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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef __LINUX_BITMAP_H |
3 | #define __LINUX_BITMAP_H | |
4 | ||
5 | #ifndef __ASSEMBLY__ | |
6 | ||
7 | #include <linux/types.h> | |
8 | #include <linux/bitops.h> | |
9 | #include <linux/string.h> | |
14ed9d23 | 10 | #include <linux/kernel.h> |
1da177e4 LT |
11 | |
12 | /* | |
13 | * bitmaps provide bit arrays that consume one or more unsigned | |
14 | * longs. The bitmap interface and available operations are listed | |
15 | * here, in bitmap.h | |
16 | * | |
17 | * Function implementations generic to all architectures are in | |
18 | * lib/bitmap.c. Functions implementations that are architecture | |
19 | * specific are in various include/asm-<arch>/bitops.h headers | |
20 | * and other arch/<arch> specific files. | |
21 | * | |
22 | * See lib/bitmap.c for more details. | |
23 | */ | |
24 | ||
7d7363e4 RD |
25 | /** |
26 | * DOC: bitmap overview | |
27 | * | |
1da177e4 LT |
28 | * The available bitmap operations and their rough meaning in the |
29 | * case that the bitmap is a single unsigned long are thus: | |
30 | * | |
08cd3657 AK |
31 | * Note that nbits should be always a compile time evaluable constant. |
32 | * Otherwise many inlines will generate horrible code. | |
33 | * | |
7d7363e4 RD |
34 | * :: |
35 | * | |
36 | * bitmap_zero(dst, nbits) *dst = 0UL | |
37 | * bitmap_fill(dst, nbits) *dst = ~0UL | |
38 | * bitmap_copy(dst, src, nbits) *dst = *src | |
39 | * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2 | |
40 | * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2 | |
41 | * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2 | |
42 | * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2) | |
43 | * bitmap_complement(dst, src, nbits) *dst = ~(*src) | |
44 | * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal? | |
45 | * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap? | |
46 | * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2? | |
47 | * bitmap_empty(src, nbits) Are all bits zero in *src? | |
48 | * bitmap_full(src, nbits) Are all bits set in *src? | |
49 | * bitmap_weight(src, nbits) Hamming Weight: number set bits | |
50 | * bitmap_set(dst, pos, nbits) Set specified bit area | |
51 | * bitmap_clear(dst, pos, nbits) Clear specified bit area | |
52 | * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area | |
53 | * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above | |
54 | * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n | |
55 | * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n | |
56 | * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src) | |
57 | * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit) | |
58 | * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap | |
59 | * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz | |
60 | * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf | |
61 | * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf | |
62 | * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf | |
63 | * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf | |
64 | * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region | |
65 | * bitmap_release_region(bitmap, pos, order) Free specified bit region | |
66 | * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region | |
67 | * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) | |
68 | * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) | |
69 | * | |
1da177e4 LT |
70 | */ |
71 | ||
7d7363e4 RD |
72 | /** |
73 | * DOC: bitmap bitops | |
74 | * | |
75 | * Also the following operations in asm/bitops.h apply to bitmaps.:: | |
76 | * | |
77 | * set_bit(bit, addr) *addr |= bit | |
78 | * clear_bit(bit, addr) *addr &= ~bit | |
79 | * change_bit(bit, addr) *addr ^= bit | |
80 | * test_bit(bit, addr) Is bit set in *addr? | |
81 | * test_and_set_bit(bit, addr) Set bit and return old value | |
82 | * test_and_clear_bit(bit, addr) Clear bit and return old value | |
