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