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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 | */ |
8bc3bcc9 PG |
6 | #include <linux/export.h> |
7 | #include <linux/thread_info.h> | |
1da177e4 LT |
8 | #include <linux/ctype.h> |
9 | #include <linux/errno.h> | |
10 | #include <linux/bitmap.h> | |
11 | #include <linux/bitops.h> | |
50af5ead | 12 | #include <linux/bug.h> |
e52bc7c2 | 13 | #include <linux/kernel.h> |
ce1091d4 | 14 | #include <linux/mm.h> |
c42b65e3 | 15 | #include <linux/slab.h> |
e52bc7c2 | 16 | #include <linux/string.h> |
13d4ea09 | 17 | #include <linux/uaccess.h> |
5aaba363 SH |
18 | |
19 | #include <asm/page.h> | |
1da177e4 | 20 | |
e371c481 YN |
21 | #include "kstrtox.h" |
22 | ||
7d7363e4 RD |
23 | /** |
24 | * DOC: bitmap introduction | |
25 | * | |
197d6c1d | 26 | * bitmaps provide an array of bits, implemented using an |
1da177e4 LT |
27 | * array of unsigned longs. The number of valid bits in a |
28 | * given bitmap does _not_ need to be an exact multiple of | |
29 | * BITS_PER_LONG. | |
30 | * | |
31 | * The possible unused bits in the last, partially used word | |
32 | * of a bitmap are 'don't care'. The implementation makes | |
33 | * no particular effort to keep them zero. It ensures that | |
34 | * their value will not affect the results of any operation. | |
35 | * The bitmap operations that return Boolean (bitmap_empty, | |
36 | * for example) or scalar (bitmap_weight, for example) results | |
37 | * carefully filter out these unused bits from impacting their | |
38 | * results. | |
39 | * | |
1da177e4 LT |
40 | * The byte ordering of bitmaps is more natural on little |
41 | * endian architectures. See the big-endian headers | |
42 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
43 | * for the best explanations of this ordering. | |
44 | */ | |
45 | ||
1da177e4 | 46 | int __bitmap_equal(const unsigned long *bitmap1, |
5e068069 | 47 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 48 | { |
5e068069 | 49 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
50 | for (k = 0; k < lim; ++k) |
51 | if (bitmap1[k] != bitmap2[k]) | |
52 | return 0; | |
53 | ||
54 | if (bits % BITS_PER_LONG) | |
55 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
56 | return 0; | |
57 | ||
58 | return 1; | |
59 | } | |
60 | EXPORT_SYMBOL(__bitmap_equal); | |
61 | ||
b9fa6442 TG |
62 | bool __bitmap_or_equal(const unsigned long *bitmap1, |
63 | const unsigned long *bitmap2, | |
64 | const unsigned long *bitmap3, | |
65 | unsigned int bits) | |
66 | { | |
67 | unsigned int k, lim = bits / BITS_PER_LONG; | |
68 | unsigned long tmp; | |
69 | ||
70 | for (k = 0; k < lim; ++k) { | |
71 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) | |
72 | return false; | |
73 | } | |
74 | ||
75 | if (!(bits % BITS_PER_LONG)) | |
76 | return true; | |
77 | ||
78 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; | |
79 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; | |
80 | } | |
81 | ||
3d6684f4 | 82 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 83 | { |
ca1250bb | 84 | unsigned int k, lim = BITS_TO_LONGS(bits); |
1da177e4 LT |
85 | for (k = 0; k < lim; ++k) |
86 | dst[k] = ~src[k]; | |
1da177e4 LT |
87 | } |
88 | EXPORT_SYMBOL(__bitmap_complement); | |
89 | ||
72fd4a35 | 90 | /** |
1da177e4 | 91 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
92 | * @dst : destination bitmap |
93 | * @src : source bitmap | |
94 | * @shift : shift by this many bits | |
2fbad299 | 95 | * @nbits : bitmap size, in bits |
1da177e4 LT |
96 | * |
97 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
98 | * direction. Zeros are fed into the vacated MS positions and the | |
99 | * LS bits shifted off the bottom are lost. | |
100 | */ | |
2fbad299 RV |
101 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
102 | unsigned shift, unsigned nbits) | |
1da177e4 | 103 | { |
cfac1d08 | 104 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 105 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 106 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
107 | for (k = 0; off + k < lim; ++k) { |
108 | unsigned long upper, lower; | |
109 | ||
110 | /* | |
111 | * If shift is not word aligned, take lower rem bits of | |
112 | * word above and make them the top rem bits of result. | |
113 | */ | |
114 | if (!rem || off + k + 1 >= lim) | |
115 | upper = 0; | |
116 | else { | |
117 | upper = src[off + k + 1]; | |
cfac1d08 | 118 | if (off + k + 1 == lim - 1) |
1da177e4 | 119 | upper &= mask; |
9d8a6b2a | 120 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
121 | } |
122 | lower = src[off + k]; | |
cfac1d08 | 123 | if (off + k == lim - 1) |
1da177e4 | 124 | lower &= mask; |
9d8a6b2a RV |
125 | lower >>= rem; |
126 | dst[k] = lower | upper; | |
1da177e4 LT |
127 | } |
128 | if (off) | |
129 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
130 | } | |
131 | EXPORT_SYMBOL(__bitmap_shift_right); | |
132 | ||
133 | ||
72fd4a35 | 134 | /** |
1da177e4 | 135 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
136 | * @dst : destination bitmap |
137 | * @src : source bitmap | |
138 | * @shift : shift by this many bits | |
dba94c25 | 139 | * @nbits : bitmap size, in bits |
1da177e4 LT |
140 | * |
141 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
142 | * direction. Zeros are fed into the vacated LS bit positions | |
143 | * and those MS bits shifted off the top are lost. | |
144 | */ | |
145 | ||
dba94c25 RV |
146 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
147 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 148 | { |
dba94c25 | 149 | int k; |
7f590657 | 150 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 151 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
152 | for (k = lim - off - 1; k >= 0; --k) { |
153 | unsigned long upper, lower; | |
154 | ||
155 | /* | |
156 | * If shift is not word aligned, take upper rem bits of | |
157 | * word below and make them the bottom rem bits of result. | |
158 | */ | |
159 | if (rem && k > 0) | |
6d874eca | 160 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
161 | else |
162 | lower = 0; | |
7f590657 | 163 | upper = src[k] << rem; |
6d874eca | 164 | dst[k + off] = lower | upper; |
1da177e4 LT |
165 | } |
166 | if (off) | |
167 | memset(dst, 0, off*sizeof(unsigned long)); | |
168 | } | |
169 | EXPORT_SYMBOL(__bitmap_shift_left); | |
170 | ||
20927671 SB |
171 | /** |
