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