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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 | ||
b9fa6442 TG |
62 | bool __bitmap_or_equal(const unsigned long *bitmap1, |
63 | const unsigned long *bitmap2, | |
64 | const unsigned long *bitmap3, | |
65 | unsigned int bits) | |
66 | { | |
67 | unsigned int k, lim = bits / BITS_PER_LONG; | |
68 | unsigned long tmp; | |
69 | ||
70 | for (k = 0; k < lim; ++k) { | |
71 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) | |
72 | return false; | |
73 | } | |
74 | ||
75 | if (!(bits % BITS_PER_LONG)) | |
76 | return true; | |
77 | ||
78 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; | |
79 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; | |
80 | } | |
81 | ||
3d6684f4 | 82 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 83 | { |
ca1250bb | 84 | unsigned int k, lim = BITS_TO_LONGS(bits); |
1da177e4 LT |
85 | for (k = 0; k < lim; ++k) |
86 | dst[k] = ~src[k]; | |
1da177e4 LT |
87 | } |
88 | EXPORT_SYMBOL(__bitmap_complement); | |
89 | ||
72fd4a35 | 90 | /** |
1da177e4 | 91 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
92 | * @dst : destination bitmap |
93 | * @src : source bitmap | |
94 | * @shift : shift by this many bits | |
2fbad299 | 95 | * @nbits : bitmap size, in bits |
1da177e4 LT |
96 | * |
97 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
98 | * direction. Zeros are fed into the vacated MS positions and the | |
99 | * LS bits shifted off the bottom are lost. | |
100 | */ | |
2fbad299 RV |
101 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
102 | unsigned shift, unsigned nbits) | |
1da177e4 | 103 | { |
cfac1d08 | 104 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 105 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 106 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
107 | for (k = 0; off + k < lim; ++k) { |
108 | unsigned long upper, lower; | |
109 | ||
110 | /* | |
111 | * If shift is not word aligned, take lower rem bits of | |
112 | * word above and make them the top rem bits of result. | |
113 | */ | |
114 | if (!rem || off + k + 1 >= lim) | |
115 | upper = 0; | |
116 | else { | |
117 | upper = src[off + k + 1]; | |
cfac1d08 | 118 | if (off + k + 1 == lim - 1) |
1da177e4 | 119 | upper &= mask; |
9d8a6b2a | 120 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
121 | } |
122 | lower = src[off + k]; | |
cfac1d08 | 123 | if (off + k == lim - 1) |
1da177e4 | 124 | lower &= mask; |
9d8a6b2a RV |
125 | lower >>= rem; |
126 | dst[k] = lower | upper; | |
1da177e4 LT |
127 | } |
128 | if (off) | |
129 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
130 | } | |
131 | EXPORT_SYMBOL(__bitmap_shift_right); | |
132 | ||
133 | ||
72fd4a35 | 134 | /** |
1da177e4 | 135 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
136 | * @dst : destination bitmap |
137 | * @src : source bitmap | |
138 | * @shift : shift by this many bits | |
dba94c25 | 139 | * @nbits : bitmap size, in bits |
1da177e4 LT |
140 | * |
141 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
142 | * direction. Zeros are fed into the vacated LS bit positions | |
143 | * and those MS bits shifted off the top are lost. | |
144 | */ | |
145 | ||
dba94c25 RV |
146 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
147 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 148 | { |
dba94c25 | 149 | int k; |
7f590657 | 150 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 151 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
152 | for (k = lim - off - 1; k >= 0; --k) { |
153 | unsigned long upper, lower; | |
154 | ||
155 | /* | |
156 | * If shift is not word aligned, take upper rem bits of | |
157 | * word below and make them the bottom rem bits of result. | |
158 | */ | |
159 | if (rem && k > 0) | |
6d874eca | 160 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
161 | else |
162 | lower = 0; | |
7f590657 | 163 | upper = src[k] << rem; |
6d874eca | 164 | dst[k + off] = lower | upper; |
1da177e4 LT |
165 | } |
166 | if (off) | |
167 | memset(dst, 0, off*sizeof(unsigned long)); | |
168 | } | |
169 | EXPORT_SYMBOL(__bitmap_shift_left); | |
170 | ||
f4b0373b | 171 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 172 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 173 | { |
2f9305eb | 174 | unsigned int k; |
7e5f97d1 | 175 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 176 | unsigned long result = 0; |
1da177e4 | 177 | |
7e5f97d1 | 178 | for (k = 0; k < lim; k++) |
f4b0373b | 179 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
180 | if (bits % BITS_PER_LONG) |
181 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
182 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 183 | return result != 0; |
1da177e4 LT |
184 | } |
185 | EXPORT_SYMBOL(__bitmap_and); | |
186 | ||
187 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 188 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 189 | { |
2f9305eb RV |
190 | unsigned int k; |
191 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
192 | |
193 | for (k = 0; k < nr; k++) | |
194 | dst[k] = bitmap1[k] | bitmap2[k]; | |
195 | } | |
196 | EXPORT_SYMBOL(__bitmap_or); | |
197 | ||
198 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 199 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 200 | { |
2f9305eb RV |
201 | unsigned int k; |
202 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
203 | |
204 | for (k = 0; k < nr; k++) | |
205 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
206 | } | |
207 | EXPORT_SYMBOL(__bitmap_xor); | |
208 | ||
f4b0373b | 209 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 210 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 211 | { |
