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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> | |
50af5ead | 9 | #include <linux/bug.h> |
c13656b9 | 10 | #include <linux/ctype.h> |
e829c2e4 | 11 | #include <linux/device.h> |
c13656b9 BG |
12 | #include <linux/errno.h> |
13 | #include <linux/export.h> | |
e52bc7c2 | 14 | #include <linux/kernel.h> |
ce1091d4 | 15 | #include <linux/mm.h> |
c42b65e3 | 16 | #include <linux/slab.h> |
e52bc7c2 | 17 | #include <linux/string.h> |
c13656b9 | 18 | #include <linux/thread_info.h> |
13d4ea09 | 19 | #include <linux/uaccess.h> |
5aaba363 SH |
20 | |
21 | #include <asm/page.h> | |
1da177e4 | 22 | |
e371c481 YN |
23 | #include "kstrtox.h" |
24 | ||
7d7363e4 RD |
25 | /** |
26 | * DOC: bitmap introduction | |
27 | * | |
197d6c1d | 28 | * bitmaps provide an array of bits, implemented using an |
1da177e4 LT |
29 | * array of unsigned longs. The number of valid bits in a |
30 | * given bitmap does _not_ need to be an exact multiple of | |
31 | * BITS_PER_LONG. | |
32 | * | |
33 | * The possible unused bits in the last, partially used word | |
34 | * of a bitmap are 'don't care'. The implementation makes | |
35 | * no particular effort to keep them zero. It ensures that | |
36 | * their value will not affect the results of any operation. | |
37 | * The bitmap operations that return Boolean (bitmap_empty, | |
38 | * for example) or scalar (bitmap_weight, for example) results | |
39 | * carefully filter out these unused bits from impacting their | |
40 | * results. | |
41 | * | |
1da177e4 LT |
42 | * The byte ordering of bitmaps is more natural on little |
43 | * endian architectures. See the big-endian headers | |
44 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
45 | * for the best explanations of this ordering. | |
46 | */ | |
47 | ||
1da177e4 | 48 | int __bitmap_equal(const unsigned long *bitmap1, |
5e068069 | 49 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 50 | { |
5e068069 | 51 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
52 | for (k = 0; k < lim; ++k) |
53 | if (bitmap1[k] != bitmap2[k]) | |
54 | return 0; | |
55 | ||
56 | if (bits % BITS_PER_LONG) | |
57 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
58 | return 0; | |
59 | ||
60 | return 1; | |
61 | } | |
62 | EXPORT_SYMBOL(__bitmap_equal); | |
63 | ||
b9fa6442 TG |
64 | bool __bitmap_or_equal(const unsigned long *bitmap1, |
65 | const unsigned long *bitmap2, | |
66 | const unsigned long *bitmap3, | |
67 | unsigned int bits) | |
68 | { | |
69 | unsigned int k, lim = bits / BITS_PER_LONG; | |
70 | unsigned long tmp; | |
71 | ||
72 | for (k = 0; k < lim; ++k) { | |
73 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) | |
74 | return false; | |
75 | } | |
76 | ||
77 | if (!(bits % BITS_PER_LONG)) | |
78 | return true; | |
79 | ||
80 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; | |
81 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; | |
82 | } | |
83 | ||
3d6684f4 | 84 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 85 | { |
ca1250bb | 86 | unsigned int k, lim = BITS_TO_LONGS(bits); |
1da177e4 LT |
87 | for (k = 0; k < lim; ++k) |
88 | dst[k] = ~src[k]; | |
1da177e4 LT |
89 | } |
90 | EXPORT_SYMBOL(__bitmap_complement); | |
91 | ||
72fd4a35 | 92 | /** |
1da177e4 | 93 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
94 | * @dst : destination bitmap |
95 | * @src : source bitmap | |
96 | * @shift : shift by this many bits | |
2fbad299 | 97 | * @nbits : bitmap size, in bits |
1da177e4 LT |
98 | * |
99 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
100 | * direction. Zeros are fed into the vacated MS positions and the | |
101 | * LS bits shifted off the bottom are lost. | |
102 | */ | |
2fbad299 RV |
103 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
104 | unsigned shift, unsigned nbits) | |
1da177e4 | 105 | { |
cfac1d08 | 106 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 107 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 108 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
109 | for (k = 0; off + k < lim; ++k) { |
110 | unsigned long upper, lower; | |
111 | ||
112 | /* | |
113 | * If shift is not word aligned, take lower rem bits of | |
114 | * word above and make them the top rem bits of result. | |
115 | */ | |
116 | if (!rem || off + k + 1 >= lim) | |
117 | upper = 0; | |
118 | else { | |
119 | upper = src[off + k + 1]; | |
cfac1d08 | 120 | if (off + k + 1 == lim - 1) |
1da177e4 | 121 | upper &= mask; |
9d8a6b2a | 122 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
123 | } |
124 | lower = src[off + k]; | |
cfac1d08 | 125 | if (off + k == lim - 1) |
1da177e4 | 126 | lower &= mask; |
9d8a6b2a RV |
127 | lower >>= rem; |
128 | dst[k] = lower | upper; | |
1da177e4 LT |
129 | } |
130 | if (off) | |
131 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
132 | } | |
133 | EXPORT_SYMBOL(__bitmap_shift_right); | |
134 | ||
135 | ||
72fd4a35 | 136 | /** |
1da177e4 | 137 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
138 | * @dst : destination bitmap |
139 | * @src : source bitmap | |
140 | * @shift : shift by this many bits | |
dba94c25 | 141 | * @nbits : bitmap size, in bits |
1da177e4 LT |
142 | * |
143 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
144 | * direction. Zeros are fed into the vacated LS bit positions | |
145 | * and those MS bits shifted off the top are lost. | |
146 | */ | |
147 | ||
dba94c25 RV |
148 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
149 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 150 | { |
dba94c25 | 151 | int k; |
7f590657 | 152 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 153 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
154 | for (k = lim - off - 1; k >= 0; --k) { |
155 | unsigned long upper, lower; | |
156 | ||
157 | /* | |
158 | * If shift is not word aligned, take upper rem bits of | |
159 | * word below and make them the bottom rem bits of result. | |
160 | */ | |
161 | if (rem && k > 0) | |
6d874eca | 162 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
163 | else |
164 | lower = 0; | |
7f590657 | 165 | upper = src[k] << rem; |
6d874eca | 166 | dst[k + off] = lower | upper; |
