1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_BITMAP_H
3 #define __LINUX_BITMAP_H
4
5 #ifndef __ASSEMBLER__
6
7 #include <linux/align.h>
8 #include <linux/bitops.h>
9 #include <linux/cleanup.h>
10 #include <linux/errno.h>
11 #include <linux/find.h>
12 #include <linux/limits.h>
13 #include <linux/string.h>
14 #include <linux/types.h>
15 #include <linux/bitmap-str.h>
16
17 struct device;
18
19 /*
20 * bitmaps provide bit arrays that consume one or more unsigned
21 * longs. The bitmap interface and available operations are listed
22 * here, in bitmap.h
23 *
24 * Function implementations generic to all architectures are in
25 * lib/bitmap.c. Functions implementations that are architecture
26 * specific are in various arch/<arch>/include/asm/bitops.h headers
27 * and other arch/<arch> specific files.
28 *
29 * See lib/bitmap.c for more details.
30 */
31
32 /**
33 * DOC: bitmap overview
34 *
35 * The available bitmap operations and their rough meaning in the
36 * case that the bitmap is a single unsigned long are thus:
37 *
38 * The generated code is more efficient when nbits is known at
39 * compile-time and at most BITS_PER_LONG.
40 *
41 * ::
42 *
43 * bitmap_zero(dst, nbits) *dst = 0UL
44 * bitmap_fill(dst, nbits) *dst = ~0UL
45 * bitmap_copy(dst, src, nbits) *dst = *src
46 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
47 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
48 * bitmap_weighted_or(dst, src1, src2, nbits) *dst = *src1 | *src2. Returns Hamming Weight of dst
49 * bitmap_weighted_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2. Returns Hamming Weight of dst
50 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
51 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
52 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
53 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
54 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
55 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
56 * bitmap_empty(src, nbits) Are all bits zero in *src?
57 * bitmap_full(src, nbits) Are all bits set in *src?
58 * bitmap_weight(src, nbits) Hamming Weight: number set bits
59 * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
60 * bitmap_weight_andnot(src1, src2, nbits) Hamming Weight of andnot'ed bitmap
61 * bitmap_weight_from(src, start, end) Hamming Weight starting from @start
62 * bitmap_set(dst, pos, nbits) Set specified bit area
63 * bitmap_clear(dst, pos, nbits) Clear specified bit area
64 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
65 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
66 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
67 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
68 * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
69 * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
70 * bitmap_scatter(dst, src, mask, nbits) *dst = map(dense, sparse)(src)
71 * bitmap_gather(dst, src, mask, nbits) *dst = map(sparse, dense)(src)
72 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
73 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
74 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
75 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
76 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
77 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
78 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
79 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
80 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
81 * bitmap_release_region(bitmap, pos, order) Free specified bit region
82 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
83 * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
84 * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst
85 * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
86 * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
87 * bitmap_get_value8(map, start) Get 8bit value from map at start
88 * bitmap_set_value8(map, value, start) Set 8bit value to map at start
89 * bitmap_read(map, start, nbits) Read an nbits-sized value from
90 * map at start
91 * bitmap_write(map, value, start, nbits) Write an nbits-sized value to
92 * map at start
93 *
94 * Note, bitmap_zero() and bitmap_fill() operate over the region of
95 * unsigned longs, that is, bits behind bitmap till the unsigned long
96 * boundary will be zeroed or filled as well. Consider to use
97 * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
98 * respectively.
99 */
100
101 /**
102 * DOC: bitmap bitops
103 *
104 * Also the following operations in asm/bitops.h apply to bitmaps.::
105 *
106 * set_bit(bit, addr) *addr |= bit
107 * clear_bit(bit, addr) *addr &= ~bit
108 * change_bit(bit, addr) *addr ^= bit
109 * test_bit(bit, addr) Is bit set in *addr?