2f9305eb | 212 | unsigned int k; |
74e76531 | 213 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 214 | unsigned long result = 0; |
1da177e4 | 215 | |
74e76531 | 216 | for (k = 0; k < lim; k++) |
f4b0373b | 217 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
218 | if (bits % BITS_PER_LONG) |
219 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
220 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 221 | return result != 0; |
1da177e4 LT |
222 | } |
223 | EXPORT_SYMBOL(__bitmap_andnot); | |
224 | ||
225 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 226 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 227 | { |
6dfe9799 | 228 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
229 | for (k = 0; k < lim; ++k) |
230 | if (bitmap1[k] & bitmap2[k]) | |
231 | return 1; | |
232 | ||
233 | if (bits % BITS_PER_LONG) | |
234 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
235 | return 1; | |
236 | return 0; | |
237 | } | |
238 | EXPORT_SYMBOL(__bitmap_intersects); | |
239 | ||
240 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 241 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 242 | { |
5be20213 | 243 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
244 | for (k = 0; k < lim; ++k) |
245 | if (bitmap1[k] & ~bitmap2[k]) | |
246 | return 0; | |
247 | ||
248 | if (bits % BITS_PER_LONG) | |
249 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
250 | return 0; | |
251 | return 1; | |
252 | } | |
253 | EXPORT_SYMBOL(__bitmap_subset); | |
254 | ||
877d9f3b | 255 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 256 | { |
877d9f3b RV |
257 | unsigned int k, lim = bits/BITS_PER_LONG; |
258 | int w = 0; | |
1da177e4 LT |
259 | |
260 | for (k = 0; k < lim; k++) | |
37d54111 | 261 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
262 | |
263 | if (bits % BITS_PER_LONG) | |
37d54111 | 264 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
265 | |
266 | return w; | |
267 | } | |
1da177e4 LT |
268 | EXPORT_SYMBOL(__bitmap_weight); |
269 | ||
e5af323c | 270 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
271 | { |
272 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 273 | const unsigned int size = start + len; |
c1a2a962 AM |
274 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
275 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
276 | ||
fb5ac542 | 277 | while (len - bits_to_set >= 0) { |
c1a2a962 | 278 | *p |= mask_to_set; |
fb5ac542 | 279 | len -= bits_to_set; |
c1a2a962 AM |
280 | bits_to_set = BITS_PER_LONG; |
281 | mask_to_set = ~0UL; | |
282 | p++; | |
283 | } | |
fb5ac542 | 284 | if (len) { |
c1a2a962 AM |
285 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
286 | *p |= mask_to_set; | |
287 | } | |
288 | } | |
e5af323c | 289 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 290 | |
e5af323c | 291 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
292 | { |
293 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 294 | const unsigned int size = start + len; |
c1a2a962 AM |
295 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
296 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
297 | ||
154f5e38 | 298 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 299 | *p &= ~mask_to_clear; |
154f5e38 | 300 | len -= bits_to_clear; |
c1a2a962 AM |
301 | bits_to_clear = BITS_PER_LONG; |
302 | mask_to_clear = ~0UL; | |
303 | p++; | |
304 | } | |
154f5e38 | 305 | if (len) { |
c1a2a962 AM |
306 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
307 | *p &= ~mask_to_clear; | |
308 | } | |
309 | } | |
e5af323c | 310 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 311 | |
5e19b013 MN |
312 | /** |
313 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
314 | * @map: The address to base the search on |
315 | * @size: The bitmap size in bits | |
316 | * @start: The bitnumber to start searching at | |
317 | * @nr: The number of zeroed bits we're looking for | |
318 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 319 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
320 | * |
321 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
322 | * the bit offset of all zero areas this function finds plus @align_offset |
323 | * is multiple of that power of 2. | |
c1a2a962 | 324 | */ |
5e19b013 MN |
325 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
326 | unsigned long size, | |
327 | unsigned long start, | |
328 | unsigned int nr, | |
329 | unsigned long align_mask, | |
330 | unsigned long align_offset) | |
c1a2a962 AM |
331 | { |
332 | unsigned long index, end, i; | |
333 | again: | |
334 | index = find_next_zero_bit(map, size, start); | |
335 | ||
336 | /* Align allocation */ | |
5e19b013 | 337 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
338 | |
339 | end = index + nr; | |
340 | if (end > size) | |
341 | return end; | |
342 | i = find_next_bit(map, end, index); | |
343 | if (i < end) { | |
344 | start = i + 1; | |
345 | goto again; | |
346 | } | |
347 | return index; | |
348 | } | |
5e19b013 | 349 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 350 | |
1da177e4 | 351 | /* |
6d49e352 | 352 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
353 | * second version by Paul Jackson, third by Joe Korty. |
354 | */ | |
355 | ||
356 | #define CHUNKSZ 32 | |
357 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
358 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
359 | ||
1da177e4 | 360 | /** |
01a3ee2b RC |
361 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
362 | * @buf: pointer to buffer containing string. | |
363 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 364 | * then it must be terminated with a \0. |
01a3ee2b | 365 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
