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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 | * | |
1da177e4 LT |
26 | * bitmaps provide an array of bits, implemented using an an |
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 | ||
3d6684f4 | 62 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 63 | { |
ca1250bb | 64 | unsigned int k, lim = BITS_TO_LONGS(bits); |
1da177e4 LT |
65 | for (k = 0; k < lim; ++k) |
66 | dst[k] = ~src[k]; | |
1da177e4 LT |
67 | } |
68 | EXPORT_SYMBOL(__bitmap_complement); | |
69 | ||
72fd4a35 | 70 | /** |
1da177e4 | 71 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
72 | * @dst : destination bitmap |
73 | * @src : source bitmap | |
74 | * @shift : shift by this many bits | |
2fbad299 | 75 | * @nbits : bitmap size, in bits |
1da177e4 LT |
76 | * |
77 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
78 | * direction. Zeros are fed into the vacated MS positions and the | |
79 | * LS bits shifted off the bottom are lost. | |
80 | */ | |
2fbad299 RV |
81 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
82 | unsigned shift, unsigned nbits) | |
1da177e4 | 83 | { |
cfac1d08 | 84 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 85 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 86 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
87 | for (k = 0; off + k < lim; ++k) { |
88 | unsigned long upper, lower; | |
89 | ||
90 | /* | |
91 | * If shift is not word aligned, take lower rem bits of | |
92 | * word above and make them the top rem bits of result. | |
93 | */ | |
94 | if (!rem || off + k + 1 >= lim) | |
95 | upper = 0; | |
96 | else { | |
97 | upper = src[off + k + 1]; | |
cfac1d08 | 98 | if (off + k + 1 == lim - 1) |
1da177e4 | 99 | upper &= mask; |
9d8a6b2a | 100 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
101 | } |
102 | lower = src[off + k]; | |
cfac1d08 | 103 | if (off + k == lim - 1) |
1da177e4 | 104 | lower &= mask; |
9d8a6b2a RV |
105 | lower >>= rem; |
106 | dst[k] = lower | upper; | |
1da177e4 LT |
107 | } |
108 | if (off) | |
109 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
110 | } | |
111 | EXPORT_SYMBOL(__bitmap_shift_right); | |
112 | ||
113 | ||
72fd4a35 | 114 | /** |
1da177e4 | 115 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
116 | * @dst : destination bitmap |
117 | * @src : source bitmap | |
118 | * @shift : shift by this many bits | |
dba94c25 | 119 | * @nbits : bitmap size, in bits |
1da177e4 LT |
120 | * |
121 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
122 | * direction. Zeros are fed into the vacated LS bit positions | |
123 | * and those MS bits shifted off the top are lost. | |
124 | */ | |
125 | ||
dba94c25 RV |
126 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
127 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 128 | { |
dba94c25 | 129 | int k; |
7f590657 | 130 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 131 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
132 | for (k = lim - off - 1; k >= 0; --k) { |
133 | unsigned long upper, lower; | |
134 | ||
135 | /* | |
136 | * If shift is not word aligned, take upper rem bits of | |
137 | * word below and make them the bottom rem bits of result. | |
138 | */ | |
139 | if (rem && k > 0) | |
6d874eca | 140 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
141 | else |
142 | lower = 0; | |
7f590657 | 143 | upper = src[k] << rem; |
6d874eca | 144 | dst[k + off] = lower | upper; |
1da177e4 LT |
145 | } |
146 | if (off) | |
147 | memset(dst, 0, off*sizeof(unsigned long)); | |
148 | } | |
149 | EXPORT_SYMBOL(__bitmap_shift_left); | |
150 | ||
f4b0373b | 151 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 152 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 153 | { |
2f9305eb | 154 | unsigned int k; |
7e5f97d1 | 155 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 156 | unsigned long result = 0; |
1da177e4 | 157 | |
7e5f97d1 | 158 | for (k = 0; k < lim; k++) |
f4b0373b | 159 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
160 | if (bits % BITS_PER_LONG) |
161 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
162 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 163 | return result != 0; |
1da177e4 LT |
164 | } |
165 | EXPORT_SYMBOL(__bitmap_and); | |
166 | ||
167 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 168 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 169 | { |
2f9305eb RV |
170 | unsigned int k; |
171 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
172 | |
173 | for (k = 0; k < nr; k++) | |
174 | dst[k] = bitmap1[k] | bitmap2[k]; | |
175 | } | |
176 | EXPORT_SYMBOL(__bitmap_or); | |
177 | ||
178 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 179 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 180 | { |
2f9305eb RV |
181 | unsigned int k; |
182 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
183 | |
184 | for (k = 0; k < nr; k++) | |
185 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
186 | } | |
187 | EXPORT_SYMBOL(__bitmap_xor); | |
188 | ||
f4b0373b | 189 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 190 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 191 | { |
2f9305eb | 192 | unsigned int k; |
74e76531 | 193 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 194 | unsigned long result = 0; |
1da177e4 | 195 | |
74e76531 | 196 | for (k = 0; k < lim; k++) |
f4b0373b | 197 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
198 | if (bits % BITS_PER_LONG) |
199 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
200 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 201 | return result != 0; |
