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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/export.h> |
9 | #include <linux/thread_info.h> |
10 | #include <linux/ctype.h> |
11 | #include <linux/errno.h> |
12 | #include <linux/bitmap.h> |
13 | #include <linux/bitops.h> |
14 | #include <linux/bug.h> |
15 | #include <asm/uaccess.h> |
16 | |
17 | /* |
18 | * bitmaps provide an array of bits, implemented using an an |
19 | * array of unsigned longs. The number of valid bits in a |
20 | * given bitmap does _not_ need to be an exact multiple of |
21 | * BITS_PER_LONG. |
22 | * |
23 | * The possible unused bits in the last, partially used word |
24 | * of a bitmap are 'don't care'. The implementation makes |
25 | * no particular effort to keep them zero. It ensures that |
26 | * their value will not affect the results of any operation. |
27 | * The bitmap operations that return Boolean (bitmap_empty, |
28 | * for example) or scalar (bitmap_weight, for example) results |
29 | * carefully filter out these unused bits from impacting their |
30 | * results. |
31 | * |
32 | * These operations actually hold to a slightly stronger rule: |
33 | * if you don't input any bitmaps to these ops that have some |
34 | * unused bits set, then they won't output any set unused bits |
35 | * in output bitmaps. |
36 | * |
37 | * The byte ordering of bitmaps is more natural on little |
38 | * endian architectures. See the big-endian headers |
39 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h |
40 | * for the best explanations of this ordering. |
41 | */ |
42 | |
43 | int __bitmap_empty(const unsigned long *bitmap, int bits) |
44 | { |
45 | int k, lim = bits/BITS_PER_LONG; |
46 | for (k = 0; k < lim; ++k) |
47 | if (bitmap[k]) |
48 | return 0; |
49 | |
50 | if (bits % BITS_PER_LONG) |
51 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
52 | return 0; |
53 | |
54 | return 1; |
55 | } |
56 | EXPORT_SYMBOL(__bitmap_empty); |
57 | |
58 | int __bitmap_full(const unsigned long *bitmap, int bits) |
59 | { |
60 | int k, lim = bits/BITS_PER_LONG; |
61 | for (k = 0; k < lim; ++k) |
62 | if (~bitmap[k]) |
63 | return 0; |
64 | |
65 | if (bits % BITS_PER_LONG) |
66 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) |
67 | return 0; |
68 | |
69 | return 1; |
70 | } |
71 | EXPORT_SYMBOL(__bitmap_full); |
72 | |
73 | int __bitmap_equal(const unsigned long *bitmap1, |
74 | const unsigned long *bitmap2, int bits) |
75 | { |
76 | int k, lim = bits/BITS_PER_LONG; |
77 | for (k = 0; k < lim; ++k) |
78 | if (bitmap1[k] != bitmap2[k]) |
79 | return 0; |
80 | |
81 | if (bits % BITS_PER_LONG) |
82 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
83 | return 0; |
84 | |
85 | return 1; |
86 | } |
87 | EXPORT_SYMBOL(__bitmap_equal); |
88 | |
89 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits) |
90 | { |
91 | int k, lim = bits/BITS_PER_LONG; |
92 | for (k = 0; k < lim; ++k) |
93 | dst[k] = ~src[k]; |
94 | |
95 | if (bits % BITS_PER_LONG) |
96 | dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits); |
97 | } |
98 | EXPORT_SYMBOL(__bitmap_complement); |
99 | |
100 | /** |
101 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
102 | * @dst : destination bitmap |
103 | * @src : source bitmap |
104 | * @shift : shift by this many bits |
105 | * @bits : bitmap size, in bits |
106 | * |
107 | * Shifting right (dividing) means moving bits in the MS -> LS bit |
108 | * direction. Zeros are fed into the vacated MS positions and the |
109 | * LS bits shifted off the bottom are lost. |
110 | */ |
111 | void __bitmap_shift_right(unsigned long *dst, |