1da177e4 LT |
167 | } |
168 | if (off) | |
169 | memset(dst, 0, off*sizeof(unsigned long)); | |
170 | } | |
171 | EXPORT_SYMBOL(__bitmap_shift_left); | |
172 | ||
20927671 SB |
173 | /** |
174 | * bitmap_cut() - remove bit region from bitmap and right shift remaining bits | |
175 | * @dst: destination bitmap, might overlap with src | |
176 | * @src: source bitmap | |
177 | * @first: start bit of region to be removed | |
178 | * @cut: number of bits to remove | |
179 | * @nbits: bitmap size, in bits | |
180 | * | |
181 | * Set the n-th bit of @dst iff the n-th bit of @src is set and | |
182 | * n is less than @first, or the m-th bit of @src is set for any | |
183 | * m such that @first <= n < nbits, and m = n + @cut. | |
184 | * | |
185 | * In pictures, example for a big-endian 32-bit architecture: | |
186 | * | |
4642289b | 187 | * The @src bitmap is:: |
20927671 | 188 | * |
4642289b MCC |
189 | * 31 63 |
190 | * | | | |
191 | * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 | |
192 | * | | | | | |
193 | * 16 14 0 32 | |
20927671 | 194 | * |
4642289b MCC |
195 | * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: |
196 | * | |
197 | * 31 63 | |
198 | * | | | |
199 | * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 | |
200 | * | | | | |
201 | * 14 (bit 17 0 32 | |
202 | * from @src) | |
20927671 SB |
203 | * |
204 | * Note that @dst and @src might overlap partially or entirely. | |
205 | * | |
206 | * This is implemented in the obvious way, with a shift and carry | |
207 | * step for each moved bit. Optimisation is left as an exercise | |
208 | * for the compiler. | |
209 | */ | |
210 | void bitmap_cut(unsigned long *dst, const unsigned long *src, | |
211 | unsigned int first, unsigned int cut, unsigned int nbits) | |
212 | { | |
213 | unsigned int len = BITS_TO_LONGS(nbits); | |
214 | unsigned long keep = 0, carry; | |
215 | int i; | |
216 | ||
20927671 SB |
217 | if (first % BITS_PER_LONG) { |
218 | keep = src[first / BITS_PER_LONG] & | |
219 | (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); | |
220 | } | |
221 | ||
5959f829 SB |
222 | memmove(dst, src, len * sizeof(*dst)); |
223 | ||
20927671 SB |
224 | while (cut--) { |
225 | for (i = first / BITS_PER_LONG; i < len; i++) { | |
226 | if (i < len - 1) | |
227 | carry = dst[i + 1] & 1UL; | |
228 | else | |
229 | carry = 0; | |
230 | ||
231 | dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); | |
232 | } | |
233 | } | |
234 | ||
235 | dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); | |
236 | dst[first / BITS_PER_LONG] |= keep; | |
237 | } | |
238 | EXPORT_SYMBOL(bitmap_cut); | |
239 | ||
f4b0373b | 240 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 241 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 242 | { |
2f9305eb | 243 | unsigned int k; |
7e5f97d1 | 244 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 245 | unsigned long result = 0; |
1da177e4 | 246 | |
7e5f97d1 | 247 | for (k = 0; k < lim; k++) |
f4b0373b | 248 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
249 | if (bits % BITS_PER_LONG) |
250 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
251 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 252 | return result != 0; |
1da177e4 LT |
253 | } |
254 | EXPORT_SYMBOL(__bitmap_and); | |
255 | ||
256 | void __bitmap_or(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_or); | |
266 | ||
267 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 268 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 269 | { |
2f9305eb RV |
270 | unsigned int k; |
271 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
272 | |
273 | for (k = 0; k < nr; k++) | |
274 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
275 | } | |
276 | EXPORT_SYMBOL(__bitmap_xor); | |
277 | ||
f4b0373b | 278 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 279 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 280 | { |
2f9305eb | 281 | unsigned int k; |
74e76531 | 282 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 283 | unsigned long result = 0; |
1da177e4 | 284 | |
74e76531 | 285 | for (k = 0; k < lim; k++) |
f4b0373b | 286 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
287 | if (bits % BITS_PER_LONG) |
288 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
289 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 290 | return result != 0; |
1da177e4 LT |
291 | } |
292 | EXPORT_SYMBOL(__bitmap_andnot); | |
293 | ||
30544ed5 AS |
294 | void __bitmap_replace(unsigned long *dst, |
295 | const unsigned long *old, const unsigned long *new, | |
296 | const unsigned long *mask, unsigned int nbits) | |
297 | { | |
298 | unsigned int k; | |
299 | unsigned int nr = BITS_TO_LONGS(nbits); | |
300 | ||
301 | for (k = 0; k < nr; k++) | |
302 | dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); | |
303 | } | |
304 | EXPORT_SYMBOL(__bitmap_replace); | |
305 | ||
1da177e4 | 306 | int __bitmap_intersects(const unsigned long *bitmap1, |
6dfe9799 | 307 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 308 | { |
6dfe9799 | 309 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
310 | for (k = 0; k < lim; ++k) |
311 | if (bitmap1[k] & bitmap2[k]) | |
312 | return 1; | |
313 | ||
314 | if (bits % BITS_PER_LONG) | |
315 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
316 | return 1; | |
317 | return 0; | |
318 | } | |
319 | EXPORT_SYMBOL(__bitmap_intersects); | |
320 | ||
321 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 322 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 323 | { |
5be20213 | 324 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
325 | for (k = 0; k < lim; ++k) |
326 | if (bitmap1[k] & ~bitmap2[k]) | |
327 | return 0; | |
328 | ||
329 | if (bits % BITS_PER_LONG) | |
330 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
331 | return 0; | |
332 | return 1; | |
333 | } | |
334 | EXPORT_SYMBOL(__bitmap_subset); | |
335 | ||
877d9f3b | 336 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 337 | { |
877d9f3b RV |
338 | unsigned int k, lim = bits/BITS_PER_LONG; |
339 | int w = 0; | |
1da177e4 LT |
340 | |
341 | for (k = 0; k < lim; k++) | |
