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1 : : // SPDX-License-Identifier: GPL-2.0-only
2 : : /*
3 : : * lib/bitmap.c
4 : : * Helper functions for bitmap.h.
5 : : */
6 : : #include <linux/export.h>
7 : : #include <linux/thread_info.h>
8 : : #include <linux/ctype.h>
9 : : #include <linux/errno.h>
10 : : #include <linux/bitmap.h>
11 : : #include <linux/bitops.h>
12 : : #include <linux/bug.h>
13 : : #include <linux/kernel.h>
14 : : #include <linux/mm.h>
15 : : #include <linux/slab.h>
16 : : #include <linux/string.h>
17 : : #include <linux/uaccess.h>
18 : :
19 : : #include <asm/page.h>
20 : :
21 : : #include "kstrtox.h"
22 : :
23 : : /**
24 : : * DOC: bitmap introduction
25 : : *
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 : : *
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 : :
46 : 0 : int __bitmap_equal(const unsigned long *bitmap1,
47 : : const unsigned long *bitmap2, unsigned int bits)
48 : : {
49 : 0 : unsigned int k, lim = bits/BITS_PER_LONG;
50 : 0 : for (k = 0; k < lim; ++k)
51 : 0 : if (bitmap1[k] != bitmap2[k])
52 : : return 0;
53 : :
54 : 0 : if (bits % BITS_PER_LONG)
55 : 0 : if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
56 : : return 0;
57 : :
58 : 0 : return 1;
59 : : }
60 : : EXPORT_SYMBOL(__bitmap_equal);
61 : :
62 : 0 : bool __bitmap_or_equal(const unsigned long *bitmap1,
63 : : const unsigned long *bitmap2,
64 : : const unsigned long *bitmap3,
65 : : unsigned int bits)
66 : : {
67 : 0 : unsigned int k, lim = bits / BITS_PER_LONG;
68 : : unsigned long tmp;
69 : :
70 : 0 : for (k = 0; k < lim; ++k) {
71 : 0 : if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
72 : : return false;
73 : : }
74 : :
75 : 0 : if (!(bits % BITS_PER_LONG))
76 : : return true;
77 : :
78 : 0 : tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
79 : 0 : return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
80 : : }
81 : :
82 : 0 : void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
83 : : {
84 : 0 : unsigned int k, lim = BITS_TO_LONGS(bits);
85 : 0 : for (k = 0; k < lim; ++k)
86 : 0 : dst[k] = ~src[k];
87 : 0 : }
88 : : EXPORT_SYMBOL(__bitmap_complement);
89 : :
90 : : /**
91 : : * __bitmap_shift_right - logical right shift of the bits in a bitmap
92 : : * @dst : destination bitmap
93 : : * @src : source bitmap
94 : : * @shift : shift by this many bits
95 : : * @nbits : bitmap size, in bits
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 : : */
101 : 0 : void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
102 : : unsigned shift, unsigned nbits)
103 : : {
104 : 0 : unsigned k, lim = BITS_TO_LONGS(nbits);
105 : 0 : unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
106 : 0 : unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
107 : 0 : 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 : 0 : if (!rem || off + k + 1 >= lim)
115 : : upper = 0;
116 : : else {
117 : 0 : upper = src[off + k + 1];
118 : 0 : if (off + k + 1 == lim - 1)
119 : 0 : upper &= mask;
120 : 0 : upper <<= (BITS_PER_LONG - rem);
121 : : }
122 : 0 : lower = src[off + k];
123 : 0 : if (off + k == lim - 1)
124 : 0 : lower &= mask;
125 : 0 : lower >>= rem;
126 : 0 : dst[k] = lower | upper;
127 : : }
128 : 0 : if (off)
129 : 0 : memset(&dst[lim - off], 0, off*sizeof(unsigned long));
130 : 0 : }
131 : : EXPORT_SYMBOL(__bitmap_shift_right);
132 : :
133 : :
134 : : /**
135 : : * __bitmap_shift_left - logical left shift of the bits in a bitmap
136 : : * @dst : destination bitmap
137 : : * @src : source bitmap
138 : : * @shift : shift by this many bits