366 | * @maskp: pointer to bitmap array that will contain result. |
367 | * @nmaskbits: size of bitmap, in bits. | |
368 | * | |
369 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
370 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
371 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
372 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
373 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
374 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
375 | */ | |
01a3ee2b RC |
376 | int __bitmap_parse(const char *buf, unsigned int buflen, |
377 | int is_user, unsigned long *maskp, | |
378 | int nmaskbits) | |
1da177e4 LT |
379 | { |
380 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
381 | u32 chunk; | |
b9c321fd | 382 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
383 | |
384 | bitmap_zero(maskp, nmaskbits); | |
385 | ||
386 | nchunks = nbits = totaldigits = c = 0; | |
387 | do { | |
d21c3d4d PX |
388 | chunk = 0; |
389 | ndigits = totaldigits; | |
1da177e4 LT |
390 | |
391 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 392 | while (buflen) { |
1da177e4 | 393 | old_c = c; |
01a3ee2b RC |
394 | if (is_user) { |
395 | if (__get_user(c, ubuf++)) | |
396 | return -EFAULT; | |
397 | } | |
398 | else | |
399 | c = *buf++; | |
400 | buflen--; | |
1da177e4 LT |
401 | if (isspace(c)) |
402 | continue; | |
403 | ||
404 | /* | |
405 | * If the last character was a space and the current | |
406 | * character isn't '\0', we've got embedded whitespace. | |
407 | * This is a no-no, so throw an error. | |
408 | */ | |
409 | if (totaldigits && c && isspace(old_c)) | |
410 | return -EINVAL; | |
411 | ||
412 | /* A '\0' or a ',' signal the end of the chunk */ | |
413 | if (c == '\0' || c == ',') | |
414 | break; | |
415 | ||
416 | if (!isxdigit(c)) | |
417 | return -EINVAL; | |
418 | ||
419 | /* | |
420 | * Make sure there are at least 4 free bits in 'chunk'. | |
421 | * If not, this hexdigit will overflow 'chunk', so | |
422 | * throw an error. | |
423 | */ | |
424 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
425 | return -EOVERFLOW; | |
426 | ||
66f1991b | 427 | chunk = (chunk << 4) | hex_to_bin(c); |
d21c3d4d | 428 | totaldigits++; |
1da177e4 | 429 | } |
d21c3d4d | 430 | if (ndigits == totaldigits) |
1da177e4 LT |
431 | return -EINVAL; |
432 | if (nchunks == 0 && chunk == 0) | |
433 | continue; | |
434 | ||
435 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
436 | *maskp |= chunk; | |
437 | nchunks++; | |
438 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
439 | if (nbits > nmaskbits) | |
440 | return -EOVERFLOW; | |
01a3ee2b | 441 | } while (buflen && c == ','); |
1da177e4 LT |
442 | |
443 | return 0; | |
444 | } | |
01a3ee2b RC |
445 | EXPORT_SYMBOL(__bitmap_parse); |
446 | ||
447 | /** | |
9a86e2ba | 448 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
449 | * |
450 | * @ubuf: pointer to user buffer containing string. | |
451 | * @ulen: buffer size in bytes. If string is smaller than this | |
452 | * then it must be terminated with a \0. | |
453 | * @maskp: pointer to bitmap array that will contain result. | |
454 | * @nmaskbits: size of bitmap, in bits. | |
455 | * | |
456 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
457 | * | |
458 | * We cannot have this as an inline function in bitmap.h because it needs | |
459 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
460 | * cyclic dependencies. | |
461 | */ | |
462 | int bitmap_parse_user(const char __user *ubuf, | |
463 | unsigned int ulen, unsigned long *maskp, | |
464 | int nmaskbits) | |
465 | { | |
96d4f267 | 466 | if (!access_ok(ubuf, ulen)) |
01a3ee2b | 467 | return -EFAULT; |
b9c321fd HS |
468 | return __bitmap_parse((const char __force *)ubuf, |
469 | ulen, 1, maskp, nmaskbits); | |
470 | ||
01a3ee2b RC |
471 | } |
472 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 473 | |
5aaba363 SH |
474 | /** |
475 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
476 | * @list: indicates whether the bitmap must be list | |
477 | * @buf: page aligned buffer into which string is placed | |
478 | * @maskp: pointer to bitmap to convert | |
479 | * @nmaskbits: size of bitmap, in bits | |
480 | * | |
481 | * Output format is a comma-separated list of decimal numbers and | |
482 | * ranges if list is specified or hex digits grouped into comma-separated | |
483 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 | 484 | * |
ce1091d4 RV |
485 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned |
486 | * area and that sufficient storage remains at @buf to accommodate the | |
487 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
488 | * actually printed to @buf, excluding terminating '\0'. | |
5aaba363 SH |
489 | */ |
490 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
491 | int nmaskbits) | |
492 | { | |
ce1091d4 | 493 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
5aaba363 | 494 | |
8ec3d768 RV |
495 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
496 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
497 | } |
498 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
499 | ||
e371c481 YN |
500 | /* |
501 | * Region 9-38:4/10 describes the following bitmap structure: | |
502 | * 0 9 12 18 38 | |
503 | * .........****......****......****...... | |
504 | * ^ ^ ^ ^ | |
505 | * start off group_len end | |
506 | */ | |
507 | struct region { | |
508 | unsigned int start; | |
509 | unsigned int off; | |
510 | unsigned int group_len; | |
511 | unsigned int end; | |
512 | }; | |
513 | ||
514 | static int bitmap_set_region(const struct region *r, | |
515 | unsigned long *bitmap, int nbits) | |
516 | { | |