37d54111 | 342 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
343 | |
344 | if (bits % BITS_PER_LONG) | |
37d54111 | 345 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
346 | |
347 | return w; | |
348 | } | |
1da177e4 LT |
349 | EXPORT_SYMBOL(__bitmap_weight); |
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 | |
1da177e4 | 432 | /* |
6d49e352 | 433 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
434 | * second version by Paul Jackson, third by Joe Korty. |
435 | */ | |
436 | ||
01a3ee2b | 437 | /** |
9a86e2ba | 438 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
439 | * |
440 | * @ubuf: pointer to user buffer containing string. | |
441 | * @ulen: buffer size in bytes. If string is smaller than this | |
442 | * then it must be terminated with a \0. | |
443 | * @maskp: pointer to bitmap array that will contain result. | |
444 | * @nmaskbits: size of bitmap, in bits. | |
01a3ee2b RC |
445 | */ |
446 | int bitmap_parse_user(const char __user *ubuf, | |
447 | unsigned int ulen, unsigned long *maskp, | |
448 | int nmaskbits) | |
449 | { | |
e66eda06 YN |
450 | char *buf; |
451 | int ret; | |
452 | ||
453 | buf = memdup_user_nul(ubuf, ulen); | |
454 | if (IS_ERR(buf)) | |
455 | return PTR_ERR(buf); | |
456 | ||
2d626158 | 457 | ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); |
b9c321fd | 458 | |
e66eda06 YN |
459 | kfree(buf); |
460 | return ret; | |
01a3ee2b RC |
461 | } |
462 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 463 | |
5aaba363 SH |
464 | /** |
465 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
466 | * @list: indicates whether the bitmap must be list | |
467 | * @buf: page aligned buffer into which string is placed | |
468 | * @maskp: pointer to bitmap to convert | |
469 | * @nmaskbits: size of bitmap, in bits | |
470 | * | |
471 | * Output format is a comma-separated list of decimal numbers and | |
472 | * ranges if list is specified or hex digits grouped into comma-separated | |
473 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 | 474 | * |
ce1091d4 RV |
475 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned |
476 | * area and that sufficient storage remains at @buf to accommodate the | |
477 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
478 | * actually printed to @buf, excluding terminating '\0'. | |
5aaba363 SH |
479 | */ |
480 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
481 | int nmaskbits) | |
482 | { | |
ce1091d4 | 483 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
5aaba363 | 484 | |
8ec3d768 RV |
485 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
486 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
487 | } |
488 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
489 | ||
e371c481 YN |
490 | /* |
491 | * Region 9-38:4/10 describes the following bitmap structure: | |
9d7a3366 PG |
492 | * 0 9 12 18 38 N |
493 | * .........****......****......****.................. | |
494 | * ^ ^ ^ ^ ^ | |
495 | * start off group_len end nbits | |
e371c481 YN |
496 | */ |
497 | struct region { | |
498 | unsigned int start; | |
499 | unsigned int off; | |
500 | unsigned int group_len; | |
501 | unsigned int end; | |
9d7a3366 | 502 | unsigned int nbits; |
e371c481 YN |
503 | }; |
504 | ||
f3c869ca | 505 | static void bitmap_set_region(const struct region *r, unsigned long *bitmap) |
e371c481 YN |
506 | { |
507 | unsigned int start; | |
508 | ||
e371c481 YN |
509 | for (start = r->start; start <= r->end; start += r->group_len) |
510 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); | |
e371c481 YN |
511 | } |
512 | ||
513 | static int bitmap_check_region(const struct region *r) | |
514 | { | |
515 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) | |
516 | return -EINVAL; | |
517 | ||
f3c869ca PG |
518 | if (r->end >= r->nbits) |
519 | return -ERANGE; | |
520 | ||
e371c481 YN |
521 | return 0; |
522 | } | |
523 | ||
2c4885d2 PG |
524 | static const char *bitmap_getnum(const char *str, unsigned int *num, |
525 | unsigned int lastbit) | |
e371c481 YN |
526 | { |
527 | unsigned long long n; | |
528 | unsigned int len; | |
529 | ||
2c4885d2 PG |
530 | if (str[0] == 'N') { |
531 | *num = lastbit; | |
532 | return str + 1; | |
533 | } | |
534 | ||
e371c481 YN |
535 | len = _parse_integer(str, 10, &n); |
536 | if (!len) | |
537 | return ERR_PTR(-EINVAL); | |
538 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) | |
539 | return ERR_PTR(-EOVERFLOW); | |
540 | ||
541 | *num = n; | |
542 | return str + len; | |
543 | } | |
544 | ||
545 | static inline bool end_of_str(char c) | |
546 | { | |
547 | return c == '\0' || c == '\n'; | |
548 | } | |
549 | ||
550 | static inline bool __end_of_region(char c) | |
551 | { | |
552 | return isspace(c) || c == ','; | |
553 | } | |
554 | ||
555 | static inline bool end_of_region(char c) | |
556 | { | |
557 | return __end_of_region(c) || end_of_str(c); | |
558 | } | |
559 | ||
560 | /* | |
20607434 | 561 | * The format allows commas and whitespaces at the beginning |
e371c481 YN |
562 | * of the region. |
563 | */ | |
564 | static const char *bitmap_find_region(const char *str) | |
565 | { | |
566 | while (__end_of_region(*str)) | |
567 | str++; | |
568 | ||
569 | return end_of_str(*str) ? NULL : str; | |
570 | } | |
571 | ||
2d626158 YN |
572 | static const char *bitmap_find_region_reverse(const char *start, const char *end) |
573 | { | |
574 | while (start <= end && __end_of_region(*end)) | |
575 | end--; | |
576 | ||
577 | return end; | |
578 | } | |
579 | ||
e371c481 YN |
580 | static const char *bitmap_parse_region(const char *str, struct region *r) |
581 | { | |
2c4885d2 PG |
582 | unsigned int lastbit = r->nbits - 1; |
583 | ||
b18def12 YN |
584 | if (!strncasecmp(str, "all", 3)) { |
585 | r->start = 0; | |
586 | r->end = lastbit; | |
587 | str += 3; | |
588 | ||
589 | goto check_pattern; | |
590 | } | |
591 | ||
2c4885d2 | 592 | str = bitmap_getnum(str, &r->start, lastbit); |
e371c481 YN |
593 | if (IS_ERR(str)) |
594 | return str; | |
595 | ||
596 | if (end_of_region(*str)) | |
597 | goto no_end; | |
598 | ||
599 | if (*str != '-') | |
600 | return ERR_PTR(-EINVAL); | |
601 | ||
2c4885d2 | 602 | str = bitmap_getnum(str + 1, &r->end, lastbit); |
