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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/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 * Note that nbits should be always a compile time evaluable constant.
32 * Otherwise many inlines will generate horrible code.
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) as above
54 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
55 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
56 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
57 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
58 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
59 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
60 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
61 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
62 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
63 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
64 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
65 * bitmap_release_region(bitmap, pos, order) Free specified bit region
66 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
67 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
68 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words)
69 *
70 */
71
72/**
73 * DOC: bitmap bitops
74 *
75 * Also the following operations in asm/bitops.h apply to bitmaps.::
76 *
77 * set_bit(bit, addr) *addr |= bit
78 * clear_bit(bit, addr) *addr &= ~bit
79 * change_bit(bit, addr) *addr ^= bit
80 * test_bit(bit, addr) Is bit set in *addr?
81 * test_and_set_bit(bit, addr) Set bit and return old value
82 * test_and_clear_bit(bit, addr) Clear bit and return old value
83 * test_and_change_bit(bit, addr) Change bit and return old value
84 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
85 * find_first_bit(addr, nbits) Position first set bit in *addr
86 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
87 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
88 *
89 */
90
91/**
92 * DOC: declare bitmap
93 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
94 * to declare an array named 'name' of just enough unsigned longs to
95 * contain all bit positions from 0 to 'bits' - 1.
96 */
97
98/*
99 * lib/bitmap.c provides these functions:
100 */
101
102extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
103extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
104extern int __bitmap_equal(const unsigned long *bitmap1,
105 const unsigned long *bitmap2, unsigned int nbits);
106extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
107 unsigned int nbits);
108extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
109 unsigned int shift, unsigned int nbits);
110extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
111 unsigned int shift, unsigned int nbits);
112extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
113 const unsigned long *bitmap2, unsigned int nbits);
114extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
115 const unsigned long *bitmap2, unsigned int nbits);
116extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
117 const unsigned long *bitmap2, unsigned int nbits);
118extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
119 const unsigned long *bitmap2, unsigned int nbits);
120extern int __bitmap_intersects(const unsigned long *bitmap1,
121 const unsigned long *bitmap2, unsigned int nbits);
122extern int __bitmap_subset(const unsigned long *bitmap1,
123 const unsigned long *bitmap2, unsigned int nbits);
124extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
125extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
126extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
127
128extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
129 unsigned long size,
130 unsigned long start,
131 unsigned int nr,
132 unsigned long align_mask,
133 unsigned long align_offset);
134
135/**
136 * bitmap_find_next_zero_area - find a contiguous aligned zero area
137 * @map: The address to base the search on
138 * @size: The bitmap size in bits
139 * @start: The bitnumber to start searching at
140 * @nr: The number of zeroed bits we're looking for
141 * @align_mask: Alignment mask for zero area
142 *
143 * The @align_mask should be one less than a power of 2; the effect is that
144 * the bit offset of all zero areas this function finds is multiples of that
145 * power of 2. A @align_mask of 0 means no alignment is required.
146 */
147static inline unsigned long
148bitmap_find_next_zero_area(unsigned long *map,
149 unsigned long size,
150 unsigned long start,
151 unsigned int nr,
152 unsigned long align_mask)
153{
154 return bitmap_find_next_zero_area_off(map, size, start, nr,
155 align_mask, 0);
156}
157
158extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
159 unsigned long *dst, int nbits);
160extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
161 unsigned long *dst, int nbits);
162extern int bitmap_parselist(const char *buf, unsigned long *maskp,
163 int nmaskbits);
164extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
165 unsigned long *dst, int nbits);
166extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
167 const unsigned long *old, const unsigned long *new, unsigned int nbits);
168extern int bitmap_bitremap(int oldbit,
169 const unsigned long *old, const unsigned long *new, int bits);
170extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
171 const unsigned long *relmap, unsigned int bits);
172extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
173 unsigned int sz, unsigned int nbits);
174extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
175extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
176extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
177extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
178 unsigned int nbits,
179 const u32 *buf,
180 unsigned int nwords);
181extern unsigned int bitmap_to_u32array(u32 *buf,
182 unsigned int nwords,
183 const unsigned long *bitmap,
184 unsigned int nbits);
185#ifdef __BIG_ENDIAN
186extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
187#else
188#define bitmap_copy_le bitmap_copy
189#endif
190extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
191extern int bitmap_print_to_pagebuf(bool list, char *buf,
192 const unsigned long *maskp, int nmaskbits);
193
194#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
195#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
196
197#define small_const_nbits(nbits) \
198 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
199
200static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
201{
202 if (small_const_nbits(nbits))
203 *dst = 0UL;
204 else {
205 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
206 memset(dst, 0, len);
207 }
208}
209
210static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
