Line data Source code
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/find.h>
10 : #include <linux/limits.h>
11 : #include <linux/string.h>
12 : #include <linux/types.h>
13 :
14 : struct device;
15 :
16 : /*
17 : * bitmaps provide bit arrays that consume one or more unsigned
18 : * longs. The bitmap interface and available operations are listed
19 : * here, in bitmap.h
20 : *
21 : * Function implementations generic to all architectures are in
22 : * lib/bitmap.c. Functions implementations that are architecture
23 : * specific are in various include/asm-<arch>/bitops.h headers
24 : * and other arch/<arch> specific files.
25 : *
26 : * See lib/bitmap.c for more details.
27 : */
28 :
29 : /**
30 : * DOC: bitmap overview
31 : *
32 : * The available bitmap operations and their rough meaning in the
33 : * case that the bitmap is a single unsigned long are thus:
34 : *
35 : * The generated code is more efficient when nbits is known at
36 : * compile-time and at most BITS_PER_LONG.
37 : *
38 : * ::
39 : *
40 : * bitmap_zero(dst, nbits) *dst = 0UL
41 : * bitmap_fill(dst, nbits) *dst = ~0UL
42 : * bitmap_copy(dst, src, nbits) *dst = *src
43 : * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
44 : * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
45 : * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
46 : * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
47 : * bitmap_complement(dst, src, nbits) *dst = ~(*src)
48 : * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
49 : * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
50 : * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
51 : * bitmap_empty(src, nbits) Are all bits zero in *src?
52 : * bitmap_full(src, nbits) Are all bits set in *src?
53 : * bitmap_weight(src, nbits) Hamming Weight: number set bits
54 : * bitmap_weight_and(src1, src2, nbits) Hamming Weight of and'ed bitmap
55 : * bitmap_set(dst, pos, nbits) Set specified bit area
56 : * bitmap_clear(dst, pos, nbits) Clear specified bit area
57 : * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
58 : * bitmap_find_next_zero_area_off(buf, len, pos, n, mask, mask_off) as above
59 : * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
60 : * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
61 : * bitmap_cut(dst, src, first, n, nbits) Cut n bits from first, copy rest
62 : * bitmap_replace(dst, old, new, mask, nbits) *dst = (*old & ~(*mask)) | (*new & *mask)
63 : * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
64 : * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
65 : * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
66 : * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
67 : * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
68 : * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
69 : * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
70 : * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
71 : * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
72 : * bitmap_release_region(bitmap, pos, order) Free specified bit region
73 : * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
74 : * bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
75 : * bitmap_from_arr64(dst, buf, nbits) Copy nbits from u64[] buf to dst
76 : * bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
77 : * bitmap_to_arr64(buf, src, nbits) Copy nbits from buf to u64[] dst
78 : * bitmap_get_value8(map, start) Get 8bit value from map at start
79 : * bitmap_set_value8(map, value, start) Set 8bit value to map at start
80 : *
81 : * Note, bitmap_zero() and bitmap_fill() operate over the region of
82 : * unsigned longs, that is, bits behind bitmap till the unsigned long
83 : * boundary will be zeroed or filled as well. Consider to use
84 : * bitmap_clear() or bitmap_set() to make explicit zeroing or filling
85 : * respectively.
86 : */
87 :
88 : /**
89 : * DOC: bitmap bitops
90 : *
91 : * Also the following operations in asm/bitops.h apply to bitmaps.::
92 : *
93 : * set_bit(bit, addr) *addr |= bit
94 : * clear_bit(bit, addr) *addr &= ~bit
95 : * change_bit(bit, addr) *addr ^= bit
96 : * test_bit(bit, addr) Is bit set in *addr?
97 : * test_and_set_bit(bit, addr) Set bit and return old value
98 : * test_and_clear_bit(bit, addr) Clear bit and return old value
99 : * test_and_change_bit(bit, addr) Change bit and return old value
100 : * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
101 : * find_first_bit(addr, nbits) Position first set bit in *addr
102 : * find_next_zero_bit(addr, nbits, bit)
103 : * Position next zero bit in *addr >= bit
104 : * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
105 : * find_next_and_bit(addr1, addr2, nbits, bit)
106 : * Same as find_next_bit, but in
107 : * (*addr1 & *addr2)
108 : *
109 : */
110 :
111 : /**
112 : * DOC: declare bitmap
113 : * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
114 : * to declare an array named 'name' of just enough unsigned longs to
115 : * contain all bit positions from 0 to 'bits' - 1.