83 | * test_and_change_bit(bit, addr) Change bit and return old value | |
84 | * find_first_zero_bit(addr, nbits) Position first zero bit in *addr | |
85 | * find_first_bit(addr, nbits) Position first set bit in *addr | |
86 | * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit | |
87 | * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit | |
1da177e4 | 88 | * |
1da177e4 LT |
89 | */ |
90 | ||
7d7363e4 RD |
91 | /** |
92 | * DOC: declare bitmap | |
1da177e4 LT |
93 | * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used |
94 | * to declare an array named 'name' of just enough unsigned longs to | |
95 | * contain all bit positions from 0 to 'bits' - 1. | |
96 | */ | |
97 | ||
98 | /* | |
99 | * lib/bitmap.c provides these functions: | |
100 | */ | |
101 | ||
0679cc48 | 102 | extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits); |
8397927c | 103 | extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits); |
1da177e4 | 104 | extern int __bitmap_equal(const unsigned long *bitmap1, |
5e068069 | 105 | const unsigned long *bitmap2, unsigned int nbits); |
1da177e4 | 106 | extern void __bitmap_complement(unsigned long *dst, const unsigned long *src, |
3d6684f4 | 107 | unsigned int nbits); |
2fbad299 RV |
108 | extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
109 | unsigned int shift, unsigned int nbits); | |
dba94c25 RV |
110 | extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
111 | unsigned int shift, unsigned int nbits); | |
f4b0373b | 112 | extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 113 | const unsigned long *bitmap2, unsigned int nbits); |
1da177e4 | 114 | extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 115 | const unsigned long *bitmap2, unsigned int nbits); |
1da177e4 | 116 | extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 117 | const unsigned long *bitmap2, unsigned int nbits); |
f4b0373b | 118 | extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 119 | const unsigned long *bitmap2, unsigned int nbits); |
1da177e4 | 120 | extern int __bitmap_intersects(const unsigned long *bitmap1, |
6dfe9799 | 121 | const unsigned long *bitmap2, unsigned int nbits); |
1da177e4 | 122 | extern int __bitmap_subset(const unsigned long *bitmap1, |
5be20213 | 123 | const unsigned long *bitmap2, unsigned int nbits); |
877d9f3b | 124 | extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits); |
e5af323c MW |
125 | extern void __bitmap_set(unsigned long *map, unsigned int start, int len); |
126 | extern void __bitmap_clear(unsigned long *map, unsigned int start, int len); | |
5e19b013 MN |
127 | |
128 | extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map, | |
129 | unsigned long size, | |
130 | unsigned long start, | |
131 | unsigned int nr, | |
132 | unsigned long align_mask, | |
133 | unsigned long align_offset); | |
134 | ||
135 | /** | |
136 | * bitmap_find_next_zero_area - find a contiguous aligned zero area | |
137 | * @map: The address to base the search on | |
138 | * @size: The bitmap size in bits | |
139 | * @start: The bitnumber to start searching at | |
140 | * @nr: The number of zeroed bits we're looking for | |
141 | * @align_mask: Alignment mask for zero area | |
142 | * | |
143 | * The @align_mask should be one less than a power of 2; the effect is that | |
144 | * the bit offset of all zero areas this function finds is multiples of that | |
145 | * power of 2. A @align_mask of 0 means no alignment is required. | |
146 | */ | |
147 | static inline unsigned long | |
148 | bitmap_find_next_zero_area(unsigned long *map, | |
149 | unsigned long size, | |
150 | unsigned long start, | |
151 | unsigned int nr, | |
152 | unsigned long align_mask) | |
153 | { | |
154 | return bitmap_find_next_zero_area_off(map, size, start, nr, | |
155 | align_mask, 0); | |
156 | } | |
c1a2a962 | 157 | |
01a3ee2b RC |
158 | extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, |
159 | unsigned long *dst, int nbits); | |
160 | extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, | |