172 | * bitmap_cut() - remove bit region from bitmap and right shift remaining bits | |
173 | * @dst: destination bitmap, might overlap with src | |
174 | * @src: source bitmap | |
175 | * @first: start bit of region to be removed | |
176 | * @cut: number of bits to remove | |
177 | * @nbits: bitmap size, in bits | |
178 | * | |
179 | * Set the n-th bit of @dst iff the n-th bit of @src is set and | |
180 | * n is less than @first, or the m-th bit of @src is set for any | |
181 | * m such that @first <= n < nbits, and m = n + @cut. | |
182 | * | |
183 | * In pictures, example for a big-endian 32-bit architecture: | |
184 | * | |
4642289b | 185 | * The @src bitmap is:: |
20927671 | 186 | * |
4642289b MCC |
187 | * 31 63 |
188 | * | | | |
189 | * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 | |
190 | * | | | | | |
191 | * 16 14 0 32 | |
20927671 | 192 | * |
4642289b MCC |
193 | * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: |
194 | * | |
195 | * 31 63 | |
196 | * | | | |
197 | * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 | |
198 | * | | | | |
199 | * 14 (bit 17 0 32 | |
200 | * from @src) | |
20927671 SB |
201 | * |
202 | * Note that @dst and @src might overlap partially or entirely. | |
203 | * | |
204 | * This is implemented in the obvious way, with a shift and carry | |
205 | * step for each moved bit. Optimisation is left as an exercise | |
206 | * for the compiler. | |
207 | */ | |
208 | void bitmap_cut(unsigned long *dst, const unsigned long *src, | |
209 | unsigned int first, unsigned int cut, unsigned int nbits) | |
210 | { | |
211 | unsigned int len = BITS_TO_LONGS(nbits); | |
212 | unsigned long keep = 0, carry; | |
213 | int i; | |
214 | ||
20927671 SB |
215 | if (first % BITS_PER_LONG) { |
216 | keep = src[first / BITS_PER_LONG] & | |
217 | (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); | |
218 | } | |
219 | ||
5959f829 SB |
220 | memmove(dst, src, len * sizeof(*dst)); |
221 | ||
20927671 SB |
222 | while (cut--) { |
223 | for (i = first / BITS_PER_LONG; i < len; i++) { | |
224 | if (i < len - 1) | |
225 | carry = dst[i + 1] & 1UL; | |
226 | else | |
227 | carry = 0; | |
228 | ||
229 | dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); | |
230 | } | |
231 | } | |
232 | ||
233 | dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); | |
234 | dst[first / BITS_PER_LONG] |= keep; | |
235 | } | |
236 | EXPORT_SYMBOL(bitmap_cut); | |
237 | ||
f4b0373b | 238 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 239 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 240 | { |
2f9305eb | 241 | unsigned int k; |
7e5f97d1 | 242 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 243 | unsigned long result = 0; |
1da177e4 | 244 | |
7e5f97d1 | 245 | for (k = 0; k < lim; k++) |
f4b0373b | 246 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
247 | if (bits % BITS_PER_LONG) |
248 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
249 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 250 | return result != 0; |
1da177e4 LT |
251 | } |
252 | EXPORT_SYMBOL(__bitmap_and); | |
253 | ||
254 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 255 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 256 | { |
2f9305eb RV |
257 | unsigned int k; |
258 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
259 | |
260 | for (k = 0; k < nr; k++) | |
261 | dst[k] = bitmap1[k] | bitmap2[k]; | |
262 | } | |
263 | EXPORT_SYMBOL(__bitmap_or); | |
264 | ||
265 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 266 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 267 | { |
2f9305eb RV |
268 | unsigned int k; |
269 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
270 | |
271 | for (k = 0; k < nr; k++) | |
272 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
273 | } | |
274 | EXPORT_SYMBOL(__bitmap_xor); | |
275 | ||
f4b0373b | 276 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 277 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 278 | { |
2f9305eb | 279 | unsigned int k; |
74e76531 | 280 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 281 | unsigned long result = 0; |
1da177e4 | 282 | |
74e76531 | 283 | for (k = 0; k < lim; k++) |
f4b0373b | 284 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
285 | if (bits % BITS_PER_LONG) |
286 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
287 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 288 | return result != 0; |
1da177e4 LT |
289 | } |
290 | EXPORT_SYMBOL(__bitmap_andnot); | |
291 | ||
30544ed5 AS |
292 | void __bitmap_replace(unsigned long *dst, |
293 | const unsigned long *old, const unsigned long *new, | |
294 | const unsigned long *mask, unsigned int nbits) | |
295 | { | |
296 | unsigned int k; | |
297 | unsigned int nr = BITS_TO_LONGS(nbits); | |
298 | ||
299 | for (k = 0; k < nr; k++) | |
300 | dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); | |
301 | } | |
302 | EXPORT_SYMBOL(__bitmap_replace); | |
303 | ||
1da177e4 | 304 | int __bitmap_intersects(const unsigned long *bitmap1, |
6dfe9799 | 305 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 306 | { |
6dfe9799 | 307 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
308 | for (k = 0; k < lim; ++k) |
309 | if (bitmap1[k] & bitmap2[k]) | |
310 | return 1; | |
311 | ||
312 | if (bits % BITS_PER_LONG) | |
313 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
314 | return 1; | |
315 | return 0; | |
316 | } | |
317 | EXPORT_SYMBOL(__bitmap_intersects); | |
318 | ||
319 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 320 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 321 | { |
5be20213 | 322 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
323 | for (k = 0; k < lim; ++k) |
324 | if (bitmap1[k] & ~bitmap2[k]) | |
325 | return 0; | |
326 | ||
327 | if (bits % BITS_PER_LONG) | |
328 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
329 | return 0; | |
330 | return 1; | |
331 | } | |
332 | EXPORT_SYMBOL(__bitmap_subset); | |
333 | ||
877d9f3b | 334 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 335 | { |
877d9f3b RV |
336 | unsigned int k, lim = bits/BITS_PER_LONG; |
337 | int w = 0; | |
1da177e4 LT |
338 | |
339 | for (k = 0; k < lim; k++) | |
37d54111 | 340 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
341 | |
342 | if (bits % BITS_PER_LONG) | |
37d54111 | 343 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
344 | |
345 | return w; | |
346 | } | |
1da177e4 LT |