112 | const unsigned long *src, int shift, int bits) |
113 | { |
114 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
115 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
116 | unsigned long mask = (1UL << left) - 1; |
117 | for (k = 0; off + k < lim; ++k) { |
118 | unsigned long upper, lower; |
119 | |
120 | /* |
121 | * If shift is not word aligned, take lower rem bits of |
122 | * word above and make them the top rem bits of result. |
123 | */ |
124 | if (!rem || off + k + 1 >= lim) |
125 | upper = 0; |
126 | else { |
127 | upper = src[off + k + 1]; |
128 | if (off + k + 1 == lim - 1 && left) |
129 | upper &= mask; |
130 | } |
131 | lower = src[off + k]; |
132 | if (left && off + k == lim - 1) |
133 | lower &= mask; |
134 | dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem; |
135 | if (left && k == lim - 1) |
136 | dst[k] &= mask; |
137 | } |
138 | if (off) |
139 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); |
140 | } |
141 | EXPORT_SYMBOL(__bitmap_shift_right); |
142 | |
143 | |
144 | /** |
145 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
146 | * @dst : destination bitmap |
147 | * @src : source bitmap |
148 | * @shift : shift by this many bits |
149 | * @bits : bitmap size, in bits |
150 | * |
151 | * Shifting left (multiplying) means moving bits in the LS -> MS |
152 | * direction. Zeros are fed into the vacated LS bit positions |
153 | * and those MS bits shifted off the top are lost. |
154 | */ |
155 | |
156 | void __bitmap_shift_left(unsigned long *dst, |
157 | const unsigned long *src, int shift, int bits) |
158 | { |
159 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
160 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
161 | for (k = lim - off - 1; k >= 0; --k) { |
162 | unsigned long upper, lower; |
163 | |
164 | /* |
165 | * If shift is not word aligned, take upper rem bits of |
166 | * word below and make them the bottom rem bits of result. |
167 | */ |
168 | if (rem && k > 0) |
169 | lower = src[k - 1]; |
170 | else |
171 | lower = 0; |
172 | upper = src[k]; |
173 | if (left && k == lim - 1) |
174 | upper &= (1UL << left) - 1; |
175 | dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; |
176 | if (left && k + off == lim - 1) |
177 | dst[k + off] &= (1UL << left) - 1; |
178 | } |
179 | if (off) |
180 | memset(dst, 0, off*sizeof(unsigned long)); |
181 | } |
182 | EXPORT_SYMBOL(__bitmap_shift_left); |
183 | |
184 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
185 | const unsigned long *bitmap2, int bits) |
186 | { |
187 | int k; |
188 | int nr = BITS_TO_LONGS(bits); |
189 | unsigned long result = 0; |
190 | |
191 | for (k = 0; k < nr; k++) |
192 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
193 | return result != 0; |
194 | } |
195 | EXPORT_SYMBOL(__bitmap_and); |
196 | |
197 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
198 | const unsigned long *bitmap2, int bits) |
199 | { |
200 | int k; |
201 | int nr = BITS_TO_LONGS(bits); |
202 | |
203 | for (k = 0; k < nr; k++) |
204 | dst[k] = bitmap1[k] | bitmap2[k]; |
205 | } |
206 | EXPORT_SYMBOL(__bitmap_or); |
207 | |
208 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
209 | const unsigned long *bitmap2, int bits) |
210 | { |
211 | int k; |
212 | int nr = BITS_TO_LONGS(bits); |
213 | |
214 | for (k = 0; k < nr; k++) |
215 | dst[k] = bitmap1[k] ^ bitmap2[k]; |
216 | } |
217 | EXPORT_SYMBOL(__bitmap_xor); |
218 | |
219 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
220 | const unsigned long *bitmap2, int bits) |
221 | { |
222 | int k; |
223 | int nr = BITS_TO_LONGS(bits); |
