Commit | Line | Data |
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40b0b3f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * lib/bitmap.c | |
4 | * Helper functions for bitmap.h. | |
1da177e4 | 5 | */ |
c13656b9 | 6 | |
1da177e4 LT |
7 | #include <linux/bitmap.h> |
8 | #include <linux/bitops.h> | |
c13656b9 | 9 | #include <linux/ctype.h> |
e829c2e4 | 10 | #include <linux/device.h> |
c13656b9 | 11 | #include <linux/export.h> |
c42b65e3 | 12 | #include <linux/slab.h> |
e371c481 | 13 | |
7d7363e4 RD |
14 | /** |
15 | * DOC: bitmap introduction | |
16 | * | |
197d6c1d | 17 | * bitmaps provide an array of bits, implemented using an |
1da177e4 LT |
18 | * array of unsigned longs. The number of valid bits in a |
19 | * given bitmap does _not_ need to be an exact multiple of | |
20 | * BITS_PER_LONG. | |
21 | * | |
22 | * The possible unused bits in the last, partially used word | |
23 | * of a bitmap are 'don't care'. The implementation makes | |
24 | * no particular effort to keep them zero. It ensures that | |
25 | * their value will not affect the results of any operation. | |
26 | * The bitmap operations that return Boolean (bitmap_empty, | |
27 | * for example) or scalar (bitmap_weight, for example) results | |
28 | * carefully filter out these unused bits from impacting their | |
29 | * results. | |
30 | * | |
1da177e4 LT |
31 | * The byte ordering of bitmaps is more natural on little |
32 | * endian architectures. See the big-endian headers | |
33 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
34 | * for the best explanations of this ordering. | |
35 | */ | |
36 | ||
005f1700 KC |
37 | bool __bitmap_equal(const unsigned long *bitmap1, |
38 | const unsigned long *bitmap2, unsigned int bits) | |
1da177e4 | 39 | { |
5e068069 | 40 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
41 | for (k = 0; k < lim; ++k) |
42 | if (bitmap1[k] != bitmap2[k]) | |
005f1700 | 43 | return false; |
1da177e4 LT |
44 | |
45 | if (bits % BITS_PER_LONG) | |
46 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
005f1700 | 47 | return false; |
1da177e4 | 48 | |
005f1700 | 49 | return true; |
1da177e4 LT |
50 | } |
51 | EXPORT_SYMBOL(__bitmap_equal); | |
52 | ||
b9fa6442 TG |
53 | bool __bitmap_or_equal(const unsigned long *bitmap1, |
54 | const unsigned long *bitmap2, | |
55 | const unsigned long *bitmap3, | |
56 | unsigned int bits) | |
57 | { | |
58 | unsigned int k, lim = bits / BITS_PER_LONG; | |
59 | unsigned long tmp; | |
60 | ||
61 | for (k = 0; k < lim; ++k) { | |
62 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) | |
63 | return false; | |
64 | } | |
65 | ||
66 | if (!(bits % BITS_PER_LONG)) | |
67 | return true; | |
68 | ||
69 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; | |
70 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; | |
71 | } | |
72 | ||
3d6684f4 | 73 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 74 | { |
ca1250bb | 75 | unsigned int k, lim = BITS_TO_LONGS(bits); |
1da177e4 LT |
76 | for (k = 0; k < lim; ++k) |
77 | dst[k] = ~src[k]; | |
1da177e4 LT |
78 | } |
79 | EXPORT_SYMBOL(__bitmap_complement); | |
80 | ||
72fd4a35 | 81 | /** |
1da177e4 | 82 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
83 | * @dst : destination bitmap |
84 | * @src : source bitmap | |
85 | * @shift : shift by this many bits | |
2fbad299 | 86 | * @nbits : bitmap size, in bits |
1da177e4 LT |
87 | * |
88 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
89 | * direction. Zeros are fed into the vacated MS positions and the | |
90 | * LS bits shifted off the bottom are lost. | |
91 | */ | |
2fbad299 RV |
92 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
93 | unsigned shift, unsigned nbits) | |
1da177e4 | 94 | { |
cfac1d08 | 95 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 96 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 97 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
98 | for (k = 0; off + k < lim; ++k) { |
99 | unsigned long upper, lower; | |
100 | ||
101 | /* | |
102 | * If shift is not word aligned, take lower rem bits of | |
103 | * word above and make them the top rem bits of result. | |
104 | */ | |
105 | if (!rem || off + k + 1 >= lim) | |
106 | upper = 0; | |
107 | else { | |
108 | upper = src[off + k + 1]; | |
cfac1d08 | 109 | if (off + k + 1 == lim - 1) |
1da177e4 | 110 | upper &= mask; |