139 : : * @nbits : bitmap size, in bits
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 : :
146 : 0 : void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
147 : : unsigned int shift, unsigned int nbits)
148 : : {
149 : : int k;
150 : 0 : unsigned int lim = BITS_TO_LONGS(nbits);
151 : 0 : unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
152 : 0 : 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 : 0 : if (rem && k > 0)
160 : 0 : lower = src[k - 1] >> (BITS_PER_LONG - rem);
161 : : else
162 : : lower = 0;
163 : 0 : upper = src[k] << rem;
164 : 0 : dst[k + off] = lower | upper;
165 : : }
166 : 0 : if (off)
167 : 0 : memset(dst, 0, off*sizeof(unsigned long));
168 : 0 : }
169 : : EXPORT_SYMBOL(__bitmap_shift_left);
170 : :
171 : 0 : int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
172 : : const unsigned long *bitmap2, unsigned int bits)
173 : : {
174 : : unsigned int k;
175 : 0 : unsigned int lim = bits/BITS_PER_LONG;
176 : : unsigned long result = 0;
177 : :
178 : 0 : for (k = 0; k < lim; k++)
179 : 0 : result |= (dst[k] = bitmap1[k] & bitmap2[k]);
180 : 0 : if (bits % BITS_PER_LONG)
181 : 0 : result |= (dst[k] = bitmap1[k] & bitmap2[k] &
182 : 0 : BITMAP_LAST_WORD_MASK(bits));
183 : 0 : return result != 0;
184 : : }
185 : : EXPORT_SYMBOL(__bitmap_and);
186 : :
187 : 0 : void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
188 : : const unsigned long *bitmap2, unsigned int bits)
189 : : {
190 : : unsigned int k;
191 : 0 : unsigned int nr = BITS_TO_LONGS(bits);
192 : :
193 : 0 : for (k = 0; k < nr; k++)
194 : 0 : dst[k] = bitmap1[k] | bitmap2[k];
195 : 0 : }
196 : : EXPORT_SYMBOL(__bitmap_or);
197 : :
198 : 0 : void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
199 : : const unsigned long *bitmap2, unsigned int bits)
200 : : {
201 : : unsigned int k;
202 : 0 : unsigned int nr = BITS_TO_LONGS(bits);
203 : :
204 : 0 : for (k = 0; k < nr; k++)
205 : 0 : dst[k] = bitmap1[k] ^ bitmap2[k];
206 : 0 : }
207 : : EXPORT_SYMBOL(__bitmap_xor);
208 : :
209 : 2 : int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
210 : : const unsigned long *bitmap2, unsigned int bits)
211 : : {
212 : : unsigned int k;
213 : 2 : unsigned int lim = bits/BITS_PER_LONG;
214 : : unsigned long result = 0;
215 : :
216 : 2 : for (k = 0; k < lim; k++)
217 : 2 : result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
218 : 2 : if (bits % BITS_PER_LONG)
219 : 0 : result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
220 : 0 : BITMAP_LAST_WORD_MASK(bits));
221 : 2 : return result != 0;
222 : : }
223 : : EXPORT_SYMBOL(__bitmap_andnot);
224 : :
225 : 0 : int __bitmap_intersects(const unsigned long *bitmap1,
226 : : const unsigned long *bitmap2, unsigned int bits)
227 : : {
228 : 0 : unsigned int k, lim = bits/BITS_PER_LONG;
229 : 0 : for (k = 0; k < lim; ++k)
230 : 0 : if (bitmap1[k] & bitmap2[k])
231 : : return 1;
232 : :
233 : 0 : if (bits % BITS_PER_LONG)
234 : 0 : if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
235 : : return 1;
236 : 0 : return 0;
237 : : }
238 : : EXPORT_SYMBOL(__bitmap_intersects);
239 : :
240 : 3 : int __bitmap_subset(const unsigned long *bitmap1,
241 : : const unsigned long *bitmap2, unsigned int bits)
242 : : {
243 : 3 : unsigned int k, lim = bits/BITS_PER_LONG;
244 : 3 : for (k = 0; k < lim; ++k)
245 : 3 : if (bitmap1[k] & ~bitmap2[k])
246 : : return 0;
247 : :
248 : 3 : if (bits % BITS_PER_LONG)
249 : 3 : if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
250 : : return 0;
251 : 3 : return 1;
252 : : }
253 : : EXPORT_SYMBOL(__bitmap_subset);
