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