347 | EXPORT_SYMBOL(__bitmap_weight); |
348 | ||
e5af323c | 349 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
350 | { |
351 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 352 | const unsigned int size = start + len; |
c1a2a962 AM |
353 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
354 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
355 | ||
fb5ac542 | 356 | while (len - bits_to_set >= 0) { |
c1a2a962 | 357 | *p |= mask_to_set; |
fb5ac542 | 358 | len -= bits_to_set; |
c1a2a962 AM |
359 | bits_to_set = BITS_PER_LONG; |
360 | mask_to_set = ~0UL; | |
361 | p++; | |
362 | } | |
fb5ac542 | 363 | if (len) { |
c1a2a962 AM |
364 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
365 | *p |= mask_to_set; | |
366 | } | |
367 | } | |
e5af323c | 368 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 369 | |
e5af323c | 370 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
371 | { |
372 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 373 | const unsigned int size = start + len; |
c1a2a962 AM |
374 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
375 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
376 | ||
154f5e38 | 377 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 378 | *p &= ~mask_to_clear; |
154f5e38 | 379 | len -= bits_to_clear; |
c1a2a962 AM |
380 | bits_to_clear = BITS_PER_LONG; |
381 | mask_to_clear = ~0UL; | |
382 | p++; | |
383 | } | |
154f5e38 | 384 | if (len) { |
c1a2a962 AM |
385 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
386 | *p &= ~mask_to_clear; | |
387 | } | |
388 | } | |
e5af323c | 389 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 390 | |
5e19b013 MN |
391 | /** |
392 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
393 | * @map: The address to base the search on |
394 | * @size: The bitmap size in bits | |
395 | * @start: The bitnumber to start searching at | |
396 | * @nr: The number of zeroed bits we're looking for | |
397 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 398 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
399 | * |
400 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
401 | * the bit offset of all zero areas this function finds plus @align_offset |
402 | * is multiple of that power of 2. | |
c1a2a962 | 403 | */ |
5e19b013 MN |
404 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
405 | unsigned long size, | |
406 | unsigned long start, | |
407 | unsigned int nr, | |
408 | unsigned long align_mask, | |
409 | unsigned long align_offset) | |
c1a2a962 AM |
410 | { |
411 | unsigned long index, end, i; | |
412 | again: | |
413 | index = find_next_zero_bit(map, size, start); | |
414 | ||
415 | /* Align allocation */ | |
5e19b013 | 416 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
417 | |
418 | end = index + nr; | |
419 | if (end > size) | |
420 | return end; | |
421 | i = find_next_bit(map, end, index); | |
422 | if (i < end) { | |
423 | start = i + 1; | |
424 | goto again; | |
425 | } | |
426 | return index; | |
427 | } | |
5e19b013 | 428 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 429 | |
1da177e4 | 430 | /* |
6d49e352 | 431 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
432 | * second version by Paul Jackson, third by Joe Korty. |
433 | */ | |
434 | ||
01a3ee2b | 435 | /** |
9a86e2ba | 436 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
437 | * |
438 | * @ubuf: pointer to user buffer containing string. | |
439 | * @ulen: buffer size in bytes. If string is smaller than this | |
440 | * then it must be terminated with a \0. | |
441 | * @maskp: pointer to bitmap array that will contain result. | |
442 | * @nmaskbits: size of bitmap, in bits. | |
01a3ee2b RC |
443 | */ |
444 | int bitmap_parse_user(const char __user *ubuf, | |
445 | unsigned int ulen, unsigned long *maskp, | |
446 | int nmaskbits) | |
447 | { | |
e66eda06 YN |
448 | char *buf; |
449 | int ret; | |
450 | ||
451 | buf = memdup_user_nul(ubuf, ulen); | |
452 | if (IS_ERR(buf)) | |
453 | return PTR_ERR(buf); | |
454 | ||
2d626158 | 455 | ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); |
b9c321fd | 456 | |
e66eda06 YN |
457 | kfree(buf); |
458 | return ret; | |
01a3ee2b RC |
459 | } |
460 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 461 | |
5aaba363 SH |
462 | /** |
463 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
464 | * @list: indicates whether the bitmap must be list | |
465 | * @buf: page aligned buffer into which string is placed | |
466 | * @maskp: pointer to bitmap to convert | |
467 | * @nmaskbits: size of bitmap, in bits | |
468 | * | |
469 | * Output format is a comma-separated list of decimal numbers and | |
470 | * ranges if list is specified or hex digits grouped into comma-separated | |
471 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 | 472 | * |
ce1091d4 RV |
473 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned |
474 | * area and that sufficient storage remains at @buf to accommodate the | |
475 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
476 | * actually printed to @buf, excluding terminating '\0'. | |
5aaba363 SH |
477 | */ |
478 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
479 | int nmaskbits) | |
480 | { | |
ce1091d4 | 481 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
5aaba363 | 482 | |
8ec3d768 RV |
483 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
484 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
485 | } |
486 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
487 | ||
e371c481 YN |
488 | /* |
489 | * Region 9-38:4/10 describes the following bitmap structure: | |
9d7a3366 PG |
490 | * 0 9 12 18 38 N |
491 | * .........****......****......****.................. | |
492 | * ^ ^ ^ ^ ^ | |
493 | * start off group_len end nbits | |
e371c481 YN |
494 | */ |
495 | struct region { | |
496 | unsigned int start; | |
497 | unsigned int off; | |
498 | unsigned int group_len; | |
499 | unsigned int end; | |
9d7a3366 | 500 | unsigned int nbits; |
e371c481 YN |
501 | }; |
502 | ||
f3c869ca | 503 | static void bitmap_set_region(const struct region *r, unsigned long *bitmap) |
e371c481 YN |
504 | { |
505 | unsigned int start; | |
506 | ||
e371c481 YN |
507 | for (start = r->start; start <= r->end; start += r->group_len) |
508 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); | |
e371c481 YN |
509 | } |
510 | ||
511 | static int bitmap_check_region(const struct region *r) | |