9d8a6b2a | 111 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
112 | } |
113 | lower = src[off + k]; | |
cfac1d08 | 114 | if (off + k == lim - 1) |
1da177e4 | 115 | lower &= mask; |
9d8a6b2a RV |
116 | lower >>= rem; |
117 | dst[k] = lower | upper; | |
1da177e4 LT |
118 | } |
119 | if (off) | |
120 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
121 | } | |
122 | EXPORT_SYMBOL(__bitmap_shift_right); | |
123 | ||
124 | ||
72fd4a35 | 125 | /** |
1da177e4 | 126 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
127 | * @dst : destination bitmap |
128 | * @src : source bitmap | |
129 | * @shift : shift by this many bits | |
dba94c25 | 130 | * @nbits : bitmap size, in bits |
1da177e4 LT |
131 | * |
132 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
133 | * direction. Zeros are fed into the vacated LS bit positions | |
134 | * and those MS bits shifted off the top are lost. | |
135 | */ | |
136 | ||
dba94c25 RV |
137 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
138 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 139 | { |
dba94c25 | 140 | int k; |
7f590657 | 141 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 142 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
143 | for (k = lim - off - 1; k >= 0; --k) { |
144 | unsigned long upper, lower; | |
145 | ||
146 | /* | |
147 | * If shift is not word aligned, take upper rem bits of | |
148 | * word below and make them the bottom rem bits of result. | |
149 | */ | |
150 | if (rem && k > 0) | |
6d874eca | 151 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
152 | else |
153 | lower = 0; | |
7f590657 | 154 | upper = src[k] << rem; |
6d874eca | 155 | dst[k + off] = lower | upper; |
1da177e4 LT |
156 | } |
157 | if (off) | |
158 | memset(dst, 0, off*sizeof(unsigned long)); | |
159 | } | |
160 | EXPORT_SYMBOL(__bitmap_shift_left); | |
161 | ||
20927671 SB |
162 | /** |
163 | * bitmap_cut() - remove bit region from bitmap and right shift remaining bits | |
164 | * @dst: destination bitmap, might overlap with src | |
165 | * @src: source bitmap | |
166 | * @first: start bit of region to be removed | |
167 | * @cut: number of bits to remove | |
168 | * @nbits: bitmap size, in bits | |
169 | * | |
170 | * Set the n-th bit of @dst iff the n-th bit of @src is set and | |
171 | * n is less than @first, or the m-th bit of @src is set for any | |
172 | * m such that @first <= n < nbits, and m = n + @cut. | |
173 | * | |
174 | * In pictures, example for a big-endian 32-bit architecture: | |
175 | * | |
4642289b | 176 | * The @src bitmap is:: |
20927671 | 177 | * |
4642289b MCC |
178 | * 31 63 |
179 | * | | | |
180 | * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 | |
181 | * | | | | | |
182 | * 16 14 0 32 | |
20927671 | 183 | * |
4642289b MCC |
184 | * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: |
185 | * | |
186 | * 31 63 | |
187 | * | | | |
188 | * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 | |
189 | * | | | | |
190 | * 14 (bit 17 0 32 | |
191 | * from @src) | |
20927671 SB |
192 | * |
193 | * Note that @dst and @src might overlap partially or entirely. | |
194 | * | |
195 | * This is implemented in the obvious way, with a shift and carry | |
196 | * step for each moved bit. Optimisation is left as an exercise | |
197 | * for the compiler. | |
198 | */ | |
199 | void bitmap_cut(unsigned long *dst, const unsigned long *src, | |
200 | unsigned int first, unsigned int cut, unsigned int nbits) | |
201 | { | |
202 | unsigned int len = BITS_TO_LONGS(nbits); | |
203 | unsigned long keep = 0, carry; | |
204 | int i; | |
205 | ||
20927671 SB |
206 | if (first % BITS_PER_LONG) { |
207 | keep = src[first / BITS_PER_LONG] & | |
208 | (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); | |
209 | } | |
210 | ||
5959f829 SB |
211 | memmove(dst, src, len * sizeof(*dst)); |
212 | ||
20927671 SB |
213 | while (cut--) { |
214 | for (i = first / BITS_PER_LONG; i < len; i++) { | |
215 | if (i < len - 1) | |
216 | carry = dst[i + 1] & 1UL; | |
217 | else | |
218 | carry = 0; | |
219 | ||
220 | dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); | |
221 | } | |
222 | } | |
223 | ||
224 | dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); | |
225 | dst[first / BITS_PER_LONG] |= keep; | |
226 | } | |
227 | EXPORT_SYMBOL(bitmap_cut); | |
228 | ||
