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_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 */
111 extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
112 extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
113 extern void bitmap_free(const unsigned long *bitmap);
114
115 /*
116 * lib/bitmap.c provides these functions:
117 */
118
119 extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
120 extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
121 extern int __bitmap_equal(const unsigned long *bitmap1,
122 const unsigned long *bitmap2, unsigned int nbits);
123 extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
124 unsigned int nbits);
125 extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
126 unsigned int shift, unsigned int nbits);
127 extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
128 unsigned int shift, unsigned int nbits);
129 extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
130 const unsigned long *bitmap2, unsigned int nbits);
131 extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
132 const unsigned long *bitmap2, unsigned int nbits);
133 extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
134 const unsigned long *bitmap2, unsigned int nbits);
135 extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
136 const unsigned long *bitmap2, unsigned int nbits);
137 extern int __bitmap_intersects(const unsigned long *bitmap1,
138 const unsigned long *bitmap2, unsigned int nbits);
139 extern int __bitmap_subset(const unsigned long *bitmap1,
140 const unsigned long *bitmap2, unsigned int nbits);
141 extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
142 extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
143 extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
144
145 extern 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 */
164 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)165 bitmap_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
175 extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
176 unsigned long *dst, int nbits);
177 extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
178 unsigned long *dst, int nbits);
179 extern int bitmap_parselist(const char *buf, unsigned long *maskp,
180 int nmaskbits);
181 extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
182 unsigned long *dst, int nbits);
183 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
184 const unsigned long *old, const unsigned long *new, unsigned int nbits);
185 extern int bitmap_bitremap(int oldbit,
186 const unsigned long *old, const unsigned long *new, int bits);
187 extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
188 const unsigned long *relmap, unsigned int bits);
189 extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
190 unsigned int sz, unsigned int nbits);
191 extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
192 extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
193 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
194
195 #ifdef __BIG_ENDIAN
196 extern 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
200 extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
201 extern 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
bitmap_zero(unsigned long * dst,unsigned int nbits)215 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
216 {
217 if (small_const_nbits(nbits))
218 *dst = 0UL;
219 else {
220 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
221 memset(dst, 0, len);
222 }
223 }
224
bitmap_fill(unsigned long * dst,unsigned int nbits)225 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
226 {
227 if (small_const_nbits(nbits))
228 *dst = ~0UL;
229 else {
230 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
231 memset(dst, 0xff, len);
232 }
233 }
234
bitmap_copy(unsigned long * dst,const unsigned long * src,unsigned int nbits)235 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
236 unsigned int nbits)
237 {
238 if (small_const_nbits(nbits))
239 *dst = *src;
240 else {
241 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
242 memcpy(dst, src, len);
243 }
244 }
245
246 /*
247 * Copy bitmap and clear tail bits in last word.
248 */
bitmap_copy_clear_tail(unsigned long * dst,const unsigned long * src,unsigned int nbits)249 static inline void bitmap_copy_clear_tail(unsigned long *dst,
250 const unsigned long *src, unsigned int nbits)
251 {
252 bitmap_copy(dst, src, nbits);
253 if (nbits % BITS_PER_LONG)
254 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
255 }
256
257 /*
258 * On 32-bit systems bitmaps are represented as u32 arrays internally, and
259 * therefore conversion is not needed when copying data from/to arrays of u32.
260 */
261 #if BITS_PER_LONG == 64
262 extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
263 unsigned int nbits);
264 extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
265 unsigned int nbits);
266 #else
267 #define bitmap_from_arr32(bitmap, buf, nbits) \
268 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
269 (const unsigned long *) (buf), (nbits))
270 #define bitmap_to_arr32(buf, bitmap, nbits) \
271 bitmap_copy_clear_tail((unsigned long *) (buf), \
272 (const unsigned long *) (bitmap), (nbits))
273 #endif
274
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)275 static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
276 const unsigned long *src2, unsigned int nbits)
277 {
278 if (small_const_nbits(nbits))
279 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
280 return __bitmap_and(dst, src1, src2, nbits);
281 }
282
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)283 static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
284 const unsigned long *src2, unsigned int nbits)
285 {
286 if (small_const_nbits(nbits))
287 *dst = *src1 | *src2;
288 else
289 __bitmap_or(dst, src1, src2, nbits);
290 }
291
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)292 static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
293 const unsigned long *src2, unsigned int nbits)
294 {
295 if (small_const_nbits(nbits))
296 *dst = *src1 ^ *src2;
297 else
298 __bitmap_xor(dst, src1, src2, nbits);
299 }
300
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)301 static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
302 const unsigned long *src2, unsigned int nbits)
303 {
304 if (small_const_nbits(nbits))
305 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
306 return __bitmap_andnot(dst, src1, src2, nbits);
307 }
308
bitmap_complement(unsigned long * dst,const unsigned long * src,unsigned int nbits)309 static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