512 | { | |
513 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) | |
514 | return -EINVAL; | |
515 | ||
f3c869ca PG |
516 | if (r->end >= r->nbits) |
517 | return -ERANGE; | |
518 | ||
e371c481 YN |
519 | return 0; |
520 | } | |
521 | ||
2c4885d2 PG |
522 | static const char *bitmap_getnum(const char *str, unsigned int *num, |
523 | unsigned int lastbit) | |
e371c481 YN |
524 | { |
525 | unsigned long long n; | |
526 | unsigned int len; | |
527 | ||
2c4885d2 PG |
528 | if (str[0] == 'N') { |
529 | *num = lastbit; | |
530 | return str + 1; | |
531 | } | |
532 | ||
e371c481 YN |
533 | len = _parse_integer(str, 10, &n); |
534 | if (!len) | |
535 | return ERR_PTR(-EINVAL); | |
536 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) | |
537 | return ERR_PTR(-EOVERFLOW); | |
538 | ||
539 | *num = n; | |
540 | return str + len; | |
541 | } | |
542 | ||
543 | static inline bool end_of_str(char c) | |
544 | { | |
545 | return c == '\0' || c == '\n'; | |
546 | } | |
547 | ||
548 | static inline bool __end_of_region(char c) | |
549 | { | |
550 | return isspace(c) || c == ','; | |
551 | } | |
552 | ||
553 | static inline bool end_of_region(char c) | |
554 | { | |
555 | return __end_of_region(c) || end_of_str(c); | |
556 | } | |
557 | ||
558 | /* | |
20607434 | 559 | * The format allows commas and whitespaces at the beginning |
e371c481 YN |
560 | * of the region. |
561 | */ | |
562 | static const char *bitmap_find_region(const char *str) | |
563 | { | |
564 | while (__end_of_region(*str)) | |
565 | str++; | |
566 | ||
567 | return end_of_str(*str) ? NULL : str; | |
568 | } | |
569 | ||
2d626158 YN |
570 | static const char *bitmap_find_region_reverse(const char *start, const char *end) |
571 | { | |
572 | while (start <= end && __end_of_region(*end)) | |
573 | end--; | |
574 | ||
575 | return end; | |
576 | } | |
577 | ||
e371c481 YN |
578 | static const char *bitmap_parse_region(const char *str, struct region *r) |
579 | { | |
2c4885d2 PG |
580 | unsigned int lastbit = r->nbits - 1; |
581 | ||
582 | str = bitmap_getnum(str, &r->start, lastbit); | |
e371c481 YN |
583 | if (IS_ERR(str)) |
584 | return str; | |
585 | ||
586 | if (end_of_region(*str)) | |
587 | goto no_end; | |
588 | ||
589 | if (*str != '-') | |
590 | return ERR_PTR(-EINVAL); | |
591 | ||
2c4885d2 | 592 | str = bitmap_getnum(str + 1, &r->end, lastbit); |
e371c481 YN |
593 | if (IS_ERR(str)) |
594 | return str; | |
595 | ||
596 | if (end_of_region(*str)) | |
597 | goto no_pattern; | |
598 | ||
599 | if (*str != ':') | |
600 | return ERR_PTR(-EINVAL); | |
601 | ||
2c4885d2 | 602 | str = bitmap_getnum(str + 1, &r->off, lastbit); |
e371c481 YN |
603 | if (IS_ERR(str)) |
604 | return str; | |
605 | ||
606 | if (*str != '/') | |
607 | return ERR_PTR(-EINVAL); | |
608 | ||
2c4885d2 | 609 | return bitmap_getnum(str + 1, &r->group_len, lastbit); |
e371c481 YN |
610 | |
611 | no_end: | |
612 | r->end = r->start; | |
613 | no_pattern: | |
614 | r->off = r->end + 1; | |
615 | r->group_len = r->end + 1; | |
616 | ||
617 | return end_of_str(*str) ? NULL : str; | |
618 | } | |
619 | ||
1da177e4 | 620 | /** |
e371c481 YN |
621 | * bitmap_parselist - convert list format ASCII string to bitmap |
622 | * @buf: read user string from this buffer; must be terminated | |
623 | * with a \0 or \n. | |
6e1907ff | 624 | * @maskp: write resulting mask here |
1da177e4 LT |
625 | * @nmaskbits: number of bits in mask to be written |
626 | * | |
627 | * Input format is a comma-separated list of decimal numbers and | |
628 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
629 | * decimal numbers, the smallest and largest bit numbers set in | |
630 | * the range. | |
2d13e6ca NC |
631 | * Optionally each range can be postfixed to denote that only parts of it |
632 | * should be set. The range will divided to groups of specific size. | |
633 | * From each group will be used only defined amount of bits. | |
634 | * Syntax: range:used_size/group_size | |
635 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
2c4885d2 PG |
636 | * The value 'N' can be used as a dynamically substituted token for the |
637 | * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is | |
638 | * dynamic, so if system changes cause the bitmap width to change, such | |
639 | * as more cores in a CPU list, then any ranges using N will also change. | |
1da177e4 | 640 | * |
40bf19a8 MCC |
641 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
642 | * | |
e371c481 | 643 | * - ``-EINVAL``: wrong region format |
40bf19a8 MCC |
644 | * - ``-EINVAL``: invalid character in string |
645 | * - ``-ERANGE``: bit number specified too large for mask | |
e371c481 | 646 | * - ``-EOVERFLOW``: integer overflow in the input parameters |
1da177e4 | 647 | */ |
e371c481 | 648 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) |
1da177e4 | 649 | { |
e371c481 YN |
650 | struct region r; |
651 | long ret; | |
1da177e4 | 652 | |
9d7a3366 PG |
653 | r.nbits = nmaskbits; |
654 | bitmap_zero(maskp, r.nbits); | |
4b060420 | 655 | |
e371c481 YN |
656 | while (buf) { |
657 | buf = bitmap_find_region(buf); | |
658 | if (buf == NULL) | |
659 | return 0; | |
2d13e6ca | 660 | |
e371c481 YN |
661 | buf = bitmap_parse_region(buf, &r); |
662 | if (IS_ERR(buf)) | |
663 | return PTR_ERR(buf); | |
2d13e6ca | 664 | |
e371c481 YN |
665 | ret = bitmap_check_region(&r); |
666 | if (ret) | |
667 | return ret; | |
4b060420 | 668 | |
f3c869ca | 669 | bitmap_set_region(&r, maskp); |
e371c481 | 670 | } |
4b060420 | 671 | |
1da177e4 LT |
672 | return 0; |
673 | } | |
674 | EXPORT_SYMBOL(bitmap_parselist); | |
675 | ||
4b060420 MT |
676 | |
677 | /** | |
678 | * bitmap_parselist_user() | |
679 | * | |
680 | * @ubuf: pointer to user buffer containing string. | |
681 | * @ulen: buffer size in bytes. If string is smaller than this | |
682 | * then it must be terminated with a \0. | |
683 | * @maskp: pointer to bitmap array that will contain result. | |
684 | * @nmaskbits: size of bitmap, in bits. | |
685 | * | |
686 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
4b060420 MT |
687 | */ |
688 | int bitmap_parselist_user(const char __user *ubuf, | |
689 | unsigned int ulen, unsigned long *maskp, | |
690 | int nmaskbits) | |
691 | { | |
281327c9 YN |
692 | char *buf; |
693 | int ret; | |
694 | ||
695 | buf = memdup_user_nul(ubuf, ulen); | |
696 | if (IS_ERR(buf)) | |
697 | return PTR_ERR(buf); | |
698 | ||
