 unsigned int nbits);
303void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
304 unsigned int nbits);
305#else
306#define bitmap_from_arr32(bitmap, buf, nbits) \
307 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
308 (const unsigned long *) (buf), (nbits))
309#define bitmap_to_arr32(buf, bitmap, nbits) \
310 bitmap_copy_clear_tail((unsigned long *) (buf), \
311 (const unsigned long *) (bitmap), (nbits))
312#endif
313
314/*
315 * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
316 * the conversion is not needed when copying data from/to arrays of u64.
317 */
318#if BITS_PER_LONG == 32
319void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
320void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
321#else
322#define bitmap_from_arr64(bitmap, buf, nbits) \
323 bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
324#define bitmap_to_arr64(buf, bitmap, nbits) \
325 bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
326#endif
327
328static __always_inline
329bool bitmap_and(unsigned long *dst, const unsigned long *src1,
330 const unsigned long *src2, unsigned int nbits)
331{
332 if (small_const_nbits(nbits))
333 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
334 return __bitmap_and(dst, src1, src2, nbits);
335}
336
337static __always_inline
338void bitmap_or(unsigned long *dst, const unsigned long *src1,
339 const unsigned long *src2, unsigned int nbits)
340{
341 if (small_const_nbits(nbits))
342 *dst = *src1 | *src2;
343 else
344 __bitmap_or(dst, src1, src2, nbits);
345}
346
347static __always_inline
348unsigned int bitmap_weighted_or(unsigned long *dst, const unsigned long *src1,
349 const unsigned long *src2, unsigned int nbits)
350{
351 if (small_const_nbits(nbits)) {
352 *dst = *src1 | *src2;
353 return hweight_long(*dst & BITMAP_LAST_WORD_MASK(nbits));
354 } else {
355 return __bitmap_weighted_or(dst, src1, src2, nbits);
356 }
357}
358
359static __always_inline
360unsigned int bitmap_weighted_xor(unsigned long *dst, const unsigned long *src1,
361 const unsigned long *src2, unsigned int nbits)
362{
363 if (small_const_nbits(nbits)) {
364 *dst = *src1 ^ *src2;
365 return hweight_long(*dst & BITMAP_LAST_WORD_MASK(nbits));
366 } else {
367 return __bitmap_weighted_xor(dst, src1, src2, nbits);
368 }
369}
370
371static __always_inline
372void bitmap_xor(unsigned long *dst, const unsigned long *src1,
373 const unsigned long *src2, unsigned int nbits)
374{
375 if (small_const_nbits(nbits))
376 *dst = *src1 ^ *src2;
377 else
378 __bitmap_xor(dst, src1, src2, nbits);
379}
380
381static __always_inline
382bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
383 const unsigned long *src2, unsigned int nbits)
384{
385 if (small_const_nbits(nbits))
386 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
387 return __bitmap_andnot(dst, src1, src2, nbits);
388}
389
390static __always_inline
391void bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int nbits)
392{
393 if (small_const_nbits(nbits))
394 *dst = ~(*src);
395 else
396 __bitmap_complement(dst, src, nbits);
397}
398
399#ifdef __LITTLE_ENDIAN
400#define BITMAP_MEM_ALIGNMENT 8
401#else
402#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
403#endif
404#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
405
406static __always_inline
407bool bitmap_equal(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
408{
409 if (small_const_nbits(nbits))
410 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
411 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
412 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
413 return !memcmp(src1, src2, nbits / 8);
414 return __bitmap_equal(src1, src2, nbits);
415}
416
417/**
418 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
419 * @src1: Pointer to bitmap 1
420 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
421 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
422 * @nbits: number of bits in each of these bitmaps
423 *
424 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
425 */
426static __always_inline
427bool bitmap_or_equal(const unsigned long *src1, const unsigned long *src2,
428 const unsigned long *src3, unsigned int nbits)
429{
430 if (!small_const_nbits(nbits))
431 return __bitmap_or_equal(src1, src2, src3, nbits);
432
433 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
434}
435
436static __always_inline
437bool bitmap_intersects(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
438{
439 if (small_const_nbits(nbits))
440 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
441 else
442 return __bitmap_intersects(src1, src2, nbits);
443}
444
445static __always_inline
446bool bitmap_subset(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
447{
448 if (small_const_nbits(nbits))
449 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
450 else