254 : :
255 : 0 : int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
256 : : {
257 : 0 : unsigned int k, lim = bits/BITS_PER_LONG;
258 : : int w = 0;
259 : :
260 : 0 : for (k = 0; k < lim; k++)
261 : 0 : w += hweight_long(bitmap[k]);
262 : :
263 : 0 : if (bits % BITS_PER_LONG)
264 : 0 : w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
265 : :
266 : 0 : return w;
267 : : }
268 : : EXPORT_SYMBOL(__bitmap_weight);
269 : :
270 : 3 : void __bitmap_set(unsigned long *map, unsigned int start, int len)
271 : : {
272 : 3 : unsigned long *p = map + BIT_WORD(start);
273 : 3 : const unsigned int size = start + len;
274 : 3 : int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
275 : 3 : unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
276 : :
277 : 3 : while (len - bits_to_set >= 0) {
278 : 3 : *p |= mask_to_set;
279 : : len -= bits_to_set;
280 : : bits_to_set = BITS_PER_LONG;
281 : : mask_to_set = ~0UL;
282 : 3 : p++;
283 : : }
284 : 3 : if (len) {
285 : 3 : mask_to_set &= BITMAP_LAST_WORD_MASK(size);
286 : 3 : *p |= mask_to_set;
287 : : }
288 : 3 : }
289 : : EXPORT_SYMBOL(__bitmap_set);
290 : :
291 : 3 : void __bitmap_clear(unsigned long *map, unsigned int start, int len)
292 : : {
293 : 3 : unsigned long *p = map + BIT_WORD(start);
294 : 3 : const unsigned int size = start + len;
295 : 3 : int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
296 : 3 : unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
297 : :
298 : 3 : while (len - bits_to_clear >= 0) {
299 : 3 : *p &= ~mask_to_clear;
300 : : len -= bits_to_clear;
301 : : bits_to_clear = BITS_PER_LONG;
302 : : mask_to_clear = ~0UL;
303 : 3 : p++;
304 : : }
305 : 3 : if (len) {
306 : 3 : mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
307 : 3 : *p &= ~mask_to_clear;
308 : : }
309 : 3 : }
310 : : EXPORT_SYMBOL(__bitmap_clear);
311 : :
312 : : /**
313 : : * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
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
319 : : * @align_offset: Alignment offset for zero area.
320 : : *
321 : : * The @align_mask should be one less than a power of 2; the effect is that
322 : : * the bit offset of all zero areas this function finds plus @align_offset
323 : : * is multiple of that power of 2.
324 : : */
325 : 3 : 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)
331 : : {
332 : : unsigned long index, end, i;
333 : : again:
334 : 3 : index = find_next_zero_bit(map, size, start);
335 : :
336 : : /* Align allocation */
337 : 3 : index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
338 : :
339 : 3 : end = index + nr;
340 : 3 : if (end > size)
341 : 0 : return end;
342 : 3 : i = find_next_bit(map, end, index);
343 : 3 : if (i < end) {
344 : 3 : start = i + 1;
345 : 3 : goto again;
346 : : }
347 : 3 : return index;
348 : : }
349 : : EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
350 : :
351 : : /*
352 : : * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
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)
358 : : #define BASEDEC 10 /* fancier cpuset lists input in decimal */
359 : :
360 : : /**
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
364 : : * then it must be terminated with a \0.
365 : : * @is_user: location of buffer, 0 indicates kernel space
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
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
373 : : * characters and for grouping errors such as "1,,5", ",44", "," and "".
374 : : * Leading and trailing whitespace accepted, but not embedded whitespace.