699 | ret = bitmap_parselist(buf, maskp, nmaskbits); | |
700 | ||
701 | kfree(buf); | |
702 | return ret; | |
4b060420 MT |
703 | } |
704 | EXPORT_SYMBOL(bitmap_parselist_user); | |
705 | ||
2d626158 YN |
706 | static const char *bitmap_get_x32_reverse(const char *start, |
707 | const char *end, u32 *num) | |
708 | { | |
709 | u32 ret = 0; | |
710 | int c, i; | |
711 | ||
712 | for (i = 0; i < 32; i += 4) { | |
713 | c = hex_to_bin(*end--); | |
714 | if (c < 0) | |
715 | return ERR_PTR(-EINVAL); | |
716 | ||
717 | ret |= c << i; | |
718 | ||
719 | if (start > end || __end_of_region(*end)) | |
720 | goto out; | |
721 | } | |
722 | ||
723 | if (hex_to_bin(*end--) >= 0) | |
724 | return ERR_PTR(-EOVERFLOW); | |
725 | out: | |
726 | *num = ret; | |
727 | return end; | |
728 | } | |
729 | ||
730 | /** | |
731 | * bitmap_parse - convert an ASCII hex string into a bitmap. | |
732 | * @start: pointer to buffer containing string. | |
733 | * @buflen: buffer size in bytes. If string is smaller than this | |
734 | * then it must be terminated with a \0 or \n. In that case, | |
735 | * UINT_MAX may be provided instead of string length. | |
736 | * @maskp: pointer to bitmap array that will contain result. | |
737 | * @nmaskbits: size of bitmap, in bits. | |
738 | * | |
739 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
740 | * bits of the resultant bitmask. No chunk may specify a value larger | |
741 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value | |
742 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
743 | * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. | |
744 | * Leading, embedded and trailing whitespace accepted. | |
745 | */ | |
746 | int bitmap_parse(const char *start, unsigned int buflen, | |
747 | unsigned long *maskp, int nmaskbits) | |
748 | { | |
749 | const char *end = strnchrnul(start, buflen, '\n') - 1; | |
750 | int chunks = BITS_TO_U32(nmaskbits); | |
751 | u32 *bitmap = (u32 *)maskp; | |
752 | int unset_bit; | |
81c4f4d9 | 753 | int chunk; |
2d626158 | 754 | |
81c4f4d9 | 755 | for (chunk = 0; ; chunk++) { |
2d626158 YN |
756 | end = bitmap_find_region_reverse(start, end); |
757 | if (start > end) | |
758 | break; | |
759 | ||
760 | if (!chunks--) | |
761 | return -EOVERFLOW; | |
762 | ||
81c4f4d9 AG |
763 | #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) |
764 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); | |
765 | #else | |
766 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); | |
767 | #endif | |
2d626158 YN |
768 | if (IS_ERR(end)) |
769 | return PTR_ERR(end); | |
770 | } | |
771 | ||
772 | unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; | |
773 | if (unset_bit < nmaskbits) { | |
774 | bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); | |
775 | return 0; | |
776 | } | |
777 | ||
778 | if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) | |
779 | return -EOVERFLOW; | |
780 | ||
781 | return 0; | |
782 | } | |
783 | EXPORT_SYMBOL(bitmap_parse); | |
784 | ||
4b060420 | 785 | |
cdc90a18 | 786 | #ifdef CONFIG_NUMA |
72fd4a35 | 787 | /** |
9a86e2ba | 788 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 789 | * @buf: pointer to a bitmap |
df1d80a9 RV |
790 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
791 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 792 | * |
df1d80a9 | 793 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 794 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 795 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
796 | * |
797 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
798 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 799 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
800 | * gets mapped to (returns) @ord value 3 in this example, that means |
801 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
802 | * | |
803 | * The bit positions 0 through @bits are valid positions in @buf. | |
804 | */ | |
df1d80a9 | 805 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 806 | { |
df1d80a9 | 807 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 808 | return -1; |
fb5eeeee | 809 | |
df1d80a9 | 810 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
811 | } |
812 | ||
813 | /** | |
9a86e2ba | 814 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
815 | * @buf: pointer to bitmap |
816 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 817 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
818 | * |
819 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
820 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
821 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
822 | * |
823 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
824 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 825 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
826 | * gets mapped to (returns) @pos value 7 in this example, that means |
827 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
828 | * | |
f6a1f5db | 829 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 830 | */ |
f6a1f5db | 831 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 832 | { |
f6a1f5db | 833 | unsigned int pos; |
fb5eeeee | 834 | |
f6a1f5db RV |
835 | for (pos = find_first_bit(buf, nbits); |
836 | pos < nbits && ord; | |
837 | pos = find_next_bit(buf, nbits, pos + 1)) | |
838 | ord--; | |
fb5eeeee PJ |
839 | |
840 | return pos; | |
841 | } | |
842 | ||
843 | /** | |
844 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 845 | * @dst: remapped result |
96b7f341 | 846 | * @src: subset to be remapped |
fb5eeeee PJ |
847 | * @old: defines domain of map |
848 | * @new: defines range of map | |
9814ec13 | 849 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
850 | * |
851 | * Let @old and @new define a mapping of bit positions, such that | |
852 | * whatever position is held by the n-th set bit in @old is mapped | |
853 | * to the n-th set bit in @new. In the more general case, allowing | |
854 | * for the possibility that the weight 'w' of @new is less than the | |
855 | * weight of @old, map the position of the n-th set bit in @old to | |
856 | * the position of the m-th set bit in @new, where m == n % w. | |
857 | * | |
96b7f341 PJ |
858 | * If either of the @old and @new bitmaps are empty, or if @src and |
859 | * @dst point to the same location, then this routine copies @src | |
860 | * to @dst. | |
fb5eeeee | 861 | * |
96b7f341 PJ |