1da177e4 | 161 | unsigned long *dst, int nbits); |
1da177e4 LT |
162 | extern int bitmap_parselist(const char *buf, unsigned long *maskp, |
163 | int nmaskbits); | |
4b060420 MT |
164 | extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, |
165 | unsigned long *dst, int nbits); | |
fb5eeeee | 166 | extern void bitmap_remap(unsigned long *dst, const unsigned long *src, |
9814ec13 | 167 | const unsigned long *old, const unsigned long *new, unsigned int nbits); |
fb5eeeee PJ |
168 | extern int bitmap_bitremap(int oldbit, |
169 | const unsigned long *old, const unsigned long *new, int bits); | |
7ea931c9 | 170 | extern void bitmap_onto(unsigned long *dst, const unsigned long *orig, |
eb569883 | 171 | const unsigned long *relmap, unsigned int bits); |
7ea931c9 | 172 | extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, |
b26ad583 | 173 | unsigned int sz, unsigned int nbits); |
9279d328 RV |
174 | extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order); |
175 | extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order); | |
176 | extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); | |
e52bc7c2 DD |
177 | extern unsigned int bitmap_from_u32array(unsigned long *bitmap, |
178 | unsigned int nbits, | |
179 | const u32 *buf, | |
180 | unsigned int nwords); | |
181 | extern unsigned int bitmap_to_u32array(u32 *buf, | |
182 | unsigned int nwords, | |
183 | const unsigned long *bitmap, | |
184 | unsigned int nbits); | |
e8f24278 | 185 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 186 | extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); |
e8f24278 RV |
187 | #else |
188 | #define bitmap_copy_le bitmap_copy | |
189 | #endif | |
f6a1f5db | 190 | extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits); |
5aaba363 SH |
191 | extern int bitmap_print_to_pagebuf(bool list, char *buf, |
192 | const unsigned long *maskp, int nmaskbits); | |
1da177e4 | 193 | |
89c1e79e RV |
194 | #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1))) |
195 | #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1))) | |
1da177e4 | 196 | |
4b0bc0bc RR |
197 | #define small_const_nbits(nbits) \ |
198 | (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG) | |
199 | ||
8b4daad5 | 200 | static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) |
1da177e4 | 201 | { |
4b0bc0bc | 202 | if (small_const_nbits(nbits)) |
1da177e4 LT |
203 | *dst = 0UL; |
204 | else { | |
8b4daad5 | 205 | unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); |
1da177e4 LT |
206 | memset(dst, 0, len); |
207 | } | |
208 | } | |
209 | ||
8b4daad5 | 210 | static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) |
1da177e4 | 211 | { |
8b4daad5 | 212 | unsigned int nlongs = BITS_TO_LONGS(nbits); |
4b0bc0bc | 213 | if (!small_const_nbits(nbits)) { |
8b4daad5 | 214 | unsigned int len = (nlongs - 1) * sizeof(unsigned long); |
1da177e4 LT |
215 | memset(dst, 0xff, len); |
216 | } | |
217 | dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); | |
218 | } | |
219 | ||
220 | static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, | |
8b4daad5 | 221 | unsigned int nbits) |
1da177e4 | 222 | { |
4b0bc0bc | 223 | if (small_const_nbits(nbits)) |
1da177e4 LT |
224 | *dst = *src; |
225 | else { | |
8b4daad5 | 226 | unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); |
1da177e4 LT |
227 | memcpy(dst, src, len); |
228 | } | |
229 | } | |
230 | ||
f4b0373b | 231 | static inline int bitmap_and(unsigned long *dst, const unsigned long *src1, |
2f9305eb | 232 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 233 | { |
4b0bc0bc | 234 | if (small_const_nbits(nbits)) |
7e5f97d1 | 235 | return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0; |
f4b0373b | 236 | return __bitmap_and(dst, src1, src2, nbits); |
1da177e4 LT |
237 | } |
238 | ||
239 | static inline void bitmap_or(unsigned long *dst, const unsigned long *src1, | |
2f9305eb | 240 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 241 | { |
4b0bc0bc | 242 | if (small_const_nbits(nbits)) |