110 * test_and_set_bit(bit, addr) Set bit and return old value
111 * test_and_clear_bit(bit, addr) Clear bit and return old value
112 * test_and_change_bit(bit, addr) Change bit and return old value
113 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
114 * find_first_bit(addr, nbits) Position first set bit in *addr
115 * find_next_zero_bit(addr, nbits, bit)
116 * Position next zero bit in *addr >= bit
117 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
118 * find_next_and_bit(addr1, addr2, nbits, bit)
119 * Same as find_next_bit, but in
120 * (*addr1 & *addr2)
121 *
122 */
123
124 /**
125 * DOC: declare bitmap
126 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
127 * to declare an array named 'name' of just enough unsigned longs to
128 * contain all bit positions from 0 to 'bits' - 1.
129 */
130
131 /*
132 * Allocation and deallocation of bitmap.
133 * Provided in lib/bitmap.c to avoid circular dependency.
134 */
135 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
136 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
137 unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
138 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
139 void bitmap_free(const unsigned long *bitmap);
140
141 DEFINE_FREE(bitmap, unsigned long *, if (_T) bitmap_free(_T))
142
143 /* Managed variants of the above. */
144 unsigned long *devm_bitmap_alloc(struct device *dev,
145 unsigned int nbits, gfp_t flags);
146 unsigned long *devm_bitmap_zalloc(struct device *dev,
147 unsigned int nbits, gfp_t flags);
148
149 /*
150 * lib/bitmap.c provides these functions:
151 */
152
153 bool __bitmap_equal(const unsigned long *bitmap1,
154 const unsigned long *bitmap2, unsigned int nbits);
155 bool __pure __bitmap_or_equal(const unsigned long *src1,
156 const unsigned long *src2,
157 const unsigned long *src3,
158 unsigned int nbits);
159 void __bitmap_complement(unsigned long *dst, const unsigned long *src,
160 unsigned int nbits);
161 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
162 unsigned int shift, unsigned int nbits);
163 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
164 unsigned int shift, unsigned int nbits);
165 void bitmap_cut(unsigned long *dst, const unsigned long *src,
166 unsigned int first, unsigned int cut, unsigned int nbits);
167 bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
168 const unsigned long *bitmap2, unsigned int nbits);
169 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
170 const unsigned long *bitmap2, unsigned int nbits);
171 unsigned int __bitmap_weighted_or(unsigned long *dst, const unsigned long *bitmap1,
172 const unsigned long *bitmap2, unsigned int nbits);
173 unsigned int __bitmap_weighted_xor(unsigned long *dst, const unsigned long *bitmap1,
174 const unsigned long *bitmap2, unsigned int nbits);
175 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
176 const unsigned long *bitmap2, unsigned int nbits);
177 bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
178 const unsigned long *bitmap2, unsigned int nbits);
179 void __bitmap_replace(unsigned long *dst,
180 const unsigned long *old, const unsigned long *new,
181 const unsigned long *mask, unsigned int nbits);
182 bool __bitmap_intersects(const unsigned long *bitmap1,
183 const unsigned long *bitmap2, unsigned int nbits);
184 bool __bitmap_subset(const unsigned long *bitmap1,
185 const unsigned long *bitmap2, unsigned int nbits);
186 unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
187 unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
188 const unsigned long *bitmap2, unsigned int nbits);
189 unsigned int __bitmap_weight_andnot(const unsigned long *bitmap1,
190 const unsigned long *bitmap2, unsigned int nbits);
191 void __bitmap_set(unsigned long *map, unsigned int start, int len);
192 void __bitmap_clear(unsigned long *map, unsigned int start, int len);
193
194 unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
195 unsigned long size,
196 unsigned long start,
197 unsigned int nr,
198 unsigned long align_mask,
199 unsigned long align_offset);
200
201 /**
202 * bitmap_find_next_zero_area - find a contiguous aligned zero area
203 * @map: The address to base the search on
204 * @size: The bitmap size in bits
205 * @start: The bitnumber to start searching at
206 * @nr: The number of zeroed bits we're looking for
207 * @align_mask: Alignment mask for zero area
208 *
209 * The @align_mask should be one less than a power of 2; the effect is that
210 * the bit offset of all zero areas this function finds is multiples of that
211 * power of 2. A @align_mask of 0 means no alignment is required.
212 *
213 * Return: The bit offset of the found area or a value >= @size
214 * if no area is found.