224 | unsigned long result = 0; |
225 | |
226 | for (k = 0; k < nr; k++) |
227 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
228 | return result != 0; |
229 | } |
230 | EXPORT_SYMBOL(__bitmap_andnot); |
231 | |
232 | int __bitmap_intersects(const unsigned long *bitmap1, |
233 | const unsigned long *bitmap2, int bits) |
234 | { |
235 | int k, lim = bits/BITS_PER_LONG; |
236 | for (k = 0; k < lim; ++k) |
237 | if (bitmap1[k] & bitmap2[k]) |
238 | return 1; |
239 | |
240 | if (bits % BITS_PER_LONG) |
241 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
242 | return 1; |
243 | return 0; |
244 | } |
245 | EXPORT_SYMBOL(__bitmap_intersects); |
246 | |
247 | int __bitmap_subset(const unsigned long *bitmap1, |
248 | const unsigned long *bitmap2, int bits) |
249 | { |
250 | int k, lim = bits/BITS_PER_LONG; |
251 | for (k = 0; k < lim; ++k) |
252 | if (bitmap1[k] & ~bitmap2[k]) |
253 | return 0; |
254 | |
255 | if (bits % BITS_PER_LONG) |
256 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
257 | return 0; |
258 | return 1; |
259 | } |
260 | EXPORT_SYMBOL(__bitmap_subset); |
261 | |
262 | int __bitmap_weight(const unsigned long *bitmap, int bits) |
263 | { |
264 | int k, w = 0, lim = bits/BITS_PER_LONG; |
265 | |
266 | for (k = 0; k < lim; k++) |
267 | w += hweight_long(bitmap[k]); |
268 | |
269 | if (bits % BITS_PER_LONG) |
270 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
271 | |
272 | return w; |
273 | } |
274 | EXPORT_SYMBOL(__bitmap_weight); |
275 | |
276 | void bitmap_set(unsigned long *map, int start, int nr) |
277 | { |
278 | unsigned long *p = map + BIT_WORD(start); |
279 | const int size = start + nr; |
280 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
281 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); |
282 | |
283 | while (nr - bits_to_set >= 0) { |
284 | *p |= mask_to_set; |
285 | nr -= bits_to_set; |
286 | bits_to_set = BITS_PER_LONG; |
287 | mask_to_set = ~0UL; |
288 | p++; |
289 | } |
290 | if (nr) { |
291 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
292 | *p |= mask_to_set; |
293 | } |
294 | } |
295 | EXPORT_SYMBOL(bitmap_set); |
296 | |
297 | void bitmap_clear(unsigned long *map, int start, int nr) |
298 | { |
299 | unsigned long *p = map + BIT_WORD(start); |
300 | const int size = start + nr; |
301 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
302 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
303 | |
304 | while (nr - bits_to_clear >= 0) { |
305 | *p &= ~mask_to_clear; |
306 | nr -= bits_to_clear; |
307 | bits_to_clear = BITS_PER_LONG; |
308 | mask_to_clear = ~0UL; |
309 | p++; |
310 | } |
311 | if (nr) { |
312 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
313 | *p &= ~mask_to_clear; |
314 | } |
315 | } |
316 | EXPORT_SYMBOL(bitmap_clear); |
317 | |
318 | /* |
319 | * bitmap_find_next_zero_area - find a contiguous aligned zero area |
320 | * @map: The address to base the search on |
321 | * @size: The bitmap size in bits |
322 | * @start: The bitnumber to start searching at |
323 | * @nr: The number of zeroed bits we're looking for |
324 | * @align_mask: Alignment mask for zero area |
325 | * |
326 | * The @align_mask should be one less than a power of 2; the effect is that |
327 | * the bit offset of all zero areas this function finds is multiples of that |
328 | * power of 2. A @align_mask of 0 means no alignment is required. |
329 | */ |
330 | unsigned long bitmap_find_next_zero_area(unsigned long *map, |
331 | unsigned long size, |
332 | unsigned long start, |
333 | unsigned int nr, |
334 | unsigned long align_mask) |