517 | unsigned int start; | |
518 | ||
519 | if (r->end >= nbits) | |
520 | return -ERANGE; | |
521 | ||
522 | for (start = r->start; start <= r->end; start += r->group_len) | |
523 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); | |
524 | ||
525 | return 0; | |
526 | } | |
527 | ||
528 | static int bitmap_check_region(const struct region *r) | |
529 | { | |
530 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) | |
531 | return -EINVAL; | |
532 | ||
533 | return 0; | |
534 | } | |
535 | ||
536 | static const char *bitmap_getnum(const char *str, unsigned int *num) | |
537 | { | |
538 | unsigned long long n; | |
539 | unsigned int len; | |
540 | ||
541 | len = _parse_integer(str, 10, &n); | |
542 | if (!len) | |
543 | return ERR_PTR(-EINVAL); | |
544 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) | |
545 | return ERR_PTR(-EOVERFLOW); | |
546 | ||
547 | *num = n; | |
548 | return str + len; | |
549 | } | |
550 | ||
551 | static inline bool end_of_str(char c) | |
552 | { | |
553 | return c == '\0' || c == '\n'; | |
554 | } | |
555 | ||
556 | static inline bool __end_of_region(char c) | |
557 | { | |
558 | return isspace(c) || c == ','; | |
559 | } | |
560 | ||
561 | static inline bool end_of_region(char c) | |
562 | { | |
563 | return __end_of_region(c) || end_of_str(c); | |
564 | } | |
565 | ||
566 | /* | |
567 | * The format allows commas and whitespases at the beginning | |
568 | * of the region. | |
569 | */ | |
570 | static const char *bitmap_find_region(const char *str) | |
571 | { | |
572 | while (__end_of_region(*str)) | |
573 | str++; | |
574 | ||
575 | return end_of_str(*str) ? NULL : str; | |
576 | } | |
577 | ||
578 | static const char *bitmap_parse_region(const char *str, struct region *r) | |
579 | { | |
580 | str = bitmap_getnum(str, &r->start); | |
581 | if (IS_ERR(str)) | |
582 | return str; | |
583 | ||
584 | if (end_of_region(*str)) | |
585 | goto no_end; | |
586 | ||
587 | if (*str != '-') | |
588 | return ERR_PTR(-EINVAL); | |
589 | ||
590 | str = bitmap_getnum(str + 1, &r->end); | |
591 | if (IS_ERR(str)) | |
592 | return str; | |
593 | ||
594 | if (end_of_region(*str)) | |
595 | goto no_pattern; | |
596 | ||
597 | if (*str != ':') | |
598 | return ERR_PTR(-EINVAL); | |
599 | ||
600 | str = bitmap_getnum(str + 1, &r->off); | |
601 | if (IS_ERR(str)) | |
602 | return str; | |
603 | ||
604 | if (*str != '/') | |
605 | return ERR_PTR(-EINVAL); | |
606 | ||
607 | return bitmap_getnum(str + 1, &r->group_len); | |
608 | ||
609 | no_end: | |
610 | r->end = r->start; | |
611 | no_pattern: | |
612 | r->off = r->end + 1; | |
613 | r->group_len = r->end + 1; | |
614 | ||
615 | return end_of_str(*str) ? NULL : str; | |
616 | } | |
617 | ||
1da177e4 | 618 | /** |
e371c481 YN |
619 | * bitmap_parselist - convert list format ASCII string to bitmap |
620 | * @buf: read user string from this buffer; must be terminated | |
621 | * with a \0 or \n. | |
6e1907ff | 622 | * @maskp: write resulting mask here |
1da177e4 LT |
623 | * @nmaskbits: number of bits in mask to be written |
624 | * | |
625 | * Input format is a comma-separated list of decimal numbers and | |
626 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
627 | * decimal numbers, the smallest and largest bit numbers set in | |
628 | * the range. | |
2d13e6ca NC |
629 | * Optionally each range can be postfixed to denote that only parts of it |
630 | * should be set. The range will divided to groups of specific size. | |
631 | * From each group will be used only defined amount of bits. | |
632 | * Syntax: range:used_size/group_size | |
633 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
1da177e4 | 634 | * |
40bf19a8 MCC |
635 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
636 | * | |
e371c481 | 637 | * - ``-EINVAL``: wrong region format |
40bf19a8 MCC |
638 | * - ``-EINVAL``: invalid character in string |
639 | * - ``-ERANGE``: bit number specified too large for mask | |
e371c481 | 640 | * - ``-EOVERFLOW``: integer overflow in the input parameters |
1da177e4 | 641 | */ |
e371c481 | 642 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) |
1da177e4 | 643 | { |
e371c481 YN |
644 | struct region r; |
645 | long ret; | |
1da177e4 LT |
646 | |
647 | bitmap_zero(maskp, nmaskbits); | |
4b060420 | 648 | |
e371c481 YN |
649 | while (buf) { |
650 | buf = bitmap_find_region(buf); | |
651 | if (buf == NULL) | |
652 | return 0; | |
2d13e6ca | 653 | |
e371c481 YN |
654 | buf = bitmap_parse_region(buf, &r); |
655 | if (IS_ERR(buf)) | |
656 | return PTR_ERR(buf); | |
2d13e6ca | 657 | |
e371c481 YN |
658 | ret = bitmap_check_region(&r); |
659 | if (ret) | |
660 | return ret; | |
4b060420 | 661 | |
e371c481 YN |
662 | ret = bitmap_set_region(&r, maskp, nmaskbits); |
663 | if (ret) | |
664 | return ret; | |
665 | } | |
4b060420 | 666 | |
1da177e4 LT |
667 | return 0; |
668 | } | |
669 | EXPORT_SYMBOL(bitmap_parselist); | |
670 | ||
4b060420 MT |
671 | |
672 | /** | |
673 | * bitmap_parselist_user() | |
674 | * | |
675 | * @ubuf: pointer to user buffer containing string. | |
676 | * @ulen: buffer size in bytes. If string is smaller than this | |
677 | * then it must be terminated with a \0. | |
678 | * @maskp: pointer to bitmap array that will contain result. | |
679 | * @nmaskbits: size of bitmap, in bits. | |
680 | * | |
681 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
4b060420 MT |
682 | */ |
683 | int bitmap_parselist_user(const char __user *ubuf, | |
684 | unsigned int ulen, unsigned long *maskp, | |
685 | int nmaskbits) | |
686 | { | |
281327c9 YN |
687 | char *buf; |
688 | int ret; | |
689 | ||
690 | buf = memdup_user_nul(ubuf, ulen); | |
691 | if (IS_ERR(buf)) | |
692 | return PTR_ERR(buf); | |