1da177e4 LT |
202 | } |
203 | EXPORT_SYMBOL(__bitmap_andnot); | |
204 | ||
205 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 206 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 207 | { |
6dfe9799 | 208 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
209 | for (k = 0; k < lim; ++k) |
210 | if (bitmap1[k] & bitmap2[k]) | |
211 | return 1; | |
212 | ||
213 | if (bits % BITS_PER_LONG) | |
214 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
215 | return 1; | |
216 | return 0; | |
217 | } | |
218 | EXPORT_SYMBOL(__bitmap_intersects); | |
219 | ||
220 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 221 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 222 | { |
5be20213 | 223 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
224 | for (k = 0; k < lim; ++k) |
225 | if (bitmap1[k] & ~bitmap2[k]) | |
226 | return 0; | |
227 | ||
228 | if (bits % BITS_PER_LONG) | |
229 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
230 | return 0; | |
231 | return 1; | |
232 | } | |
233 | EXPORT_SYMBOL(__bitmap_subset); | |
234 | ||
877d9f3b | 235 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 236 | { |
877d9f3b RV |
237 | unsigned int k, lim = bits/BITS_PER_LONG; |
238 | int w = 0; | |
1da177e4 LT |
239 | |
240 | for (k = 0; k < lim; k++) | |
37d54111 | 241 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
242 | |
243 | if (bits % BITS_PER_LONG) | |
37d54111 | 244 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
245 | |
246 | return w; | |
247 | } | |
1da177e4 LT |
248 | EXPORT_SYMBOL(__bitmap_weight); |
249 | ||
e5af323c | 250 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
251 | { |
252 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 253 | const unsigned int size = start + len; |
c1a2a962 AM |
254 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
255 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
256 | ||
fb5ac542 | 257 | while (len - bits_to_set >= 0) { |
c1a2a962 | 258 | *p |= mask_to_set; |
fb5ac542 | 259 | len -= bits_to_set; |
c1a2a962 AM |
260 | bits_to_set = BITS_PER_LONG; |
261 | mask_to_set = ~0UL; | |
262 | p++; | |
263 | } | |
fb5ac542 | 264 | if (len) { |
c1a2a962 AM |
265 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
266 | *p |= mask_to_set; | |
267 | } | |
268 | } | |
e5af323c | 269 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 270 | |
e5af323c | 271 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
272 | { |
273 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 274 | const unsigned int size = start + len; |
c1a2a962 AM |
275 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
276 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
277 | ||
154f5e38 | 278 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 279 | *p &= ~mask_to_clear; |
154f5e38 | 280 | len -= bits_to_clear; |
c1a2a962 AM |
281 | bits_to_clear = BITS_PER_LONG; |
282 | mask_to_clear = ~0UL; | |
283 | p++; | |
284 | } | |
154f5e38 | 285 | if (len) { |
c1a2a962 AM |
286 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
287 | *p &= ~mask_to_clear; | |
288 | } | |
289 | } | |
e5af323c | 290 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 291 | |
5e19b013 MN |
292 | /** |
293 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
294 | * @map: The address to base the search on |
295 | * @size: The bitmap size in bits | |
296 | * @start: The bitnumber to start searching at | |
297 | * @nr: The number of zeroed bits we're looking for | |
298 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 299 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
300 | * |
301 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
302 | * the bit offset of all zero areas this function finds plus @align_offset |
303 | * is multiple of that power of 2. | |
c1a2a962 | 304 | */ |
5e19b013 MN |
305 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
306 | unsigned long size, | |
307 | unsigned long start, | |
308 | unsigned int nr, | |
309 | unsigned long align_mask, | |
310 | unsigned long align_offset) | |
c1a2a962 AM |
311 | { |
312 | unsigned long index, end, i; | |
313 | again: | |
314 | index = find_next_zero_bit(map, size, start); | |
315 | ||
316 | /* Align allocation */ | |
5e19b013 | 317 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
318 | |
319 | end = index + nr; | |
320 | if (end > size) | |
321 | return end; | |
322 | i = find_next_bit(map, end, index); | |
323 | if (i < end) { | |
324 | start = i + 1; | |
325 | goto again; | |
326 | } | |
327 | return index; | |
328 | } | |
5e19b013 | 329 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 330 | |
1da177e4 | 331 | /* |
6d49e352 | 332 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
333 | * second version by Paul Jackson, third by Joe Korty. |
334 | */ | |
335 | ||
336 | #define CHUNKSZ 32 | |
337 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
338 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
339 | ||
1da177e4 | 340 | /** |
01a3ee2b RC |
341 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
342 | * @buf: pointer to buffer containing string. | |
343 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 344 | * then it must be terminated with a \0. |
01a3ee2b | 345 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
346 | * @maskp: pointer to bitmap array that will contain result. |
347 | * @nmaskbits: size of bitmap, in bits. | |
348 | * | |
349 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
350 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
351 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
352 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