e2863a78 | 229 | bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 230 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 231 | { |
2f9305eb | 232 | unsigned int k; |
7e5f97d1 | 233 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 234 | unsigned long result = 0; |
1da177e4 | 235 | |
7e5f97d1 | 236 | for (k = 0; k < lim; k++) |
f4b0373b | 237 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
238 | if (bits % BITS_PER_LONG) |
239 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
240 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 241 | return result != 0; |
1da177e4 LT |
242 | } |
243 | EXPORT_SYMBOL(__bitmap_and); | |
244 | ||
245 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 246 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 247 | { |
2f9305eb RV |
248 | unsigned int k; |
249 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
250 | |
251 | for (k = 0; k < nr; k++) | |
252 | dst[k] = bitmap1[k] | bitmap2[k]; | |
253 | } | |
254 | EXPORT_SYMBOL(__bitmap_or); | |
255 | ||
256 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 257 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 258 | { |
2f9305eb RV |
259 | unsigned int k; |
260 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
261 | |
262 | for (k = 0; k < nr; k++) | |
263 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
264 | } | |
265 | EXPORT_SYMBOL(__bitmap_xor); | |
266 | ||
e2863a78 | 267 | bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 268 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 269 | { |
2f9305eb | 270 | unsigned int k; |
74e76531 | 271 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 272 | unsigned long result = 0; |
1da177e4 | 273 | |
74e76531 | 274 | for (k = 0; k < lim; k++) |
f4b0373b | 275 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
276 | if (bits % BITS_PER_LONG) |
277 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
278 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 279 | return result != 0; |
1da177e4 LT |
280 | } |
281 | EXPORT_SYMBOL(__bitmap_andnot); | |
282 | ||
30544ed5 AS |
283 | void __bitmap_replace(unsigned long *dst, |
284 | const unsigned long *old, const unsigned long *new, | |
285 | const unsigned long *mask, unsigned int nbits) | |
286 | { | |
287 | unsigned int k; | |
288 | unsigned int nr = BITS_TO_LONGS(nbits); | |
289 | ||
290 | for (k = 0; k < nr; k++) | |
291 | dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); | |
292 | } | |
293 | EXPORT_SYMBOL(__bitmap_replace); | |
294 | ||
005f1700 KC |
295 | bool __bitmap_intersects(const unsigned long *bitmap1, |
296 | const unsigned long *bitmap2, unsigned int bits) | |
1da177e4 | 297 | { |
6dfe9799 | 298 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
299 | for (k = 0; k < lim; ++k) |
300 | if (bitmap1[k] & bitmap2[k]) | |
005f1700 | 301 | return true; |
1da177e4 LT |
302 | |
303 | if (bits % BITS_PER_LONG) | |
304 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
005f1700 KC |
305 | return true; |
306 | return false; | |
1da177e4 LT |
307 | } |
308 | EXPORT_SYMBOL(__bitmap_intersects); | |
309 | ||
005f1700 KC |
310 | bool __bitmap_subset(const unsigned long *bitmap1, |
311 | const unsigned long *bitmap2, unsigned int bits) | |
1da177e4 | 312 | { |
5be20213 | 313 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
314 | for (k = 0; k < lim; ++k) |
315 | if (bitmap1[k] & ~bitmap2[k]) | |
005f1700 | 316 | return false; |
1da177e4 LT |
317 | |
318 | if (bits % BITS_PER_LONG) | |
319 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
005f1700 KC |
320 | return false; |
321 | return true; | |
1da177e4 LT |
322 | } |
323 | EXPORT_SYMBOL(__bitmap_subset); | |
324 | ||
24291caf YN |
325 | #define BITMAP_WEIGHT(FETCH, bits) \ |
326 | ({ \ | |
327 | unsigned int __bits = (bits), idx, w = 0; \ | |
328 | \ | |
329 | for (idx = 0; idx < __bits / BITS_PER_LONG; idx++) \ | |
330 | w += hweight_long(FETCH); \ | |
331 | \ | |
332 | if (__bits % BITS_PER_LONG) \ | |
333 | w += hweight_long((FETCH) & BITMAP_LAST_WORD_MASK(__bits)); \ | |
334 | \ | |
335 | w; \ | |
336 | }) | |
337 | ||
4e23eeeb | 338 | unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 339 | { |
24291caf | 340 | return BITMAP_WEIGHT(bitmap[idx], bits); |
1da177e4 | 341 | } |
1da177e4 LT |
342 | EXPORT_SYMBOL(__bitmap_weight); |
343 | ||
24291caf YN |