693 | ||
694 | ret = bitmap_parselist(buf, maskp, nmaskbits); | |
695 | ||
696 | kfree(buf); | |
697 | return ret; | |
4b060420 MT |
698 | } |
699 | EXPORT_SYMBOL(bitmap_parselist_user); | |
700 | ||
701 | ||
cdc90a18 | 702 | #ifdef CONFIG_NUMA |
72fd4a35 | 703 | /** |
9a86e2ba | 704 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 705 | * @buf: pointer to a bitmap |
df1d80a9 RV |
706 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
707 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 708 | * |
df1d80a9 | 709 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 710 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 711 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
712 | * |
713 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
714 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 715 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
716 | * gets mapped to (returns) @ord value 3 in this example, that means |
717 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
718 | * | |
719 | * The bit positions 0 through @bits are valid positions in @buf. | |
720 | */ | |
df1d80a9 | 721 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 722 | { |
df1d80a9 | 723 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 724 | return -1; |
fb5eeeee | 725 | |
df1d80a9 | 726 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
727 | } |
728 | ||
729 | /** | |
9a86e2ba | 730 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
731 | * @buf: pointer to bitmap |
732 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 733 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
734 | * |
735 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
736 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
737 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
738 | * |
739 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
740 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 741 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
742 | * gets mapped to (returns) @pos value 7 in this example, that means |
743 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
744 | * | |
f6a1f5db | 745 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 746 | */ |
f6a1f5db | 747 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 748 | { |
f6a1f5db | 749 | unsigned int pos; |
fb5eeeee | 750 | |
f6a1f5db RV |
751 | for (pos = find_first_bit(buf, nbits); |
752 | pos < nbits && ord; | |
753 | pos = find_next_bit(buf, nbits, pos + 1)) | |
754 | ord--; | |
fb5eeeee PJ |
755 | |
756 | return pos; | |
757 | } | |
758 | ||
759 | /** | |
760 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 761 | * @dst: remapped result |
96b7f341 | 762 | * @src: subset to be remapped |
fb5eeeee PJ |
763 | * @old: defines domain of map |
764 | * @new: defines range of map | |
9814ec13 | 765 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
766 | * |
767 | * Let @old and @new define a mapping of bit positions, such that | |
768 | * whatever position is held by the n-th set bit in @old is mapped | |
769 | * to the n-th set bit in @new. In the more general case, allowing | |
770 | * for the possibility that the weight 'w' of @new is less than the | |
771 | * weight of @old, map the position of the n-th set bit in @old to | |
772 | * the position of the m-th set bit in @new, where m == n % w. | |
773 | * | |
96b7f341 PJ |
774 | * If either of the @old and @new bitmaps are empty, or if @src and |
775 | * @dst point to the same location, then this routine copies @src | |
776 | * to @dst. | |
fb5eeeee | 777 | * |
96b7f341 PJ |
778 | * The positions of unset bits in @old are mapped to themselves |
779 | * (the identify map). | |
fb5eeeee PJ |
780 | * |
781 | * Apply the above specified mapping to @src, placing the result in | |
782 | * @dst, clearing any bits previously set in @dst. | |
783 | * | |
fb5eeeee PJ |
784 | * For example, lets say that @old has bits 4 through 7 set, and |
785 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
786 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
787 | * bit positions unchanged. So if say @src comes into this routine |
788 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
789 | * 13 and 15 set. | |
fb5eeeee PJ |
790 | */ |
791 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
792 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 793 | unsigned int nbits) |
fb5eeeee | 794 | { |
9814ec13 | 795 | unsigned int oldbit, w; |
fb5eeeee | 796 | |
fb5eeeee PJ |
797 | if (dst == src) /* following doesn't handle inplace remaps */ |
798 | return; | |
9814ec13 | 799 | bitmap_zero(dst, nbits); |
96b7f341 | 800 | |
9814ec13 RV |
801 | w = bitmap_weight(new, nbits); |
802 | for_each_set_bit(oldbit, src, nbits) { | |
803 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 804 | |
96b7f341 PJ |
805 | if (n < 0 || w == 0) |
806 | set_bit(oldbit, dst); /* identity map */ | |
807 | else | |
9814ec13 | 808 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
809 | } |
810 | } | |
fb5eeeee PJ |
811 | |
812 | /** | |
813 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
814 | * @oldbit: bit position to be mapped |
815 | * @old: defines domain of map | |
816 | * @new: defines range of map | |
817 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
818 | * |
819 | * Let @old and @new define a mapping of bit positions, such that | |
820 | * whatever position is held by the n-th set bit in @old is mapped | |
821 | * to the n-th set bit in @new. In the more general case, allowing | |
822 | * for the possibility that the weight 'w' of @new is less than the | |
823 | * weight of @old, map the position of the n-th set bit in @old to | |
