Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * lib/bitmap.c | |
3 | * Helper functions for bitmap.h. | |
4 | * | |
5 | * This source code is licensed under the GNU General Public License, | |
6 | * Version 2. See the file COPYING for more details. | |
7 | */ | |
8 | #include <linux/module.h> | |
9 | #include <linux/ctype.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/bitmap.h> | |
12 | #include <linux/bitops.h> | |
13 | #include <asm/uaccess.h> | |
14 | ||
15 | /* | |
16 | * bitmaps provide an array of bits, implemented using an an | |
17 | * array of unsigned longs. The number of valid bits in a | |
18 | * given bitmap does _not_ need to be an exact multiple of | |
19 | * BITS_PER_LONG. | |
20 | * | |
21 | * The possible unused bits in the last, partially used word | |
22 | * of a bitmap are 'don't care'. The implementation makes | |
23 | * no particular effort to keep them zero. It ensures that | |
24 | * their value will not affect the results of any operation. | |
25 | * The bitmap operations that return Boolean (bitmap_empty, | |
26 | * for example) or scalar (bitmap_weight, for example) results | |
27 | * carefully filter out these unused bits from impacting their | |
28 | * results. | |
29 | * | |
30 | * These operations actually hold to a slightly stronger rule: | |
31 | * if you don't input any bitmaps to these ops that have some | |
32 | * unused bits set, then they won't output any set unused bits | |
33 | * in output bitmaps. | |
34 | * | |
35 | * The byte ordering of bitmaps is more natural on little | |
36 | * endian architectures. See the big-endian headers | |
37 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
38 | * for the best explanations of this ordering. | |
39 | */ | |
40 | ||
41 | int __bitmap_empty(const unsigned long *bitmap, int bits) | |
42 | { | |
43 | int k, lim = bits/BITS_PER_LONG; | |
44 | for (k = 0; k < lim; ++k) | |
45 | if (bitmap[k]) | |
46 | return 0; | |
47 | ||
48 | if (bits % BITS_PER_LONG) | |
49 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
50 | return 0; | |
51 | ||
52 | return 1; | |
53 | } | |
54 | EXPORT_SYMBOL(__bitmap_empty); | |
55 | ||
56 | int __bitmap_full(const unsigned long *bitmap, int bits) | |
57 | { | |
58 | int k, lim = bits/BITS_PER_LONG; | |
59 | for (k = 0; k < lim; ++k) | |
60 | if (~bitmap[k]) | |
61 | return 0; | |
62 | ||
63 | if (bits % BITS_PER_LONG) | |
64 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
65 | return 0; | |
66 | ||
67 | return 1; | |
68 | } | |
69 | EXPORT_SYMBOL(__bitmap_full); | |
70 | ||
71 | int __bitmap_equal(const unsigned long *bitmap1, | |
72 | const unsigned long *bitmap2, int bits) | |
73 | { | |
74 | int k, lim = bits/BITS_PER_LONG; | |
75 | for (k = 0; k < lim; ++k) | |
76 | if (bitmap1[k] != bitmap2[k]) | |
77 | return 0; | |
78 | ||
79 | if (bits % BITS_PER_LONG) | |
80 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
81 | return 0; | |
82 | ||
83 | return 1; | |
84 | } | |
85 | EXPORT_SYMBOL(__bitmap_equal); | |
86 | ||
87 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits) | |
88 | { | |
89 | int k, lim = bits/BITS_PER_LONG; | |
90 | for (k = 0; k < lim; ++k) | |
91 | dst[k] = ~src[k]; | |
92 | ||
93 | if (bits % BITS_PER_LONG) | |
94 | dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits); | |
95 | } | |
96 | EXPORT_SYMBOL(__bitmap_complement); | |
97 | ||
72fd4a35 | 98 | /** |
1da177e4 | 99 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
100 | * @dst : destination bitmap |
101 | * @src : source bitmap | |
102 | * @shift : shift by this many bits | |
103 | * @bits : bitmap size, in bits | |
1da177e4 LT |
104 | * |
105 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
106 | * direction. Zeros are fed into the vacated MS positions and the | |
107 | * LS bits shifted off the bottom are lost. | |
108 | */ | |
109 | void __bitmap_shift_right(unsigned long *dst, | |
110 | const unsigned long *src, int shift, int bits) | |
111 | { | |
112 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; | |
113 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
114 | unsigned long mask = (1UL << left) - 1; | |
115 | for (k = 0; off + k < lim; ++k) { | |
116 | unsigned long upper, lower; | |
117 | ||
118 | /* | |
119 | * If shift is not word aligned, take lower rem bits of | |
120 | * word above and make them the top rem bits of result. | |
121 | */ | |
122 | if (!rem || off + k + 1 >= lim) | |
123 | upper = 0; | |
124 | else { | |
125 | upper = src[off + k + 1]; | |
126 | if (off + k + 1 == lim - 1 && left) | |
127 | upper &= mask; | |
128 | } | |
129 | lower = src[off + k]; | |
130 | if (left && off + k == lim - 1) | |
131 | lower &= mask; | |
132 | dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem; | |
133 | if (left && k == lim - 1) | |
134 | dst[k] &= mask; | |
135 | } | |
136 | if (off) | |