344 | unsigned int __bitmap_weight_and(const unsigned long *bitmap1, |
345 | const unsigned long *bitmap2, unsigned int bits) | |
346 | { | |
347 | return BITMAP_WEIGHT(bitmap1[idx] & bitmap2[idx], bits); | |
348 | } | |
349 | EXPORT_SYMBOL(__bitmap_weight_and); | |
350 | ||
e5af323c | 351 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
352 | { |
353 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 354 | const unsigned int size = start + len; |
c1a2a962 AM |
355 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
356 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
357 | ||
fb5ac542 | 358 | while (len - bits_to_set >= 0) { |
c1a2a962 | 359 | *p |= mask_to_set; |
fb5ac542 | 360 | len -= bits_to_set; |
c1a2a962 AM |
361 | bits_to_set = BITS_PER_LONG; |
362 | mask_to_set = ~0UL; | |
363 | p++; | |
364 | } | |
fb5ac542 | 365 | if (len) { |
c1a2a962 AM |
366 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
367 | *p |= mask_to_set; | |
368 | } | |
369 | } | |
e5af323c | 370 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 371 | |
e5af323c | 372 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
373 | { |
374 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 375 | const unsigned int size = start + len; |
c1a2a962 AM |
376 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
377 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
378 | ||
154f5e38 | 379 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 380 | *p &= ~mask_to_clear; |
154f5e38 | 381 | len -= bits_to_clear; |
c1a2a962 AM |
382 | bits_to_clear = BITS_PER_LONG; |
383 | mask_to_clear = ~0UL; | |
384 | p++; | |
385 | } | |
154f5e38 | 386 | if (len) { |
c1a2a962 AM |
387 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
388 | *p &= ~mask_to_clear; | |
389 | } | |
390 | } | |
e5af323c | 391 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 392 | |
5e19b013 MN |
393 | /** |
394 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
395 | * @map: The address to base the search on |
396 | * @size: The bitmap size in bits | |
397 | * @start: The bitnumber to start searching at | |
398 | * @nr: The number of zeroed bits we're looking for | |
399 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 400 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
401 | * |
402 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
403 | * the bit offset of all zero areas this function finds plus @align_offset |
404 | * is multiple of that power of 2. | |
c1a2a962 | 405 | */ |
5e19b013 MN |
406 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
407 | unsigned long size, | |
408 | unsigned long start, | |
409 | unsigned int nr, | |
410 | unsigned long align_mask, | |
411 | unsigned long align_offset) | |
c1a2a962 AM |
412 | { |
413 | unsigned long index, end, i; | |
414 | again: | |
415 | index = find_next_zero_bit(map, size, start); | |
416 | ||
417 | /* Align allocation */ | |
5e19b013 | 418 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
419 | |
420 | end = index + nr; | |
421 | if (end > size) | |
422 | return end; | |
423 | i = find_next_bit(map, end, index); | |
424 | if (i < end) { | |
425 | start = i + 1; | |
426 | goto again; | |
427 | } | |
428 | return index; | |
429 | } | |
5e19b013 | 430 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 431 | |
72fd4a35 | 432 | /** |
9a86e2ba | 433 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 434 | * @buf: pointer to a bitmap |
df1d80a9 RV |
435 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
436 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 437 | * |
df1d80a9 | 438 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 439 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 440 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
441 | * |
442 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
443 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 444 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
445 | * gets mapped to (returns) @ord value 3 in this example, that means |
446 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
447 | * | |
448 | * The bit positions 0 through @bits are valid positions in @buf. | |
449 | */ | |
df1d80a9 | 450 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 451 | { |
df1d80a9 | 452 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 453 | return -1; |