824 | * the position of the m-th set bit in @new, where m == n % w. | |
825 | * | |
96b7f341 PJ |
826 | * The positions of unset bits in @old are mapped to themselves |
827 | * (the identify map). | |
fb5eeeee PJ |
828 | * |
829 | * Apply the above specified mapping to bit position @oldbit, returning | |
830 | * the new bit position. | |
831 | * | |
832 | * For example, lets say that @old has bits 4 through 7 set, and | |
833 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
834 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
835 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
836 | * returns 13. | |
fb5eeeee PJ |
837 | */ |
838 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
839 | const unsigned long *new, int bits) | |
840 | { | |
96b7f341 PJ |
841 | int w = bitmap_weight(new, bits); |
842 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
843 | if (n < 0 || w == 0) | |
844 | return oldbit; | |
845 | else | |
846 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee | 847 | } |
fb5eeeee | 848 | |
7ea931c9 PJ |
849 | /** |
850 | * bitmap_onto - translate one bitmap relative to another | |
851 | * @dst: resulting translated bitmap | |
852 | * @orig: original untranslated bitmap | |
853 | * @relmap: bitmap relative to which translated | |
854 | * @bits: number of bits in each of these bitmaps | |
855 | * | |
856 | * Set the n-th bit of @dst iff there exists some m such that the | |
857 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
858 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
859 | * (If you understood the previous sentence the first time your | |
860 | * read it, you're overqualified for your current job.) | |
861 | * | |
862 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 863 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
864 | * m-th set bit of @relmap }. |
865 | * | |
866 | * Any set bits in @orig above bit number W, where W is the | |
867 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
868 | * In particular, if for all bits m set in @orig, m >= W, then | |
869 | * @dst will end up empty. In situations where the possibility | |
870 | * of such an empty result is not desired, one way to avoid it is | |
871 | * to use the bitmap_fold() operator, below, to first fold the | |
872 | * @orig bitmap over itself so that all its set bits x are in the | |
873 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
874 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
875 | * | |
876 | * Example [1] for bitmap_onto(): | |
877 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
878 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
879 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
880 | * | |
881 | * When bit 0 is set in @orig, it means turn on the bit in | |
882 | * @dst corresponding to whatever is the first bit (if any) | |
883 | * that is turned on in @relmap. Since bit 0 was off in the | |
884 | * above example, we leave off that bit (bit 30) in @dst. | |
885 | * | |
886 | * When bit 1 is set in @orig (as in the above example), it | |
887 | * means turn on the bit in @dst corresponding to whatever | |
888 | * is the second bit that is turned on in @relmap. The second | |
889 | * bit in @relmap that was turned on in the above example was | |
890 | * bit 31, so we turned on bit 31 in @dst. | |
891 | * | |
892 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
893 | * because they were the 4th, 6th, 8th and 10th set bits | |
894 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
895 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
896 | * | |
897 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 898 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
899 | * turned on in @relmap. In the above example, there were |
900 | * only ten bits turned on in @relmap (30..39), so that bit | |
901 | * 11 was set in @orig had no affect on @dst. | |
902 | * | |
903 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
904 | * Let's say @relmap has these ten bits set:: |
905 | * | |
7ea931c9 | 906 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 907 | * |
7ea931c9 PJ |
908 | * (for the curious, that's 40 plus the first ten terms of the |
909 | * Fibonacci sequence.) | |
910 | * | |
911 | * Further lets say we use the following code, invoking | |
912 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 913 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
914 | * |
915 | * unsigned long *tmp; // a temporary bitmap's bits | |
916 | * | |
917 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
918 | * bitmap_onto(dst, tmp, relmap, bits); | |
919 | * | |
920 | * Then this table shows what various values of @dst would be, for | |
921 | * various @orig's. I list the zero-based positions of each set bit. | |
922 | * The tmp column shows the intermediate result, as computed by | |
923 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 924 | * (the weight of @relmap): |
7ea931c9 | 925 | * |
40bf19a8 | 926 | * =============== ============== ================= |
7ea931c9 PJ |
927 | * @orig tmp @dst |
928 | * 0 0 40 | |
929 | * 1 1 41 | |
930 | * 9 9 95 | |
40bf19a8 | 931 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
932 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
933 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
934 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
935 | * 0 10 20 30 0 40 | |
936 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
937 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
938 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
939 | * =============== ============== ================= | |
940 | * | |
941 | * .. [#f1] | |
7ea931c9 | 942 | * |