e371c481 YN |
603 | if (IS_ERR(str)) |
604 | return str; | |
605 | ||
b18def12 | 606 | check_pattern: |
e371c481 YN |
607 | if (end_of_region(*str)) |
608 | goto no_pattern; | |
609 | ||
610 | if (*str != ':') | |
611 | return ERR_PTR(-EINVAL); | |
612 | ||
2c4885d2 | 613 | str = bitmap_getnum(str + 1, &r->off, lastbit); |
e371c481 YN |
614 | if (IS_ERR(str)) |
615 | return str; | |
616 | ||
617 | if (*str != '/') | |
618 | return ERR_PTR(-EINVAL); | |
619 | ||
2c4885d2 | 620 | return bitmap_getnum(str + 1, &r->group_len, lastbit); |
e371c481 YN |
621 | |
622 | no_end: | |
623 | r->end = r->start; | |
624 | no_pattern: | |
625 | r->off = r->end + 1; | |
626 | r->group_len = r->end + 1; | |
627 | ||
628 | return end_of_str(*str) ? NULL : str; | |
629 | } | |
630 | ||
1da177e4 | 631 | /** |
e371c481 YN |
632 | * bitmap_parselist - convert list format ASCII string to bitmap |
633 | * @buf: read user string from this buffer; must be terminated | |
634 | * with a \0 or \n. | |
6e1907ff | 635 | * @maskp: write resulting mask here |
1da177e4 LT |
636 | * @nmaskbits: number of bits in mask to be written |
637 | * | |
638 | * Input format is a comma-separated list of decimal numbers and | |
639 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
640 | * decimal numbers, the smallest and largest bit numbers set in | |
641 | * the range. | |
2d13e6ca NC |
642 | * Optionally each range can be postfixed to denote that only parts of it |
643 | * should be set. The range will divided to groups of specific size. | |
644 | * From each group will be used only defined amount of bits. | |
645 | * Syntax: range:used_size/group_size | |
646 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
2c4885d2 PG |
647 | * The value 'N' can be used as a dynamically substituted token for the |
648 | * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is | |
649 | * dynamic, so if system changes cause the bitmap width to change, such | |
650 | * as more cores in a CPU list, then any ranges using N will also change. | |
1da177e4 | 651 | * |
40bf19a8 MCC |
652 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
653 | * | |
e371c481 | 654 | * - ``-EINVAL``: wrong region format |
40bf19a8 MCC |
655 | * - ``-EINVAL``: invalid character in string |
656 | * - ``-ERANGE``: bit number specified too large for mask | |
e371c481 | 657 | * - ``-EOVERFLOW``: integer overflow in the input parameters |
1da177e4 | 658 | */ |
e371c481 | 659 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) |
1da177e4 | 660 | { |
e371c481 YN |
661 | struct region r; |
662 | long ret; | |
1da177e4 | 663 | |
9d7a3366 PG |
664 | r.nbits = nmaskbits; |
665 | bitmap_zero(maskp, r.nbits); | |
4b060420 | 666 | |
e371c481 YN |
667 | while (buf) { |
668 | buf = bitmap_find_region(buf); | |
669 | if (buf == NULL) | |
670 | return 0; | |
2d13e6ca | 671 | |
e371c481 YN |
672 | buf = bitmap_parse_region(buf, &r); |
673 | if (IS_ERR(buf)) | |
674 | return PTR_ERR(buf); | |
2d13e6ca | 675 | |
e371c481 YN |
676 | ret = bitmap_check_region(&r); |
677 | if (ret) | |
678 | return ret; | |
4b060420 | 679 | |
f3c869ca | 680 | bitmap_set_region(&r, maskp); |
e371c481 | 681 | } |
4b060420 | 682 | |
1da177e4 LT |
683 | return 0; |
684 | } | |
685 | EXPORT_SYMBOL(bitmap_parselist); | |
686 | ||
4b060420 MT |
687 | |
688 | /** | |
689 | * bitmap_parselist_user() | |
690 | * | |
691 | * @ubuf: pointer to user buffer containing string. | |
692 | * @ulen: buffer size in bytes. If string is smaller than this | |
693 | * then it must be terminated with a \0. | |
694 | * @maskp: pointer to bitmap array that will contain result. | |
695 | * @nmaskbits: size of bitmap, in bits. | |
696 | * | |
697 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
4b060420 MT |
698 | */ |
699 | int bitmap_parselist_user(const char __user *ubuf, | |
700 | unsigned int ulen, unsigned long *maskp, | |
701 | int nmaskbits) | |
702 | { | |
281327c9 YN |
703 | char *buf; |
704 | int ret; | |
705 | ||
706 | buf = memdup_user_nul(ubuf, ulen); | |
707 | if (IS_ERR(buf)) | |
708 | return PTR_ERR(buf); | |
709 | ||
710 | ret = bitmap_parselist(buf, maskp, nmaskbits); | |
711 | ||
712 | kfree(buf); | |
713 | return ret; | |
4b060420 MT |
714 | } |
715 | EXPORT_SYMBOL(bitmap_parselist_user); | |
716 | ||
2d626158 YN |
717 | static const char *bitmap_get_x32_reverse(const char *start, |
718 | const char *end, u32 *num) | |
719 | { | |
720 | u32 ret = 0; | |
721 | int c, i; | |
722 | ||
723 | for (i = 0; i < 32; i += 4) { | |
724 | c = hex_to_bin(*end--); | |
725 | if (c < 0) | |
726 | return ERR_PTR(-EINVAL); | |
727 | ||
728 | ret |= c << i; | |
729 | ||
730 | if (start > end || __end_of_region(*end)) | |
731 | goto out; | |
732 | } | |
733 | ||
734 | if (hex_to_bin(*end--) >= 0) | |
735 | return ERR_PTR(-EOVERFLOW); | |
736 | out: | |
737 | *num = ret; | |
738 | return end; | |
739 | } | |
740 | ||
741 | /** | |
742 | * bitmap_parse - convert an ASCII hex string into a bitmap. | |
743 | * @start: pointer to buffer containing string. | |
744 | * @buflen: buffer size in bytes. If string is smaller than this | |
745 | * then it must be terminated with a \0 or \n. In that case, | |
746 | * UINT_MAX may be provided instead of string length. | |
747 | * @maskp: pointer to bitmap array that will contain result. | |
748 | * @nmaskbits: size of bitmap, in bits. | |
749 | * | |
750 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
751 | * bits of the resultant bitmask. No chunk may specify a value larger | |
752 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value | |
753 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
754 | * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. | |
755 | * Leading, embedded and trailing whitespace accepted. | |
756 | */ | |
757 | int bitmap_parse(const char *start, unsigned int buflen, | |
758 | unsigned long *maskp, int nmaskbits) | |
759 | { | |
760 | const char *end = strnchrnul(start, buflen, '\n') - 1; | |
761 | int chunks = BITS_TO_U32(nmaskbits); | |
762 | u32 *bitmap = (u32 *)maskp; | |
763 | int unset_bit; | |
81c4f4d9 | 764 | int chunk; |
2d626158 | 765 | |
81c4f4d9 | 766 | for (chunk = 0; ; chunk++) { |