fb5eeeee | 454 | |
70a1cb10 | 455 | return bitmap_weight(buf, pos); |
fb5eeeee PJ |
456 | } |
457 | ||
fb5eeeee PJ |
458 | /** |
459 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 460 | * @dst: remapped result |
96b7f341 | 461 | * @src: subset to be remapped |
fb5eeeee PJ |
462 | * @old: defines domain of map |
463 | * @new: defines range of map | |
9814ec13 | 464 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
465 | * |
466 | * Let @old and @new define a mapping of bit positions, such that | |
467 | * whatever position is held by the n-th set bit in @old is mapped | |
468 | * to the n-th set bit in @new. In the more general case, allowing | |
469 | * for the possibility that the weight 'w' of @new is less than the | |
470 | * weight of @old, map the position of the n-th set bit in @old to | |
471 | * the position of the m-th set bit in @new, where m == n % w. | |
472 | * | |
96b7f341 PJ |
473 | * If either of the @old and @new bitmaps are empty, or if @src and |
474 | * @dst point to the same location, then this routine copies @src | |
475 | * to @dst. | |
fb5eeeee | 476 | * |
96b7f341 | 477 | * The positions of unset bits in @old are mapped to themselves |
8ed13a76 | 478 | * (the identity map). |
fb5eeeee PJ |
479 | * |
480 | * Apply the above specified mapping to @src, placing the result in | |
481 | * @dst, clearing any bits previously set in @dst. | |
482 | * | |
fb5eeeee PJ |
483 | * For example, lets say that @old has bits 4 through 7 set, and |
484 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
485 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
486 | * bit positions unchanged. So if say @src comes into this routine |
487 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
488 | * 13 and 15 set. | |
fb5eeeee PJ |
489 | */ |
490 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
491 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 492 | unsigned int nbits) |
fb5eeeee | 493 | { |
9814ec13 | 494 | unsigned int oldbit, w; |
fb5eeeee | 495 | |
fb5eeeee PJ |
496 | if (dst == src) /* following doesn't handle inplace remaps */ |
497 | return; | |
9814ec13 | 498 | bitmap_zero(dst, nbits); |
96b7f341 | 499 | |
9814ec13 RV |
500 | w = bitmap_weight(new, nbits); |
501 | for_each_set_bit(oldbit, src, nbits) { | |
502 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 503 | |
96b7f341 PJ |
504 | if (n < 0 || w == 0) |
505 | set_bit(oldbit, dst); /* identity map */ | |
506 | else | |
97848c10 | 507 | set_bit(find_nth_bit(new, nbits, n % w), dst); |
fb5eeeee PJ |
508 | } |
509 | } | |
cde3d0f8 | 510 | EXPORT_SYMBOL(bitmap_remap); |
fb5eeeee PJ |
511 | |
512 | /** | |
513 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
514 | * @oldbit: bit position to be mapped |
515 | * @old: defines domain of map | |
516 | * @new: defines range of map | |
517 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
518 | * |
519 | * Let @old and @new define a mapping of bit positions, such that | |
520 | * whatever position is held by the n-th set bit in @old is mapped | |
521 | * to the n-th set bit in @new. In the more general case, allowing | |
522 | * for the possibility that the weight 'w' of @new is less than the | |
523 | * weight of @old, map the position of the n-th set bit in @old to | |
524 | * the position of the m-th set bit in @new, where m == n % w. | |
525 | * | |
96b7f341 | 526 | * The positions of unset bits in @old are mapped to themselves |
8ed13a76 | 527 | * (the identity map). |
fb5eeeee PJ |
528 | * |
529 | * Apply the above specified mapping to bit position @oldbit, returning | |
530 | * the new bit position. | |
531 | * | |
532 | * For example, lets say that @old has bits 4 through 7 set, and | |
533 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
534 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
535 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
536 | * returns 13. | |
fb5eeeee PJ |
537 | */ |
538 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
539 | const unsigned long *new, int bits) | |
540 | { | |
96b7f341 PJ |
541 | int w = bitmap_weight(new, bits); |
542 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
543 | if (n < 0 || w == 0) | |
544 | return oldbit; | |
545 | else | |
97848c10 | 546 | return find_nth_bit(new, bits, n % w); |
fb5eeeee | 547 | } |
cde3d0f8 | 548 | EXPORT_SYMBOL(bitmap_bitremap); |