451 return __bitmap_subset(src1, src2, nbits);
452}
453
454static __always_inline
455bool bitmap_empty(const unsigned long *src, unsigned nbits)
456{
457 if (small_const_nbits(nbits))
458 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
459
460 return find_first_bit(src, nbits) == nbits;
461}
462
463static __always_inline
464bool bitmap_full(const unsigned long *src, unsigned int nbits)
465{
466 if (small_const_nbits(nbits))
467 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
468
469 return find_first_zero_bit(src, nbits) == nbits;
470}
471
472static __always_inline
473unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
474{
475 if (small_const_nbits(nbits))
476 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
477 return __bitmap_weight(src, nbits);
478}
479
480static __always_inline
481unsigned long bitmap_weight_and(const unsigned long *src1,
482 const unsigned long *src2, unsigned int nbits)
483{
484 if (small_const_nbits(nbits))
485 return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits));
486 return __bitmap_weight_and(src1, src2, nbits);
487}
488
489static __always_inline
490unsigned long bitmap_weight_andnot(const unsigned long *src1,
491 const unsigned long *src2, unsigned int nbits)
492{
493 if (small_const_nbits(nbits))
494 return hweight_long(*src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits));
495 return __bitmap_weight_andnot(src1, src2, nbits);
496}
497
498/**
499 * bitmap_weight_from - Hamming weight for a memory region
500 * @bitmap: The base address
501 * @start: The bitnumber to starts weighting
502 * @end: the bitmap size in bits
503 *
504 * Returns the number of set bits in the region. If @start >= @end,
505 * return >= end.
506 */
507static __always_inline
508unsigned long bitmap_weight_from(const unsigned long *bitmap,
509 unsigned int start, unsigned int end)
510{
511 unsigned long w;
512
513 if (unlikely(start >= end))
514 return end;
515
516 if (small_const_nbits(end))
517 return hweight_long(*bitmap & GENMASK(end - 1, start));
518
519 bitmap += start / BITS_PER_LONG;
520 /* Opencode round_down() to not include math.h */
521 end -= start & ~(BITS_PER_LONG - 1);
522 start %= BITS_PER_LONG;
523 w = bitmap_weight(bitmap, end);
524 if (start)
525 w -= hweight_long(*bitmap & BITMAP_LAST_WORD_MASK(start));
526
527 return w;
528}
529
530static __always_inline
531void bitmap_set(unsigned long *map, unsigned int start, unsigned int nbits)
532{
533 if (__builtin_constant_p(nbits) && nbits == 1)
534 __set_bit(start, map);
535 else if (small_const_nbits(start + nbits))
536 *map |= GENMASK(start + nbits - 1, start);
537 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
538 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
539 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
540 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
541 memset((char *)map + start / 8, 0xff, nbits / 8);
542 else
543 __bitmap_set(map, start, nbits);
544}
545
546static __always_inline
547void bitmap_clear(unsigned long *map, unsigned int start, unsigned int nbits)
548{
549 if (__builtin_constant_p(nbits) && nbits == 1)
550 __clear_bit(start, map);
551 else if (small_const_nbits(start + nbits))
552 *map &= ~GENMASK(start + nbits - 1, start);
553 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
554 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
555 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
556 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
557 memset((char *)map + start / 8, 0, nbits / 8);
558 else
559 __bitmap_clear(map, start, nbits);
560}
561
562static __always_inline
563void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
564 unsigned int shift, unsigned int nbits)
565{
566 if (small_const_nbits(nbits))
567 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
568 else
569 __bitmap_shift_right(dst, src, shift, nbits);
570}
571
572static __always_inline
573void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
574 unsigned int shift, unsigned int nbits)
575{
576 if (small_const_nbits(nbits))
577 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
578 else
579 __bitmap_shift_left(dst, src, shift, nbits);
580}
581
582static __always_inline
583void bitmap_replace(unsigned long *dst,
584 const unsigned long *old,
585 const unsigned long *new,
586 const unsigned long *mask,
587 unsigned int nbits)
588{
589 if (small_const_nbits(nbits))
590 *dst = (*old & ~(*mask)) | (*new & *mask);
591 else
592 __bitmap_replace(dst, old, new, mask, nbits);
593}
594
595/**
596 * bitmap_scatter - Scatter a bitmap according to the given mask
597 * @dst: scattered bitmap
598 * @src: gathered bitmap
599 * @mask: mask representing bits to assign to in the scattered bitmap
600 * @nbits: number of bits in each of these bitmaps
601 *
602 * Scatters bitmap with sequential bits according to the given @mask.