137 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
138 | } | |
139 | EXPORT_SYMBOL(__bitmap_shift_right); | |
140 | ||
141 | ||
72fd4a35 | 142 | /** |
1da177e4 | 143 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
144 | * @dst : destination bitmap |
145 | * @src : source bitmap | |
146 | * @shift : shift by this many bits | |
147 | * @bits : bitmap size, in bits | |
1da177e4 LT |
148 | * |
149 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
150 | * direction. Zeros are fed into the vacated LS bit positions | |
151 | * and those MS bits shifted off the top are lost. | |
152 | */ | |
153 | ||
154 | void __bitmap_shift_left(unsigned long *dst, | |
155 | const unsigned long *src, int shift, int bits) | |
156 | { | |
157 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; | |
158 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
159 | for (k = lim - off - 1; k >= 0; --k) { | |
160 | unsigned long upper, lower; | |
161 | ||
162 | /* | |
163 | * If shift is not word aligned, take upper rem bits of | |
164 | * word below and make them the bottom rem bits of result. | |
165 | */ | |
166 | if (rem && k > 0) | |
167 | lower = src[k - 1]; | |
168 | else | |
169 | lower = 0; | |
170 | upper = src[k]; | |
171 | if (left && k == lim - 1) | |
172 | upper &= (1UL << left) - 1; | |
173 | dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; | |
174 | if (left && k + off == lim - 1) | |
175 | dst[k + off] &= (1UL << left) - 1; | |
176 | } | |
177 | if (off) | |
178 | memset(dst, 0, off*sizeof(unsigned long)); | |
179 | } | |
180 | EXPORT_SYMBOL(__bitmap_shift_left); | |
181 | ||
182 | void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, | |
183 | const unsigned long *bitmap2, int bits) | |
184 | { | |
185 | int k; | |
186 | int nr = BITS_TO_LONGS(bits); | |
187 | ||
188 | for (k = 0; k < nr; k++) | |
189 | dst[k] = bitmap1[k] & bitmap2[k]; | |
190 | } | |
191 | EXPORT_SYMBOL(__bitmap_and); | |
192 | ||
193 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
194 | const unsigned long *bitmap2, int bits) | |
195 | { | |
196 | int k; | |
197 | int nr = BITS_TO_LONGS(bits); | |
198 | ||
199 | for (k = 0; k < nr; k++) | |
200 | dst[k] = bitmap1[k] | bitmap2[k]; | |
201 | } | |
202 | EXPORT_SYMBOL(__bitmap_or); | |
203 | ||
204 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
205 | const unsigned long *bitmap2, int bits) | |
206 | { | |
207 | int k; | |
208 | int nr = BITS_TO_LONGS(bits); | |
209 | ||
210 | for (k = 0; k < nr; k++) | |
211 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
212 | } | |
213 | EXPORT_SYMBOL(__bitmap_xor); | |
214 | ||
215 | void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, | |
216 | const unsigned long *bitmap2, int bits) | |
217 | { | |
218 | int k; | |
219 | int nr = BITS_TO_LONGS(bits); | |
220 | ||
221 | for (k = 0; k < nr; k++) | |
222 | dst[k] = bitmap1[k] & ~bitmap2[k]; | |
223 | } | |
224 | EXPORT_SYMBOL(__bitmap_andnot); | |
225 | ||
226 | int __bitmap_intersects(const unsigned long *bitmap1, | |
227 | const unsigned long *bitmap2, int bits) | |
228 | { | |
229 | int k, lim = bits/BITS_PER_LONG; | |
230 | for (k = 0; k < lim; ++k) | |
231 | if (bitmap1[k] & bitmap2[k]) | |
232 | return 1; | |
233 | ||
234 | if (bits % BITS_PER_LONG) | |
235 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
236 | return 1; | |
237 | return 0; | |
238 | } | |
239 | EXPORT_SYMBOL(__bitmap_intersects); | |
240 | ||
241 | int __bitmap_subset(const unsigned long *bitmap1, | |
242 | const unsigned long *bitmap2, int bits) | |
243 | { | |
244 | int k, lim = bits/BITS_PER_LONG; | |
245 | for (k = 0; k < lim; ++k) | |
246 | if (bitmap1[k] & ~bitmap2[k]) | |
247 | return 0; | |
248 | ||
249 | if (bits % BITS_PER_LONG) | |
250 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
251 | return 0; | |
252 | return 1; | |
253 | } | |
254 | EXPORT_SYMBOL(__bitmap_subset); | |
255 | ||
1da177e4 LT |
256 | int __bitmap_weight(const unsigned long *bitmap, int bits) |
257 | { | |
258 | int k, w = 0, lim = bits/BITS_PER_LONG; | |
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 | ||
270 | /* | |
271 | * Bitmap printing & parsing functions: first version by Bill Irwin, | |
272 | * second version by Paul Jackson, third by Joe Korty. | |
273 | */ | |
274 | ||
275 | #define CHUNKSZ 32 | |
276 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
277 | #define unhex(c) (isdigit(c) ? (c - '0') : (toupper(c) - 'A' + 10)) |
278 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ | |
279 | ||
280 | /** | |
281 | * bitmap_scnprintf - convert bitmap to an ASCII hex string. | |
282 | * @buf: byte buffer into which string is placed | |
283 | * @buflen: reserved size of @buf, in bytes | |
284 | * @maskp: pointer to bitmap to convert | |
285 | * @nmaskbits: size of bitmap, in bits | |
286 | * | |
287 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into | |