862 | * The positions of unset bits in @old are mapped to themselves |
863 | * (the identify map). | |
fb5eeeee PJ |
864 | * |
865 | * Apply the above specified mapping to @src, placing the result in | |
866 | * @dst, clearing any bits previously set in @dst. | |
867 | * | |
fb5eeeee PJ |
868 | * For example, lets say that @old has bits 4 through 7 set, and |
869 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
870 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
871 | * bit positions unchanged. So if say @src comes into this routine |
872 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
873 | * 13 and 15 set. | |
fb5eeeee PJ |
874 | */ |
875 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
876 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 877 | unsigned int nbits) |
fb5eeeee | 878 | { |
9814ec13 | 879 | unsigned int oldbit, w; |
fb5eeeee | 880 | |
fb5eeeee PJ |
881 | if (dst == src) /* following doesn't handle inplace remaps */ |
882 | return; | |
9814ec13 | 883 | bitmap_zero(dst, nbits); |
96b7f341 | 884 | |
9814ec13 RV |
885 | w = bitmap_weight(new, nbits); |
886 | for_each_set_bit(oldbit, src, nbits) { | |
887 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 888 | |
96b7f341 PJ |
889 | if (n < 0 || w == 0) |
890 | set_bit(oldbit, dst); /* identity map */ | |
891 | else | |
9814ec13 | 892 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
893 | } |
894 | } | |
fb5eeeee PJ |
895 | |
896 | /** | |
897 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
898 | * @oldbit: bit position to be mapped |
899 | * @old: defines domain of map | |
900 | * @new: defines range of map | |
901 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
902 | * |
903 | * Let @old and @new define a mapping of bit positions, such that | |
904 | * whatever position is held by the n-th set bit in @old is mapped | |
905 | * to the n-th set bit in @new. In the more general case, allowing | |
906 | * for the possibility that the weight 'w' of @new is less than the | |
907 | * weight of @old, map the position of the n-th set bit in @old to | |
908 | * the position of the m-th set bit in @new, where m == n % w. | |
909 | * | |
96b7f341 PJ |
910 | * The positions of unset bits in @old are mapped to themselves |
911 | * (the identify map). | |
fb5eeeee PJ |
912 | * |
913 | * Apply the above specified mapping to bit position @oldbit, returning | |
914 | * the new bit position. | |
915 | * | |
916 | * For example, lets say that @old has bits 4 through 7 set, and | |
917 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
918 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
919 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
920 | * returns 13. | |
fb5eeeee PJ |
921 | */ |
922 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
923 | const unsigned long *new, int bits) | |
924 | { | |
96b7f341 PJ |
925 | int w = bitmap_weight(new, bits); |
926 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
927 | if (n < 0 || w == 0) | |
928 | return oldbit; | |
929 | else | |
930 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee | 931 | } |
fb5eeeee | 932 | |
7ea931c9 PJ |
933 | /** |
934 | * bitmap_onto - translate one bitmap relative to another | |
935 | * @dst: resulting translated bitmap | |
936 | * @orig: original untranslated bitmap | |
937 | * @relmap: bitmap relative to which translated | |
938 | * @bits: number of bits in each of these bitmaps | |
939 | * | |
940 | * Set the n-th bit of @dst iff there exists some m such that the | |
941 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
942 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
943 | * (If you understood the previous sentence the first time your | |
944 | * read it, you're overqualified for your current job.) | |
945 | * | |
946 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 947 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
948 | * m-th set bit of @relmap }. |
949 | * | |
950 | * Any set bits in @orig above bit number W, where W is the | |
951 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
952 | * In particular, if for all bits m set in @orig, m >= W, then | |
953 | * @dst will end up empty. In situations where the possibility | |
954 | * of such an empty result is not desired, one way to avoid it is | |
955 | * to use the bitmap_fold() operator, below, to first fold the | |
956 | * @orig bitmap over itself so that all its set bits x are in the | |
957 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
958 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
959 | * | |
960 | * Example [1] for bitmap_onto(): | |
961 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
962 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
963 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
964 | * | |
965 | * When bit 0 is set in @orig, it means turn on the bit in | |
966 | * @dst corresponding to whatever is the first bit (if any) | |
967 | * that is turned on in @relmap. Since bit 0 was off in the | |
968 | * above example, we leave off that bit (bit 30) in @dst. | |
969 | * | |
970 | * When bit 1 is set in @orig (as in the above example), it | |
971 | * means turn on the bit in @dst corresponding to whatever | |
972 | * is the second bit that is turned on in @relmap. The second | |
973 | * bit in @relmap that was turned on in the above example was | |
974 | * bit 31, so we turned on bit 31 in @dst. | |
975 | * | |
976 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
977 | * because they were the 4th, 6th, 8th and 10th set bits | |
978 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
979 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
980 | * | |
981 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 982 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
983 | * turned on in @relmap. In the above example, there were |
984 | * only ten bits turned on in @relmap (30..39), so that bit | |
985 | * 11 was set in @orig had no affect on @dst. | |
986 | * | |
987 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
988 | * Let's say @relmap has these ten bits set:: |
989 | * | |
7ea931c9 | 990 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 991 | * |
7ea931c9 PJ |
992 | * (for the curious, that's 40 plus the first ten terms of the |
993 | * Fibonacci sequence.) | |
994 | * | |
995 | * Further lets say we use the following code, invoking | |