116 : */
117 :
118 : /*
119 : * Allocation and deallocation of bitmap.
120 : * Provided in lib/bitmap.c to avoid circular dependency.
121 : */
122 : unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
123 : unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
124 : unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node);
125 : unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node);
126 : void bitmap_free(const unsigned long *bitmap);
127 :
128 : /* Managed variants of the above. */
129 : unsigned long *devm_bitmap_alloc(struct device *dev,
130 : unsigned int nbits, gfp_t flags);
131 : unsigned long *devm_bitmap_zalloc(struct device *dev,
132 : unsigned int nbits, gfp_t flags);
133 :
134 : /*
135 : * lib/bitmap.c provides these functions:
136 : */
137 :
138 : bool __bitmap_equal(const unsigned long *bitmap1,
139 : const unsigned long *bitmap2, unsigned int nbits);
140 : bool __pure __bitmap_or_equal(const unsigned long *src1,
141 : const unsigned long *src2,
142 : const unsigned long *src3,
143 : unsigned int nbits);
144 : void __bitmap_complement(unsigned long *dst, const unsigned long *src,
145 : unsigned int nbits);
146 : void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
147 : unsigned int shift, unsigned int nbits);
148 : void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
149 : unsigned int shift, unsigned int nbits);
150 : void bitmap_cut(unsigned long *dst, const unsigned long *src,
151 : unsigned int first, unsigned int cut, unsigned int nbits);
152 : bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
153 : const unsigned long *bitmap2, unsigned int nbits);
154 : void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
155 : const unsigned long *bitmap2, unsigned int nbits);
156 : void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
157 : const unsigned long *bitmap2, unsigned int nbits);
158 : bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
159 : const unsigned long *bitmap2, unsigned int nbits);
160 : void __bitmap_replace(unsigned long *dst,
161 : const unsigned long *old, const unsigned long *new,
162 : const unsigned long *mask, unsigned int nbits);
163 : bool __bitmap_intersects(const unsigned long *bitmap1,
164 : const unsigned long *bitmap2, unsigned int nbits);
165 : bool __bitmap_subset(const unsigned long *bitmap1,
166 : const unsigned long *bitmap2, unsigned int nbits);
167 : unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
168 : unsigned int __bitmap_weight_and(const unsigned long *bitmap1,
169 : const unsigned long *bitmap2, unsigned int nbits);
170 : void __bitmap_set(unsigned long *map, unsigned int start, int len);
171 : void __bitmap_clear(unsigned long *map, unsigned int start, int len);
172 :
173 : unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
174 : unsigned long size,
175 : unsigned long start,
176 : unsigned int nr,
177 : unsigned long align_mask,
178 : unsigned long align_offset);
179 :
180 : /**
181 : * bitmap_find_next_zero_area - find a contiguous aligned zero area
182 : * @map: The address to base the search on
183 : * @size: The bitmap size in bits
184 : * @start: The bitnumber to start searching at
185 : * @nr: The number of zeroed bits we're looking for
186 : * @align_mask: Alignment mask for zero area
187 : *
188 : * The @align_mask should be one less than a power of 2; the effect is that
189 : * the bit offset of all zero areas this function finds is multiples of that
190 : * power of 2. A @align_mask of 0 means no alignment is required.