375 : : */
376 : 0 : int __bitmap_parse(const char *buf, unsigned int buflen,
377 : : int is_user, unsigned long *maskp,
378 : : int nmaskbits)
379 : : {
380 : : int c, old_c, totaldigits, ndigits, nchunks, nbits;
381 : : u32 chunk;
382 : : const char __user __force *ubuf = (const char __user __force *)buf;
383 : :
384 : 0 : bitmap_zero(maskp, nmaskbits);
385 : :
386 : : nchunks = nbits = totaldigits = c = 0;
387 : : do {
388 : : chunk = 0;
389 : : ndigits = totaldigits;
390 : :
391 : : /* Get the next chunk of the bitmap */
392 : 0 : while (buflen) {
393 : : old_c = c;
394 : 0 : if (is_user) {
395 : 0 : if (__get_user(c, ubuf++))
396 : : return -EFAULT;
397 : : }
398 : : else
399 : 0 : c = *buf++;
400 : 0 : buflen--;
401 : 0 : if (isspace(c))
402 : 0 : 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 : 0 : if (totaldigits && c && isspace(old_c))
410 : : return -EINVAL;
411 : :
412 : : /* A '\0' or a ',' signal the end of the chunk */
413 : 0 : if (c == '\0' || c == ',')
414 : : break;
415 : :
416 : 0 : 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 : 0 : if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
425 : : return -EOVERFLOW;
426 : :
427 : 0 : chunk = (chunk << 4) | hex_to_bin(c);
428 : 0 : totaldigits++;
429 : : }
430 : 0 : if (ndigits == totaldigits)
431 : : return -EINVAL;
432 : 0 : if (nchunks == 0 && chunk == 0)
433 : 0 : continue;
434 : :
435 : 0 : __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
436 : 0 : *maskp |= chunk;
437 : 0 : nchunks++;
438 : 0 : nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
439 : 0 : if (nbits > nmaskbits)
440 : : return -EOVERFLOW;
441 : 0 : } while (buflen && c == ',');
442 : :
443 : : return 0;
444 : : }
445 : : EXPORT_SYMBOL(__bitmap_parse);
446 : :
447 : : /**
448 : : * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
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 : 0 : int bitmap_parse_user(const char __user *ubuf,
463 : : unsigned int ulen, unsigned long *maskp,
464 : : int nmaskbits)
465 : : {
466 : 0 : if (!access_ok(ubuf, ulen))
467 : : return -EFAULT;
468 : 0 : return __bitmap_parse((const char __force *)ubuf,
469 : : ulen, 1, maskp, nmaskbits);
470 : :
471 : : }
472 : : EXPORT_SYMBOL(bitmap_parse_user);
473 : :
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.
484 : : *
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'.
489 : : */
490 : 3 : int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
491 : : int nmaskbits)
492 : : {
493 : 3 : ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
494 : :
495 : 3 : return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
496 : : scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
497 : : }
498 : : EXPORT_SYMBOL(bitmap_print_to_pagebuf);
499 : :
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 : 0 : static int bitmap_set_region(const struct region *r,
515 : : unsigned long *bitmap, int nbits)
516 : : {
517 : : unsigned int start;
518 : :
519 : 0 : if (r->end >= nbits)
520 : : return -ERANGE;
521 : :
522 : 0 : for (start = r->start; start <= r->end; start += r->group_len)
523 : 0 : 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 : 0 : if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
531 : : return -EINVAL;
532 : :
533 : : return 0;
534 : : }
535 : :
536 : 0 : static const char *bitmap_getnum(const char *str, unsigned int *num)
537 : : {
538 : : unsigned long long n;
539 : : unsigned int len;
540 : :
541 : 0 : len = _parse_integer(str, 10, &n);
542 : 0 : if (!len)
543 : : return ERR_PTR(-EINVAL);
544 : 0 : if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
545 : : return ERR_PTR(-EOVERFLOW);
546 : :
547 : 0 : *num = n;
548 : 0 : return str + len;
549 : : }
550 : :
551 : : static inline bool end_of_str(char c)
552 : : {
553 : 0 : return c == '\0' || c == '\n';
554 : : }
555 : :
556 : : static inline bool __end_of_region(char c)
557 : : {
558 : 0 : return isspace(c) || c == ',';
559 : : }
560 : :
561 : : static inline bool end_of_region(char c)
562 : : {
563 : 0 : 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 : 0 : static const char *bitmap_find_region(const char *str)
571 : : {
572 : 0 : while (__end_of_region(*str))
573 : 0 : str++;
574 : :
575 : 0 : return end_of_str(*str) ? NULL : str;
576 : : }
577 : :
578 : 0 : static const char *bitmap_parse_region(const char *str, struct region *r)
579 : : {
580 : 0 : str = bitmap_getnum(str, &r->start);
581 : 0 : if (IS_ERR(str))
582 : : return str;
583 : :
584 : 0 : if (end_of_region(*str))
585 : : goto no_end;
586 : :
587 : 0 : if (*str != '-')
588 : : return ERR_PTR(-EINVAL);
589 : :
590 : 0 : str = bitmap_getnum(str + 1, &r->end);
591 : 0 : if (IS_ERR(str))
592 : : return str;
593 : :
594 : 0 : if (end_of_region(*str))
595 : : goto no_pattern;
596 : :
597 : 0 : if (*str != ':')
598 : : return ERR_PTR(-EINVAL);
599 : :
600 : 0 : str = bitmap_getnum(str + 1, &r->off);
601 : 0 : if (IS_ERR(str))
602 : : return str;
603 : :
604 : 0 : if (*str != '/')
605 : : return ERR_PTR(-EINVAL);
606 : :
607 : 0 : return bitmap_getnum(str + 1, &r->group_len);
608 : :
609 : : no_end:
610 : 0 : r->end = r->start;
611 : : no_pattern:
612 : 0 : r->off = r->end + 1;
613 : 0 : r->group_len = r->end + 1;
614 : :
615 : 0 : return end_of_str(*str) ? NULL : str;
616 : : }
617 : :
618 : : /**
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.
