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 * The available bitmap operations and their rough meaning in the
27 * case that the bitmap is a single unsigned long are thus:
28 *
29 * Note that nbits should be always a compile time evaluable constant.
30 * Otherwise many inlines will generate horrible code.
31 *
32 * bitmap_zero(dst, nbits) *dst = 0UL
33 * bitmap_fill(dst, nbits) *dst = ~0UL
34 * bitmap_copy(dst, src, nbits) *dst = *src
35 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
36 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
37 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
38 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
39 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
40 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
41 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
42 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
43 * bitmap_empty(src, nbits) Are all bits zero in *src?
44 * bitmap_full(src, nbits) Are all bits set in *src?
45 * bitmap_weight(src, nbits) Hamming Weight: number set bits
46 * bitmap_set(dst, pos, nbits) Set specified bit area
47 * bitmap_clear(dst, pos, nbits) Clear specified bit area
48 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
49 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
50 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
51 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
52 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
53 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
54 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
55 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
56 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
57 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
58 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
59 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
60 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
61 * bitmap_release_region(bitmap, pos, order) Free specified bit region
62 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
63 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
64 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words)
65 */
66
67 /*
68 * Also the following operations in asm/bitops.h apply to bitmaps.
69 *
70 * set_bit(bit, addr) *addr |= bit
71 * clear_bit(bit, addr) *addr &= ~bit
72 * change_bit(bit, addr) *addr ^= bit
73 * test_bit(bit, addr) Is bit set in *addr?
74 * test_and_set_bit(bit, addr) Set bit and return old value
75 * test_and_clear_bit(bit, addr) Clear bit and return old value
76 * test_and_change_bit(bit, addr) Change bit and return old value
77 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
78 * find_first_bit(addr, nbits) Position first set bit in *addr
79 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
80 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
81 */
82
83 /*
84 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
85 * to declare an array named 'name' of just enough unsigned longs to
86 * contain all bit positions from 0 to 'bits' - 1.
87 */
88
89 /*
90 * Allocation and deallocation of bitmap.
91 * Provided in lib/bitmap.c to avoid circular dependency.
92 */
93 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
94 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
95 extern void bitmap_free(const unsigned long *bitmap);
96
97 /*
98 * lib/bitmap.c provides these functions:
99 */
100
101 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
102 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
103 extern int __bitmap_equal(const unsigned long *bitmap1,
104 const unsigned long *bitmap2, unsigned int nbits);
105 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
106 unsigned int nbits);
107 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
108 unsigned int shift, unsigned int nbits);
109 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
110 unsigned int shift, unsigned int nbits);
111 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
112 const unsigned long *bitmap2, unsigned int nbits);
113 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
114 const unsigned long *bitmap2, unsigned int nbits);
115 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
116 const unsigned long *bitmap2, unsigned int nbits);
117 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
118 const unsigned long *bitmap2, unsigned int nbits);
119 extern int __bitmap_intersects(const unsigned long *bitmap1,
120 const unsigned long *bitmap2, unsigned int nbits);
121 extern int __bitmap_subset(const unsigned long *bitmap1,
122 const unsigned long *bitmap2, unsigned int nbits);
123 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
124 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
125 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
126
127 extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
128 unsigned long size,
129 unsigned long start,
130 unsigned int nr,
131 unsigned long align_mask,
132 unsigned long align_offset);
133
134 /**
135 * bitmap_find_next_zero_area - find a contiguous aligned zero area
136 * @map: The address to base the search on
137 * @size: The bitmap size in bits
138 * @start: The bitnumber to start searching at
139 * @nr: The number of zeroed bits we're looking for
140 * @align_mask: Alignment mask for zero area
141 *
142 * The @align_mask should be one less than a power of 2; the effect is that
143 * the bit offset of all zero areas this function finds is multiples of that
144 * power of 2. A @align_mask of 0 means no alignment is required.