191 : */
192 : static inline unsigned long
193 : bitmap_find_next_zero_area(unsigned long *map,
194 : unsigned long size,
195 : unsigned long start,
196 : unsigned int nr,
197 : unsigned long align_mask)
198 : {
199 0 : return bitmap_find_next_zero_area_off(map, size, start, nr,
200 : align_mask, 0);
201 : }
202 :
203 : int bitmap_parse(const char *buf, unsigned int buflen,
204 : unsigned long *dst, int nbits);
205 : int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
206 : unsigned long *dst, int nbits);
207 : int bitmap_parselist(const char *buf, unsigned long *maskp,
208 : int nmaskbits);
209 : int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
210 : unsigned long *dst, int nbits);
211 : void bitmap_remap(unsigned long *dst, const unsigned long *src,
212 : const unsigned long *old, const unsigned long *new, unsigned int nbits);
213 : int bitmap_bitremap(int oldbit,
214 : const unsigned long *old, const unsigned long *new, int bits);
215 : void bitmap_onto(unsigned long *dst, const unsigned long *orig,
216 : const unsigned long *relmap, unsigned int bits);
217 : void bitmap_fold(unsigned long *dst, const unsigned long *orig,
218 : unsigned int sz, unsigned int nbits);
219 : int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
220 : void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
221 : int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
222 :
223 : #ifdef __BIG_ENDIAN
224 : void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
225 : #else
226 : #define bitmap_copy_le bitmap_copy
227 : #endif
228 : int bitmap_print_to_pagebuf(bool list, char *buf,
229 : const unsigned long *maskp, int nmaskbits);
230 :
231 : extern int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp,
232 : int nmaskbits, loff_t off, size_t count);
233 :
234 : extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
235 : int nmaskbits, loff_t off, size_t count);
236 :
237 : #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
238 : #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
239 :
240 0 : static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
241 : {
242 1 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
243 :
244 0 : if (small_const_nbits(nbits))
245 1 : *dst = 0;
246 : else
247 0 : memset(dst, 0, len);
248 0 : }
249 :
250 3 : static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
251 : {
252 851 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
253 :
254 3 : if (small_const_nbits(nbits))
255 848 : *dst = ~0UL;
256 : else
257 3 : memset(dst, 0xff, len);
258 3 : }
259 :
260 2 : static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
261 : unsigned int nbits)
262 : {
263 37 : unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
264 :
265 2 : if (small_const_nbits(nbits))
266 35 : *dst = *src;
267 : else
268 2 : memcpy(dst, src, len);
269 2 : }
270 :
271 : /*
272 : * Copy bitmap and clear tail bits in last word.
273 : */
274 : static inline void bitmap_copy_clear_tail(unsigned long *dst,
275 : const unsigned long *src, unsigned int nbits)
276 : {
277 : bitmap_copy(dst, src, nbits);
278 : if (nbits % BITS_PER_LONG)
279 : dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
280 : }
281 :
282 : /*
283 : * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
284 : * machines the order of hi and lo parts of numbers match the bitmap structure.
285 : * In both cases conversion is not needed when copying data from/to arrays of
286 : * u32. But in LE64 case, typecast in bitmap_copy_clear_tail() may lead
287 : * to out-of-bound access. To avoid that, both LE and BE variants of 64-bit
288 : * architectures are not using bitmap_copy_clear_tail().
289 : */
290 : #if BITS_PER_LONG == 64
291 : void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
292 : unsigned int nbits);
293 : void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
294 : unsigned int nbits);
295 : #else
296 : #define bitmap_from_arr32(bitmap, buf, nbits) \
297 : bitmap_copy_clear_tail((unsigned long *) (bitmap), \
298 : (const unsigned long *) (buf), (nbits))
299 : #define bitmap_to_arr32(buf, bitmap, nbits) \
300 : bitmap_copy_clear_tail((unsigned long *) (buf), \
301 : (const unsigned long *) (bitmap), (nbits))
302 : #endif
303 :
304 : /*
305 : * On 64-bit systems bitmaps are represented as u64 arrays internally. On LE32
306 : * machines the order of hi and lo parts of numbers match the bitmap structure.
307 : * In both cases conversion is not needed when copying data from/to arrays of
308 : * u64.
309 : */
310 : #if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN)
311 : void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits);
312 : void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits);
313 : #else
314 : #define bitmap_from_arr64(bitmap, buf, nbits) \
315 : bitmap_copy_clear_tail((unsigned long *)(bitmap), (const unsigned long *)(buf), (nbits))
316 : #define bitmap_to_arr64(buf, bitmap, nbits) \
317 : bitmap_copy_clear_tail((unsigned long *)(buf), (const unsigned long *)(bitmap), (nbits))
318 : #endif
319 :
320 : static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1,
321 : const unsigned long *src2, unsigned int nbits)