353 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
354 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
355 | */ | |
01a3ee2b RC |
356 | int __bitmap_parse(const char *buf, unsigned int buflen, |
357 | int is_user, unsigned long *maskp, | |
358 | int nmaskbits) | |
1da177e4 LT |
359 | { |
360 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
361 | u32 chunk; | |
b9c321fd | 362 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
363 | |
364 | bitmap_zero(maskp, nmaskbits); | |
365 | ||
366 | nchunks = nbits = totaldigits = c = 0; | |
367 | do { | |
d21c3d4d PX |
368 | chunk = 0; |
369 | ndigits = totaldigits; | |
1da177e4 LT |
370 | |
371 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 372 | while (buflen) { |
1da177e4 | 373 | old_c = c; |
01a3ee2b RC |
374 | if (is_user) { |
375 | if (__get_user(c, ubuf++)) | |
376 | return -EFAULT; | |
377 | } | |
378 | else | |
379 | c = *buf++; | |
380 | buflen--; | |
1da177e4 LT |
381 | if (isspace(c)) |
382 | continue; | |
383 | ||
384 | /* | |
385 | * If the last character was a space and the current | |
386 | * character isn't '\0', we've got embedded whitespace. | |
387 | * This is a no-no, so throw an error. | |
388 | */ | |
389 | if (totaldigits && c && isspace(old_c)) | |
390 | return -EINVAL; | |
391 | ||
392 | /* A '\0' or a ',' signal the end of the chunk */ | |
393 | if (c == '\0' || c == ',') | |
394 | break; | |
395 | ||
396 | if (!isxdigit(c)) | |
397 | return -EINVAL; | |
398 | ||
399 | /* | |
400 | * Make sure there are at least 4 free bits in 'chunk'. | |
401 | * If not, this hexdigit will overflow 'chunk', so | |
402 | * throw an error. | |
403 | */ | |
404 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
405 | return -EOVERFLOW; | |
406 | ||
66f1991b | 407 | chunk = (chunk << 4) | hex_to_bin(c); |
d21c3d4d | 408 | totaldigits++; |
1da177e4 | 409 | } |
d21c3d4d | 410 | if (ndigits == totaldigits) |
1da177e4 LT |
411 | return -EINVAL; |
412 | if (nchunks == 0 && chunk == 0) | |
413 | continue; | |
414 | ||
415 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
416 | *maskp |= chunk; | |
417 | nchunks++; | |
418 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
419 | if (nbits > nmaskbits) | |
420 | return -EOVERFLOW; | |
01a3ee2b | 421 | } while (buflen && c == ','); |
1da177e4 LT |
422 | |
423 | return 0; | |
424 | } | |
01a3ee2b RC |
425 | EXPORT_SYMBOL(__bitmap_parse); |
426 | ||
427 | /** | |
9a86e2ba | 428 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
429 | * |
430 | * @ubuf: pointer to user buffer containing string. | |
431 | * @ulen: buffer size in bytes. If string is smaller than this | |
432 | * then it must be terminated with a \0. | |
433 | * @maskp: pointer to bitmap array that will contain result. | |
434 | * @nmaskbits: size of bitmap, in bits. | |
435 | * | |
436 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
437 | * | |
438 | * We cannot have this as an inline function in bitmap.h because it needs | |
439 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
440 | * cyclic dependencies. | |
441 | */ | |
442 | int bitmap_parse_user(const char __user *ubuf, | |
443 | unsigned int ulen, unsigned long *maskp, | |
444 | int nmaskbits) | |
445 | { | |
96d4f267 | 446 | if (!access_ok(ubuf, ulen)) |
01a3ee2b | 447 | return -EFAULT; |
b9c321fd HS |
448 | return __bitmap_parse((const char __force *)ubuf, |
449 | ulen, 1, maskp, nmaskbits); | |
450 | ||
01a3ee2b RC |
451 | } |
452 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 453 | |
5aaba363 SH |
454 | /** |
455 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
456 | * @list: indicates whether the bitmap must be list | |
457 | * @buf: page aligned buffer into which string is placed | |
458 | * @maskp: pointer to bitmap to convert | |
459 | * @nmaskbits: size of bitmap, in bits | |
460 | * | |
461 | * Output format is a comma-separated list of decimal numbers and | |
462 | * ranges if list is specified or hex digits grouped into comma-separated | |
463 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 | 464 | * |
ce1091d4 RV |
465 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned |
466 | * area and that sufficient storage remains at @buf to accommodate the | |
467 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
468 | * actually printed to @buf, excluding terminating '\0'. | |
5aaba363 SH |
469 | */ |
470 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
471 | int nmaskbits) | |
472 | { | |
ce1091d4 | 473 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
5aaba363 | 474 | |
8ec3d768 RV |
475 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
476 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
477 | } |
478 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
479 | ||
e371c481 YN |
480 | /* |
481 | * Region 9-38:4/10 describes the following bitmap structure: | |
482 | * 0 9 12 18 38 | |
483 | * .........****......****......****...... | |
484 | * ^ ^ ^ ^ | |
485 | * start off group_len end | |
486 | */ | |
487 | struct region { | |
488 | unsigned int start; | |
489 | unsigned int off; | |
490 | unsigned int group_len; | |
491 | unsigned int end; | |
492 | }; | |
493 | ||
494 | static int bitmap_set_region(const struct region *r, | |
495 | unsigned long *bitmap, int nbits) | |
496 | { | |
497 | unsigned int start; | |
498 | ||
499 | if (r->end >= nbits) | |
500 | return -ERANGE; | |
501 | ||
502 | for (start = r->start; start <= r->end; start += r->group_len) | |
503 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
508 | static int bitmap_check_region(const struct region *r) | |
509 | { | |