215 */
216 static __always_inline
bitmap_find_next_zero_area(unsigned long * map,unsigned long size,unsigned long start,unsigned int nr,unsigned long align_mask)217 unsigned long bitmap_find_next_zero_area(unsigned long *map,
218 unsigned long size,
219 unsigned long start,
220 unsigned int nr,
221 unsigned long align_mask)
222 {
223 return bitmap_find_next_zero_area_off(map, size, start, nr,
224 align_mask, 0);
225 }
226
227 void bitmap_remap(unsigned long *dst, const unsigned long *src,
228 const unsigned long *old, const unsigned long *new, unsigned int nbits);
229 int bitmap_bitremap(int oldbit,
230 const unsigned long *old, const unsigned long *new, int bits);
231 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
232 const unsigned long *relmap, unsigned int bits);
233 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
234 unsigned int sz, unsigned int nbits);
235
236 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
237 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
238
239 #define bitmap_size(nbits) (ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
240
bitmap_zero(unsigned long * dst,unsigned int nbits)241 static __always_inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
242 {
243 unsigned int len = bitmap_size(nbits);
244
245 if (small_const_nbits(nbits))
246 *dst = 0;
247 else
248 memset(dst, 0, len);
249 }
250
bitmap_fill(unsigned long * dst,unsigned int nbits)251 static __always_inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
252 {
253 unsigned int len = bitmap_size(nbits);
254
255 if (small_const_nbits(nbits))
256 *dst = ~0UL;
257 else
258 memset(dst, 0xff, len);
259 }
260
261 static __always_inline
bitmap_copy(unsigned long * dst,const unsigned long * src,unsigned int nbits)262 void bitmap_copy(unsigned long *dst, const unsigned long *src, unsigned int nbits)
263 {
264 unsigned int len = bitmap_size(nbits);
265
266 if (small_const_nbits(nbits))
267 *dst = *src;
268 else
269 memcpy(dst, src, len);
270 }
271
272 /*
273 * Copy bitmap and clear tail bits in last word.
274 */
275 static __always_inline
bitmap_copy_clear_tail(unsigned long * dst,const unsigned long * src,unsigned int nbits)276 void bitmap_copy_clear_tail(unsigned long *dst, const unsigned long *src, unsigned int nbits)
277 {
278 bitmap_copy(dst, src, nbits);
279 if (nbits % BITS_PER_LONG)
280 dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
281 }
282
bitmap_copy_and_extend(unsigned long * to,const unsigned long * from,unsigned int count,unsigned int size)283 static inline void bitmap_copy_and_extend(unsigned long *to,
284 const unsigned long *from,
285 unsigned int count, unsigned int size)
286 {
287 unsigned int copy = BITS_TO_LONGS(count);
288
289 memcpy(to, from, copy * sizeof(long));
290 if (count % BITS_PER_LONG)
291 to[copy - 1] &= BITMAP_LAST_WORD_MASK(count);
292 memset(to + copy, 0, bitmap_size(size) - copy * sizeof(long));
293 }
294
295 /*
296 * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
297 * machines the order of hi and lo parts of numbers match the bitmap structure.
298 * In both cases conversion is not needed when copying data from/to arrays of
299 * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead
300 * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit
301 * architectures are not using bitmap_copy_clear_tail().
302 */
303 #if BITS_PER_LONG == 64
304 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
305 unsigned int nbits);
306 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
307 unsigned int nbits);
308 #else
309 #define bitmap_from_arr32(bitmap, buf, nbits) \
310 bitmap_copy_clear_tail((unsigned long *) (bitmap), \
311 (const unsigned long *) (buf), (nbits))
312 #define bitmap_to_arr32(buf, bitmap, nbits) \
313 bitmap_copy_clear_tail((unsigned long *) (buf), \
314 (const unsigned long *) (bitmap), (nbits))
315 #endif
316
317 /*
318 * On 64-bit systems bitmaps are represented as u64 arrays internally. So,
319 * the conversion is not needed when copying data from/to arrays of u64.
