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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 * 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) 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_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
68 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
69 *
70 * Note, bitmap_zero() and bitmap_fill() operate over the region of
71 * unsigned longs, that is, bits behind bitmap till the unsigned long
72 * boundary will be zeroed or filled as well. Consider to use
73 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
74 * respectively.
75 */
76
77/**
78 * DOC: bitmap bitops
79 *
80 * Also the following operations in asm/bitops.h apply to bitmaps.::
81 *
82 * set_bit(bit, addr) *addr |= bit
83 * clear_bit(bit, addr) *addr &= ~bit
84 * change_bit(bit, addr) *addr ^= bit
85 * test_bit(bit, addr) Is bit set in *addr?
86 * test_and_set_bit(bit, addr) Set bit and return old value
87 * test_and_clear_bit(bit, addr) Clear bit and return old value
88 * test_and_change_bit(bit, addr) Change bit and return old value
89 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
90 * find_first_bit(addr, nbits) Position first set bit in *addr
91 * find_next_zero_bit(addr, nbits, bit)
92 * Position next zero bit in *addr >= bit
93 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
94 * find_next_and_bit(addr1, addr2, nbits, bit)
95 * Same as find_next_bit, but in
96 * (*addr1 & *addr2)
97 *
98 */
99
100/**
101 * DOC: declare bitmap
102 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
103 * to declare an array named 'name' of just enough unsigned longs to
104 * contain all bit positions from 0 to 'bits' - 1.
105 */
106
107/*
108 * Allocation and deallocation of bitmap.
109 * Provided in lib/bitmap.c to avoid circular dependency.
110 */
111extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
112extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
113extern void bitmap_free(const unsigned long *bitmap);
114
115/*
116 * lib/bitmap.c provides these functions:
117 */
118
119extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
120extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
121extern int __bitmap_equal(const unsigned long *bitmap1,
122 const unsigned long *bitmap2, unsigned int nbits);
123extern bool __pure __bitmap_or_equal(const unsigned long *src1,
124 const unsigned long *src2,
125 const unsigned long *src3,
126 unsigned int nbits);
127extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
128 unsigned int nbits);
129extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
130 unsigned int shift, unsigned int nbits);
131extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
132 unsigned int shift, unsigned int nbits);
133extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
134 const unsigned long *bitmap2, unsigned int nbits);
135extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
136 const unsigned long *bitmap2, unsigned int nbits);
137extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
138 const unsigned long *bitmap2, unsigned int nbits);
139extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
140 const unsigned long *bitmap2, unsigned int nbits);
141extern int __bitmap_intersects(const unsigned long *bitmap1,
142 const unsigned long *bitmap2, unsigned int nbits);
143extern int __bitmap_subset(const unsigned long *bitmap1,
144 const unsigned long *bitmap2, unsigned int nbits);
145extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
146extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
147extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
148
149extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
150 unsigned long size,
151 unsigned long start,
152 unsigned int nr,
153 unsigned long align_mask,
154 unsigned long align_offset);
155
156/**
157 * bitmap_find_next_zero_area - find a contiguous aligned zero area
158 * @map: The address to base the search on
159 * @size: The bitmap size in bits
160 * @start: The bitnumber to start searching at
161 * @nr: The number of zeroed bits we're looking for
162 * @align_mask: Alignment mask for zero area
163 *
164 * The @align_mask should be one less than a power of 2; the effect is that
165 * the bit offset of all zero areas this function finds is multiples of that
166 * power of 2. A @align_mask of 0 means no alignment is required.