510 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) | |
511 | return -EINVAL; | |
512 | ||
513 | return 0; | |
514 | } | |
515 | ||
516 | static const char *bitmap_getnum(const char *str, unsigned int *num) | |
517 | { | |
518 | unsigned long long n; | |
519 | unsigned int len; | |
520 | ||
521 | len = _parse_integer(str, 10, &n); | |
522 | if (!len) | |
523 | return ERR_PTR(-EINVAL); | |
524 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) | |
525 | return ERR_PTR(-EOVERFLOW); | |
526 | ||
527 | *num = n; | |
528 | return str + len; | |
529 | } | |
530 | ||
531 | static inline bool end_of_str(char c) | |
532 | { | |
533 | return c == '\0' || c == '\n'; | |
534 | } | |
535 | ||
536 | static inline bool __end_of_region(char c) | |
537 | { | |
538 | return isspace(c) || c == ','; | |
539 | } | |
540 | ||
541 | static inline bool end_of_region(char c) | |
542 | { | |
543 | return __end_of_region(c) || end_of_str(c); | |
544 | } | |
545 | ||
546 | /* | |
547 | * The format allows commas and whitespases at the beginning | |
548 | * of the region. | |
549 | */ | |
550 | static const char *bitmap_find_region(const char *str) | |
551 | { | |
552 | while (__end_of_region(*str)) | |
553 | str++; | |
554 | ||
555 | return end_of_str(*str) ? NULL : str; | |
556 | } | |
557 | ||
558 | static const char *bitmap_parse_region(const char *str, struct region *r) | |
559 | { | |
560 | str = bitmap_getnum(str, &r->start); | |
561 | if (IS_ERR(str)) | |
562 | return str; | |
563 | ||
564 | if (end_of_region(*str)) | |
565 | goto no_end; | |
566 | ||
567 | if (*str != '-') | |
568 | return ERR_PTR(-EINVAL); | |
569 | ||
570 | str = bitmap_getnum(str + 1, &r->end); | |
571 | if (IS_ERR(str)) | |
572 | return str; | |
573 | ||
574 | if (end_of_region(*str)) | |
575 | goto no_pattern; | |
576 | ||
577 | if (*str != ':') | |
578 | return ERR_PTR(-EINVAL); | |
579 | ||
580 | str = bitmap_getnum(str + 1, &r->off); | |
581 | if (IS_ERR(str)) | |
582 | return str; | |
583 | ||
584 | if (*str != '/') | |
585 | return ERR_PTR(-EINVAL); | |
586 | ||
587 | return bitmap_getnum(str + 1, &r->group_len); | |
588 | ||
589 | no_end: | |
590 | r->end = r->start; | |
591 | no_pattern: | |
592 | r->off = r->end + 1; | |
593 | r->group_len = r->end + 1; | |
594 | ||
595 | return end_of_str(*str) ? NULL : str; | |
596 | } | |
597 | ||
1da177e4 | 598 | /** |
e371c481 YN |
599 | * bitmap_parselist - convert list format ASCII string to bitmap |
600 | * @buf: read user string from this buffer; must be terminated | |
601 | * with a \0 or \n. | |
6e1907ff | 602 | * @maskp: write resulting mask here |
1da177e4 LT |
603 | * @nmaskbits: number of bits in mask to be written |
604 | * | |
605 | * Input format is a comma-separated list of decimal numbers and | |
606 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
607 | * decimal numbers, the smallest and largest bit numbers set in | |
608 | * the range. | |
2d13e6ca NC |
609 | * Optionally each range can be postfixed to denote that only parts of it |
610 | * should be set. The range will divided to groups of specific size. | |
611 | * From each group will be used only defined amount of bits. | |
612 | * Syntax: range:used_size/group_size | |
613 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
1da177e4 | 614 | * |
40bf19a8 MCC |
615 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
616 | * | |
e371c481 | 617 | * - ``-EINVAL``: wrong region format |
40bf19a8 MCC |
618 | * - ``-EINVAL``: invalid character in string |
619 | * - ``-ERANGE``: bit number specified too large for mask | |
e371c481 | 620 | * - ``-EOVERFLOW``: integer overflow in the input parameters |
1da177e4 | 621 | */ |
e371c481 | 622 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) |
1da177e4 | 623 | { |
e371c481 YN |
624 | struct region r; |
625 | long ret; | |
1da177e4 LT |
626 | |
627 | bitmap_zero(maskp, nmaskbits); | |
4b060420 | 628 | |
e371c481 YN |
629 | while (buf) { |
630 | buf = bitmap_find_region(buf); | |
631 | if (buf == NULL) | |
632 | return 0; | |
2d13e6ca | 633 | |
e371c481 YN |
634 | buf = bitmap_parse_region(buf, &r); |
635 | if (IS_ERR(buf)) | |
636 | return PTR_ERR(buf); | |
2d13e6ca | 637 | |
e371c481 YN |
638 | ret = bitmap_check_region(&r); |
639 | if (ret) | |
640 | return ret; | |
4b060420 | 641 | |
e371c481 YN |
642 | ret = bitmap_set_region(&r, maskp, nmaskbits); |
643 | if (ret) | |
644 | return ret; | |
645 | } | |
4b060420 | 646 | |
1da177e4 LT |
647 | return 0; |
648 | } | |
649 | EXPORT_SYMBOL(bitmap_parselist); | |
650 | ||
4b060420 MT |
651 | |
652 | /** | |
653 | * bitmap_parselist_user() | |
654 | * | |
655 | * @ubuf: pointer to user buffer containing string. | |
656 | * @ulen: buffer size in bytes. If string is smaller than this | |
657 | * then it must be terminated with a \0. | |
658 | * @maskp: pointer to bitmap array that will contain result. | |
659 | * @nmaskbits: size of bitmap, in bits. | |
660 | * | |
661 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
4b060420 MT |
662 | */ |
663 | int bitmap_parselist_user(const char __user *ubuf, | |
664 | unsigned int ulen, unsigned long *maskp, | |
665 | int nmaskbits) | |
666 | { | |
281327c9 YN |
667 | char *buf; |
668 | int ret; | |
669 | ||
670 | buf = memdup_user_nul(ubuf, ulen); | |
671 | if (IS_ERR(buf)) | |
672 | return PTR_ERR(buf); | |
673 | ||
674 | ret = bitmap_parselist(buf, maskp, nmaskbits); | |
675 | ||
676 | kfree(buf); | |
677 | return ret; | |
4b060420 MT |
678 | } |
679 | EXPORT_SYMBOL(bitmap_parselist_user); | |
680 | ||
681 | ||
cdc90a18 | 682 | #ifdef CONFIG_NUMA |
72fd4a35 | 683 | /** |