320 */
321 #if BITS_PER_LONG == 32
322 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
323 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
324 #else
325 #define bitmap_from_arr64(bitmap, buf, nbits) \
326 bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
327 #define bitmap_to_arr64(buf, bitmap, nbits) \
328 bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
329 #endif
330
331 static __always_inline
bitmap_and(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)332 bool bitmap_and(unsigned long *dst, const unsigned long *src1,
333 const unsigned long *src2, unsigned int nbits)
334 {
335 if (small_const_nbits(nbits))
336 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
337 return __bitmap_and(dst, src1, src2, nbits);
338 }
339
340 static __always_inline
bitmap_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)341 void bitmap_or(unsigned long *dst, const unsigned long *src1,
342 const unsigned long *src2, unsigned int nbits)
343 {
344 if (small_const_nbits(nbits))
345 *dst = *src1 | *src2;
346 else
347 __bitmap_or(dst, src1, src2, nbits);
348 }
349
350 static __always_inline
bitmap_weighted_or(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)351 unsigned int bitmap_weighted_or(unsigned long *dst, const unsigned long *src1,
352 const unsigned long *src2, unsigned int nbits)
353 {
354 if (small_const_nbits(nbits)) {
355 *dst = *src1 | *src2;
356 return hweight_long(*dst & BITMAP_LAST_WORD_MASK(nbits));
357 } else {
358 return __bitmap_weighted_or(dst, src1, src2, nbits);
359 }
360 }
361
362 static __always_inline
bitmap_weighted_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)363 unsigned int bitmap_weighted_xor(unsigned long *dst, const unsigned long *src1,
364 const unsigned long *src2, unsigned int nbits)
365 {
366 if (small_const_nbits(nbits)) {
367 *dst = *src1 ^ *src2;
368 return hweight_long(*dst & BITMAP_LAST_WORD_MASK(nbits));
369 } else {
370 return __bitmap_weighted_xor(dst, src1, src2, nbits);
371 }
372 }
373
374 static __always_inline
bitmap_xor(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)375 void bitmap_xor(unsigned long *dst, const unsigned long *src1,
376 const unsigned long *src2, unsigned int nbits)
377 {
378 if (small_const_nbits(nbits))
379 *dst = *src1 ^ *src2;
380 else
381 __bitmap_xor(dst, src1, src2, nbits);
382 }
383
384 static __always_inline
bitmap_andnot(unsigned long * dst,const unsigned long * src1,const unsigned long * src2,unsigned int nbits)385 bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
386 const unsigned long *src2, unsigned int nbits)
387 {
388 if (small_const_nbits(nbits))
389 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
390 return __bitmap_andnot(dst, src1, src2, nbits);
391 }
392
393 static __always_inline
bitmap_complement(unsigned long * dst,const unsigned long * src,unsigned int nbits)394 void bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int nbits)
395 {
396 if (small_const_nbits(nbits))
397 *dst = ~(*src);
398 else
399 __bitmap_complement(dst, src, nbits);
400 }
401
402 #ifdef __LITTLE_ENDIAN
403 #define BITMAP_MEM_ALIGNMENT 8
404 #else
405 #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
406 #endif
407 #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
408
409 static __always_inline
bitmap_equal(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)410 bool bitmap_equal(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
411 {
412 if (small_const_nbits(nbits))
413 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
414 if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
415 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
416 return !memcmp(src1, src2, nbits / 8);
417 return __bitmap_equal(src1, src2, nbits);
418 }
419
420 /**
421 * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
422 * @src1: Pointer to bitmap 1
423 * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
424 * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
425 * @nbits: number of bits in each of these bitmaps
426 *
427 * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
428 */
429 static __always_inline
bitmap_or_equal(const unsigned long * src1,const unsigned long * src2,const unsigned long * src3,unsigned int nbits)430 bool bitmap_or_equal(const unsigned long *src1, const unsigned long *src2,
431 const unsigned long *src3, unsigned int nbits)
432 {
433 if (!small_const_nbits(nbits))
434 return __bitmap_or_equal(src1, src2, src3, nbits);