167 */
168static inline unsigned long
169bitmap_find_next_zero_area(unsigned long *map,
170 unsigned long size,
171 unsigned long start,
172 unsigned int nr,
173 unsigned long align_mask)
174{
175 return bitmap_find_next_zero_area_off(map, size, start, nr,
176 align_mask, 0);
177}
178
179extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
180 unsigned long *dst, int nbits);
181extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
182 unsigned long *dst, int nbits);
183extern int bitmap_parselist(const char *buf, unsigned long *maskp,
184 int nmaskbits);
185extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
186 unsigned long *dst, int nbits);
187extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
188 const unsigned long *old, const unsigned long *new, unsigned int nbits);
189extern int bitmap_bitremap(int oldbit,
190 const unsigned long *old, const unsigned long *new, int bits);
191extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
192 const unsigned long *relmap, unsigned int bits);
193extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
194 unsigned int sz, unsigned int nbits);
195extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
196extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
197extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
198
199#ifdef __BIG_ENDIAN
200extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
201#else
202#define bitmap_copy_le bitmap_copy
203#endif
204extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
205extern int bitmap_print_to_pagebuf(bool list, char *buf,
206 const unsigned long *maskp, int nmaskbits);
207
208#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
209#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
210
211/*
212 * The static inlines below do not handle constant nbits==0 correctly,
213 * so make such users (should any ever turn up) call the out-of-line
214 * versions.
215 */
216#define small_const_nbits(nbits) \
217 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
218
219static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
220{
221 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
222 memset(dst, 0, len);
223}
224
225static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
226{
227 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
228 memset(dst, 0xff, len);
229}
230
231static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
232 unsigned int nbits)
233{
234 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
235 memcpy(dst, src, len);
236}
237
238/*
239 * Copy bitmap and clear tail bits in last word.
240 */
241static inline void bitmap_copy_clear_tail(unsigned long *dst,
242 const unsigned long *src, unsigned int nbits)
243{
244 bitmap_copy(dst, src, nbits);
245 if (nbits % BITS_PER_LONG)
246 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
247}
248
249/*
250 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
251 * therefore conversion is not needed when copying data from/to arrays of u32.
252 */
253#if BITS_PER_LONG == 64
254extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
255 unsigned int nbits);
256extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
257 unsigned int nbits);
258#else
259#define bitmap_from_arr32(bitmap, buf, nbits) \
260 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
261 (const unsigned long *) (buf), (nbits))
262#define bitmap_to_arr32(buf, bitmap, nbits) \
263 bitmap_copy_clear_tail((unsigned long *) (buf), \
264 (const unsigned long *) (bitmap), (nbits))
265#endif
266
267static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
268 const unsigned long *src2, unsigned int nbits)
269{
270 if (small_const_nbits(nbits))
271 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
272 return __bitmap_and(dst, src1, src2, nbits);
273}
274
275static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
276 const unsigned long *src2, unsigned int nbits)
277{
278 if (small_const_nbits(nbits))
279 *dst = *src1 | *src2;
280 else
281 __bitmap_or(dst, src1, src2, nbits);
282}
283
284static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
285 const unsigned long *src2, unsigned int nbits)
286{
287 if (small_const_nbits(nbits))
288 *dst = *src1 ^ *src2;
289 else
290 __bitmap_xor(dst, src1, src2, nbits);
291}
292
293static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
294 const unsigned long *src2, unsigned int nbits)
295{
296 if (small_const_nbits(nbits))
297 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
298 return __bitmap_andnot(dst, src1, src2, nbits);
299}
300
301static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
302 unsigned int nbits)
303{
304 if (small_const_nbits(nbits))
305 *dst = ~(*src);
306 else
307 __bitmap_complement(dst, src, nbits);
308}
309
310#ifdef __LITTLE_ENDIAN
311#define BITMAP_MEM_ALIGNMENT 8
312#else
313#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
314#endif
315#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
316
317static inline int bitmap_equal(const unsigned long *src1,
318 const unsigned long *src2, unsigned int nbits)
319{
320 if (small_const_nbits(nbits))
321 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
322 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
323 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
324 return !memcmp(src1, src2, nbits / 8);
325 return __bitmap_equal(src1, src2, nbits);
326}
327
328/**
329 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
330 * @src1: Pointer to bitmap 1