2d626158 YN |
767 | end = bitmap_find_region_reverse(start, end); |
768 | if (start > end) | |
769 | break; | |
770 | ||
771 | if (!chunks--) | |
772 | return -EOVERFLOW; | |
773 | ||
81c4f4d9 AG |
774 | #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) |
775 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); | |
776 | #else | |
777 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); | |
778 | #endif | |
2d626158 YN |
779 | if (IS_ERR(end)) |
780 | return PTR_ERR(end); | |
781 | } | |
782 | ||
783 | unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; | |
784 | if (unset_bit < nmaskbits) { | |
785 | bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); | |
786 | return 0; | |
787 | } | |
788 | ||
789 | if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) | |
790 | return -EOVERFLOW; | |
791 | ||
792 | return 0; | |
793 | } | |
794 | EXPORT_SYMBOL(bitmap_parse); | |
795 | ||
72fd4a35 | 796 | /** |
9a86e2ba | 797 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 798 | * @buf: pointer to a bitmap |
df1d80a9 RV |
799 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
800 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 801 | * |
df1d80a9 | 802 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 803 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 804 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
805 | * |
806 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
807 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 808 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
809 | * gets mapped to (returns) @ord value 3 in this example, that means |
810 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
811 | * | |
812 | * The bit positions 0 through @bits are valid positions in @buf. | |
813 | */ | |
df1d80a9 | 814 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 815 | { |
df1d80a9 | 816 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 817 | return -1; |
fb5eeeee | 818 | |
df1d80a9 | 819 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
820 | } |
821 | ||
822 | /** | |
9a86e2ba | 823 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
824 | * @buf: pointer to bitmap |
825 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 826 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
827 | * |
828 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
829 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
830 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
831 | * |
832 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
833 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 834 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
835 | * gets mapped to (returns) @pos value 7 in this example, that means |
836 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
837 | * | |
f6a1f5db | 838 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 839 | */ |
f6a1f5db | 840 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 841 | { |
f6a1f5db | 842 | unsigned int pos; |
fb5eeeee | 843 | |
f6a1f5db RV |
844 | for (pos = find_first_bit(buf, nbits); |
845 | pos < nbits && ord; | |
846 | pos = find_next_bit(buf, nbits, pos + 1)) | |
847 | ord--; | |
fb5eeeee PJ |
848 | |
849 | return pos; | |
850 | } | |
851 | ||
852 | /** | |
853 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 854 | * @dst: remapped result |
96b7f341 | 855 | * @src: subset to be remapped |
fb5eeeee PJ |
856 | * @old: defines domain of map |
857 | * @new: defines range of map | |
9814ec13 | 858 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
859 | * |
860 | * Let @old and @new define a mapping of bit positions, such that | |
861 | * whatever position is held by the n-th set bit in @old is mapped | |
862 | * to the n-th set bit in @new. In the more general case, allowing | |
863 | * for the possibility that the weight 'w' of @new is less than the | |
864 | * weight of @old, map the position of the n-th set bit in @old to | |
865 | * the position of the m-th set bit in @new, where m == n % w. | |
866 | * | |
96b7f341 PJ |
867 | * If either of the @old and @new bitmaps are empty, or if @src and |
868 | * @dst point to the same location, then this routine copies @src | |
869 | * to @dst. | |
fb5eeeee | 870 | * |
96b7f341 PJ |
871 | * The positions of unset bits in @old are mapped to themselves |
872 | * (the identify map). | |
fb5eeeee PJ |
873 | * |
874 | * Apply the above specified mapping to @src, placing the result in | |
875 | * @dst, clearing any bits previously set in @dst. | |
876 | * | |
fb5eeeee PJ |
877 | * For example, lets say that @old has bits 4 through 7 set, and |
878 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
879 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
880 | * bit positions unchanged. So if say @src comes into this routine |
881 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
882 | * 13 and 15 set. | |
fb5eeeee PJ |
883 | */ |
884 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
885 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 886 | unsigned int nbits) |
fb5eeeee | 887 | { |
9814ec13 | 888 | unsigned int oldbit, w; |
fb5eeeee | 889 | |
fb5eeeee PJ |
890 | if (dst == src) /* following doesn't handle inplace remaps */ |
891 | return; | |
9814ec13 | 892 | bitmap_zero(dst, nbits); |
96b7f341 | 893 | |
9814ec13 RV |
894 | w = bitmap_weight(new, nbits); |
895 | for_each_set_bit(oldbit, src, nbits) { | |
896 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 897 | |
96b7f341 PJ |
898 | if (n < 0 || w == 0) |
899 | set_bit(oldbit, dst); /* identity map */ | |
900 | else | |
9814ec13 | 901 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
902 | } |
903 | } | |
cde3d0f8 | 904 | EXPORT_SYMBOL(bitmap_remap); |
fb5eeeee PJ |
905 | |
906 | /** | |
907 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
908 | * @oldbit: bit position to be mapped |
909 | * @old: defines domain of map | |
910 | * @new: defines range of map | |
911 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
912 | * |
913 | * Let @old and @new define a mapping of bit positions, such that | |
914 | * whatever position is held by the n-th set bit in @old is mapped | |