fb5eeeee | 549 | |
cde3d0f8 | 550 | #ifdef CONFIG_NUMA |
7ea931c9 PJ |
551 | /** |
552 | * bitmap_onto - translate one bitmap relative to another | |
553 | * @dst: resulting translated bitmap | |
554 | * @orig: original untranslated bitmap | |
555 | * @relmap: bitmap relative to which translated | |
556 | * @bits: number of bits in each of these bitmaps | |
557 | * | |
558 | * Set the n-th bit of @dst iff there exists some m such that the | |
559 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
560 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
561 | * (If you understood the previous sentence the first time your | |
562 | * read it, you're overqualified for your current job.) | |
563 | * | |
564 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 565 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
566 | * m-th set bit of @relmap }. |
567 | * | |
568 | * Any set bits in @orig above bit number W, where W is the | |
569 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
570 | * In particular, if for all bits m set in @orig, m >= W, then | |
571 | * @dst will end up empty. In situations where the possibility | |
572 | * of such an empty result is not desired, one way to avoid it is | |
573 | * to use the bitmap_fold() operator, below, to first fold the | |
574 | * @orig bitmap over itself so that all its set bits x are in the | |
575 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
576 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
577 | * | |
578 | * Example [1] for bitmap_onto(): | |
579 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
580 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
581 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
582 | * | |
583 | * When bit 0 is set in @orig, it means turn on the bit in | |
584 | * @dst corresponding to whatever is the first bit (if any) | |
585 | * that is turned on in @relmap. Since bit 0 was off in the | |
586 | * above example, we leave off that bit (bit 30) in @dst. | |
587 | * | |
588 | * When bit 1 is set in @orig (as in the above example), it | |
589 | * means turn on the bit in @dst corresponding to whatever | |
590 | * is the second bit that is turned on in @relmap. The second | |
591 | * bit in @relmap that was turned on in the above example was | |
592 | * bit 31, so we turned on bit 31 in @dst. | |
593 | * | |
594 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
595 | * because they were the 4th, 6th, 8th and 10th set bits | |
596 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
597 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
598 | * | |
599 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 600 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
601 | * turned on in @relmap. In the above example, there were |
602 | * only ten bits turned on in @relmap (30..39), so that bit | |
603 | * 11 was set in @orig had no affect on @dst. | |
604 | * | |
605 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 | 606 | * Let's say @relmap has these ten bits set:: |
607 | * | |
7ea931c9 | 608 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 609 | * |
7ea931c9 PJ |
610 | * (for the curious, that's 40 plus the first ten terms of the |
611 | * Fibonacci sequence.) | |
612 | * | |
613 | * Further lets say we use the following code, invoking | |
614 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 615 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
616 | * |
617 | * unsigned long *tmp; // a temporary bitmap's bits | |
618 | * | |
619 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
620 | * bitmap_onto(dst, tmp, relmap, bits); | |
621 | * | |
622 | * Then this table shows what various values of @dst would be, for | |
623 | * various @orig's. I list the zero-based positions of each set bit. | |
624 | * The tmp column shows the intermediate result, as computed by | |
625 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 626 | * (the weight of @relmap): |
7ea931c9 | 627 | * |
40bf19a8 | 628 | * =============== ============== ================= |
7ea931c9 PJ |
629 | * @orig tmp @dst |
630 | * 0 0 40 | |
631 | * 1 1 41 | |
632 | * 9 9 95 | |
40bf19a8 | 633 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
634 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
635 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