322 : {
323 : if (small_const_nbits(nbits))
324 7 : return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
325 : return __bitmap_and(dst, src1, src2, nbits);
326 : }
327 :
328 0 : static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
329 : const unsigned long *src2, unsigned int nbits)
330 : {
331 0 : if (small_const_nbits(nbits))
332 0 : *dst = *src1 | *src2;
333 : else
334 0 : __bitmap_or(dst, src1, src2, nbits);
335 0 : }
336 :
337 : static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
338 : const unsigned long *src2, unsigned int nbits)
339 : {
340 : if (small_const_nbits(nbits))
341 : *dst = *src1 ^ *src2;
342 : else
343 : __bitmap_xor(dst, src1, src2, nbits);
344 : }
345 :
346 : static inline bool bitmap_andnot(unsigned long *dst, const unsigned long *src1,
347 : const unsigned long *src2, unsigned int nbits)
348 : {
349 : if (small_const_nbits(nbits))
350 0 : return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
351 : return __bitmap_andnot(dst, src1, src2, nbits);
352 : }
353 :
354 : static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
355 : unsigned int nbits)
356 : {
357 : if (small_const_nbits(nbits))
358 : *dst = ~(*src);
359 : else
360 0 : __bitmap_complement(dst, src, nbits);
361 : }
362 :
363 : #ifdef __LITTLE_ENDIAN
364 : #define BITMAP_MEM_ALIGNMENT 8
365 : #else
366 : #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
367 : #endif
368 : #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
369 :
370 4 : static inline bool bitmap_equal(const unsigned long *src1,
371 : const unsigned long *src2, unsigned int nbits)
372 : {
373 4 : if (small_const_nbits(nbits))
374 4 : return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
375 0 : if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
376 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
377 0 : return !memcmp(src1, src2, nbits / 8);
378 0 : return __bitmap_equal(src1, src2, nbits);
379 : }
380 :
381 : /**
382 : * bitmap_or_equal - Check whether the or of two bitmaps is equal to a third
383 : * @src1: Pointer to bitmap 1
384 : * @src2: Pointer to bitmap 2 will be or'ed with bitmap 1
385 : * @src3: Pointer to bitmap 3. Compare to the result of *@src1 | *@src2
386 : * @nbits: number of bits in each of these bitmaps
387 : *
388 : * Returns: True if (*@src1 | *@src2) == *@src3, false otherwise
389 : */
390 : static inline bool bitmap_or_equal(const unsigned long *src1,
391 : const unsigned long *src2,
392 : const unsigned long *src3,
393 : unsigned int nbits)
394 : {
395 : if (!small_const_nbits(nbits))
396 : return __bitmap_or_equal(src1, src2, src3, nbits);
397 :
398 : return !(((*src1 | *src2) ^ *src3) & BITMAP_LAST_WORD_MASK(nbits));
399 : }
400 :
401 : static inline bool bitmap_intersects(const unsigned long *src1,
402 : const unsigned long *src2,
403 : unsigned int nbits)
404 : {
405 : if (small_const_nbits(nbits))
406 0 : return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
407 : else
408 : return __bitmap_intersects(src1, src2, nbits);
409 : }
410 :
411 : static inline bool bitmap_subset(const unsigned long *src1,
412 : const unsigned long *src2, unsigned int nbits)
413 : {
414 : if (small_const_nbits(nbits))
415 0 : return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
416 : else
417 0 : return __bitmap_subset(src1, src2, nbits);
418 : }
419 :
420 53 : static inline bool bitmap_empty(const unsigned long *src, unsigned nbits)
421 : {
422 53 : if (small_const_nbits(nbits))
423 58 : return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
424 :
425 0 : return find_first_bit(src, nbits) == nbits;
426 : }
427 :
428 : static inline bool bitmap_full(const unsigned long *src, unsigned int nbits)
429 : {
430 : if (small_const_nbits(nbits))
431 : return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
432 :
433 119 : return find_first_zero_bit(src, nbits) == nbits;
434 : }
435 :
436 : static __always_inline
437 : unsigned int bitmap_weight(const unsigned long *src, unsigned int nbits)
438 : {
439 1 : if (small_const_nbits(nbits))
440 8 : return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
441 0 : return __bitmap_weight(src, nbits);
442 : }
443 :
444 : static __always_inline
445 : unsigned long bitmap_weight_and(const unsigned long *src1,
446 : const unsigned long *src2, unsigned int nbits)
447 : {
448 : if (small_const_nbits(nbits))
449 : return hweight_long(*src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits));
450 : return __bitmap_weight_and(src1, src2, nbits);
451 : }
452 :
453 : static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
454 : unsigned int nbits)
455 : {
456 293 : if (__builtin_constant_p(nbits) && nbits == 1)
457 128 : __set_bit(start, map);
458 293 : else if (small_const_nbits(start + nbits))
459 0 : *map |= GENMASK(start + nbits - 1, start);
460 293 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
461 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
462 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
463 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
464 0 : memset((char *)map + start / 8, 0xff, nbits / 8);
465 : else