915 | * to the n-th set bit in @new. In the more general case, allowing | |
916 | * for the possibility that the weight 'w' of @new is less than the | |
917 | * weight of @old, map the position of the n-th set bit in @old to | |
918 | * the position of the m-th set bit in @new, where m == n % w. | |
919 | * | |
96b7f341 PJ |
920 | * The positions of unset bits in @old are mapped to themselves |
921 | * (the identify map). | |
fb5eeeee PJ |
922 | * |
923 | * Apply the above specified mapping to bit position @oldbit, returning | |
924 | * the new bit position. | |
925 | * | |
926 | * For example, lets say that @old has bits 4 through 7 set, and | |
927 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
928 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
929 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
930 | * returns 13. | |
fb5eeeee PJ |
931 | */ |
932 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
933 | const unsigned long *new, int bits) | |
934 | { | |
96b7f341 PJ |
935 | int w = bitmap_weight(new, bits); |
936 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
937 | if (n < 0 || w == 0) | |
938 | return oldbit; | |
939 | else | |
940 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee | 941 | } |
cde3d0f8 | 942 | EXPORT_SYMBOL(bitmap_bitremap); |
fb5eeeee | 943 | |
cde3d0f8 | 944 | #ifdef CONFIG_NUMA |
7ea931c9 PJ |
945 | /** |
946 | * bitmap_onto - translate one bitmap relative to another | |
947 | * @dst: resulting translated bitmap | |
948 | * @orig: original untranslated bitmap | |
949 | * @relmap: bitmap relative to which translated | |
950 | * @bits: number of bits in each of these bitmaps | |
951 | * | |
952 | * Set the n-th bit of @dst iff there exists some m such that the | |
953 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
954 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
955 | * (If you understood the previous sentence the first time your | |
956 | * read it, you're overqualified for your current job.) | |
957 | * | |
958 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 959 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
960 | * m-th set bit of @relmap }. |
961 | * | |
962 | * Any set bits in @orig above bit number W, where W is the | |
963 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
964 | * In particular, if for all bits m set in @orig, m >= W, then | |
965 | * @dst will end up empty. In situations where the possibility | |
966 | * of such an empty result is not desired, one way to avoid it is | |
967 | * to use the bitmap_fold() operator, below, to first fold the | |
968 | * @orig bitmap over itself so that all its set bits x are in the | |
969 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
970 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
971 | * | |
972 | * Example [1] for bitmap_onto(): | |
973 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
974 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
975 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
976 | * | |
977 | * When bit 0 is set in @orig, it means turn on the bit in | |
978 | * @dst corresponding to whatever is the first bit (if any) | |
979 | * that is turned on in @relmap. Since bit 0 was off in the | |
980 | * above example, we leave off that bit (bit 30) in @dst. | |
981 | * | |
982 | * When bit 1 is set in @orig (as in the above example), it | |
983 | * means turn on the bit in @dst corresponding to whatever | |
984 | * is the second bit that is turned on in @relmap. The second | |
985 | * bit in @relmap that was turned on in the above example was | |
986 | * bit 31, so we turned on bit 31 in @dst. | |
987 | * | |
988 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
989 | * because they were the 4th, 6th, 8th and 10th set bits | |
990 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
991 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
992 | * | |
993 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 994 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
995 | * turned on in @relmap. In the above example, there were |
996 | * only ten bits turned on in @relmap (30..39), so that bit | |
997 | * 11 was set in @orig had no affect on @dst. | |
998 | * | |
999 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
1000 | * Let's say @relmap has these ten bits set:: |
1001 | * | |
7ea931c9 | 1002 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 1003 | * |
7ea931c9 PJ |
1004 | * (for the curious, that's 40 plus the first ten terms of the |
1005 | * Fibonacci sequence.) | |
1006 | * | |
1007 | * Further lets say we use the following code, invoking | |
1008 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 1009 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
1010 | * |
1011 | * unsigned long *tmp; // a temporary bitmap's bits | |
1012 | * | |
1013 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
1014 | * bitmap_onto(dst, tmp, relmap, bits); | |
1015 | * | |
1016 | * Then this table shows what various values of @dst would be, for | |
1017 | * various @orig's. I list the zero-based positions of each set bit. | |
1018 | * The tmp column shows the intermediate result, as computed by | |
1019 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 1020 | * (the weight of @relmap): |
7ea931c9 | 1021 | * |
40bf19a8 | 1022 | * =============== ============== ================= |
7ea931c9 PJ |
1023 | * @orig tmp @dst |
1024 | * 0 0 40 | |
1025 | * 1 1 41 | |
1026 | * 9 9 95 | |
40bf19a8 | 1027 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
1028 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
1029 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
1030 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
1031 | * 0 10 20 30 0 40 | |
1032 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
1033 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
1034 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
1035 | * =============== ============== ================= | |
1036 | * | |
1037 | * .. [#f1] | |
7ea931c9 | 1038 | * |
40bf19a8 | 1039 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