288 | * comma-separated sets of eight digits per set. | |
289 | */ | |
290 | int bitmap_scnprintf(char *buf, unsigned int buflen, | |
291 | const unsigned long *maskp, int nmaskbits) | |
292 | { | |
293 | int i, word, bit, len = 0; | |
294 | unsigned long val; | |
295 | const char *sep = ""; | |
296 | int chunksz; | |
297 | u32 chunkmask; | |
298 | ||
299 | chunksz = nmaskbits & (CHUNKSZ - 1); | |
300 | if (chunksz == 0) | |
301 | chunksz = CHUNKSZ; | |
302 | ||
8c0e33c1 | 303 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ; |
1da177e4 LT |
304 | for (; i >= 0; i -= CHUNKSZ) { |
305 | chunkmask = ((1ULL << chunksz) - 1); | |
306 | word = i / BITS_PER_LONG; | |
307 | bit = i % BITS_PER_LONG; | |
308 | val = (maskp[word] >> bit) & chunkmask; | |
309 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep, | |
310 | (chunksz+3)/4, val); | |
311 | chunksz = CHUNKSZ; | |
312 | sep = ","; | |
313 | } | |
314 | return len; | |
315 | } | |
316 | EXPORT_SYMBOL(bitmap_scnprintf); | |
317 | ||
30ca60c1 MT |
318 | /** |
319 | * bitmap_scnprintf_len - return buffer length needed to convert | |
320 | * bitmap to an ASCII hex string. | |
321 | * @len: number of bits to be converted | |
322 | */ | |
323 | int bitmap_scnprintf_len(unsigned int len) | |
324 | { | |
325 | /* we need 9 chars per word for 32 bit words (8 hexdigits + sep/null) */ | |
326 | int bitslen = ALIGN(len, CHUNKSZ); | |
327 | int wordlen = CHUNKSZ / 4; | |
328 | int buflen = (bitslen / wordlen) * (wordlen + 1) * sizeof(char); | |
329 | ||
330 | return buflen; | |
331 | } | |
332 | EXPORT_SYMBOL(bitmap_scnprintf_len); | |
333 | ||
1da177e4 | 334 | /** |
01a3ee2b RC |
335 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
336 | * @buf: pointer to buffer containing string. | |
337 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 338 | * then it must be terminated with a \0. |
01a3ee2b | 339 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
340 | * @maskp: pointer to bitmap array that will contain result. |
341 | * @nmaskbits: size of bitmap, in bits. | |
342 | * | |
343 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
344 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
345 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
346 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
347 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
348 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
349 | */ | |
01a3ee2b RC |
350 | int __bitmap_parse(const char *buf, unsigned int buflen, |
351 | int is_user, unsigned long *maskp, | |
352 | int nmaskbits) | |
1da177e4 LT |
353 | { |
354 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
355 | u32 chunk; | |
01a3ee2b | 356 | const char __user *ubuf = buf; |
1da177e4 LT |
357 | |
358 | bitmap_zero(maskp, nmaskbits); | |
359 | ||
360 | nchunks = nbits = totaldigits = c = 0; | |
361 | do { | |
362 | chunk = ndigits = 0; | |
363 | ||
364 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 365 | while (buflen) { |
1da177e4 | 366 | old_c = c; |
01a3ee2b RC |
367 | if (is_user) { |
368 | if (__get_user(c, ubuf++)) | |
369 | return -EFAULT; | |
370 | } | |
371 | else | |
372 | c = *buf++; | |
373 | buflen--; | |
1da177e4 LT |
374 | if (isspace(c)) |
375 | continue; | |
376 | ||
377 | /* | |
378 | * If the last character was a space and the current | |
379 | * character isn't '\0', we've got embedded whitespace. | |
380 | * This is a no-no, so throw an error. | |
381 | */ | |
382 | if (totaldigits && c && isspace(old_c)) | |
383 | return -EINVAL; | |
384 | ||
385 | /* A '\0' or a ',' signal the end of the chunk */ | |
386 | if (c == '\0' || c == ',') | |
387 | break; | |
388 | ||
389 | if (!isxdigit(c)) | |
390 | return -EINVAL; | |
391 | ||
392 | /* | |
393 | * Make sure there are at least 4 free bits in 'chunk'. | |
394 | * If not, this hexdigit will overflow 'chunk', so | |
395 | * throw an error. | |
396 | */ | |
397 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
398 | return -EOVERFLOW; | |
399 | ||
400 | chunk = (chunk << 4) | unhex(c); | |
401 | ndigits++; totaldigits++; | |
402 | } | |
403 | if (ndigits == 0) | |
404 | return -EINVAL; | |
405 | if (nchunks == 0 && chunk == 0) | |
406 | continue; | |
407 | ||
408 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
409 | *maskp |= chunk; | |
410 | nchunks++; | |
411 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
412 | if (nbits > nmaskbits) | |
413 | return -EOVERFLOW; | |
01a3ee2b | 414 | } while (buflen && c == ','); |
1da177e4 LT |
415 | |
416 | return 0; | |
417 | } | |
01a3ee2b RC |
418 | EXPORT_SYMBOL(__bitmap_parse); |
419 | ||
420 | /** | |
421 | * bitmap_parse_user() | |
422 | * | |
423 | * @ubuf: pointer to user buffer containing string. | |
424 | * @ulen: buffer size in bytes. If string is smaller than this | |
425 | * then it must be terminated with a \0. | |