435
436 return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
437 }
438
439 static __always_inline
bitmap_intersects(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)440 bool bitmap_intersects(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
441 {
442 if (small_const_nbits(nbits))
443 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
444 else
445 return __bitmap_intersects(src1, src2, nbits);
446 }
447
448 static __always_inline
bitmap_subset(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)449 bool bitmap_subset(const unsigned long *src1, const unsigned long *src2, unsigned int nbits)
450 {
451 if (small_const_nbits(nbits))
452 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
453 else
454 return __bitmap_subset(src1, src2, nbits);
455 }
456
457 static __always_inline
bitmap_empty(const unsigned long * src,unsigned nbits)458 bool bitmap_empty(const unsigned long *src, unsigned nbits)
459 {
460 if (small_const_nbits(nbits))
461 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
462
463 return find_first_bit(src, nbits) == nbits;
464 }
465
466 static __always_inline
bitmap_full(const unsigned long * src,unsigned int nbits)467 bool bitmap_full(const unsigned long *src, unsigned int nbits)
468 {
469 if (small_const_nbits(nbits))
470 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
471
472 return find_first_zero_bit(src, nbits) == nbits;
473 }
474
475 static __always_inline
bitmap_weight(const unsigned long * src,unsigned int nbits)476 unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
477 {
478 if (small_const_nbits(nbits))
479 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
480 return __bitmap_weight(src, nbits);
481 }
482
483 static __always_inline
bitmap_weight_and(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)484 unsigned long bitmap_weight_and(const unsigned long *src1,
485 const unsigned long *src2, unsigned int nbits)
486 {
487 if (small_const_nbits(nbits))
488 return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits));
489 return __bitmap_weight_and(src1, src2, nbits);
490 }
491
492 static __always_inline
bitmap_weight_andnot(const unsigned long * src1,const unsigned long * src2,unsigned int nbits)493 unsigned long bitmap_weight_andnot(const unsigned long *src1,
494 const unsigned long *src2, unsigned int nbits)
495 {
496 if (small_const_nbits(nbits))
497 return hweight_long(*src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits));
498 return __bitmap_weight_andnot(src1, src2, nbits);
499 }
500
501 /**
502 * bitmap_weight_from - Hamming weight for a memory region
503 * @bitmap: The base address
504 * @start: The bitnumber to starts weighting
505 * @end: the bitmap size in bits
506 *
507 * Returns the number of set bits in the region. If @start >= @end,
508 * return >= end.
509 */
510 static __always_inline
bitmap_weight_from(const unsigned long * bitmap,unsigned int start,unsigned int end)511 unsigned long bitmap_weight_from(const unsigned long *bitmap,
512 unsigned int start, unsigned int end)
513 {
514 unsigned long w;
515
516 if (unlikely(start >= end))
517 return end;
518
519 if (small_const_nbits(end))
520 return hweight_long(*bitmap & GENMASK(end - 1, start));
521
522 bitmap += start / BITS_PER_LONG;
523 /* Opencode round_down() to not include math.h */
524 end -= start & ~(BITS_PER_LONG - 1);
525 start %= BITS_PER_LONG;
526 w = bitmap_weight(bitmap, end);
527 if (start)
528 w -= hweight_long(*bitmap & BITMAP_LAST_WORD_MASK(start));
529
530 return w;
531 }
532
533 static __always_inline
bitmap_set(unsigned long * map,unsigned int start,unsigned int nbits)534 void bitmap_set(unsigned long *map, unsigned int start, unsigned int nbits)
535 {
536 if (__builtin_constant_p(nbits) && nbits == 1)
537 __set_bit(start, map);
538 else if (small_const_nbits(start + nbits))
539 *map |= GENMASK(start + nbits - 1, start);
540 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
541 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
542 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
543 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
544 memset((char *)map + start / 8, 0xff, nbits / 8);
545 else
546 __bitmap_set(map, start, nbits);
547 }
548
549 static __always_inline
bitmap_clear(unsigned long * map,unsigned int start,unsigned int nbits)550 void bitmap_clear(unsigned long *map, unsigned int start, unsigned int nbits)
551 {
552 if (__builtin_constant_p(nbits) && nbits == 1)