622 : : * @maskp: write resulting mask here
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.
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
634 : : *
635 : : * Returns: 0 on success, -errno on invalid input strings. Error values:
636 : : *
637 : : * - ``-EINVAL``: wrong region format
638 : : * - ``-EINVAL``: invalid character in string
639 : : * - ``-ERANGE``: bit number specified too large for mask
640 : : * - ``-EOVERFLOW``: integer overflow in the input parameters
641 : : */
642 : 0 : int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
643 : : {
644 : : struct region r;
645 : : long ret;
646 : :
647 : 0 : bitmap_zero(maskp, nmaskbits);
648 : :
649 : 0 : while (buf) {
650 : 0 : buf = bitmap_find_region(buf);
651 : 0 : if (buf == NULL)
652 : : return 0;
653 : :
654 : 0 : buf = bitmap_parse_region(buf, &r);
655 : 0 : if (IS_ERR(buf))
656 : 0 : return PTR_ERR(buf);
657 : :
658 : : ret = bitmap_check_region(&r);
659 : 0 : if (ret)
660 : 0 : return ret;
661 : :
662 : 0 : ret = bitmap_set_region(&r, maskp, nmaskbits);
663 : 0 : if (ret)
664 : 0 : return ret;
665 : : }
666 : :
667 : : return 0;
668 : : }
669 : : EXPORT_SYMBOL(bitmap_parselist);
670 : :
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.
682 : : */
683 : 0 : int bitmap_parselist_user(const char __user *ubuf,
684 : : unsigned int ulen, unsigned long *maskp,
685 : : int nmaskbits)
686 : : {
687 : : char *buf;
688 : : int ret;
689 : :
690 : 0 : buf = memdup_user_nul(ubuf, ulen);
691 : 0 : if (IS_ERR(buf))
692 : 0 : return PTR_ERR(buf);
693 : :
694 : 0 : ret = bitmap_parselist(buf, maskp, nmaskbits);
695 : :
696 : 0 : kfree(buf);
697 : 0 : return ret;
698 : : }
699 : : EXPORT_SYMBOL(bitmap_parselist_user);
700 : :
701 : :
702 : : #ifdef CONFIG_NUMA
703 : : /**
704 : : * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
705 : : * @buf: pointer to a bitmap
706 : : * @pos: a bit position in @buf (0 <= @pos < @nbits)
707 : : * @nbits: number of valid bit positions in @buf
708 : : *
709 : : * Map the bit at position @pos in @buf (of length @nbits) to the
710 : : * ordinal of which set bit it is. If it is not set or if @pos
711 : : * is not a valid bit position, map to -1.
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,
715 : : * and other @pos values will get mapped to -1. When @pos value 7
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 : : */
721 : : static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
722 : : {
723 : : if (pos >= nbits || !test_bit(pos, buf))
724 : : return -1;
725 : :
726 : : return __bitmap_weight(buf, pos);
727 : : }
728 : :
729 : : /**
730 : : * bitmap_ord_to_pos - find position of n-th set bit in bitmap
731 : : * @buf: pointer to bitmap
732 : : * @ord: ordinal bit position (n-th set bit, n >= 0)
733 : : * @nbits: number of valid bit positions in @buf
734 : : *
735 : : * Map the ordinal offset of bit @ord in @buf to its position in @buf.
736 : : * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
737 : : * >= weight(buf), returns @nbits.
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,
741 : : * and all other @ord values returns @nbits. When @ord value 3
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 : : *
745 : : * The bit positions 0 through @nbits-1 are valid positions in @buf.