426 | * @maskp: pointer to bitmap array that will contain result. | |
427 | * @nmaskbits: size of bitmap, in bits. | |
428 | * | |
429 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
430 | * | |
431 | * We cannot have this as an inline function in bitmap.h because it needs | |
432 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
433 | * cyclic dependencies. | |
434 | */ | |
435 | int bitmap_parse_user(const char __user *ubuf, | |
436 | unsigned int ulen, unsigned long *maskp, | |
437 | int nmaskbits) | |
438 | { | |
439 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
440 | return -EFAULT; | |
441 | return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits); | |
442 | } | |
443 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 LT |
444 | |
445 | /* | |
446 | * bscnl_emit(buf, buflen, rbot, rtop, bp) | |
447 | * | |
448 | * Helper routine for bitmap_scnlistprintf(). Write decimal number | |
449 | * or range to buf, suppressing output past buf+buflen, with optional | |
450 | * comma-prefix. Return len of what would be written to buf, if it | |
451 | * all fit. | |
452 | */ | |
453 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) | |
454 | { | |
455 | if (len > 0) | |
456 | len += scnprintf(buf + len, buflen - len, ","); | |
457 | if (rbot == rtop) | |
458 | len += scnprintf(buf + len, buflen - len, "%d", rbot); | |
459 | else | |
460 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop); | |
461 | return len; | |
462 | } | |
463 | ||
464 | /** | |
465 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string | |
466 | * @buf: byte buffer into which string is placed | |
467 | * @buflen: reserved size of @buf, in bytes | |
468 | * @maskp: pointer to bitmap to convert | |
469 | * @nmaskbits: size of bitmap, in bits | |
470 | * | |
471 | * Output format is a comma-separated list of decimal numbers and | |
472 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
473 | * decimal numbers, the smallest and largest bit numbers set in | |
474 | * the range. Output format is compatible with the format | |
475 | * accepted as input by bitmap_parselist(). | |
476 | * | |
477 | * The return value is the number of characters which would be | |
478 | * generated for the given input, excluding the trailing '\0', as | |
479 | * per ISO C99. | |
480 | */ | |
481 | int bitmap_scnlistprintf(char *buf, unsigned int buflen, | |
482 | const unsigned long *maskp, int nmaskbits) | |
483 | { | |
484 | int len = 0; | |
485 | /* current bit is 'cur', most recently seen range is [rbot, rtop] */ | |
486 | int cur, rbot, rtop; | |
487 | ||
0b030c2c AK |
488 | if (buflen == 0) |
489 | return 0; | |
490 | buf[0] = 0; | |
491 | ||
1da177e4 LT |
492 | rbot = cur = find_first_bit(maskp, nmaskbits); |
493 | while (cur < nmaskbits) { | |
494 | rtop = cur; | |
495 | cur = find_next_bit(maskp, nmaskbits, cur+1); | |
496 | if (cur >= nmaskbits || cur > rtop + 1) { | |
497 | len = bscnl_emit(buf, buflen, rbot, rtop, len); | |
498 | rbot = cur; | |
499 | } | |
500 | } | |
501 | return len; | |
502 | } | |
503 | EXPORT_SYMBOL(bitmap_scnlistprintf); | |
504 | ||
505 | /** | |
506 | * bitmap_parselist - convert list format ASCII string to bitmap | |
6e1907ff RD |
507 | * @bp: read nul-terminated user string from this buffer |
508 | * @maskp: write resulting mask here | |
1da177e4 LT |
509 | * @nmaskbits: number of bits in mask to be written |
510 | * | |
511 | * Input format is a comma-separated list of decimal numbers and | |
512 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
513 | * decimal numbers, the smallest and largest bit numbers set in | |
514 | * the range. | |
515 | * | |
6e1907ff RD |
516 | * Returns 0 on success, -errno on invalid input strings. |
517 | * Error values: | |
518 | * %-EINVAL: second number in range smaller than first | |
519 | * %-EINVAL: invalid character in string | |
520 | * %-ERANGE: bit number specified too large for mask | |
1da177e4 LT |
521 | */ |
522 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) | |
523 | { | |
524 | unsigned a, b; | |
525 | ||
526 | bitmap_zero(maskp, nmaskbits); | |
527 | do { | |
528 | if (!isdigit(*bp)) | |
529 | return -EINVAL; | |
530 | b = a = simple_strtoul(bp, (char **)&bp, BASEDEC); | |
531 | if (*bp == '-') { | |
532 | bp++; | |
533 | if (!isdigit(*bp)) | |
534 | return -EINVAL; | |
535 | b = simple_strtoul(bp, (char **)&bp, BASEDEC); | |
536 | } | |
537 | if (!(a <= b)) | |
538 | return -EINVAL; | |
539 | if (b >= nmaskbits) | |
540 | return -ERANGE; | |
541 | while (a <= b) { | |
542 | set_bit(a, maskp); | |
543 | a++; | |
544 | } | |
545 | if (*bp == ',') | |
546 | bp++; | |
547 | } while (*bp != '\0' && *bp != '\n'); | |
548 | return 0; | |
549 | } | |
550 | EXPORT_SYMBOL(bitmap_parselist); | |
551 | ||
72fd4a35 | 552 | /** |
fb5eeeee PJ |
553 | * bitmap_pos_to_ord(buf, pos, bits) |