9a86e2ba | 684 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 685 | * @buf: pointer to a bitmap |
df1d80a9 RV |
686 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
687 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 688 | * |
df1d80a9 | 689 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 690 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 691 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
692 | * |
693 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
694 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 695 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
696 | * gets mapped to (returns) @ord value 3 in this example, that means |
697 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
698 | * | |
699 | * The bit positions 0 through @bits are valid positions in @buf. | |
700 | */ | |
df1d80a9 | 701 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 702 | { |
df1d80a9 | 703 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 704 | return -1; |
fb5eeeee | 705 | |
df1d80a9 | 706 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
707 | } |
708 | ||
709 | /** | |
9a86e2ba | 710 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
711 | * @buf: pointer to bitmap |
712 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 713 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
714 | * |
715 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
716 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
717 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
718 | * |
719 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
720 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 721 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
722 | * gets mapped to (returns) @pos value 7 in this example, that means |
723 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
724 | * | |
f6a1f5db | 725 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 726 | */ |
f6a1f5db | 727 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 728 | { |
f6a1f5db | 729 | unsigned int pos; |
fb5eeeee | 730 | |
f6a1f5db RV |
731 | for (pos = find_first_bit(buf, nbits); |
732 | pos < nbits && ord; | |
733 | pos = find_next_bit(buf, nbits, pos + 1)) | |
734 | ord--; | |
fb5eeeee PJ |
735 | |
736 | return pos; | |
737 | } | |
738 | ||
739 | /** | |
740 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 741 | * @dst: remapped result |
96b7f341 | 742 | * @src: subset to be remapped |
fb5eeeee PJ |
743 | * @old: defines domain of map |
744 | * @new: defines range of map | |
9814ec13 | 745 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
746 | * |
747 | * Let @old and @new define a mapping of bit positions, such that | |
748 | * whatever position is held by the n-th set bit in @old is mapped | |
749 | * to the n-th set bit in @new. In the more general case, allowing | |
750 | * for the possibility that the weight 'w' of @new is less than the | |
751 | * weight of @old, map the position of the n-th set bit in @old to | |
752 | * the position of the m-th set bit in @new, where m == n % w. | |
753 | * | |
96b7f341 PJ |
754 | * If either of the @old and @new bitmaps are empty, or if @src and |
755 | * @dst point to the same location, then this routine copies @src | |
756 | * to @dst. | |
fb5eeeee | 757 | * |
96b7f341 PJ |
758 | * The positions of unset bits in @old are mapped to themselves |
759 | * (the identify map). | |
fb5eeeee PJ |
760 | * |
761 | * Apply the above specified mapping to @src, placing the result in | |
762 | * @dst, clearing any bits previously set in @dst. | |
763 | * | |
fb5eeeee PJ |
764 | * For example, lets say that @old has bits 4 through 7 set, and |
765 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
766 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
767 | * bit positions unchanged. So if say @src comes into this routine |
768 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
769 | * 13 and 15 set. | |
fb5eeeee PJ |
770 | */ |
771 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
772 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 773 | unsigned int nbits) |
fb5eeeee | 774 | { |
9814ec13 | 775 | unsigned int oldbit, w; |
fb5eeeee | 776 | |
fb5eeeee PJ |
777 | if (dst == src) /* following doesn't handle inplace remaps */ |
778 | return; | |
9814ec13 | 779 | bitmap_zero(dst, nbits); |
96b7f341 | 780 | |
9814ec13 RV |
781 | w = bitmap_weight(new, nbits); |
782 | for_each_set_bit(oldbit, src, nbits) { | |
783 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 784 | |
96b7f341 PJ |
785 | if (n < 0 || w == 0) |
786 | set_bit(oldbit, dst); /* identity map */ | |
787 | else | |
9814ec13 | 788 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
789 | } |
790 | } | |
fb5eeeee PJ |
791 | |
792 | /** | |
793 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
794 | * @oldbit: bit position to be mapped |
795 | * @old: defines domain of map | |
796 | * @new: defines range of map | |
797 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
798 | * |
799 | * Let @old and @new define a mapping of bit positions, such that | |
800 | * whatever position is held by the n-th set bit in @old is mapped | |
801 | * to the n-th set bit in @new. In the more general case, allowing | |
802 | * for the possibility that the weight 'w' of @new is less than the | |
803 | * weight of @old, map the position of the n-th set bit in @old to | |
804 | * the position of the m-th set bit in @new, where m == n % w. | |
805 | * | |
96b7f341 PJ |
806 | * The positions of unset bits in @old are mapped to themselves |
807 | * (the identify map). | |
fb5eeeee PJ |