466 293 : __bitmap_set(map, start, nbits);
467 : }
468 :
469 : static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
470 : unsigned int nbits)
471 : {
472 359 : if (__builtin_constant_p(nbits) && nbits == 1)
473 0 : __clear_bit(start, map);
474 359 : else if (small_const_nbits(start + nbits))
475 0 : *map &= ~GENMASK(start + nbits - 1, start);
476 359 : else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
477 0 : IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
478 0 : __builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
479 : IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
480 0 : memset((char *)map + start / 8, 0, nbits / 8);
481 : else
482 359 : __bitmap_clear(map, start, nbits);
483 : }
484 :
485 : static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
486 : unsigned int shift, unsigned int nbits)
487 : {
488 : if (small_const_nbits(nbits))
489 : *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
490 : else
491 : __bitmap_shift_right(dst, src, shift, nbits);
492 : }
493 :
494 : static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
495 : unsigned int shift, unsigned int nbits)
496 : {
497 : if (small_const_nbits(nbits))
498 : *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
499 : else
500 : __bitmap_shift_left(dst, src, shift, nbits);
501 : }
502 :
503 : static inline void bitmap_replace(unsigned long *dst,
504 : const unsigned long *old,
505 : const unsigned long *new,
506 : const unsigned long *mask,
507 : unsigned int nbits)
508 : {
509 : if (small_const_nbits(nbits))
510 : *dst = (*old & ~(*mask)) | (*new & *mask);
511 : else
512 : __bitmap_replace(dst, old, new, mask, nbits);
513 : }
514 :
515 : static inline void bitmap_next_set_region(unsigned long *bitmap,
516 : unsigned int *rs, unsigned int *re,
517 : unsigned int end)
518 : {
519 : *rs = find_next_bit(bitmap, end, *rs);
520 : *re = find_next_zero_bit(bitmap, end, *rs + 1);
521 : }
522 :
523 : /**
524 : * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
525 : * @n: u64 value
526 : *
527 : * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
528 : * integers in 32-bit environment, and 64-bit integers in 64-bit one.
529 : *
530 : * There are four combinations of endianness and length of the word in linux
531 : * ABIs: LE64, BE64, LE32 and BE32.
532 : *
533 : * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
534 : * bitmaps and therefore don't require any special handling.
535 : *
536 : * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
537 : * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
538 : * other hand is represented as an array of 32-bit words and the position of
539 : * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
540 : * word. For example, bit #42 is located at 10th position of 2nd word.
541 : * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
542 : * values in memory as it usually does. But for BE we need to swap hi and lo
543 : * words manually.
544 : *
545 : * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
546 : * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
547 : * hi and lo words, as is expected by bitmap.
548 : */
549 : #if __BITS_PER_LONG == 64
550 : #define BITMAP_FROM_U64(n) (n)
551 : #else
552 : #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
553 : ((unsigned long) ((u64)(n) >> 32))
554 : #endif
555 :
556 : /**
557 : * bitmap_from_u64 - Check and swap words within u64.
558 : * @mask: source bitmap
559 : * @dst: destination bitmap
560 : *
561 : * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
562 : * to read u64 mask, we will get the wrong word.
563 : * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
564 : * but we expect the lower 32-bits of u64.
565 : */
566 : static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
567 : {
568 : bitmap_from_arr64(dst, &mask, 64);
569 : }
570 :
571 : /**
572 : * bitmap_get_value8 - get an 8-bit value within a memory region
573 : * @map: address to the bitmap memory region
574 : * @start: bit offset of the 8-bit value; must be a multiple of 8
575 : *
576 : * Returns the 8-bit value located at the @start bit offset within the @src
577 : * memory region.
578 : */
579 : static inline unsigned long bitmap_get_value8(const unsigned long *map,
580 : unsigned long start)
581 : {
582 0 : const size_t index = BIT_WORD(start);
583 0 : const unsigned long offset = start % BITS_PER_LONG;
584 :
585 0 : return (map[index] >> offset) & 0xFF;
586 : }
587 :
588 : /**
589 : * bitmap_set_value8 - set an 8-bit value within a memory region
590 : * @map: address to the bitmap memory region
591 : * @value: the 8-bit value; values wider than 8 bits may clobber bitmap
592 : * @start: bit offset of the 8-bit value; must be a multiple of 8
593 : */
594 : static inline void bitmap_set_value8(unsigned long *map, unsigned long value,
595 : unsigned long start)
596 : {
597 : const size_t index = BIT_WORD(start);
598 : const unsigned long offset = start % BITS_PER_LONG;
599 :
600 : map[index] &= ~(0xFFUL << offset);
601 : map[index] |= value << offset;
602 : }
603 :
604 : #endif /* __ASSEMBLY__ */
605 :
606 : #endif /* __LINUX_BITMAP_H */
|