335 | { |
336 | unsigned long index, end, i; |
337 | again: |
338 | index = find_next_zero_bit(map, size, start); |
339 | |
340 | /* Align allocation */ |
341 | index = __ALIGN_MASK(index, align_mask); |
342 | |
343 | end = index + nr; |
344 | if (end > size) |
345 | return end; |
346 | i = find_next_bit(map, end, index); |
347 | if (i < end) { |
348 | start = i + 1; |
349 | goto again; |
350 | } |
351 | return index; |
352 | } |
353 | EXPORT_SYMBOL(bitmap_find_next_zero_area); |
354 | |
355 | /* |
356 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
357 | * second version by Paul Jackson, third by Joe Korty. |
358 | */ |
359 | |
360 | #define CHUNKSZ 32 |
361 | #define nbits_to_hold_value(val) fls(val) |
362 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
363 | |
364 | /** |
365 | * bitmap_scnprintf - convert bitmap to an ASCII hex string. |
366 | * @buf: byte buffer into which string is placed |
367 | * @buflen: reserved size of @buf, in bytes |
368 | * @maskp: pointer to bitmap to convert |
369 | * @nmaskbits: size of bitmap, in bits |
370 | * |
371 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into |
372 | * comma-separated sets of eight digits per set. Returns the number of |
373 | * characters which were written to *buf, excluding the trailing \0. |
374 | */ |
375 | int bitmap_scnprintf(char *buf, unsigned int buflen, |
376 | const unsigned long *maskp, int nmaskbits) |
377 | { |
378 | int i, word, bit, len = 0; |
379 | unsigned long val; |
380 | const char *sep = ""; |
381 | int chunksz; |
382 | u32 chunkmask; |
383 | |
384 | chunksz = nmaskbits & (CHUNKSZ - 1); |
385 | if (chunksz == 0) |
386 | chunksz = CHUNKSZ; |
387 | |
388 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ; |
389 | for (; i >= 0; i -= CHUNKSZ) { |
390 | chunkmask = ((1ULL << chunksz) - 1); |
391 | word = i / BITS_PER_LONG; |
392 | bit = i % BITS_PER_LONG; |
393 | val = (maskp[word] >> bit) & chunkmask; |
394 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep, |
395 | (chunksz+3)/4, val); |
396 | chunksz = CHUNKSZ; |
397 | sep = ","; |
398 | } |
399 | return len; |
400 | } |
401 | EXPORT_SYMBOL(bitmap_scnprintf); |
402 | |
403 | /** |
404 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
405 | * @buf: pointer to buffer containing string. |
406 | * @buflen: buffer size in bytes. If string is smaller than this |
407 | * then it must be terminated with a \0. |
408 | * @is_user: location of buffer, 0 indicates kernel space |
409 | * @maskp: pointer to bitmap array that will contain result. |
410 | * @nmaskbits: size of bitmap, in bits. |
411 | * |
412 | * Commas group hex digits into chunks. Each chunk defines exactly 32 |
413 | * bits of the resultant bitmask. No chunk may specify a value larger |
414 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
415 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal |
416 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
417 | * Leading and trailing whitespace accepted, but not embedded whitespace. |
418 | */ |
419 | int __bitmap_parse(const char *buf, unsigned int buflen, |
420 | int is_user, unsigned long *maskp, |
421 | int nmaskbits) |
422 | { |
423 | int c, old_c, totaldigits, ndigits, nchunks, nbits; |
424 | u32 chunk; |
425 | const char __user __force *ubuf = (const char __user __force *)buf; |
426 | |
427 | bitmap_zero(maskp, nmaskbits); |
428 | |
429 | nchunks = nbits = totaldigits = c = 0; |
430 | do { |
431 | chunk = ndigits = 0; |
432 | |
433 | /* Get the next chunk of the bitmap */ |
434 | while (buflen) { |
435 | old_c = c; |
436 | if (is_user) { |