1da177e4 LT |
243 | *dst = *src1 | *src2; |
244 | else | |
245 | __bitmap_or(dst, src1, src2, nbits); | |
246 | } | |
247 | ||
248 | static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1, | |
2f9305eb | 249 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 250 | { |
4b0bc0bc | 251 | if (small_const_nbits(nbits)) |
1da177e4 LT |
252 | *dst = *src1 ^ *src2; |
253 | else | |
254 | __bitmap_xor(dst, src1, src2, nbits); | |
255 | } | |
256 | ||
f4b0373b | 257 | static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1, |
2f9305eb | 258 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 259 | { |
4b0bc0bc | 260 | if (small_const_nbits(nbits)) |
74e76531 | 261 | return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; |
f4b0373b | 262 | return __bitmap_andnot(dst, src1, src2, nbits); |
1da177e4 LT |
263 | } |
264 | ||
265 | static inline void bitmap_complement(unsigned long *dst, const unsigned long *src, | |
3d6684f4 | 266 | unsigned int nbits) |
1da177e4 | 267 | { |
4b0bc0bc | 268 | if (small_const_nbits(nbits)) |
65b4ee62 | 269 | *dst = ~(*src); |
1da177e4 LT |
270 | else |
271 | __bitmap_complement(dst, src, nbits); | |
272 | } | |
273 | ||
274 | static inline int bitmap_equal(const unsigned long *src1, | |
3d6684f4 | 275 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 276 | { |
4b0bc0bc | 277 | if (small_const_nbits(nbits)) |
4b9d314c | 278 | return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)); |
2c6deb01 | 279 | if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) |
7dd96816 | 280 | return !memcmp(src1, src2, nbits / 8); |
4b9d314c | 281 | return __bitmap_equal(src1, src2, nbits); |
1da177e4 LT |
282 | } |
283 | ||
284 | static inline int bitmap_intersects(const unsigned long *src1, | |
6dfe9799 | 285 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 286 | { |
4b0bc0bc | 287 | if (small_const_nbits(nbits)) |
1da177e4 LT |
288 | return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0; |
289 | else | |
290 | return __bitmap_intersects(src1, src2, nbits); | |
291 | } | |
292 | ||
293 | static inline int bitmap_subset(const unsigned long *src1, | |
5be20213 | 294 | const unsigned long *src2, unsigned int nbits) |
1da177e4 | 295 | { |
4b0bc0bc | 296 | if (small_const_nbits(nbits)) |
1da177e4 LT |
297 | return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits)); |
298 | else | |
299 | return __bitmap_subset(src1, src2, nbits); | |
300 | } | |
301 | ||
0679cc48 | 302 | static inline int bitmap_empty(const unsigned long *src, unsigned nbits) |
1da177e4 | 303 | { |
4b0bc0bc | 304 | if (small_const_nbits(nbits)) |
1da177e4 | 305 | return ! (*src & BITMAP_LAST_WORD_MASK(nbits)); |
2afe27c7 YN |
306 | |
307 | return find_first_bit(src, nbits) == nbits; | |
1da177e4 LT |
308 | } |
309 | ||
8397927c | 310 | static inline int bitmap_full(const unsigned long *src, unsigned int nbits) |
1da177e4 | 311 | { |
4b0bc0bc | 312 | if (small_const_nbits(nbits)) |
1da177e4 | 313 | return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits)); |
2afe27c7 YN |
314 | |
315 | return find_first_zero_bit(src, nbits) == nbits; | |
1da177e4 LT |
316 | } |
317 | ||
1a1d48a4 | 318 | static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits) |
1da177e4 | 319 | { |
4b0bc0bc | 320 | if (small_const_nbits(nbits)) |
08cd3657 | 321 | return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits)); |
1da177e4 LT |
322 | return __bitmap_weight(src, nbits); |
323 | } | |
324 | ||
e5af323c MW |
325 | static __always_inline void bitmap_set(unsigned long *map, unsigned int start, |
326 | unsigned int nbits) | |
327 | { | |
328 | if (__builtin_constant_p(nbits) && nbits == 1) | |
329 | __set_bit(start, map); | |
2a98dc02 MW |
330 | else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && |
331 | __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) | |
332 | memset((char *)map + start / 8, 0xff, nbits / 8); | |
e5af323c MW |
333 | else |
334 | __bitmap_set(map, start, nbits); | |
335 | } | |
336 | ||