1040 | * into tmp, then the @dst result would have been empty. |
1041 | * | |
1042 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
1043 | * will be returned empty. | |
1044 | * | |
1045 | * If (as explained above) the only set bits in @orig are in positions | |
1046 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
1047 | * once again be returned empty. | |
1048 | * | |
1049 | * All bits in @dst not set by the above rule are cleared. | |
1050 | */ | |
1051 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 1052 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 1053 | { |
eb569883 | 1054 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
1055 | |
1056 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1057 | return; | |
1058 | bitmap_zero(dst, bits); | |
1059 | ||
1060 | /* | |
1061 | * The following code is a more efficient, but less | |
1062 | * obvious, equivalent to the loop: | |
1063 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
1064 | * n = bitmap_ord_to_pos(orig, m, bits); | |
1065 | * if (test_bit(m, orig)) | |
1066 | * set_bit(n, dst); | |
1067 | * } | |
1068 | */ | |
1069 | ||
1070 | m = 0; | |
08564fb7 | 1071 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
1072 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
1073 | if (test_bit(m, orig)) | |
1074 | set_bit(n, dst); | |
1075 | m++; | |
1076 | } | |
1077 | } | |
7ea931c9 PJ |
1078 | |
1079 | /** | |
1080 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
1081 | * @dst: resulting smaller bitmap | |
1082 | * @orig: original larger bitmap | |
1083 | * @sz: specified size | |
b26ad583 | 1084 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
1085 | * |
1086 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
1087 | * Clear all other bits in @dst. See further the comment and | |
1088 | * Example [2] for bitmap_onto() for why and how to use this. | |
1089 | */ | |
1090 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 1091 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 1092 | { |
b26ad583 | 1093 | unsigned int oldbit; |
7ea931c9 PJ |
1094 | |
1095 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1096 | return; | |
b26ad583 | 1097 | bitmap_zero(dst, nbits); |
7ea931c9 | 1098 | |
b26ad583 | 1099 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
1100 | set_bit(oldbit % sz, dst); |
1101 | } | |
cdc90a18 | 1102 | #endif /* CONFIG_NUMA */ |
7ea931c9 | 1103 | |
3cf64b93 PJ |
1104 | /* |
1105 | * Common code for bitmap_*_region() routines. | |
1106 | * bitmap: array of unsigned longs corresponding to the bitmap | |
1107 | * pos: the beginning of the region | |
1108 | * order: region size (log base 2 of number of bits) | |
1109 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 1110 | * |
3cf64b93 PJ |
1111 | * Can set, verify and/or release a region of bits in a bitmap, |
1112 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 1113 | * |
3cf64b93 PJ |
1114 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1115 | * some size '1 << order' (a power of two), aligned to that same | |
1116 | * '1 << order' power of two. | |
1117 | * | |
1118 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1119 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 1120 | */ |
3cf64b93 PJ |
1121 | |
1122 | enum { | |
1123 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1124 | REG_OP_ALLOC, /* set all bits in region */ | |
1125 | REG_OP_RELEASE, /* clear all bits in region */ | |
1126 | }; | |
1127 | ||
9279d328 | 1128 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 1129 | { |
3cf64b93 PJ |
1130 | int nbits_reg; /* number of bits in region */ |
1131 | int index; /* index first long of region in bitmap */ | |
1132 | int offset; /* bit offset region in bitmap[index] */ | |
1133 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1134 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1135 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1136 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1137 | int ret = 0; /* return value */ |
74373c6a | 1138 | |
3cf64b93 PJ |
1139 | /* |
1140 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1141 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1142 | */ | |
1143 | nbits_reg = 1 << order; | |
1144 | index = pos / BITS_PER_LONG; | |
1145 | offset = pos - (index * BITS_PER_LONG); | |
1146 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1147 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1148 | |
3cf64b93 PJ |
1149 | /* |
1150 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1151 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1152 | */ | |
74373c6a | 1153 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1154 | mask += mask - 1; |
3cf64b93 | 1155 | mask <<= offset; |
1da177e4 | 1156 | |
3cf64b93 PJ |
1157 | switch (reg_op) { |
1158 | case REG_OP_ISFREE: | |
1159 | for (i = 0; i < nlongs_reg; i++) { | |
1160 | if (bitmap[index + i] & mask) | |
1161 | goto done; | |
1162 | } | |
1163 | ret = 1; /* all bits in region free (zero) */ | |
1164 | break; | |
1165 | ||
1166 | case REG_OP_ALLOC: | |
1167 | for (i = 0; i < nlongs_reg; i++) | |
1168 | bitmap[index + i] |= mask; | |
1169 | break; | |
1170 | ||
1171 | case REG_OP_RELEASE: | |
1172 | for (i = 0; i < nlongs_reg; i++) | |
1173 | bitmap[index + i] &= ~mask; | |
1174 | break; | |
1da177e4 | 1175 | } |
3cf64b93 PJ |
1176 | done: |
1177 | return ret; | |
1178 | } | |
1179 | ||
1180 | /** | |
1181 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1182 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1183 | * @bits: number of bits in the bitmap | |
1184 | * @order: region size (log base 2 of number of bits) to find | |
1185 | * | |
1186 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1187 | * allocate them (set them to one). Only consider regions of length | |
1188 | * a power (@order) of two, aligned to that power of two, which | |
1189 | * makes the search algorithm much faster. | |
1190 | * | |
1191 | * Return the bit offset in bitmap of the allocated region, | |
1192 | * or -errno on failure. | |
1193 | */ | |
9279d328 | 1194 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1195 | { |