603 *
604 * Example:
605 * If @src bitmap = 0x005a, with @mask = 0x1313, @dst will be 0x0302.
606 *
607 * Or in binary form
608 * @src @mask @dst
609 * 0000000001011010 0001001100010011 0000001100000010
610 *
611 * (Bits 0, 1, 2, 3, 4, 5 are copied to the bits 0, 1, 4, 8, 9, 12)
612 *
613 * A more 'visual' description of the operation::
614 *
615 * src: 0000000001011010
616 * ||||||
617 * +------+|||||
618 * | +----+||||
619 * | |+----+|||
620 * | || +-+||
621 * | || | ||
622 * mask: ...v..vv...v..vv
623 * ...0..11...0..10
624 * dst: 0000001100000010
625 *
626 * A relationship exists between bitmap_scatter() and bitmap_gather(). See
627 * bitmap_gather() for the bitmap gather detailed operations. TL;DR:
628 * bitmap_gather() can be seen as the 'reverse' bitmap_scatter() operation.
629 */
630static __always_inline
631void bitmap_scatter(unsigned long *dst, const unsigned long *src,
632 const unsigned long *mask, unsigned int nbits)
633{
634 unsigned int n = 0;
635 unsigned int bit;
636
637 bitmap_zero(dst, nbits);
638
639 for_each_set_bit(bit, mask, nbits)
640 __assign_bit(bit, dst, test_bit(n++, src));
641}
642
643/**
644 * bitmap_gather - Gather a bitmap according to given mask
645 * @dst: gathered bitmap
646 * @src: scattered bitmap
647 * @mask: mask representing bits to extract from in the scattered bitmap
648 * @nbits: number of bits in each of these bitmaps
649 *
650 * Gathers bitmap with sparse bits according to the given @mask.
651 *
652 * Example:
653 * If @src bitmap = 0x0302, with @mask = 0x1313, @dst will be 0x001a.
654 *
655 * Or in binary form
656 * @src @mask @dst
657 * 0000001100000010 0001001100010011 0000000000011010
658 *
659 * (Bits 0, 1, 4, 8, 9, 12 are copied to the bits 0, 1, 2, 3, 4, 5)
660 *
661 * A more 'visual' description of the operation::
662 *
663 * mask: ...v..vv...v..vv
664 * src: 0000001100000010
665 * ^ ^^ ^ 0
666 * | || | 10
667 * | || > 010
668 * | |+--> 1010
669 * | +--> 11010
670 * +----> 011010
671 * dst: 0000000000011010
672 *
673 * A relationship exists between bitmap_gather() and bitmap_scatter(). See
674 * bitmap_scatter() for the bitmap scatter detailed operations. TL;DR:
675 * bitmap_scatter() can be seen as the 'reverse' bitmap_gather() operation.