145 */
146 static inline unsigned long
bitmap_find_next_zero_area(unsigned long * map,unsigned long size,unsigned long start,unsigned int nr,unsigned long align_mask)147 bitmap_find_next_zero_area(unsigned long *map,
148 unsigned long size,
149 unsigned long start,
150 unsigned int nr,
151 unsigned long align_mask)
152 {
153 return bitmap_find_next_zero_area_off(map, size, start, nr,
154 align_mask, 0);
155 }
156
157 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
158 unsigned long *dst, int nbits);
159 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
160 unsigned long *dst, int nbits);
161 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
162 int nmaskbits);
163 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
164 unsigned long *dst, int nbits);
165 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
166 const unsigned long *old, const unsigned long *new, unsigned int nbits);
167 extern int bitmap_bitremap(int oldbit,
168 const unsigned long *old, const unsigned long *new, int bits);
169 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
170 const unsigned long *relmap, unsigned int bits);
171 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
172 unsigned int sz, unsigned int nbits);
173 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
174 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
175 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
176 extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
177 unsigned int nbits,
178 const u32 *buf,
179 unsigned int nwords);
180 extern unsigned int bitmap_to_u32array(u32 *buf,
181 unsigned int nwords,
182 const unsigned long *bitmap,
183 unsigned int nbits);
184 #ifdef __BIG_ENDIAN
185 extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
186 #else
187 #define bitmap_copy_le bitmap_copy
188 #endif
189 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
190 extern int bitmap_print_to_pagebuf(bool list, char *buf,
191 const unsigned long *maskp, int nmaskbits);
192
193 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
194 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
195
196 /*
197 * The static inlines below do not handle constant nbits==0 correctly,
198 * so make such users (should any ever turn up) call the out-of-line
199 * versions.
200 */
201 #define small_const_nbits(nbits) \
202 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
203
bitmap_zero(unsigned long * dst,unsigned int nbits)204 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
205 {
206 if (small_const_nbits(nbits))
207 *dst = 0UL;
208 else {
209 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
210 memset(dst, 0, len);
211 }
212 }
213
bitmap_fill(unsigned long * dst,unsigned int nbits)214 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
215 {
216 unsigned int nlongs = BITS_TO_LONGS(nbits);
217 if (!small_const_nbits(nbits)) {
218 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
219 memset(dst, 0xff, len);
220 }
221 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
222 }
223
bitmap_copy(unsigned long * dst,const unsigned long * src,unsigned int nbits)224 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
225 unsigned int nbits)
226 {
227 if (small_const_nbits(nbits))
228 *dst = *src;
229 else {
230 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
231 memcpy(dst, src, len);
232 }
233 }
234
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)235 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
236 const unsigned long *src2, unsigned int nbits)
237 {
238 if (small_const_nbits(nbits))
239 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
240 return __bitmap_and(dst, src1, src2, nbits);
241 }
242
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)243 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
244 const unsigned long *src2, unsigned int nbits)
245 {
246 if (small_const_nbits(nbits))
247 *dst = *src1 | *src2;
248 else
249 __bitmap_or(dst, src1, src2, nbits);
250 }
251
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)252 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
253 const unsigned long *src2, unsigned int nbits)
254 {
255 if (small_const_nbits(nbits))
256 *dst = *src1 ^ *src2;
257 else
258 __bitmap_xor(dst, src1, src2, nbits);
259 }
260
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)261 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
262 const unsigned long *src2, unsigned int nbits)
263 {
264 if (small_const_nbits(nbits))
265 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
266 return __bitmap_andnot(dst, src1, src2, nbits);
267 }
268
bitmap_complement(unsigned long * dst,const unsigned long * src,unsigned int nbits)269 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
270 unsigned int nbits)
271 {
272 if (small_const_nbits(nbits))
273 *dst = ~(*src);
274 else
275 __bitmap_complement(dst, src, nbits);
276 }
277
278 #ifdef __LITTLE_ENDIAN
279 #define BITMAP_MEM_ALIGNMENT 8
280 #else
281 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
282 #endif
283 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
284
bitmap_equal(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)285 static inline int bitmap_equal(const unsigned long *src1,
286 const unsigned long *src2, unsigned int nbits)
287 {
288 if (small_const_nbits(nbits))
289 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
290 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
291 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
292 return !memcmp(src1, src2, nbits / 8);
293 return __bitmap_equal(src1, src2, nbits);
294 }
295