996 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 997 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
998 | * |
999 | * unsigned long *tmp; // a temporary bitmap's bits | |
1000 | * | |
1001 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
1002 | * bitmap_onto(dst, tmp, relmap, bits); | |
1003 | * | |
1004 | * Then this table shows what various values of @dst would be, for | |
1005 | * various @orig's. I list the zero-based positions of each set bit. | |
1006 | * The tmp column shows the intermediate result, as computed by | |
1007 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 1008 | * (the weight of @relmap): |
7ea931c9 | 1009 | * |
40bf19a8 | 1010 | * =============== ============== ================= |
7ea931c9 PJ |
1011 | * @orig tmp @dst |
1012 | * 0 0 40 | |
1013 | * 1 1 41 | |
1014 | * 9 9 95 | |
40bf19a8 | 1015 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
1016 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
1017 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
1018 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
1019 | * 0 10 20 30 0 40 | |
1020 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
1021 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
1022 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
1023 | * =============== ============== ================= | |
1024 | * | |
1025 | * .. [#f1] | |
7ea931c9 | 1026 | * |
40bf19a8 | 1027 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
1028 | * into tmp, then the @dst result would have been empty. |
1029 | * | |
1030 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
1031 | * will be returned empty. | |
1032 | * | |
1033 | * If (as explained above) the only set bits in @orig are in positions | |
1034 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
1035 | * once again be returned empty. | |
1036 | * | |
1037 | * All bits in @dst not set by the above rule are cleared. | |
1038 | */ | |
1039 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 1040 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 1041 | { |
eb569883 | 1042 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
1043 | |
1044 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1045 | return; | |
1046 | bitmap_zero(dst, bits); | |
1047 | ||
1048 | /* | |
1049 | * The following code is a more efficient, but less | |
1050 | * obvious, equivalent to the loop: | |
1051 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
1052 | * n = bitmap_ord_to_pos(orig, m, bits); | |
1053 | * if (test_bit(m, orig)) | |
1054 | * set_bit(n, dst); | |
1055 | * } | |
1056 | */ | |
1057 | ||
1058 | m = 0; | |
08564fb7 | 1059 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
1060 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
1061 | if (test_bit(m, orig)) | |
1062 | set_bit(n, dst); | |
1063 | m++; | |
1064 | } | |
1065 | } | |
7ea931c9 PJ |
1066 | |
1067 | /** | |
1068 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
1069 | * @dst: resulting smaller bitmap | |
1070 | * @orig: original larger bitmap | |
1071 | * @sz: specified size | |
b26ad583 | 1072 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
1073 | * |
1074 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
1075 | * Clear all other bits in @dst. See further the comment and | |
1076 | * Example [2] for bitmap_onto() for why and how to use this. | |
1077 | */ | |
1078 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 1079 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 1080 | { |
b26ad583 | 1081 | unsigned int oldbit; |
7ea931c9 PJ |
1082 | |
1083 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1084 | return; | |
b26ad583 | 1085 | bitmap_zero(dst, nbits); |
7ea931c9 | 1086 | |
b26ad583 | 1087 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
1088 | set_bit(oldbit % sz, dst); |
1089 | } | |
cdc90a18 | 1090 | #endif /* CONFIG_NUMA */ |
7ea931c9 | 1091 | |
3cf64b93 PJ |
1092 | /* |
1093 | * Common code for bitmap_*_region() routines. | |
1094 | * bitmap: array of unsigned longs corresponding to the bitmap | |
1095 | * pos: the beginning of the region | |
1096 | * order: region size (log base 2 of number of bits) | |
1097 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 1098 | * |
3cf64b93 PJ |
1099 | * Can set, verify and/or release a region of bits in a bitmap, |
1100 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 1101 | * |
3cf64b93 PJ |
1102 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1103 | * some size '1 << order' (a power of two), aligned to that same | |
1104 | * '1 << order' power of two. | |
1105 | * | |
1106 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1107 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 1108 | */ |
3cf64b93 PJ |
1109 | |
1110 | enum { | |
1111 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1112 | REG_OP_ALLOC, /* set all bits in region */ | |
1113 | REG_OP_RELEASE, /* clear all bits in region */ | |
1114 | }; | |
1115 | ||
9279d328 | 1116 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 1117 | { |
3cf64b93 PJ |
1118 | int nbits_reg; /* number of bits in region */ |
1119 | int index; /* index first long of region in bitmap */ | |
1120 | int offset; /* bit offset region in bitmap[index] */ | |
1121 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1122 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1123 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1124 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1125 | int ret = 0; /* return value */ |
74373c6a | 1126 | |
3cf64b93 PJ |
1127 | /* |
1128 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1129 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1130 | */ | |
1131 | nbits_reg = 1 << order; | |
1132 | index = pos / BITS_PER_LONG; | |
1133 | offset = pos - (index * BITS_PER_LONG); | |
1134 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1135 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1136 | |
3cf64b93 PJ |
1137 | /* |
1138 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1139 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1140 | */ | |
74373c6a | 1141 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1142 | mask += mask - 1; |
3cf64b93 | 1143 | mask <<= offset; |
1da177e4 | 1144 | |
3cf64b93 PJ |
1145 | switch (reg_op) { |
1146 | case REG_OP_ISFREE: | |
1147 | for (i = 0; i < nlongs_reg; i++) { | |
1148 | if (bitmap[index + i] & mask) | |
1149 | goto done; | |
1150 | } | |