331 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
332 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
333 * @nbits: number of bits in each of these bitmaps
334 *
335 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
336 */
337static inline bool bitmap_or_equal(const unsigned long *src1,
338 const unsigned long *src2,
339 const unsigned long *src3,
340 unsigned int nbits)
341{
342 if (!small_const_nbits(nbits))
343 return __bitmap_or_equal(src1, src2, src3, nbits);
344
345 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
346}
347
348static inline int bitmap_intersects(const unsigned long *src1,
349 const unsigned long *src2, unsigned int nbits)
350{
351 if (small_const_nbits(nbits))
352 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
353 else
354 return __bitmap_intersects(src1, src2, nbits);
355}
356
357static inline int bitmap_subset(const unsigned long *src1,
358 const unsigned long *src2, unsigned int nbits)
359{
360 if (small_const_nbits(nbits))
361 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
362 else
363 return __bitmap_subset(src1, src2, nbits);
364}
365
366static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
367{
368 if (small_const_nbits(nbits))
369 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
370
371 return find_first_bit(src, nbits) == nbits;
372}
373
374static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
375{
376 if (small_const_nbits(nbits))
377 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
378
379 return find_first_zero_bit(src, nbits) == nbits;
380}
381
382static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
383{
384 if (small_const_nbits(nbits))
385 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
386 return __bitmap_weight(src, nbits);
387}
388
389static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
390 unsigned int nbits)
391{
392 if (__builtin_constant_p(nbits) && nbits == 1)
393 __set_bit(start, map);
394 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
395 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
396 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
397 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
398 memset((char *)map + start / 8, 0xff, nbits / 8);
399 else
400 __bitmap_set(map, start, nbits);
401}
402
403static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
404 unsigned int nbits)
405{
406 if (__builtin_constant_p(nbits) && nbits == 1)
407 __clear_bit(start, map);
408 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
409 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
410 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
411 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
412 memset((char *)map + start / 8, 0, nbits / 8);
413 else
414 __bitmap_clear(map, start, nbits);
415}
416
417static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
418 unsigned int shift, unsigned int nbits)
419{
420 if (small_const_nbits(nbits))
421 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
422 else
423 __bitmap_shift_right(dst, src, shift, nbits);
424}
425
426static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
427 unsigned int shift, unsigned int nbits)
428{
429 if (small_const_nbits(nbits))
430 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
431 else
432 __bitmap_shift_left(dst, src, shift, nbits);
433}
434
435static inline int bitmap_parse(const char *buf, unsigned int buflen,
436 unsigned long *maskp, int nmaskbits)
437{
438 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
439}
440
441/**
442 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
443 * @n: u64 value
444 *
445 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
446 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
447 *
448 * There are four combinations of endianness and length of the word in linux
449 * ABIs: LE64, BE64, LE32 and BE32.
450 *
451 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
452 * bitmaps and therefore don't require any special handling.
453 *
454 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
455 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
456 * other hand is represented as an array of 32-bit words and the position of
457 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
458 * word. For example, bit #42 is located at 10th position of 2nd word.
459 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
460 * values in memory as it usually does. But for BE we need to swap hi and lo
461 * words manually.
462 *
463 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
464 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
465 * hi and lo words, as is expected by bitmap.
466 */
467#if __BITS_PER_LONG == 64
468#define BITMAP_FROM_U64(n) (n)
469#else
470#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
471 ((unsigned long) ((u64)(n) >> 32))
472#endif
473
474/**
475 * bitmap_from_u64 - Check and swap words within u64.
476 * @mask: source bitmap
477 * @dst: destination bitmap
478 *
479 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
480 * to read u64 mask, we will get the wrong word.
481 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
482 * but we expect the lower 32-bits of u64.
483 */
484static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
485{
486 dst[0] = mask & ULONG_MAX;
487
488 if (sizeof(mask) > sizeof(unsigned long))
489 dst[1] = mask >> 32;
490}
491
492#endif /* __ASSEMBLY__ */
493
494#endif /* __LINUX_BITMAP_H */