310 unsigned int nbits)
311 {
312 if (small_const_nbits(nbits))
313 *dst = ~(*src);
314 else
315 __bitmap_complement(dst, src, nbits);
316 }
317
318 #ifdef __LITTLE_ENDIAN
319 #define BITMAP_MEM_ALIGNMENT 8
320 #else
321 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
322 #endif
323 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
324
bitmap_equal(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)325 static inline int bitmap_equal(const unsigned long *src1,
326 const unsigned long *src2, unsigned int nbits)
327 {
328 if (small_const_nbits(nbits))
329 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
330 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
331 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
332 return !memcmp(src1, src2, nbits / 8);
333 return __bitmap_equal(src1, src2, nbits);
334 }
335
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)336 static inline int bitmap_intersects(const unsigned long *src1,
337 const unsigned long *src2, unsigned int nbits)
338 {
339 if (small_const_nbits(nbits))
340 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
341 else
342 return __bitmap_intersects(src1, src2, nbits);
343 }
344
bitmap_subset(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)345 static inline int bitmap_subset(const unsigned long *src1,
346 const unsigned long *src2, unsigned int nbits)
347 {
348 if (small_const_nbits(nbits))
349 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
350 else
351 return __bitmap_subset(src1, src2, nbits);
352 }
353
bitmap_empty(const unsigned long * src,unsigned nbits)354 static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
355 {
356 if (small_const_nbits(nbits))
357 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
358
359 return find_first_bit(src, nbits) == nbits;
360 }
361
bitmap_full(const unsigned long * src,unsigned int nbits)362 static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
363 {
364 if (small_const_nbits(nbits))
365 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
366
367 return find_first_zero_bit(src, nbits) == nbits;
368 }
369
bitmap_weight(const unsigned long * src,unsigned int nbits)370 static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
371 {
372 if (small_const_nbits(nbits))
373 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
374 return __bitmap_weight(src, nbits);
375 }
376
bitmap_set(unsigned long * map,unsigned int start,unsigned int nbits)377 static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
378 unsigned int nbits)
379 {
380 if (__builtin_constant_p(nbits) && nbits == 1)
381 __set_bit(start, map);
382 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
383 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
384 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
385 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
386 memset((char *)map + start / 8, 0xff, nbits / 8);
387 else
388 __bitmap_set(map, start, nbits);
389 }
390
bitmap_clear(unsigned long * map,unsigned int start,unsigned int nbits)391 static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
392 unsigned int nbits)
393 {
394 if (__builtin_constant_p(nbits) && nbits == 1)
395 __clear_bit(start, map);
396 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
397 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
398 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
399 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
400 memset((char *)map + start / 8, 0, nbits / 8);
401 else
402 __bitmap_clear(map, start, nbits);
403 }
404
bitmap_shift_right(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)405 static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
406 unsigned int shift, unsigned int nbits)
407 {
408 if (small_const_nbits(nbits))
409 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
410 else
411 __bitmap_shift_right(dst, src, shift, nbits);
412 }
413
bitmap_shift_left(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)414 static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
415 unsigned int shift, unsigned int nbits)
416 {
417 if (small_const_nbits(nbits))
418 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
419 else
420 __bitmap_shift_left(dst, src, shift, nbits);
421 }
422
bitmap_parse(const char * buf,unsigned int buflen,unsigned long * maskp,int nmaskbits)423 static inline int bitmap_parse(const char *buf, unsigned int buflen,
424 unsigned long *maskp, int nmaskbits)
425 {
426 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
427 }
428
429 /**
430 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
431 * @n: u64 value
432 *
433 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
434 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
435 *
436 * There are four combinations of endianness and length of the word in linux
437 * ABIs: LE64, BE64, LE32 and BE32.
438 *
439 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
440 * bitmaps and therefore don't require any special handling.
441 *
442 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
443 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
444 * other hand is represented as an array of 32-bit words and the position of
445 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
446 * word. For example, bit #42 is located at 10th position of 2nd word.
447 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
448 * values in memory as it usually does. But for BE we need to swap hi and lo
449 * words manually.
450 *
451 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
452 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
453 * hi and lo words, as is expected by bitmap.
454 */
455 #if __BITS_PER_LONG == 64
456 #define BITMAP_FROM_U64(n) (n)
457 #else
458 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
459 ((unsigned long) ((u64)(n) >> 32))
460 #endif
461
462 /**
463 * bitmap_from_u64 - Check and swap words within u64.
464 * @mask: source bitmap
465 * @dst: destination bitmap
466 *
467 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
468 * to read u64 mask, we will get the wrong word.
469 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
470 * but we expect the lower 32-bits of u64.
471 */
bitmap_from_u64(unsigned long * dst,u64 mask)472 static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
473 {
474 dst[0] = mask & ULONG_MAX;
475
476 if (sizeof(mask) > sizeof(unsigned long))
477 dst[1] = mask >> 32;
478 }
479
480 #endif /* __ASSEMBLY__ */
481
482 #endif /* __LINUX_BITMAP_H */
483