9279d328 | 1196 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1197 | |
9279d328 | 1198 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1199 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1200 | continue; | |
1201 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1202 | return pos; | |
1203 | } | |
1204 | return -ENOMEM; | |
1da177e4 LT |
1205 | } |
1206 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1207 | ||
1208 | /** | |
87e24802 | 1209 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1210 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1211 | * @pos: beginning of bit region to release | |
1212 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1213 | * |
72fd4a35 | 1214 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1215 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1216 | * |
1217 | * No return value. | |
1da177e4 | 1218 | */ |
9279d328 | 1219 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1220 | { |
3cf64b93 | 1221 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1222 | } |
1223 | EXPORT_SYMBOL(bitmap_release_region); | |
1224 | ||
87e24802 PJ |
1225 | /** |
1226 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1227 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1228 | * @pos: beginning of bit region to allocate | |
1229 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1230 | * |
1231 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1232 | * |
6e1907ff | 1233 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1234 | * free (not all bits were zero). |
1235 | */ | |
9279d328 | 1236 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1237 | { |
3cf64b93 PJ |
1238 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1239 | return -EBUSY; | |
2ac521d3 | 1240 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1241 | } |
1242 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1243 | |
1244 | /** | |
1245 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1246 | * @dst: destination buffer | |
1247 | * @src: bitmap to copy | |
1248 | * @nbits: number of bits in the bitmap | |
1249 | * | |
1250 | * Require nbits % BITS_PER_LONG == 0. | |
1251 | */ | |
e8f24278 | 1252 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1253 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1254 | { |
9b6c2d2e | 1255 | unsigned int i; |
ccbe329b DV |
1256 | |
1257 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1258 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1259 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1260 | else |
9b6c2d2e | 1261 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1262 | } |
1263 | } | |
1264 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1265 | #endif |
c724f193 | 1266 | |
c42b65e3 AS |
1267 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) |
1268 | { | |
1269 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1270 | flags); | |
1271 | } | |
1272 | EXPORT_SYMBOL(bitmap_alloc); | |
1273 | ||
1274 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1275 | { | |
1276 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1277 | } | |
1278 | EXPORT_SYMBOL(bitmap_zalloc); | |
1279 | ||
1280 | void bitmap_free(const unsigned long *bitmap) | |
1281 | { | |
1282 | kfree(bitmap); | |
1283 | } | |
1284 | EXPORT_SYMBOL(bitmap_free); | |
1285 | ||
e829c2e4 BG |
1286 | static void devm_bitmap_free(void *data) |
1287 | { | |
1288 | unsigned long *bitmap = data; | |
1289 | ||
1290 | bitmap_free(bitmap); | |
1291 | } | |
1292 | ||
1293 | unsigned long *devm_bitmap_alloc(struct device *dev, | |
1294 | unsigned int nbits, gfp_t flags) | |
1295 | { | |
1296 | unsigned long *bitmap; | |
1297 | int ret; | |
1298 | ||
1299 | bitmap = bitmap_alloc(nbits, flags); | |
1300 | if (!bitmap) | |
1301 | return NULL; | |
1302 | ||
1303 | ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap); | |
1304 | if (ret) | |
1305 | return NULL; | |
1306 | ||
1307 | return bitmap; | |
1308 | } | |
1309 | EXPORT_SYMBOL_GPL(devm_bitmap_alloc); | |
1310 | ||
1311 | unsigned long *devm_bitmap_zalloc(struct device *dev, | |
1312 | unsigned int nbits, gfp_t flags) | |
1313 | { | |
1314 | return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO); | |
1315 | } | |
1316 | EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); | |
1317 | ||
c724f193 YN |
1318 | #if BITS_PER_LONG == 64 |
1319 | /** | |
1320 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
1321 | * @bitmap: array of unsigned longs, the destination bitmap | |
1322 | * @buf: array of u32 (in host byte order), the source bitmap | |
1323 | * @nbits: number of bits in @bitmap | |
1324 | */ | |
ccf7a6d4 | 1325 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) |
c724f193 YN |
1326 | { |
1327 | unsigned int i, halfwords; | |
1328 | ||
c724f193 YN |
1329 | halfwords = DIV_ROUND_UP(nbits, 32); |
1330 | for (i = 0; i < halfwords; i++) { | |
1331 | bitmap[i/2] = (unsigned long) buf[i]; | |
1332 | if (++i < halfwords) | |
1333 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
1334 | } | |
1335 | ||
1336 | /* Clear tail bits in last word beyond nbits. */ | |
1337 | if (nbits % BITS_PER_LONG) | |
1338 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
1339 | } | |
1340 | EXPORT_SYMBOL(bitmap_from_arr32); | |
1341 | ||
1342 | /** | |
1343 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
1344 | * @buf: array of u32 (in host byte order), the dest bitmap | |
1345 | * @bitmap: array of unsigned longs, the source bitmap | |
1346 | * @nbits: number of bits in @bitmap | |
1347 | */ | |
1348 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1349 | { | |
1350 | unsigned int i, halfwords; | |
1351 | ||
c724f193 YN |
1352 | halfwords = DIV_ROUND_UP(nbits, 32); |
1353 | for (i = 0; i < halfwords; i++) { | |
1354 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
1355 | if (++i < halfwords) | |
1356 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
1357 | } | |
1358 | ||
1359 | /* Clear tail bits in last element of array beyond nbits. */ | |
1360 | if (nbits % BITS_PER_LONG) | |
1361 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
1362 | } | |
1363 | EXPORT_SYMBOL(bitmap_to_arr32); | |
1364 | ||
1365 | #endif |