40bf19a8 | 943 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
944 | * into tmp, then the @dst result would have been empty. |
945 | * | |
946 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
947 | * will be returned empty. | |
948 | * | |
949 | * If (as explained above) the only set bits in @orig are in positions | |
950 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
951 | * once again be returned empty. | |
952 | * | |
953 | * All bits in @dst not set by the above rule are cleared. | |
954 | */ | |
955 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 956 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 957 | { |
eb569883 | 958 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
959 | |
960 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
961 | return; | |
962 | bitmap_zero(dst, bits); | |
963 | ||
964 | /* | |
965 | * The following code is a more efficient, but less | |
966 | * obvious, equivalent to the loop: | |
967 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
968 | * n = bitmap_ord_to_pos(orig, m, bits); | |
969 | * if (test_bit(m, orig)) | |
970 | * set_bit(n, dst); | |
971 | * } | |
972 | */ | |
973 | ||
974 | m = 0; | |
08564fb7 | 975 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
976 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
977 | if (test_bit(m, orig)) | |
978 | set_bit(n, dst); | |
979 | m++; | |
980 | } | |
981 | } | |
7ea931c9 PJ |
982 | |
983 | /** | |
984 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
985 | * @dst: resulting smaller bitmap | |
986 | * @orig: original larger bitmap | |
987 | * @sz: specified size | |
b26ad583 | 988 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
989 | * |
990 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
991 | * Clear all other bits in @dst. See further the comment and | |
992 | * Example [2] for bitmap_onto() for why and how to use this. | |
993 | */ | |
994 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 995 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 996 | { |
b26ad583 | 997 | unsigned int oldbit; |
7ea931c9 PJ |
998 | |
999 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1000 | return; | |
b26ad583 | 1001 | bitmap_zero(dst, nbits); |
7ea931c9 | 1002 | |
b26ad583 | 1003 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
1004 | set_bit(oldbit % sz, dst); |
1005 | } | |
cdc90a18 | 1006 | #endif /* CONFIG_NUMA */ |
7ea931c9 | 1007 | |
3cf64b93 PJ |
1008 | /* |
1009 | * Common code for bitmap_*_region() routines. | |
1010 | * bitmap: array of unsigned longs corresponding to the bitmap | |
1011 | * pos: the beginning of the region | |
1012 | * order: region size (log base 2 of number of bits) | |
1013 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 1014 | * |
3cf64b93 PJ |
1015 | * Can set, verify and/or release a region of bits in a bitmap, |
1016 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 1017 | * |
3cf64b93 PJ |
1018 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1019 | * some size '1 << order' (a power of two), aligned to that same | |
1020 | * '1 << order' power of two. | |
1021 | * | |
1022 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1023 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 1024 | */ |
3cf64b93 PJ |
1025 | |
1026 | enum { | |
1027 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1028 | REG_OP_ALLOC, /* set all bits in region */ | |
1029 | REG_OP_RELEASE, /* clear all bits in region */ | |
1030 | }; | |
1031 | ||
9279d328 | 1032 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 1033 | { |
3cf64b93 PJ |
1034 | int nbits_reg; /* number of bits in region */ |
1035 | int index; /* index first long of region in bitmap */ | |
1036 | int offset; /* bit offset region in bitmap[index] */ | |
1037 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1038 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1039 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1040 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1041 | int ret = 0; /* return value */ |
74373c6a | 1042 | |
3cf64b93 PJ |
1043 | /* |
1044 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1045 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1046 | */ | |
1047 | nbits_reg = 1 << order; | |
1048 | index = pos / BITS_PER_LONG; | |
1049 | offset = pos - (index * BITS_PER_LONG); | |
1050 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1051 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1052 | |
3cf64b93 PJ |
1053 | /* |
1054 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1055 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1056 | */ | |
74373c6a | 1057 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1058 | mask += mask - 1; |
3cf64b93 | 1059 | mask <<= offset; |
1da177e4 | 1060 | |
3cf64b93 PJ |
1061 | switch (reg_op) { |
1062 | case REG_OP_ISFREE: | |
1063 | for (i = 0; i < nlongs_reg; i++) { | |
1064 | if (bitmap[index + i] & mask) | |
1065 | goto done; | |
1066 | } | |
1067 | ret = 1; /* all bits in region free (zero) */ | |
1068 | break; | |
1069 | ||
1070 | case REG_OP_ALLOC: | |
1071 | for (i = 0; i < nlongs_reg; i++) | |
1072 | bitmap[index + i] |= mask; | |
1073 | break; | |
1074 | ||
1075 | case REG_OP_RELEASE: | |
1076 | for (i = 0; i < nlongs_reg; i++) | |
1077 | bitmap[index + i] &= ~mask; | |
1078 | break; | |
1da177e4 | 1079 | } |
3cf64b93 PJ |
1080 | done: |
1081 | return ret; | |
1082 | } | |
1083 | ||
1084 | /** | |
1085 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1086 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1087 | * @bits: number of bits in the bitmap | |
1088 | * @order: region size (log base 2 of number of bits) to find | |
1089 | * | |