553 __clear_bit(start, map);
554 else if (small_const_nbits(start + nbits))
555 *map &= ~GENMASK(start + nbits - 1, start);
556 else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
557 IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
558 __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
559 IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
560 memset((char *)map + start / 8, 0, nbits / 8);
561 else
562 __bitmap_clear(map, start, nbits);
563 }
564
565 static __always_inline
bitmap_shift_right(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)566 void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
567 unsigned int shift, unsigned int nbits)
568 {
569 if (small_const_nbits(nbits))
570 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
571 else
572 __bitmap_shift_right(dst, src, shift, nbits);
573 }
574
575 static __always_inline
bitmap_shift_left(unsigned long * dst,const unsigned long * src,unsigned int shift,unsigned int nbits)576 void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
577 unsigned int shift, unsigned int nbits)
578 {
579 if (small_const_nbits(nbits))
580 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
581 else
582 __bitmap_shift_left(dst, src, shift, nbits);
583 }
584
585 static __always_inline
bitmap_replace(unsigned long * dst,const unsigned long * old,const unsigned long * new,const unsigned long * mask,unsigned int nbits)586 void bitmap_replace(unsigned long *dst,
587 const unsigned long *old,
588 const unsigned long *new,
589 const unsigned long *mask,
590 unsigned int nbits)
591 {
592 if (small_const_nbits(nbits))
593 *dst = (*old & ~(*mask)) | (*new & *mask);
594 else
595 __bitmap_replace(dst, old, new, mask, nbits);
596 }
597
598 /**
599 * bitmap_scatter - Scatter a bitmap according to the given mask
600 * @dst: scattered bitmap
601 * @src: gathered bitmap
602 * @mask: mask representing bits to assign to in the scattered bitmap
603 * @nbits: number of bits in each of these bitmaps
604 *
605 * Scatters bitmap with sequential bits according to the given @mask.
606 *
607 * Example:
608 * If @src bitmap = 0x005a, with @mask = 0x1313, @dst will be 0x0302.
609 *
610 * Or in binary form
611 * @src @mask @dst
612 * 0000000001011010 0001001100010011 0000001100000010
613 *
614 * (Bits 0, 1, 2, 3, 4, 5 are copied to the bits 0, 1, 4, 8, 9, 12)
615 *
616 * A more 'visual' description of the operation::
617 *
618 * src: 0000000001011010
619 * ||||||
620 * +------+|||||
621 * | +----+||||
622 * | |+----+|||
623 * | || +-+||
624 * | || | ||
625 * mask: ...v..vv...v..vv
626 * ...0..11...0..10
627 * dst: 0000001100000010
628 *
629 * A relationship exists between bitmap_scatter() and bitmap_gather(). See
630 * bitmap_gather() for the bitmap gather detailed operations. TL;DR:
631 * bitmap_gather() can be seen as the 'reverse' bitmap_scatter() operation.
632 */
633 static __always_inline
bitmap_scatter(unsigned long * dst,const unsigned long * src,const unsigned long * mask,unsigned int nbits)634 void bitmap_scatter(unsigned long *dst, const unsigned long *src,
635 const unsigned long *mask, unsigned int nbits)
636 {
637 unsigned int n = 0;
638 unsigned int bit;
639
640 bitmap_zero(dst, nbits);
641
642 for_each_set_bit(bit, mask, nbits)
643 __assign_bit(bit, dst, test_bit(n++, src));
644 }
645
646 /**
647 * bitmap_gather - Gather a bitmap according to given mask
648 * @dst: gathered bitmap
649 * @src: scattered bitmap
650 * @mask: mask representing bits to extract from in the scattered bitmap
651 * @nbits: number of bits in each of these bitmaps
652 *
653 * Gathers bitmap with sparse bits according to the given @mask.
654 *
655 * Example:
656 * If @src bitmap = 0x0302, with @mask = 0x1313, @dst will be 0x001a.
657 *
658 * Or in binary form
659 * @src @mask @dst
660 * 0000001100000010 0001001100010011 0000000000011010
661 *
662 * (Bits 0, 1, 4, 8, 9, 12 are copied to the bits 0, 1, 2, 3, 4, 5)
663 *
664 * A more 'visual' description of the operation::
665 *
666 * mask: ...v..vv...v..vv
667 * src: 0000001100000010
668 * ^ ^^ ^ 0
669 * | || | 10
670 * | || > 010
671 * | |+--> 1010
672 * | +--> 11010
673 * +----> 011010
674 * dst: 0000000000011010
675 *
676 * A relationship exists between bitmap_gather() and bitmap_scatter(). See
677 * bitmap_scatter() for the bitmap scatter detailed operations. TL;DR:
678 * bitmap_scatter() can be seen as the 'reverse' bitmap_gather() operation.