554 | * @buf: pointer to a bitmap | |
555 | * @pos: a bit position in @buf (0 <= @pos < @bits) | |
556 | * @bits: number of valid bit positions in @buf | |
557 | * | |
558 | * Map the bit at position @pos in @buf (of length @bits) to the | |
559 | * ordinal of which set bit it is. If it is not set or if @pos | |
96b7f341 | 560 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
561 | * |
562 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
563 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
564 | * and other @pos values will get mapped to 0. When @pos value 7 | |
565 | * gets mapped to (returns) @ord value 3 in this example, that means | |
566 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
567 | * | |
568 | * The bit positions 0 through @bits are valid positions in @buf. | |
569 | */ | |
570 | static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) | |
571 | { | |
96b7f341 | 572 | int i, ord; |
fb5eeeee | 573 | |
96b7f341 PJ |
574 | if (pos < 0 || pos >= bits || !test_bit(pos, buf)) |
575 | return -1; | |
fb5eeeee | 576 | |
96b7f341 PJ |
577 | i = find_first_bit(buf, bits); |
578 | ord = 0; | |
579 | while (i < pos) { | |
580 | i = find_next_bit(buf, bits, i + 1); | |
581 | ord++; | |
fb5eeeee | 582 | } |
96b7f341 PJ |
583 | BUG_ON(i != pos); |
584 | ||
fb5eeeee PJ |
585 | return ord; |
586 | } | |
587 | ||
588 | /** | |
589 | * bitmap_ord_to_pos(buf, ord, bits) | |
590 | * @buf: pointer to bitmap | |
591 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
592 | * @bits: number of valid bit positions in @buf | |
593 | * | |
594 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
96b7f341 PJ |
595 | * Value of @ord should be in range 0 <= @ord < weight(buf), else |
596 | * results are undefined. | |
fb5eeeee PJ |
597 | * |
598 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
599 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
96b7f341 | 600 | * and all other @ord values return undefined values. When @ord value 3 |
fb5eeeee PJ |
601 | * gets mapped to (returns) @pos value 7 in this example, that means |
602 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
603 | * | |
604 | * The bit positions 0 through @bits are valid positions in @buf. | |
605 | */ | |
606 | static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) | |
607 | { | |
608 | int pos = 0; | |
609 | ||
610 | if (ord >= 0 && ord < bits) { | |
611 | int i; | |
612 | ||
613 | for (i = find_first_bit(buf, bits); | |
614 | i < bits && ord > 0; | |
615 | i = find_next_bit(buf, bits, i + 1)) | |
616 | ord--; | |
617 | if (i < bits && ord == 0) | |
618 | pos = i; | |
619 | } | |
620 | ||
621 | return pos; | |
622 | } | |
623 | ||
624 | /** | |
625 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 626 | * @dst: remapped result |
96b7f341 | 627 | * @src: subset to be remapped |
fb5eeeee PJ |
628 | * @old: defines domain of map |
629 | * @new: defines range of map | |
630 | * @bits: number of bits in each of these bitmaps | |
631 | * | |
632 | * Let @old and @new define a mapping of bit positions, such that | |
633 | * whatever position is held by the n-th set bit in @old is mapped | |
634 | * to the n-th set bit in @new. In the more general case, allowing | |
635 | * for the possibility that the weight 'w' of @new is less than the | |
636 | * weight of @old, map the position of the n-th set bit in @old to | |
637 | * the position of the m-th set bit in @new, where m == n % w. | |
638 | * | |
96b7f341 PJ |
639 | * If either of the @old and @new bitmaps are empty, or if @src and |
640 | * @dst point to the same location, then this routine copies @src | |
641 | * to @dst. | |
fb5eeeee | 642 | * |
96b7f341 PJ |
643 | * The positions of unset bits in @old are mapped to themselves |
644 | * (the identify map). | |
fb5eeeee PJ |
645 | * |
646 | * Apply the above specified mapping to @src, placing the result in | |
647 | * @dst, clearing any bits previously set in @dst. | |
648 | * | |
fb5eeeee PJ |
649 | * For example, lets say that @old has bits 4 through 7 set, and |
650 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
651 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
652 | * bit positions unchanged. So if say @src comes into this routine |
653 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
654 | * 13 and 15 set. | |
fb5eeeee PJ |
655 | */ |
656 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
657 | const unsigned long *old, const unsigned long *new, | |
658 | int bits) | |
659 | { | |
96b7f341 | 660 | int oldbit, w; |
fb5eeeee | 661 | |
fb5eeeee PJ |
662 | if (dst == src) /* following doesn't handle inplace remaps */ |
663 | return; | |
fb5eeeee | 664 | bitmap_zero(dst, bits); |
96b7f341 PJ |
665 | |
666 | w = bitmap_weight(new, bits); | |
667 | for (oldbit = find_first_bit(src, bits); | |
668 | oldbit < bits; | |