746 : : */
747 : : unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
748 : : {
749 : : unsigned int pos;
750 : :
751 : : for (pos = find_first_bit(buf, nbits);
752 : : pos < nbits && ord;
753 : : pos = find_next_bit(buf, nbits, pos + 1))
754 : : ord--;
755 : :
756 : : return pos;
757 : : }
758 : :
759 : : /**
760 : : * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
761 : : * @dst: remapped result
762 : : * @src: subset to be remapped
763 : : * @old: defines domain of map
764 : : * @new: defines range of map
765 : : * @nbits: number of bits in each of these bitmaps
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 : : *
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.
777 : : *
778 : : * The positions of unset bits in @old are mapped to themselves
779 : : * (the identify map).
780 : : *
781 : : * Apply the above specified mapping to @src, placing the result in
782 : : * @dst, clearing any bits previously set in @dst.
783 : : *
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
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.
790 : : */
791 : : void bitmap_remap(unsigned long *dst, const unsigned long *src,
792 : : const unsigned long *old, const unsigned long *new,
793 : : unsigned int nbits)
794 : : {
795 : : unsigned int oldbit, w;
796 : :
797 : : if (dst == src) /* following doesn't handle inplace remaps */
798 : : return;
799 : : bitmap_zero(dst, nbits);
800 : :
801 : : w = bitmap_weight(new, nbits);
802 : : for_each_set_bit(oldbit, src, nbits) {
803 : : int n = bitmap_pos_to_ord(old, oldbit, nbits);
804 : :
805 : : if (n < 0 || w == 0)
806 : : set_bit(oldbit, dst); /* identity map */
807 : : else
808 : : set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
809 : : }
810 : : }
811 : :
812 : : /**
813 : : * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
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
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 : : *
826 : : * The positions of unset bits in @old are mapped to themselves
827 : : * (the identify map).
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
835 : : * bit positions unchanged. So if say @oldbit is 5, then this routine
836 : : * returns 13.
837 : : */
838 : : int bitmap_bitremap(int oldbit, const unsigned long *old,
839 : : const unsigned long *new, int bits)
840 : : {
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);
847 : : }
848 : :
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,
863 : : * using the map { <n, m> | the n-th bit of @relmap is the
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
898 : : * @dst corresponding to whatever is the twelfth bit that is
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():
904 : : * Let's say @relmap has these ten bits set::
905 : : *
906 : : * 40 41 42 43 45 48 53 61 74 95
907 : : *
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
913 : : * avoid the possibility of an empty @dst result::
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
924 : : * (the weight of @relmap):
925 : : *
926 : : * =============== ============== =================
927 : : * @orig tmp @dst
928 : : * 0 0 40
929 : : * 1 1 41
930 : : * 9 9 95
931 : : * 10 0 40 [#f1]_
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
938 : : * 78 102 211 1 2 8 41 42 74 [#f1]_
939 : : * =============== ============== =================
940 : : *
941 : : * .. [#f1]
942 : : *
943 : : * For these marked lines, if we hadn't first done bitmap_fold()
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,
956 : : const unsigned long *relmap, unsigned int bits)
957 : : {
958 : : unsigned int n, m; /* same meaning as in above comment */
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;
975 : : for_each_set_bit(n, relmap, bits) {
976 : : /* m == bitmap_pos_to_ord(relmap, n, bits) */
977 : : if (test_bit(m, orig))
978 : : set_bit(n, dst);
979 : : m++;
980 : : }
981 : : }
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
988 : : * @nbits: number of bits in each of these bitmaps
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,
995 : : unsigned int sz, unsigned int nbits)
996 : : {
997 : : unsigned int oldbit;
998 : :
999 : : if (dst == orig) /* following doesn't handle inplace mappings */
1000 : : return;
1001 : : bitmap_zero(dst, nbits);
1002 : :
1003 : : for_each_set_bit(oldbit, orig, nbits)
1004 : : set_bit(oldbit % sz, dst);
1005 : : }
1006 : : #endif /* CONFIG_NUMA */
1007 : :
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
1014 : : *
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.
1017 : : *
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.
