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