669 | oldbit = find_next_bit(src, bits, oldbit + 1)) { | |
670 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
671 | if (n < 0 || w == 0) | |
672 | set_bit(oldbit, dst); /* identity map */ | |
673 | else | |
674 | set_bit(bitmap_ord_to_pos(new, n % w, bits), dst); | |
fb5eeeee PJ |
675 | } |
676 | } | |
677 | EXPORT_SYMBOL(bitmap_remap); | |
678 | ||
679 | /** | |
680 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
681 | * @oldbit: bit position to be mapped |
682 | * @old: defines domain of map | |
683 | * @new: defines range of map | |
684 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
685 | * |
686 | * Let @old and @new define a mapping of bit positions, such that | |
687 | * whatever position is held by the n-th set bit in @old is mapped | |
688 | * to the n-th set bit in @new. In the more general case, allowing | |
689 | * for the possibility that the weight 'w' of @new is less than the | |
690 | * weight of @old, map the position of the n-th set bit in @old to | |
691 | * the position of the m-th set bit in @new, where m == n % w. | |
692 | * | |
96b7f341 PJ |
693 | * The positions of unset bits in @old are mapped to themselves |
694 | * (the identify map). | |
fb5eeeee PJ |
695 | * |
696 | * Apply the above specified mapping to bit position @oldbit, returning | |
697 | * the new bit position. | |
698 | * | |
699 | * For example, lets say that @old has bits 4 through 7 set, and | |
700 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
701 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
702 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
703 | * returns 13. | |
fb5eeeee PJ |
704 | */ |
705 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
706 | const unsigned long *new, int bits) | |
707 | { | |
96b7f341 PJ |
708 | int w = bitmap_weight(new, bits); |
709 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
710 | if (n < 0 || w == 0) | |
711 | return oldbit; | |
712 | else | |
713 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee PJ |
714 | } |
715 | EXPORT_SYMBOL(bitmap_bitremap); | |
716 | ||
7ea931c9 PJ |
717 | /** |
718 | * bitmap_onto - translate one bitmap relative to another | |
719 | * @dst: resulting translated bitmap | |
720 | * @orig: original untranslated bitmap | |
721 | * @relmap: bitmap relative to which translated | |
722 | * @bits: number of bits in each of these bitmaps | |
723 | * | |
724 | * Set the n-th bit of @dst iff there exists some m such that the | |
725 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
726 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
727 | * (If you understood the previous sentence the first time your | |
728 | * read it, you're overqualified for your current job.) | |
729 | * | |
730 | * In other words, @orig is mapped onto (surjectively) @dst, | |
731 | * using the the map { <n, m> | the n-th bit of @relmap is the | |
732 | * m-th set bit of @relmap }. | |
733 | * | |
734 | * Any set bits in @orig above bit number W, where W is the | |
735 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
736 | * In particular, if for all bits m set in @orig, m >= W, then | |
737 | * @dst will end up empty. In situations where the possibility | |
738 | * of such an empty result is not desired, one way to avoid it is | |
739 | * to use the bitmap_fold() operator, below, to first fold the | |
740 | * @orig bitmap over itself so that all its set bits x are in the | |
741 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
742 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
743 | * | |
744 | * Example [1] for bitmap_onto(): | |
745 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
746 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
747 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
748 | * | |
749 | * When bit 0 is set in @orig, it means turn on the bit in | |
750 | * @dst corresponding to whatever is the first bit (if any) | |
751 | * that is turned on in @relmap. Since bit 0 was off in the | |
752 | * above example, we leave off that bit (bit 30) in @dst. | |
753 | * | |
754 | * When bit 1 is set in @orig (as in the above example), it | |
755 | * means turn on the bit in @dst corresponding to whatever | |
756 | * is the second bit that is turned on in @relmap. The second | |
757 | * bit in @relmap that was turned on in the above example was | |
758 | * bit 31, so we turned on bit 31 in @dst. | |
759 | * | |
760 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
761 | * because they were the 4th, 6th, 8th and 10th set bits | |
762 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
763 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
764 | * | |
765 | * When bit 11 is set in @orig, it means turn on the bit in | |
766 | * @dst corresponding to whatever is the twelth bit that is | |
767 | * turned on in @relmap. In the above example, there were | |