808 | * |
809 | * Apply the above specified mapping to bit position @oldbit, returning | |
810 | * the new bit position. | |
811 | * | |
812 | * For example, lets say that @old has bits 4 through 7 set, and | |
813 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
814 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
815 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
816 | * returns 13. | |
fb5eeeee PJ |
817 | */ |
818 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
819 | const unsigned long *new, int bits) | |
820 | { | |
96b7f341 PJ |
821 | int w = bitmap_weight(new, bits); |
822 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
823 | if (n < 0 || w == 0) | |
824 | return oldbit; | |
825 | else | |
826 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee | 827 | } |
fb5eeeee | 828 | |
7ea931c9 PJ |
829 | /** |
830 | * bitmap_onto - translate one bitmap relative to another | |
831 | * @dst: resulting translated bitmap | |
832 | * @orig: original untranslated bitmap | |
833 | * @relmap: bitmap relative to which translated | |
834 | * @bits: number of bits in each of these bitmaps | |
835 | * | |
836 | * Set the n-th bit of @dst iff there exists some m such that the | |
837 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
838 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
839 | * (If you understood the previous sentence the first time your | |
840 | * read it, you're overqualified for your current job.) | |
841 | * | |
842 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 843 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
844 | * m-th set bit of @relmap }. |
845 | * | |
846 | * Any set bits in @orig above bit number W, where W is the | |
847 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
848 | * In particular, if for all bits m set in @orig, m >= W, then | |
849 | * @dst will end up empty. In situations where the possibility | |
850 | * of such an empty result is not desired, one way to avoid it is | |
851 | * to use the bitmap_fold() operator, below, to first fold the | |
852 | * @orig bitmap over itself so that all its set bits x are in the | |
853 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
854 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
855 | * | |
856 | * Example [1] for bitmap_onto(): | |
857 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
858 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
859 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
860 | * | |
861 | * When bit 0 is set in @orig, it means turn on the bit in | |
862 | * @dst corresponding to whatever is the first bit (if any) | |
863 | * that is turned on in @relmap. Since bit 0 was off in the | |
864 | * above example, we leave off that bit (bit 30) in @dst. | |
865 | * | |
866 | * When bit 1 is set in @orig (as in the above example), it | |
867 | * means turn on the bit in @dst corresponding to whatever | |
868 | * is the second bit that is turned on in @relmap. The second | |
869 | * bit in @relmap that was turned on in the above example was | |
870 | * bit 31, so we turned on bit 31 in @dst. | |
871 | * | |
872 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
873 | * because they were the 4th, 6th, 8th and 10th set bits | |
874 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
875 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
876 | * | |
877 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 878 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
879 | * turned on in @relmap. In the above example, there were |
880 | * only ten bits turned on in @relmap (30..39), so that bit | |
881 | * 11 was set in @orig had no affect on @dst. | |
882 | * | |
883 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
884 | * Let's say @relmap has these ten bits set:: |
885 | * | |
7ea931c9 | 886 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 887 | * |
7ea931c9 PJ |
888 | * (for the curious, that's 40 plus the first ten terms of the |
889 | * Fibonacci sequence.) | |
890 | * | |
891 | * Further lets say we use the following code, invoking | |
892 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 893 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
894 | * |
895 | * unsigned long *tmp; // a temporary bitmap's bits | |
896 | * | |
897 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
898 | * bitmap_onto(dst, tmp, relmap, bits); | |
899 | * | |
900 | * Then this table shows what various values of @dst would be, for | |
901 | * various @orig's. I list the zero-based positions of each set bit. | |
902 | * The tmp column shows the intermediate result, as computed by | |
903 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 904 | * (the weight of @relmap): |
7ea931c9 | 905 | * |
40bf19a8 | 906 | * =============== ============== ================= |
7ea931c9 PJ |
907 | * @orig tmp @dst |
908 | * 0 0 40 | |
909 | * 1 1 41 | |
910 | * 9 9 95 | |
40bf19a8 | 911 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
912 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
913 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
914 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
915 | * 0 10 20 30 0 40 | |
916 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
917 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
918 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
919 | * =============== ============== ================= | |
920 | * | |
921 | * .. [#f1] | |
7ea931c9 | 922 | * |
40bf19a8 | 923 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
924 | * into tmp, then the @dst result would have been empty. |
925 | * | |