337 | static __always_inline void bitmap_clear(unsigned long *map, unsigned int start, | |
338 | unsigned int nbits) | |
339 | { | |
340 | if (__builtin_constant_p(nbits) && nbits == 1) | |
341 | __clear_bit(start, map); | |
2a98dc02 MW |
342 | else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) && |
343 | __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8)) | |
344 | memset((char *)map + start / 8, 0, nbits / 8); | |
e5af323c MW |
345 | else |
346 | __bitmap_clear(map, start, nbits); | |
347 | } | |
348 | ||
2fbad299 RV |
349 | static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
350 | unsigned int shift, int nbits) | |
1da177e4 | 351 | { |
4b0bc0bc | 352 | if (small_const_nbits(nbits)) |
2fbad299 | 353 | *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift; |
1da177e4 | 354 | else |
2fbad299 | 355 | __bitmap_shift_right(dst, src, shift, nbits); |
1da177e4 LT |
356 | } |
357 | ||
dba94c25 RV |
358 | static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
359 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 360 | { |
4b0bc0bc | 361 | if (small_const_nbits(nbits)) |
dba94c25 | 362 | *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 | 363 | else |
dba94c25 | 364 | __bitmap_shift_left(dst, src, shift, nbits); |
1da177e4 LT |
365 | } |
366 | ||
01a3ee2b RC |
367 | static inline int bitmap_parse(const char *buf, unsigned int buflen, |
368 | unsigned long *maskp, int nmaskbits) | |
369 | { | |
370 | return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits); | |
371 | } | |
372 | ||
404376af | 373 | /** |
60ef6900 | 374 | * BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap. |
404376af | 375 | * @n: u64 value |
60ef6900 YN |
376 | * |
377 | * Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit | |
378 | * integers in 32-bit environment, and 64-bit integers in 64-bit one. | |
379 | * | |
380 | * There are four combinations of endianness and length of the word in linux | |
381 | * ABIs: LE64, BE64, LE32 and BE32. | |
382 | * | |
383 | * On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in | |
384 | * bitmaps and therefore don't require any special handling. | |
385 | * | |
386 | * On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory | |
387 | * prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the | |
388 | * other hand is represented as an array of 32-bit words and the position of | |
389 | * bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that | |
390 | * word. For example, bit #42 is located at 10th position of 2nd word. | |
391 | * It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit | |
392 | * values in memory as it usually does. But for BE we need to swap hi and lo | |
393 | * words manually. | |
394 | * | |
395 | * With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and | |
396 | * lo parts of u64. For LE32 it does nothing, and for BE environment it swaps | |
397 | * hi and lo words, as is expected by bitmap. | |
398 | */ | |
399 | #if __BITS_PER_LONG == 64 | |
400 | #define BITMAP_FROM_U64(n) (n) | |
401 | #else | |
402 | #define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \ | |
403 | ((unsigned long) ((u64)(n) >> 32)) | |
404 | #endif | |
405 | ||
404376af | 406 | /** |
29dd3288 MS |
407 | * bitmap_from_u64 - Check and swap words within u64. |
408 | * @mask: source bitmap | |
409 | * @dst: destination bitmap | |
410 | * | |
404376af | 411 | * In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]`` |
29dd3288 | 412 | * to read u64 mask, we will get the wrong word. |
404376af | 413 | * That is ``(u32 *)(&val)[0]`` gets the upper 32 bits, |
29dd3288 MS |
414 | * but we expect the lower 32-bits of u64. |
415 | */ | |
416 | static inline void bitmap_from_u64(unsigned long *dst, u64 mask) | |
417 | { | |
418 | dst[0] = mask & ULONG_MAX; | |
419 | ||
420 | if (sizeof(mask) > sizeof(unsigned long)) | |
421 | dst[1] = mask >> 32; | |
422 | } | |
423 | ||
1da177e4 LT |
424 | #endif /* __ASSEMBLY__ */ |
425 | ||
426 | #endif /* __LINUX_BITMAP_H */ |