636 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
637 | * 0 10 20 30 0 40 | |
638 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
639 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 | 640 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
641 | * =============== ============== ================= | |
642 | * | |
643 | * .. [#f1] | |
7ea931c9 | 644 | * |
40bf19a8 | 645 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
646 | * into tmp, then the @dst result would have been empty. |
647 | * | |
648 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
649 | * will be returned empty. | |
650 | * | |
651 | * If (as explained above) the only set bits in @orig are in positions | |
652 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
653 | * once again be returned empty. | |
654 | * | |
655 | * All bits in @dst not set by the above rule are cleared. | |
656 | */ | |
657 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 658 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 659 | { |
eb569883 | 660 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
661 | |
662 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
663 | return; | |
664 | bitmap_zero(dst, bits); | |
665 | ||
666 | /* | |
667 | * The following code is a more efficient, but less | |
668 | * obvious, equivalent to the loop: | |
669 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
97848c10 | 670 | * n = find_nth_bit(orig, bits, m); |
7ea931c9 PJ |
671 | * if (test_bit(m, orig)) |
672 | * set_bit(n, dst); | |
673 | * } | |
674 | */ | |
675 | ||
676 | m = 0; | |
08564fb7 | 677 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
678 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
679 | if (test_bit(m, orig)) | |
680 | set_bit(n, dst); | |
681 | m++; | |
682 | } | |
683 | } | |
7ea931c9 PJ |
684 | |
685 | /** | |
686 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
687 | * @dst: resulting smaller bitmap | |
688 | * @orig: original larger bitmap | |
689 | * @sz: specified size | |
b26ad583 | 690 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
691 | * |
692 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
693 | * Clear all other bits in @dst. See further the comment and | |
694 | * Example [2] for bitmap_onto() for why and how to use this. | |
695 | */ | |
696 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 697 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 698 | { |
b26ad583 | 699 | unsigned int oldbit; |
7ea931c9 PJ |
700 | |
701 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
702 | return; | |
b26ad583 | 703 | bitmap_zero(dst, nbits); |
7ea931c9 | 704 | |
b26ad583 | 705 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
706 | set_bit(oldbit % sz, dst); |
707 | } | |
cdc90a18 | 708 | #endif /* CONFIG_NUMA */ |
7ea931c9 | 709 | |
c42b65e3 AS |
710 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) |
711 | { | |
712 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
713 | flags); | |
714 | } | |
715 | EXPORT_SYMBOL(bitmap_alloc); | |
716 | ||
717 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
718 | { | |
719 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
720 | } | |
721 | EXPORT_SYMBOL(bitmap_zalloc); | |
722 | ||
7529cc7f TT |
723 | unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node) |
724 | { | |
725 | return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
726 | flags, node); | |
727 | } | |
728 | EXPORT_SYMBOL(bitmap_alloc_node); | |
729 | ||
730 | unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node) | |
731 | { | |
732 | return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node); | |
733 | } | |
734 | EXPORT_SYMBOL(bitmap_zalloc_node); | |
735 | ||
c42b65e3 AS |
736 | void bitmap_free(const unsigned long *bitmap) |
737 | { | |
738 | kfree(bitmap); | |
739 | } | |
740 | EXPORT_SYMBOL(bitmap_free); | |
741 | ||
e829c2e4 BG |
742 | static void devm_bitmap_free(void *data) |
743 | { | |
744 | unsigned long *bitmap = data; | |
745 | ||
746 | bitmap_free(bitmap); | |
747 | } | |
748 | ||
749 | unsigned long *devm_bitmap_alloc(struct device *dev, | |
750 | unsigned int nbits, gfp_t flags) | |
751 | { | |
752 | unsigned long *bitmap; | |
753 | int ret; | |
754 | ||
755 | bitmap = bitmap_alloc(nbits, flags); | |
756 | if (!bitmap) | |
757 | return NULL; | |
758 | ||