676 *
677 * Suppose scattered computed using bitmap_scatter(scattered, src, mask, n).
678 * The operation bitmap_gather(result, scattered, mask, n) leads to a result
679 * equal or equivalent to src.
680 *
681 * The result can be 'equivalent' because bitmap_scatter() and bitmap_gather()
682 * are not bijective.
683 * The result and src values are equivalent in that sense that a call to
684 * bitmap_scatter(res, src, mask, n) and a call to
685 * bitmap_scatter(res, result, mask, n) will lead to the same res value.
686 */
687static __always_inline
688void bitmap_gather(unsigned long *dst, const unsigned long *src,
689 const unsigned long *mask, unsigned int nbits)
690{
691 unsigned int n = 0;
692 unsigned int bit;
693
694 bitmap_zero(dst, nbits);
695
696 for_each_set_bit(bit, mask, nbits)
697 __assign_bit(n++, dst, test_bit(bit, src));
698}
699
700static __always_inline
701void bitmap_next_set_region(unsigned long *bitmap, unsigned int *rs,
702 unsigned int *re, unsigned int end)
703{
704 *rs = find_next_bit(bitmap, end, *rs);
705 *re = find_next_zero_bit(bitmap, end, *rs + 1);
706}
707
708/**
709 * bitmap_release_region - release allocated bitmap region
710 * @bitmap: array of unsigned longs corresponding to the bitmap
711 * @pos: beginning of bit region to release
712 * @order: region size (log base 2 of number of bits) to release
713 *
714 * This is the complement to __bitmap_find_free_region() and releases
715 * the found region (by clearing it in the bitmap).
716 */
717static __always_inline
718void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
719{
720 bitmap_clear(bitmap, pos, BIT(order));
721}
722
723/**
724 * bitmap_allocate_region - allocate bitmap region
725 * @bitmap: array of unsigned longs corresponding to the bitmap
726 * @pos: beginning of bit region to allocate
727 * @order: region size (log base 2 of number of bits) to allocate
728 *
729 * Allocate (set bits in) a specified region of a bitmap.
730 *
731 * Returns: 0 on success, or %-EBUSY if specified region wasn't
732 * free (not all bits were zero).
733 */
734static __always_inline
735int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
736{
737 unsigned int len = BIT(order);
738
739 if (find_next_bit(bitmap, pos + len, pos) < pos + len)
740 return -EBUSY;
741 bitmap_set(bitmap, pos, len);
742 return 0;
743}
744
745/**
746 * bitmap_find_free_region - find a contiguous aligned mem region
747 * @bitmap: array of unsigned longs corresponding to the bitmap
748 * @bits: number of bits in the bitmap
749 * @order: region size (log base 2 of number of bits) to find
750 *
751 * Find a region of free (zero) bits in a @bitmap of @bits bits and
752 * allocate them (set them to one). Only consider regions of length
753 * a power (@order) of two, aligned to that power of two, which
754 * makes the search algorithm much faster.
755 *
756 * Returns: the bit offset in bitmap of the allocated region,
757 * or -errno on failure.
758 */
759static __always_inline
760int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
761{
762 unsigned int pos, end; /* scans bitmap by regions of size order */
763
764 for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {
765 if (!bitmap_allocate_region(bitmap, pos, order))
766 return pos;
767 }
768 return -ENOMEM;
769}
770
771/**
772 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
773 * @n: u64 value
774 *
775 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
776 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
777 *
778 * There are four combinations of endianness and length of the word in linux
779 * ABIs: LE64, BE64, LE32 and BE32.
780 *
781 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
782 * bitmaps and therefore don't require any special handling.
783 *
784 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
785 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
786 * other hand is represented as an array of 32-bit words and the position of
787 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
788 * word. For example, bit #42 is located at 10th position of 2nd word.