1151 | ret = 1; /* all bits in region free (zero) */ | |
1152 | break; | |
1153 | ||
1154 | case REG_OP_ALLOC: | |
1155 | for (i = 0; i < nlongs_reg; i++) | |
1156 | bitmap[index + i] |= mask; | |
1157 | break; | |
1158 | ||
1159 | case REG_OP_RELEASE: | |
1160 | for (i = 0; i < nlongs_reg; i++) | |
1161 | bitmap[index + i] &= ~mask; | |
1162 | break; | |
1da177e4 | 1163 | } |
3cf64b93 PJ |
1164 | done: |
1165 | return ret; | |
1166 | } | |
1167 | ||
1168 | /** | |
1169 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1170 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1171 | * @bits: number of bits in the bitmap | |
1172 | * @order: region size (log base 2 of number of bits) to find | |
1173 | * | |
1174 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1175 | * allocate them (set them to one). Only consider regions of length | |
1176 | * a power (@order) of two, aligned to that power of two, which | |
1177 | * makes the search algorithm much faster. | |
1178 | * | |
1179 | * Return the bit offset in bitmap of the allocated region, | |
1180 | * or -errno on failure. | |
1181 | */ | |
9279d328 | 1182 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1183 | { |
9279d328 | 1184 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1185 | |
9279d328 | 1186 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1187 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1188 | continue; | |
1189 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1190 | return pos; | |
1191 | } | |
1192 | return -ENOMEM; | |
1da177e4 LT |
1193 | } |
1194 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1195 | ||
1196 | /** | |
87e24802 | 1197 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1198 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1199 | * @pos: beginning of bit region to release | |
1200 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1201 | * |
72fd4a35 | 1202 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1203 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1204 | * |
1205 | * No return value. | |
1da177e4 | 1206 | */ |
9279d328 | 1207 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1208 | { |
3cf64b93 | 1209 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1210 | } |
1211 | EXPORT_SYMBOL(bitmap_release_region); | |
1212 | ||
87e24802 PJ |
1213 | /** |
1214 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1215 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1216 | * @pos: beginning of bit region to allocate | |
1217 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1218 | * |
1219 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1220 | * |
6e1907ff | 1221 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1222 | * free (not all bits were zero). |
1223 | */ | |
9279d328 | 1224 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1225 | { |
3cf64b93 PJ |
1226 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1227 | return -EBUSY; | |
2ac521d3 | 1228 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1229 | } |
1230 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1231 | |
1232 | /** | |
1233 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1234 | * @dst: destination buffer | |
1235 | * @src: bitmap to copy | |
1236 | * @nbits: number of bits in the bitmap | |
1237 | * | |
1238 | * Require nbits % BITS_PER_LONG == 0. | |
1239 | */ | |
e8f24278 | 1240 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1241 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1242 | { |
9b6c2d2e | 1243 | unsigned int i; |
ccbe329b DV |
1244 | |
1245 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1246 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1247 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1248 | else |
9b6c2d2e | 1249 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1250 | } |
1251 | } | |
1252 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1253 | #endif |
c724f193 | 1254 | |
c42b65e3 AS |
1255 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) |
1256 | { | |
1257 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1258 | flags); | |
1259 | } | |
1260 | EXPORT_SYMBOL(bitmap_alloc); | |
1261 | ||
1262 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1263 | { | |
1264 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1265 | } | |
1266 | EXPORT_SYMBOL(bitmap_zalloc); | |
1267 | ||
1268 | void bitmap_free(const unsigned long *bitmap) | |
1269 | { | |
1270 | kfree(bitmap); | |
1271 | } | |
1272 | EXPORT_SYMBOL(bitmap_free); | |
1273 | ||
c724f193 YN |
1274 | #if BITS_PER_LONG == 64 |
1275 | /** | |
1276 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
1277 | * @bitmap: array of unsigned longs, the destination bitmap | |
1278 | * @buf: array of u32 (in host byte order), the source bitmap | |
1279 | * @nbits: number of bits in @bitmap | |
1280 | */ | |
ccf7a6d4 | 1281 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) |
c724f193 YN |
1282 | { |
1283 | unsigned int i, halfwords; | |
1284 | ||
c724f193 YN |
1285 | halfwords = DIV_ROUND_UP(nbits, 32); |
1286 | for (i = 0; i < halfwords; i++) { | |
1287 | bitmap[i/2] = (unsigned long) buf[i]; | |
1288 | if (++i < halfwords) | |
1289 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
1290 | } | |
1291 | ||
1292 | /* Clear tail bits in last word beyond nbits. */ | |
1293 | if (nbits % BITS_PER_LONG) | |
1294 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
1295 | } | |
1296 | EXPORT_SYMBOL(bitmap_from_arr32); | |
1297 | ||
1298 | /** | |
1299 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
1300 | * @buf: array of u32 (in host byte order), the dest bitmap | |
1301 | * @bitmap: array of unsigned longs, the source bitmap | |
1302 | * @nbits: number of bits in @bitmap | |
1303 | */ | |
1304 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1305 | { | |
1306 | unsigned int i, halfwords; | |
1307 | ||
c724f193 YN |
1308 | halfwords = DIV_ROUND_UP(nbits, 32); |
1309 | for (i = 0; i < halfwords; i++) { | |
1310 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
1311 | if (++i < halfwords) | |
1312 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
1313 | } | |
1314 | ||
1315 | /* Clear tail bits in last element of array beyond nbits. */ | |
1316 | if (nbits % BITS_PER_LONG) | |
1317 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
1318 | } | |
1319 | EXPORT_SYMBOL(bitmap_to_arr32); | |
1320 | ||
1321 | #endif |