1090 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1091 | * allocate them (set them to one). Only consider regions of length | |
1092 | * a power (@order) of two, aligned to that power of two, which | |
1093 | * makes the search algorithm much faster. | |
1094 | * | |
1095 | * Return the bit offset in bitmap of the allocated region, | |
1096 | * or -errno on failure. | |
1097 | */ | |
9279d328 | 1098 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1099 | { |
9279d328 | 1100 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1101 | |
9279d328 | 1102 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1103 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1104 | continue; | |
1105 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1106 | return pos; | |
1107 | } | |
1108 | return -ENOMEM; | |
1da177e4 LT |
1109 | } |
1110 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1111 | ||
1112 | /** | |
87e24802 | 1113 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1114 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1115 | * @pos: beginning of bit region to release | |
1116 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1117 | * |
72fd4a35 | 1118 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1119 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1120 | * |
1121 | * No return value. | |
1da177e4 | 1122 | */ |
9279d328 | 1123 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1124 | { |
3cf64b93 | 1125 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1126 | } |
1127 | EXPORT_SYMBOL(bitmap_release_region); | |
1128 | ||
87e24802 PJ |
1129 | /** |
1130 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1131 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1132 | * @pos: beginning of bit region to allocate | |
1133 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1134 | * |
1135 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1136 | * |
6e1907ff | 1137 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1138 | * free (not all bits were zero). |
1139 | */ | |
9279d328 | 1140 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1141 | { |
3cf64b93 PJ |
1142 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1143 | return -EBUSY; | |
2ac521d3 | 1144 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1145 | } |
1146 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1147 | |
1148 | /** | |
1149 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1150 | * @dst: destination buffer | |
1151 | * @src: bitmap to copy | |
1152 | * @nbits: number of bits in the bitmap | |
1153 | * | |
1154 | * Require nbits % BITS_PER_LONG == 0. | |
1155 | */ | |
e8f24278 | 1156 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1157 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1158 | { |
9b6c2d2e | 1159 | unsigned int i; |
ccbe329b DV |
1160 | |
1161 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1162 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1163 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1164 | else |
9b6c2d2e | 1165 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1166 | } |
1167 | } | |
1168 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1169 | #endif |
c724f193 | 1170 | |
c42b65e3 AS |
1171 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) |
1172 | { | |
1173 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1174 | flags); | |
1175 | } | |
1176 | EXPORT_SYMBOL(bitmap_alloc); | |
1177 | ||
1178 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1179 | { | |
1180 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1181 | } | |
1182 | EXPORT_SYMBOL(bitmap_zalloc); | |
1183 | ||
1184 | void bitmap_free(const unsigned long *bitmap) | |
1185 | { | |
1186 | kfree(bitmap); | |
1187 | } | |
1188 | EXPORT_SYMBOL(bitmap_free); | |
1189 | ||
c724f193 YN |
1190 | #if BITS_PER_LONG == 64 |
1191 | /** | |
1192 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
1193 | * @bitmap: array of unsigned longs, the destination bitmap | |
1194 | * @buf: array of u32 (in host byte order), the source bitmap | |
1195 | * @nbits: number of bits in @bitmap | |
1196 | */ | |
ccf7a6d4 | 1197 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) |
c724f193 YN |
1198 | { |
1199 | unsigned int i, halfwords; | |
1200 | ||
c724f193 YN |
1201 | halfwords = DIV_ROUND_UP(nbits, 32); |
1202 | for (i = 0; i < halfwords; i++) { | |
1203 | bitmap[i/2] = (unsigned long) buf[i]; | |
1204 | if (++i < halfwords) | |
1205 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
1206 | } | |
1207 | ||
1208 | /* Clear tail bits in last word beyond nbits. */ | |
1209 | if (nbits % BITS_PER_LONG) | |
1210 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
1211 | } | |
1212 | EXPORT_SYMBOL(bitmap_from_arr32); | |
1213 | ||
1214 | /** | |
1215 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
1216 | * @buf: array of u32 (in host byte order), the dest bitmap | |
1217 | * @bitmap: array of unsigned longs, the source bitmap | |
1218 | * @nbits: number of bits in @bitmap | |
1219 | */ | |
1220 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1221 | { | |
1222 | unsigned int i, halfwords; | |
1223 | ||
c724f193 YN |
1224 | halfwords = DIV_ROUND_UP(nbits, 32); |
1225 | for (i = 0; i < halfwords; i++) { | |
1226 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
1227 | if (++i < halfwords) | |
1228 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
1229 | } | |
1230 | ||
1231 | /* Clear tail bits in last element of array beyond nbits. */ | |
1232 | if (nbits % BITS_PER_LONG) | |
1233 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
1234 | } | |
1235 | EXPORT_SYMBOL(bitmap_to_arr32); | |
1236 | ||
1237 | #endif |