789 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
790 * values in memory as it usually does. But for BE we need to swap hi and lo
791 * words manually.
792 *
793 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
794 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
795 * hi and lo words, as is expected by bitmap.
796 */
797#if __BITS_PER_LONG == 64
798#define BITMAP_FROM_U64(n) (n)
799#else
800#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
801 ((unsigned long) ((u64)(n) >> 32))
802#endif
803
804/**
805 * bitmap_from_u64 - Check and swap words within u64.
806 * @mask: source bitmap
807 * @dst: destination bitmap
808 *
809 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
810 * to read u64 mask, we will get the wrong word.
811 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
812 * but we expect the lower 32-bits of u64.
813 */
814static __always_inline void bitmap_from_u64(unsigned long *dst, u64 mask)
815{
816 bitmap_from_arr64(dst, &mask, 64);
817}
818
819/**
820 * bitmap_read - read a value of n-bits from the memory region
821 * @map: address to the bitmap memory region
822 * @start: bit offset of the n-bit value
823 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG
824 *
825 * Returns: value of @nbits bits located at the @start bit offset within the
826 * @map memory region. For @nbits = 0 and @nbits > BITS_PER_LONG the return
827 * value is undefined.
828 */
829static __always_inline
830unsigned long bitmap_read(const unsigned long *map, unsigned long start, unsigned long nbits)
831{
832 size_t index = BIT_WORD(start);
833 unsigned long offset = start % BITS_PER_LONG;
834 unsigned long space = BITS_PER_LONG - offset;
835 unsigned long value_low, value_high;
836
837 if (unlikely(!nbits || nbits > BITS_PER_LONG))
838 return 0;
839
840 if (space >= nbits)
841 return (map[index] >> offset) & BITMAP_LAST_WORD_MASK(nbits);
842
843 value_low = map[index] & BITMAP_FIRST_WORD_MASK(start);
844 value_high = map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits);
845 return (value_low >> offset) | (value_high << space);
846}
847
848/**
849 * bitmap_write - write n-bit value within a memory region
850 * @map: address to the bitmap memory region
851 * @value: value to write, clamped to nbits
852 * @start: bit offset of the n-bit value
853 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG.
854 *
855 * bitmap_write() behaves as-if implemented as @nbits calls of __assign_bit(),
856 * i.e. bits beyond @nbits are ignored:
857 *
858 * for (bit = 0; bit < nbits; bit++)
859 * __assign_bit(start + bit, bitmap, val & BIT(bit));
860 *
861 * For @nbits == 0 and @nbits > BITS_PER_LONG no writes are performed.
862 */
863static __always_inline
864void bitmap_write(unsigned long *map, unsigned long value,
865 unsigned long start, unsigned long nbits)
866{
867 size_t index;
868 unsigned long offset;
869 unsigned long space;
870 unsigned long mask;
871 bool fit;
872
873 if (unlikely(!nbits || nbits > BITS_PER_LONG))
874 return;
875
876 mask = BITMAP_LAST_WORD_MASK(nbits);
877 value &= mask;
878 offset = start % BITS_PER_LONG;
879 space = BITS_PER_LONG - offset;
880 fit = space >= nbits;
881 index = BIT_WORD(start);
882
883 map[index] &= (fit ? (~(mask << offset)) : ~BITMAP_FIRST_WORD_MASK(start));
884 map[index] |= value << offset;
885 if (fit)
886 return;
887
888 map[index + 1] &= BITMAP_FIRST_WORD_MASK(start + nbits);
889 map[index + 1] |= (value >> space);
890}
891
892#define bitmap_get_value8(map, start) \
893 bitmap_read(map, start, BITS_PER_BYTE)
894#define bitmap_set_value8(map, value, start) \
895 bitmap_write(map, value, start, BITS_PER_BYTE)
896
897#endif /* __ASSEMBLY__ */
898
899#endif /* __LINUX_BITMAP_H */