679 *
680 * Suppose scattered computed using bitmap_scatter(scattered, src, mask, n).
681 * The operation bitmap_gather(result, scattered, mask, n) leads to a result
682 * equal or equivalent to src.
683 *
684 * The result can be 'equivalent' because bitmap_scatter() and bitmap_gather()
685 * are not bijective.
686 * The result and src values are equivalent in that sense that a call to
687 * bitmap_scatter(res, src, mask, n) and a call to
688 * bitmap_scatter(res, result, mask, n) will lead to the same res value.
689 */
690 static __always_inline
bitmap_gather(unsigned long * dst,const unsigned long * src,const unsigned long * mask,unsigned int nbits)691 void bitmap_gather(unsigned long *dst, const unsigned long *src,
692 const unsigned long *mask, unsigned int nbits)
693 {
694 unsigned int n = 0;
695 unsigned int bit;
696
697 bitmap_zero(dst, nbits);
698
699 for_each_set_bit(bit, mask, nbits)
700 __assign_bit(n++, dst, test_bit(bit, src));
701 }
702
703 /**
704 * bitmap_release_region - release allocated bitmap region
705 * @bitmap: array of unsigned longs corresponding to the bitmap
706 * @pos: beginning of bit region to release
707 * @order: region size (log base 2 of number of bits) to release
708 *
709 * This is the complement to __bitmap_find_free_region() and releases
710 * the found region (by clearing it in the bitmap).
711 */
712 static __always_inline
bitmap_release_region(unsigned long * bitmap,unsigned int pos,int order)713 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
714 {
715 bitmap_clear(bitmap, pos, BIT(order));
716 }
717
718 /**
719 * bitmap_allocate_region - allocate bitmap region
720 * @bitmap: array of unsigned longs corresponding to the bitmap
721 * @pos: beginning of bit region to allocate
722 * @order: region size (log base 2 of number of bits) to allocate
723 *
724 * Allocate (set bits in) a specified region of a bitmap.
725 *
726 * Returns: 0 on success, or %-EBUSY if specified region wasn't
727 * free (not all bits were zero).
728 */
729 static __always_inline
bitmap_allocate_region(unsigned long * bitmap,unsigned int pos,int order)730 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
731 {
732 unsigned int len = BIT(order);
733
734 if (find_next_bit(bitmap, pos + len, pos) < pos + len)
735 return -EBUSY;
736 bitmap_set(bitmap, pos, len);
737 return 0;
738 }
739
740 /**
741 * bitmap_find_free_region - find a contiguous aligned mem region
742 * @bitmap: array of unsigned longs corresponding to the bitmap
743 * @bits: number of bits in the bitmap
744 * @order: region size (log base 2 of number of bits) to find
745 *
746 * Find a region of free (zero) bits in a @bitmap of @bits bits and
747 * allocate them (set them to one). Only consider regions of length
748 * a power (@order) of two, aligned to that power of two, which
749 * makes the search algorithm much faster.
750 *
751 * Returns: the bit offset in bitmap of the allocated region,
752 * or -errno on failure.
753 */
754 static __always_inline
bitmap_find_free_region(unsigned long * bitmap,unsigned int bits,int order)755 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
756 {
757 unsigned int pos, end; /* scans bitmap by regions of size order */
758
759 for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {
760 if (!bitmap_allocate_region(bitmap, pos, order))
761 return pos;
762 }
763 return -ENOMEM;
764 }
765
766 /**
767 * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
768 * @n: u64 value
769 *
770 * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
771 * integers in 32-bit environment, and 64-bit integers in 64-bit one.
772 *
773 * There are four combinations of endianness and length of the word in linux
774 * ABIs: LE64, BE64, LE32 and BE32.
775 *
776 * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
777 * bitmaps and therefore don't require any special handling.
778 *
779 * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
780 * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
781 * other hand is represented as an array of 32-bit words and the position of
782 * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
783 * word. For example, bit #42 is located at 10th position of 2nd word.
784 * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
785 * values in memory as it usually does. But for BE we need to swap hi and lo
786 * words manually.
787 *
788 * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
789 * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
790 * hi and lo words, as is expected by bitmap.