768 | * only ten bits turned on in @relmap (30..39), so that bit | |
769 | * 11 was set in @orig had no affect on @dst. | |
770 | * | |
771 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
772 | * Let's say @relmap has these ten bits set: | |
773 | * 40 41 42 43 45 48 53 61 74 95 | |
774 | * (for the curious, that's 40 plus the first ten terms of the | |
775 | * Fibonacci sequence.) | |
776 | * | |
777 | * Further lets say we use the following code, invoking | |
778 | * bitmap_fold() then bitmap_onto, as suggested above to | |
779 | * avoid the possitility of an empty @dst result: | |
780 | * | |
781 | * unsigned long *tmp; // a temporary bitmap's bits | |
782 | * | |
783 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
784 | * bitmap_onto(dst, tmp, relmap, bits); | |
785 | * | |
786 | * Then this table shows what various values of @dst would be, for | |
787 | * various @orig's. I list the zero-based positions of each set bit. | |
788 | * The tmp column shows the intermediate result, as computed by | |
789 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
790 | * (the weight of @relmap). | |
791 | * | |
792 | * @orig tmp @dst | |
793 | * 0 0 40 | |
794 | * 1 1 41 | |
795 | * 9 9 95 | |
796 | * 10 0 40 (*) | |
797 | * 1 3 5 7 1 3 5 7 41 43 48 61 | |
798 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
799 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
800 | * 0 10 20 30 0 40 | |
801 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
802 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
803 | * 78 102 211 1 2 8 41 42 74 (*) | |
804 | * | |
805 | * (*) For these marked lines, if we hadn't first done bitmap_fold() | |
806 | * into tmp, then the @dst result would have been empty. | |
807 | * | |
808 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
809 | * will be returned empty. | |
810 | * | |
811 | * If (as explained above) the only set bits in @orig are in positions | |
812 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
813 | * once again be returned empty. | |
814 | * | |
815 | * All bits in @dst not set by the above rule are cleared. | |
816 | */ | |
817 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
818 | const unsigned long *relmap, int bits) | |
819 | { | |
820 | int n, m; /* same meaning as in above comment */ | |
821 | ||
822 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
823 | return; | |
824 | bitmap_zero(dst, bits); | |
825 | ||
826 | /* | |
827 | * The following code is a more efficient, but less | |
828 | * obvious, equivalent to the loop: | |
829 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
830 | * n = bitmap_ord_to_pos(orig, m, bits); | |
831 | * if (test_bit(m, orig)) | |
832 | * set_bit(n, dst); | |
833 | * } | |
834 | */ | |
835 | ||
836 | m = 0; | |
837 | for (n = find_first_bit(relmap, bits); | |
838 | n < bits; | |
839 | n = find_next_bit(relmap, bits, n + 1)) { | |
840 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ | |
841 | if (test_bit(m, orig)) | |
842 | set_bit(n, dst); | |
843 | m++; | |
844 | } | |
845 | } | |
846 | EXPORT_SYMBOL(bitmap_onto); | |
847 | ||
848 | /** | |
849 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
850 | * @dst: resulting smaller bitmap | |
851 | * @orig: original larger bitmap | |
852 | * @sz: specified size | |
853 | * @bits: number of bits in each of these bitmaps | |
854 | * | |
855 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
856 | * Clear all other bits in @dst. See further the comment and | |
857 | * Example [2] for bitmap_onto() for why and how to use this. | |
858 | */ | |
859 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
860 | int sz, int bits) | |
861 | { | |
862 | int oldbit; | |
863 | ||
864 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
865 | return; | |
866 | bitmap_zero(dst, bits); | |
867 | ||
868 | for (oldbit = find_first_bit(orig, bits); | |
869 | oldbit < bits; | |
870 | oldbit = find_next_bit(orig, bits, oldbit + 1)) | |
871 | set_bit(oldbit % sz, dst); | |
872 | } | |
873 | EXPORT_SYMBOL(bitmap_fold); | |
874 | ||
3cf64b93 PJ |
875 | /* |
876 | * Common code for bitmap_*_region() routines. | |
877 | * bitmap: array of unsigned longs corresponding to the bitmap | |
878 | * pos: the beginning of the region | |
879 | * order: region size (log base 2 of number of bits) | |
880 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 881 | * |
3cf64b93 PJ |
882 | * Can set, verify and/or release a region of bits in a bitmap, |
883 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 884 | * |
3cf64b93 PJ |
885 | * A region of a bitmap is a sequence of bits in the bitmap, of |
886 | * some size '1 << order' (a power of two), aligned to that same | |
887 | * '1 << order' power of two. | |
888 | * | |
889 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
890 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 891 | */ |