759 | ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap); | |
760 | if (ret) | |
761 | return NULL; | |
762 | ||
763 | return bitmap; | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(devm_bitmap_alloc); | |
766 | ||
767 | unsigned long *devm_bitmap_zalloc(struct device *dev, | |
768 | unsigned int nbits, gfp_t flags) | |
769 | { | |
770 | return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO); | |
771 | } | |
772 | EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); | |
773 | ||
c724f193 YN |
774 | #if BITS_PER_LONG == 64 |
775 | /** | |
776 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
777 | * @bitmap: array of unsigned longs, the destination bitmap | |
778 | * @buf: array of u32 (in host byte order), the source bitmap | |
779 | * @nbits: number of bits in @bitmap | |
780 | */ | |
ccf7a6d4 | 781 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) |
c724f193 YN |
782 | { |
783 | unsigned int i, halfwords; | |
784 | ||
c724f193 YN |
785 | halfwords = DIV_ROUND_UP(nbits, 32); |
786 | for (i = 0; i < halfwords; i++) { | |
787 | bitmap[i/2] = (unsigned long) buf[i]; | |
788 | if (++i < halfwords) | |
789 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
790 | } | |
791 | ||
792 | /* Clear tail bits in last word beyond nbits. */ | |
793 | if (nbits % BITS_PER_LONG) | |
794 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
795 | } | |
796 | EXPORT_SYMBOL(bitmap_from_arr32); | |
797 | ||
798 | /** | |
799 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
800 | * @buf: array of u32 (in host byte order), the dest bitmap | |
801 | * @bitmap: array of unsigned longs, the source bitmap | |
802 | * @nbits: number of bits in @bitmap | |
803 | */ | |
804 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
805 | { | |
806 | unsigned int i, halfwords; | |
807 | ||
c724f193 YN |
808 | halfwords = DIV_ROUND_UP(nbits, 32); |
809 | for (i = 0; i < halfwords; i++) { | |
810 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
811 | if (++i < halfwords) | |
812 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
813 | } | |
814 | ||
815 | /* Clear tail bits in last element of array beyond nbits. */ | |
816 | if (nbits % BITS_PER_LONG) | |
817 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
818 | } | |
819 | EXPORT_SYMBOL(bitmap_to_arr32); | |
0a97953f YN |
820 | #endif |
821 | ||
c1d2ba10 | 822 | #if BITS_PER_LONG == 32 |
0a97953f YN |
823 | /** |
824 | * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap | |
825 | * @bitmap: array of unsigned longs, the destination bitmap | |
826 | * @buf: array of u64 (in host byte order), the source bitmap | |
827 | * @nbits: number of bits in @bitmap | |
828 | */ | |
829 | void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits) | |
830 | { | |
831 | int n; | |
832 | ||
833 | for (n = nbits; n > 0; n -= 64) { | |
834 | u64 val = *buf++; | |
835 | ||
836 | *bitmap++ = val; | |
837 | if (n > 32) | |
838 | *bitmap++ = val >> 32; | |
839 | } | |
840 | ||
841 | /* | |
842 | * Clear tail bits in the last word beyond nbits. | |
843 | * | |
844 | * Negative index is OK because here we point to the word next | |
845 | * to the last word of the bitmap, except for nbits == 0, which | |
846 | * is tested implicitly. | |
847 | */ | |
848 | if (nbits % BITS_PER_LONG) | |
849 | bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits); | |
850 | } | |
851 | EXPORT_SYMBOL(bitmap_from_arr64); | |
852 | ||
853 | /** | |
854 | * bitmap_to_arr64 - copy the contents of bitmap to a u64 array of bits | |
855 | * @buf: array of u64 (in host byte order), the dest bitmap | |
856 | * @bitmap: array of unsigned longs, the source bitmap | |
857 | * @nbits: number of bits in @bitmap | |
858 | */ | |
859 | void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits) | |
860 | { | |
861 | const unsigned long *end = bitmap + BITS_TO_LONGS(nbits); | |
c724f193 | 862 | |
0a97953f YN |
863 | while (bitmap < end) { |
864 | *buf = *bitmap++; | |
865 | if (bitmap < end) | |
866 | *buf |= (u64)(*bitmap++) << 32; | |
867 | buf++; | |
868 | } | |
869 | ||
870 | /* Clear tail bits in the last element of array beyond nbits. */ | |
871 | if (nbits % 64) | |
428bc098 | 872 | buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0); |
0a97953f YN |
873 | } |
874 | EXPORT_SYMBOL(bitmap_to_arr64); | |
c724f193 | 875 | #endif |