926 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
927 | * will be returned empty. | |
928 | * | |
929 | * If (as explained above) the only set bits in @orig are in positions | |
930 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
931 | * once again be returned empty. | |
932 | * | |
933 | * All bits in @dst not set by the above rule are cleared. | |
934 | */ | |
935 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 936 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 937 | { |
eb569883 | 938 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
939 | |
940 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
941 | return; | |
942 | bitmap_zero(dst, bits); | |
943 | ||
944 | /* | |
945 | * The following code is a more efficient, but less | |
946 | * obvious, equivalent to the loop: | |
947 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
948 | * n = bitmap_ord_to_pos(orig, m, bits); | |
949 | * if (test_bit(m, orig)) | |
950 | * set_bit(n, dst); | |
951 | * } | |
952 | */ | |
953 | ||
954 | m = 0; | |
08564fb7 | 955 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
956 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
957 | if (test_bit(m, orig)) | |
958 | set_bit(n, dst); | |
959 | m++; | |
960 | } | |
961 | } | |
7ea931c9 PJ |
962 | |
963 | /** | |
964 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
965 | * @dst: resulting smaller bitmap | |
966 | * @orig: original larger bitmap | |
967 | * @sz: specified size | |
b26ad583 | 968 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
969 | * |
970 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
971 | * Clear all other bits in @dst. See further the comment and | |
972 | * Example [2] for bitmap_onto() for why and how to use this. | |
973 | */ | |
974 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 975 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 976 | { |
b26ad583 | 977 | unsigned int oldbit; |
7ea931c9 PJ |
978 | |
979 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
980 | return; | |
b26ad583 | 981 | bitmap_zero(dst, nbits); |
7ea931c9 | 982 | |
b26ad583 | 983 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
984 | set_bit(oldbit % sz, dst); |
985 | } | |
cdc90a18 | 986 | #endif /* CONFIG_NUMA */ |
7ea931c9 | 987 | |
3cf64b93 PJ |
988 | /* |
989 | * Common code for bitmap_*_region() routines. | |
990 | * bitmap: array of unsigned longs corresponding to the bitmap | |
991 | * pos: the beginning of the region | |
992 | * order: region size (log base 2 of number of bits) | |
993 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 994 | * |
3cf64b93 PJ |
995 | * Can set, verify and/or release a region of bits in a bitmap, |
996 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 997 | * |
3cf64b93 PJ |
998 | * A region of a bitmap is a sequence of bits in the bitmap, of |
999 | * some size '1 << order' (a power of two), aligned to that same | |
1000 | * '1 << order' power of two. | |
1001 | * | |
1002 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1003 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 1004 | */ |
3cf64b93 PJ |
1005 | |
1006 | enum { | |
1007 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1008 | REG_OP_ALLOC, /* set all bits in region */ | |
1009 | REG_OP_RELEASE, /* clear all bits in region */ | |
1010 | }; | |
1011 | ||
9279d328 | 1012 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 1013 | { |
3cf64b93 PJ |
1014 | int nbits_reg; /* number of bits in region */ |
1015 | int index; /* index first long of region in bitmap */ | |
1016 | int offset; /* bit offset region in bitmap[index] */ | |
1017 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1018 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1019 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1020 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1021 | int ret = 0; /* return value */ |
74373c6a | 1022 | |
3cf64b93 PJ |
1023 | /* |
1024 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1025 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1026 | */ | |
1027 | nbits_reg = 1 << order; | |
1028 | index = pos / BITS_PER_LONG; | |
1029 | offset = pos - (index * BITS_PER_LONG); | |
1030 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1031 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1032 | |
3cf64b93 PJ |
1033 | /* |
1034 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1035 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1036 | */ | |
74373c6a | 1037 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1038 | mask += mask - 1; |
3cf64b93 | 1039 | mask <<= offset; |
1da177e4 | 1040 | |
3cf64b93 PJ |
1041 | switch (reg_op) { |
1042 | case REG_OP_ISFREE: | |
1043 | for (i = 0; i < nlongs_reg; i++) { | |
1044 | if (bitmap[index + i] & mask) | |
1045 | goto done; | |
1046 | } | |
1047 | ret = 1; /* all bits in region free (zero) */ | |
1048 | break; | |
1049 | ||
1050 | case REG_OP_ALLOC: | |
1051 | for (i = 0; i < nlongs_reg; i++) | |
1052 | bitmap[index + i] |= mask; | |
1053 | break; | |
1054 | ||
1055 | case REG_OP_RELEASE: | |
1056 | for (i = 0; i < nlongs_reg; i++) | |
1057 | bitmap[index + i] &= ~mask; | |
1058 | break; | |
1da177e4 | 1059 | } |
3cf64b93 PJ |
1060 | done: |
1061 | return ret; | |
1062 | } | |
1063 | ||
1064 | /** | |
1065 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1066 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1067 | * @bits: number of bits in the bitmap | |
1068 | * @order: region size (log base 2 of number of bits) to find | |
1069 | * | |