3cf64b93 PJ |
892 | |
893 | enum { | |
894 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
895 | REG_OP_ALLOC, /* set all bits in region */ | |
896 | REG_OP_RELEASE, /* clear all bits in region */ | |
897 | }; | |
898 | ||
899 | static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) | |
1da177e4 | 900 | { |
3cf64b93 PJ |
901 | int nbits_reg; /* number of bits in region */ |
902 | int index; /* index first long of region in bitmap */ | |
903 | int offset; /* bit offset region in bitmap[index] */ | |
904 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 905 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 906 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 907 | int i; /* scans bitmap by longs */ |
3cf64b93 | 908 | int ret = 0; /* return value */ |
74373c6a | 909 | |
3cf64b93 PJ |
910 | /* |
911 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
912 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
913 | */ | |
914 | nbits_reg = 1 << order; | |
915 | index = pos / BITS_PER_LONG; | |
916 | offset = pos - (index * BITS_PER_LONG); | |
917 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
918 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 919 | |
3cf64b93 PJ |
920 | /* |
921 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
922 | * overflows if nbitsinlong == BITS_PER_LONG. | |
923 | */ | |
74373c6a | 924 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 925 | mask += mask - 1; |
3cf64b93 | 926 | mask <<= offset; |
1da177e4 | 927 | |
3cf64b93 PJ |
928 | switch (reg_op) { |
929 | case REG_OP_ISFREE: | |
930 | for (i = 0; i < nlongs_reg; i++) { | |
931 | if (bitmap[index + i] & mask) | |
932 | goto done; | |
933 | } | |
934 | ret = 1; /* all bits in region free (zero) */ | |
935 | break; | |
936 | ||
937 | case REG_OP_ALLOC: | |
938 | for (i = 0; i < nlongs_reg; i++) | |
939 | bitmap[index + i] |= mask; | |
940 | break; | |
941 | ||
942 | case REG_OP_RELEASE: | |
943 | for (i = 0; i < nlongs_reg; i++) | |
944 | bitmap[index + i] &= ~mask; | |
945 | break; | |
1da177e4 | 946 | } |
3cf64b93 PJ |
947 | done: |
948 | return ret; | |
949 | } | |
950 | ||
951 | /** | |
952 | * bitmap_find_free_region - find a contiguous aligned mem region | |
953 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
954 | * @bits: number of bits in the bitmap | |
955 | * @order: region size (log base 2 of number of bits) to find | |
956 | * | |
957 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
958 | * allocate them (set them to one). Only consider regions of length | |
959 | * a power (@order) of two, aligned to that power of two, which | |
960 | * makes the search algorithm much faster. | |
961 | * | |
962 | * Return the bit offset in bitmap of the allocated region, | |
963 | * or -errno on failure. | |
964 | */ | |
965 | int bitmap_find_free_region(unsigned long *bitmap, int bits, int order) | |
966 | { | |
967 | int pos; /* scans bitmap by regions of size order */ | |
968 | ||
969 | for (pos = 0; pos < bits; pos += (1 << order)) | |
970 | if (__reg_op(bitmap, pos, order, REG_OP_ISFREE)) | |
971 | break; | |
972 | if (pos == bits) | |
973 | return -ENOMEM; | |
974 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
975 | return pos; | |
1da177e4 LT |
976 | } |
977 | EXPORT_SYMBOL(bitmap_find_free_region); | |
978 | ||
979 | /** | |
87e24802 | 980 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
981 | * @bitmap: array of unsigned longs corresponding to the bitmap |
982 | * @pos: beginning of bit region to release | |
983 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 984 | * |
72fd4a35 | 985 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 986 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
987 | * |
988 | * No return value. | |
1da177e4 LT |
989 | */ |
990 | void bitmap_release_region(unsigned long *bitmap, int pos, int order) | |
991 | { | |
3cf64b93 | 992 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
993 | } |
994 | EXPORT_SYMBOL(bitmap_release_region); | |
995 | ||
87e24802 PJ |
996 | /** |
997 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
998 | * @bitmap: array of unsigned longs corresponding to the bitmap |
999 | * @pos: beginning of bit region to allocate | |
1000 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1001 | * |
1002 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1003 | * |
6e1907ff | 1004 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1005 | * free (not all bits were zero). |
1006 | */ | |
1da177e4 LT |
1007 | int bitmap_allocate_region(unsigned long *bitmap, int pos, int order) |
1008 | { | |
3cf64b93 PJ |
1009 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1010 | return -EBUSY; | |
1011 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1da177e4 LT |
1012 | return 0; |
1013 | } | |
1014 | EXPORT_SYMBOL(bitmap_allocate_region); |