211{
212 unsigned int nlongs = BITS_TO_LONGS(nbits);
213 if (!small_const_nbits(nbits)) {
214 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
215 memset(dst, 0xff, len);
216 }
217 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
218}
219
220static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
221 unsigned int nbits)
222{
223 if (small_const_nbits(nbits))
224 *dst = *src;
225 else {
226 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
227 memcpy(dst, src, len);
228 }
229}
230
231static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
232 const unsigned long *src2, unsigned int nbits)
233{
234 if (small_const_nbits(nbits))
235 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
236 return __bitmap_and(dst, src1, src2, nbits);
237}
238
239static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
240 const unsigned long *src2, unsigned int nbits)
241{
242 if (small_const_nbits(nbits))
243 *dst = *src1 | *src2;
244 else
245 __bitmap_or(dst, src1, src2, nbits);
246}
247
248static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
249 const unsigned long *src2, unsigned int nbits)
250{
251 if (small_const_nbits(nbits))
252 *dst = *src1 ^ *src2;
253 else
254 __bitmap_xor(dst, src1, src2, nbits);
255}
256
257static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
258 const unsigned long *src2, unsigned int nbits)
259{
260 if (small_const_nbits(nbits))
261 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
262 return __bitmap_andnot(dst, src1, src2, nbits);
263}
264
265static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
266 unsigned int nbits)
267{
268 if (small_const_nbits(nbits))
269 *dst = ~(*src);
270 else
271 __bitmap_complement(dst, src, nbits);
272}
273
274static inline int bitmap_equal(const unsigned long *src1,
275 const unsigned long *src2, unsigned int nbits)
276{
277 if (small_const_nbits(nbits))
278 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
279 if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
280 return !memcmp(src1, src2, nbits / 8);
281 return __bitmap_equal(src1, src2, nbits);
282}
283
284static inline int bitmap_intersects(const unsigned long *src1,
285 const unsigned long *src2, unsigned int nbits)
286{
287 if (small_const_nbits(nbits))
288 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
289 else
290 return __bitmap_intersects(src1, src2, nbits);
291}
292
293static inline int bitmap_subset(const unsigned long *src1,
294 const unsigned long *src2, unsigned int nbits)
295{
296 if (small_const_nbits(nbits))
297 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
298 else
299 return __bitmap_subset(src1, src2, nbits);
300}
301
302static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
303{
304 if (small_const_nbits(nbits))
305 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
306
307 return find_first_bit(src, nbits) == nbits;
308}
309
310static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
311{
312 if (small_const_nbits(nbits))
313 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
314
315 return find_first_zero_bit(src, nbits) == nbits;
316}
317
318static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
319{
320 if (small_const_nbits(nbits))
321 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
322 return __bitmap_weight(src, nbits);
323}
324
325static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
326 unsigned int nbits)
327{
328 if (__builtin_constant_p(nbits) && nbits == 1)
329 __set_bit(start, map);
330 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
331 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
332 memset((char *)map + start / 8, 0xff, nbits / 8);
333 else
334 __bitmap_set(map, start, nbits);
335}
336
337static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
338 unsigned int nbits)
339{
340 if (__builtin_constant_p(nbits) && nbits == 1)
341 __clear_bit(start, map);
342 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
343 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
344 memset((char *)map + start / 8, 0, nbits / 8);
345 else
346 __bitmap_clear(map, start, nbits);
347}
348
349static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
350 unsigned int shift, int nbits)
351{
352 if (small_const_nbits(nbits))
353 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
354 else
355 __bitmap_shift_right(dst, src, shift, nbits);
356}
357
358static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
359 unsigned int shift, unsigned int nbits)
360{
361 if (small_const_nbits(nbits))
362 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
363 else
364 __bitmap_shift_left(dst, src, shift, nbits);
365}
366
367static inline int bitmap_parse(const char *buf, unsigned int buflen,
368 unsigned long *maskp, int nmaskbits)
369{
370 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
371}
372
373/**
374 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
375 * @n: u64 value
376 *
377 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
378 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
379 *
380 * There are four combinations of endianness and length of the word in linux
381 * ABIs: LE64, BE64, LE32 and BE32.
382 *
383 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
384 * bitmaps and therefore don't require any special handling.
385 *
386 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
387 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
388 * other hand is represented as an array of 32-bit words and the position of
389 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
390 * word. For example, bit #42 is located at 10th position of 2nd word.
391 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
392 * values in memory as it usually does. But for BE we need to swap hi and lo
393 * words manually.
394 *
395 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
396 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
397 * hi and lo words, as is expected by bitmap.
398 */
399#if __BITS_PER_LONG == 64
400#define BITMAP_FROM_U64(n) (n)
401#else
402#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
403 ((unsigned long) ((u64)(n) >> 32))
404#endif
405
406/**
407 * bitmap_from_u64 - Check and swap words within u64.
408 * @mask: source bitmap
409 * @dst: destination bitmap
410 *
411 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
412 * to read u64 mask, we will get the wrong word.
413 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
414 * but we expect the lower 32-bits of u64.
415 */
416static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
417{
418 dst[0] = mask & ULONG_MAX;
419
420 if (sizeof(mask) > sizeof(unsigned long))
421 dst[1] = mask >> 32;
422}
423
424#endif /* __ASSEMBLY__ */
425
426#endif /* __LINUX_BITMAP_H */