1070 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1071 | * allocate them (set them to one). Only consider regions of length | |
1072 | * a power (@order) of two, aligned to that power of two, which | |
1073 | * makes the search algorithm much faster. | |
1074 | * | |
1075 | * Return the bit offset in bitmap of the allocated region, | |
1076 | * or -errno on failure. | |
1077 | */ | |
9279d328 | 1078 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1079 | { |
9279d328 | 1080 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1081 | |
9279d328 | 1082 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1083 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1084 | continue; | |
1085 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1086 | return pos; | |
1087 | } | |
1088 | return -ENOMEM; | |
1da177e4 LT |
1089 | } |
1090 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1091 | ||
1092 | /** | |
87e24802 | 1093 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1094 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1095 | * @pos: beginning of bit region to release | |
1096 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1097 | * |
72fd4a35 | 1098 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1099 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1100 | * |
1101 | * No return value. | |
1da177e4 | 1102 | */ |
9279d328 | 1103 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1104 | { |
3cf64b93 | 1105 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1106 | } |
1107 | EXPORT_SYMBOL(bitmap_release_region); | |
1108 | ||
87e24802 PJ |
1109 | /** |
1110 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1111 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1112 | * @pos: beginning of bit region to allocate | |
1113 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1114 | * |
1115 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1116 | * |
6e1907ff | 1117 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1118 | * free (not all bits were zero). |
1119 | */ | |
9279d328 | 1120 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1121 | { |
3cf64b93 PJ |
1122 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1123 | return -EBUSY; | |
2ac521d3 | 1124 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1125 | } |
1126 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1127 | |
1128 | /** | |
1129 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1130 | * @dst: destination buffer | |
1131 | * @src: bitmap to copy | |
1132 | * @nbits: number of bits in the bitmap | |
1133 | * | |
1134 | * Require nbits % BITS_PER_LONG == 0. | |
1135 | */ | |
e8f24278 | 1136 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1137 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1138 | { |
9b6c2d2e | 1139 | unsigned int i; |
ccbe329b DV |
1140 | |
1141 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1142 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1143 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1144 | else |
9b6c2d2e | 1145 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1146 | } |
1147 | } | |
1148 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1149 | #endif |
c724f193 | 1150 | |
c42b65e3 AS |
1151 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) |
1152 | { | |
1153 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1154 | flags); | |
1155 | } | |
1156 | EXPORT_SYMBOL(bitmap_alloc); | |
1157 | ||
1158 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1159 | { | |
1160 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1161 | } | |
1162 | EXPORT_SYMBOL(bitmap_zalloc); | |
1163 | ||
1164 | void bitmap_free(const unsigned long *bitmap) | |
1165 | { | |
1166 | kfree(bitmap); | |
1167 | } | |
1168 | EXPORT_SYMBOL(bitmap_free); | |
1169 | ||
c724f193 YN |
1170 | #if BITS_PER_LONG == 64 |
1171 | /** | |
1172 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
1173 | * @bitmap: array of unsigned longs, the destination bitmap | |
1174 | * @buf: array of u32 (in host byte order), the source bitmap | |
1175 | * @nbits: number of bits in @bitmap | |
1176 | */ | |
ccf7a6d4 | 1177 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) |
c724f193 YN |
1178 | { |
1179 | unsigned int i, halfwords; | |
1180 | ||
c724f193 YN |
1181 | halfwords = DIV_ROUND_UP(nbits, 32); |
1182 | for (i = 0; i < halfwords; i++) { | |
1183 | bitmap[i/2] = (unsigned long) buf[i]; | |
1184 | if (++i < halfwords) | |
1185 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
1186 | } | |
1187 | ||
1188 | /* Clear tail bits in last word beyond nbits. */ | |
1189 | if (nbits % BITS_PER_LONG) | |
1190 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
1191 | } | |
1192 | EXPORT_SYMBOL(bitmap_from_arr32); | |
1193 | ||
1194 | /** | |
1195 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
1196 | * @buf: array of u32 (in host byte order), the dest bitmap | |
1197 | * @bitmap: array of unsigned longs, the source bitmap | |
1198 | * @nbits: number of bits in @bitmap | |
1199 | */ | |
1200 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1201 | { | |
1202 | unsigned int i, halfwords; | |
1203 | ||
c724f193 YN |
1204 | halfwords = DIV_ROUND_UP(nbits, 32); |
1205 | for (i = 0; i < halfwords; i++) { | |
1206 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
1207 | if (++i < halfwords) | |
1208 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
1209 | } | |
1210 | ||
1211 | /* Clear tail bits in last element of array beyond nbits. */ | |
1212 | if (nbits % BITS_PER_LONG) | |
1213 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
1214 | } | |
1215 | EXPORT_SYMBOL(bitmap_to_arr32); | |
1216 | ||
1217 | #endif |