1024 : : */
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 : :
1032 : 0 : static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
1033 : : {
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 */
1038 : : int nbitsinlong; /* num bits of region in each spanned long */
1039 : : unsigned long mask; /* bitmask for one long of region */
1040 : : int i; /* scans bitmap by longs */
1041 : : int ret = 0; /* return value */
1042 : :
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 : 0 : nbits_reg = 1 << order;
1048 : 0 : index = pos / BITS_PER_LONG;
1049 : 0 : offset = pos - (index * BITS_PER_LONG);
1050 : 0 : nlongs_reg = BITS_TO_LONGS(nbits_reg);
1051 : 0 : nbitsinlong = min(nbits_reg, BITS_PER_LONG);
1052 : :
1053 : : /*
1054 : : * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1055 : : * overflows if nbitsinlong == BITS_PER_LONG.
1056 : : */
1057 : 0 : mask = (1UL << (nbitsinlong - 1));
1058 : 0 : mask += mask - 1;
1059 : 0 : mask <<= offset;
1060 : :
1061 : 0 : switch (reg_op) {
1062 : : case REG_OP_ISFREE:
1063 : 0 : for (i = 0; i < nlongs_reg; i++) {
1064 : 0 : 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 : 0 : for (i = 0; i < nlongs_reg; i++)
1072 : 0 : bitmap[index + i] |= mask;
1073 : : break;
1074 : :
1075 : : case REG_OP_RELEASE:
1076 : 0 : for (i = 0; i < nlongs_reg; i++)
1077 : 0 : bitmap[index + i] &= ~mask;
1078 : : break;
1079 : : }
1080 : : done:
1081 : 0 : 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 : : */
1098 : 0 : int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
1099 : : {
1100 : : unsigned int pos, end; /* scans bitmap by regions of size order */
1101 : :
1102 : 0 : for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
1103 : 0 : if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1104 : 0 : continue;
1105 : 0 : __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1106 : 0 : return pos;
1107 : : }
1108 : : return -ENOMEM;
1109 : : }
1110 : : EXPORT_SYMBOL(bitmap_find_free_region);
1111 : :
1112 : : /**
1113 : : * bitmap_release_region - release allocated bitmap region
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
1117 : : *
1118 : : * This is the complement to __bitmap_find_free_region() and releases
1119 : : * the found region (by clearing it in the bitmap).
1120 : : *
1121 : : * No return value.
1122 : : */
1123 : 0 : void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
1124 : : {
1125 : 0 : __reg_op(bitmap, pos, order, REG_OP_RELEASE);
1126 : 0 : }
1127 : : EXPORT_SYMBOL(bitmap_release_region);
1128 : :
1129 : : /**
1130 : : * bitmap_allocate_region - allocate bitmap region
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
1134 : : *
1135 : : * Allocate (set bits in) a specified region of a bitmap.
1136 : : *
1137 : : * Return 0 on success, or %-EBUSY if specified region wasn't
1138 : : * free (not all bits were zero).
1139 : : */
1140 : 0 : int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
1141 : : {
1142 : 0 : if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1143 : : return -EBUSY;
1144 : 0 : return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1145 : : }
1146 : : EXPORT_SYMBOL(bitmap_allocate_region);
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 : : */
1156 : : #ifdef __BIG_ENDIAN
1157 : : void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
1158 : : {
1159 : : unsigned int i;
1160 : :
1161 : : for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1162 : : if (BITS_PER_LONG == 64)
1163 : : dst[i] = cpu_to_le64(src[i]);
1164 : : else
1165 : : dst[i] = cpu_to_le32(src[i]);
1166 : : }
1167 : : }
1168 : : EXPORT_SYMBOL(bitmap_copy_le);
1169 : : #endif
1170 : :
1171 : 3 : unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
1172 : : {
1173 : 3 : return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
1174 : : flags);
1175 : : }
1176 : : EXPORT_SYMBOL(bitmap_alloc);
1177 : :
1178 : 3 : unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
1179 : : {
1180 : 3 : return bitmap_alloc(nbits, flags | __GFP_ZERO);
1181 : : }
1182 : : EXPORT_SYMBOL(bitmap_zalloc);
1183 : :
1184 : 3 : void bitmap_free(const unsigned long *bitmap)
1185 : : {
1186 : 3 : kfree(bitmap);
1187 : 3 : }
1188 : : EXPORT_SYMBOL(bitmap_free);
1189 : :
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 : : */
1197 : : void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
1198 : : {
1199 : : unsigned int i, halfwords;
1200 : :
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 : :
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
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