791 */
792 #if __BITS_PER_LONG == 64
793 #define BITMAP_FROM_U64(n) (n)
794 #else
795 #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
796 ((unsigned long) ((u64)(n) >> 32))
797 #endif
798
799 /**
800 * bitmap_from_u64 - Check and swap words within u64.
801 * @mask: source bitmap
802 * @dst: destination bitmap
803 *
804 * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
805 * to read u64 mask, we will get the wrong word.
806 * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
807 * but we expect the lower 32-bits of u64.
808 */
bitmap_from_u64(unsigned long * dst,u64 mask)809 static __always_inline void bitmap_from_u64(unsigned long *dst, u64 mask)
810 {
811 bitmap_from_arr64(dst, &mask, 64);
812 }
813
814 /**
815 * bitmap_read - read a value of n-bits from the memory region
816 * @map: address to the bitmap memory region
817 * @start: bit offset of the n-bit value
818 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG
819 *
820 * Returns: value of @nbits bits located at the @start bit offset within the
821 * @map memory region. For @nbits = 0 and @nbits > BITS_PER_LONG the return
822 * value is undefined.
823 */
824 static __always_inline
bitmap_read(const unsigned long * map,unsigned long start,unsigned long nbits)825 unsigned long bitmap_read(const unsigned long *map, unsigned long start, unsigned long nbits)
826 {
827 size_t index = BIT_WORD(start);
828 unsigned long offset = start % BITS_PER_LONG;
829 unsigned long space = BITS_PER_LONG - offset;
830 unsigned long value_low, value_high;
831
832 if (unlikely(!nbits || nbits > BITS_PER_LONG))
833 return 0;
834
835 if (space >= nbits)
836 return (map[index] >> offset) & BITMAP_LAST_WORD_MASK(nbits);
837
838 value_low = map[index] & BITMAP_FIRST_WORD_MASK(start);
839 value_high = map[index + 1] & BITMAP_LAST_WORD_MASK(start + nbits);
840 return (value_low >> offset) | (value_high << space);
841 }
842
843 /**
844 * bitmap_write - write n-bit value within a memory region
845 * @map: address to the bitmap memory region
846 * @value: value to write, clamped to nbits
847 * @start: bit offset of the n-bit value
848 * @nbits: size of value in bits, nonzero, up to BITS_PER_LONG.
849 *
850 * bitmap_write() behaves as-if implemented as @nbits calls of __assign_bit(),
851 * i.e. bits beyond @nbits are ignored:
852 *
853 * for (bit = 0; bit < nbits; bit++)
854 * __assign_bit(start + bit, bitmap, val & BIT(bit));
855 *
856 * For @nbits == 0 and @nbits > BITS_PER_LONG no writes are performed.
857 */
858 static __always_inline
bitmap_write(unsigned long * map,unsigned long value,unsigned long start,unsigned long nbits)859 void bitmap_write(unsigned long *map, unsigned long value,
860 unsigned long start, unsigned long nbits)
861 {
862 size_t index;
863 unsigned long offset;
864 unsigned long space;
865 unsigned long mask;
866 bool fit;
867
868 if (unlikely(!nbits || nbits > BITS_PER_LONG))
869 return;
870
871 mask = BITMAP_LAST_WORD_MASK(nbits);
872 value &= mask;
873 offset = start % BITS_PER_LONG;
874 space = BITS_PER_LONG - offset;
875 fit = space >= nbits;
876 index = BIT_WORD(start);
877
878 map[index] &= (fit ? (~(mask << offset)) : ~BITMAP_FIRST_WORD_MASK(start));
879 map[index] |= value << offset;
880 if (fit)
881 return;
882
883 map[index + 1] &= BITMAP_FIRST_WORD_MASK(start + nbits);
884 map[index + 1] |= (value >> space);
885 }
886
887 #define bitmap_get_value8(map, start) \
888 bitmap_read(map, start, BITS_PER_BYTE)
889 #define bitmap_set_value8(map, value, start) \
890 bitmap_write(map, value, start, BITS_PER_BYTE)
891
892 #endif /* __ASSEMBLER__ */
893
894 #endif /* __LINUX_BITMAP_H */
895