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)296 static inline int bitmap_intersects(const unsigned long *src1,
297 const unsigned long *src2, unsigned int nbits)
298 {
299 if (small_const_nbits(nbits))
300 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
301 else
302 return __bitmap_intersects(src1, src2, nbits);
303 }
304
bitmap_subset(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)305 static inline int bitmap_subset(const unsigned long *src1,
306 const unsigned long *src2, unsigned int nbits)
307 {
308 if (small_const_nbits(nbits))
309 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
310 else
311 return __bitmap_subset(src1, src2, nbits);
312 }
313
bitmap_empty(const unsigned long * src,unsigned nbits)314 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
315 {
316 if (small_const_nbits(nbits))
317 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
318
319 return find_first_bit(src, nbits) == nbits;
320 }
321
bitmap_full(const unsigned long * src,unsigned int nbits)322 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
323 {
324 if (small_const_nbits(nbits))
325 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
326
327 return find_first_zero_bit(src, nbits) == nbits;
328 }
329
bitmap_weight(const unsigned long * src,unsigned int nbits)330 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
331 {
332 if (small_const_nbits(nbits))
333 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
334 return __bitmap_weight(src, nbits);
335 }
336
bitmap_set(unsigned long * map,unsigned int start,unsigned int nbits)337 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
338 unsigned int nbits)
339 {
340 if (__builtin_constant_p(nbits) && nbits == 1)
341 __set_bit(start, map);
342 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
343 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
344 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
345 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
346 memset((char *)map + start / 8, 0xff, nbits / 8);
347 else
348 __bitmap_set(map, start, nbits);
349 }
350
bitmap_clear(unsigned long * map,unsigned int start,unsigned int nbits)351 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
352 unsigned int nbits)
353 {
354 if (__builtin_constant_p(nbits) && nbits == 1)
355 __clear_bit(start, map);
356 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
357 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
358 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
359 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
360 memset((char *)map + start / 8, 0, nbits / 8);
361 else
362 __bitmap_clear(map, start, nbits);
363 }
364
bitmap_shift_right(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)365 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
366 unsigned int shift, unsigned int nbits)
367 {
368 if (small_const_nbits(nbits))
369 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
370 else
371 __bitmap_shift_right(dst, src, shift, nbits);
372 }
373
bitmap_shift_left(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)374 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
375 unsigned int shift, unsigned int nbits)
376 {
377 if (small_const_nbits(nbits))
378 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
379 else
380 __bitmap_shift_left(dst, src, shift, nbits);
381 }
382
bitmap_parse(const char * buf,unsigned int buflen,unsigned long * maskp,int nmaskbits)383 static inline int bitmap_parse(const char *buf, unsigned int buflen,
384 unsigned long *maskp, int nmaskbits)
385 {
386 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
387 }
388
389 /*
390 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
391 *
392 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
393 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
394 *
395 * There are four combinations of endianness and length of the word in linux
396 * ABIs: LE64, BE64, LE32 and BE32.
397 *
398 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
399 * bitmaps and therefore don't require any special handling.
400 *
401 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
402 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
403 * other hand is represented as an array of 32-bit words and the position of
404 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
405 * word. For example, bit #42 is located at 10th position of 2nd word.
406 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
407 * values in memory as it usually does. But for BE we need to swap hi and lo
408 * words manually.
409 *
410 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
411 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
412 * hi and lo words, as is expected by bitmap.
413 */
414 #if __BITS_PER_LONG == 64
415 #define BITMAP_FROM_U64(n) (n)
416 #else
417 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
418 ((unsigned long) ((u64)(n) >> 32))
419 #endif
420
421 /*
422 * bitmap_from_u64 - Check and swap words within u64.
423 * @mask: source bitmap
424 * @dst: destination bitmap
425 *
426 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
427 * to read u64 mask, we will get the wrong word.
428 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
429 * but we expect the lower 32-bits of u64.
430 */
bitmap_from_u64(unsigned long * dst,u64 mask)431 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
432 {
433 dst[0] = mask & ULONG_MAX;
434
435 if (sizeof(mask) > sizeof(unsigned long))
436 dst[1] = mask >> 32;
437 }
438
439 #endif /* __ASSEMBLY__ */
440
441 #endif /* __LINUX_BITMAP_H */
442