437 | if (__get_user(c, ubuf++)) |
438 | return -EFAULT; |
439 | } |
440 | else |
441 | c = *buf++; |
442 | buflen--; |
443 | if (isspace(c)) |
444 | continue; |
445 | |
446 | /* |
447 | * If the last character was a space and the current |
448 | * character isn't '\0', we've got embedded whitespace. |
449 | * This is a no-no, so throw an error. |
450 | */ |
451 | if (totaldigits && c && isspace(old_c)) |
452 | return -EINVAL; |
453 | |
454 | /* A '\0' or a ',' signal the end of the chunk */ |
455 | if (c == '\0' || c == ',') |
456 | break; |
457 | |
458 | if (!isxdigit(c)) |
459 | return -EINVAL; |
460 | |
461 | /* |
462 | * Make sure there are at least 4 free bits in 'chunk'. |
463 | * If not, this hexdigit will overflow 'chunk', so |
464 | * throw an error. |
465 | */ |
466 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) |
467 | return -EOVERFLOW; |
468 | |
469 | chunk = (chunk << 4) | hex_to_bin(c); |
470 | ndigits++; totaldigits++; |
471 | } |
472 | if (ndigits == 0) |
473 | return -EINVAL; |
474 | if (nchunks == 0 && chunk == 0) |
475 | continue; |
476 | |
477 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); |
478 | *maskp |= chunk; |
479 | nchunks++; |
480 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; |
481 | if (nbits > nmaskbits) |
482 | return -EOVERFLOW; |
483 | } while (buflen && c == ','); |
484 | |
485 | return 0; |
486 | } |
487 | EXPORT_SYMBOL(__bitmap_parse); |
488 | |
489 | /** |
490 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
491 | * |
492 | * @ubuf: pointer to user buffer containing string. |
493 | * @ulen: buffer size in bytes. If string is smaller than this |
494 | * then it must be terminated with a \0. |
495 | * @maskp: pointer to bitmap array that will contain result. |
496 | * @nmaskbits: size of bitmap, in bits. |
497 | * |
498 | * Wrapper for __bitmap_parse(), providing it with user buffer. |
499 | * |
500 | * We cannot have this as an inline function in bitmap.h because it needs |
501 | * linux/uaccess.h to get the access_ok() declaration and this causes |
502 | * cyclic dependencies. |
503 | */ |
504 | int bitmap_parse_user(const char __user *ubuf, |
505 | unsigned int ulen, unsigned long *maskp, |
506 | int nmaskbits) |
507 | { |
508 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
509 | return -EFAULT; |
510 | return __bitmap_parse((const char __force *)ubuf, |
511 | ulen, 1, maskp, nmaskbits); |
512 | |
513 | } |
514 | EXPORT_SYMBOL(bitmap_parse_user); |
515 | |
516 | /* |
517 | * bscnl_emit(buf, buflen, rbot, rtop, bp) |
518 | * |
519 | * Helper routine for bitmap_scnlistprintf(). Write decimal number |
520 | * or range to buf, suppressing output past buf+buflen, with optional |
521 | * comma-prefix. Return len of what was written to *buf, excluding the |
522 | * trailing \0. |
523 | */ |
524 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) |
525 | { |
526 | if (len > 0) |
527 | len += scnprintf(buf + len, buflen - len, ","); |
528 | if (rbot == rtop) |
529 | len += scnprintf(buf + len, buflen - len, "%d", rbot); |
530 | else |
531 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop); |
532 | return len; |
533 | } |
534 | |
535 | /** |
536 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string |
537 | * @buf: byte buffer into which string is placed |
538 | * @buflen: reserved size of @buf, in bytes |
539 | * @maskp: pointer to bitmap to convert |
540 | * @nmaskbits: size of bitmap, in bits |
541 | * |
542 | * Output format is a comma-separated list of decimal numbers and |
543 | * ranges. Consecutively set bits are shown as two hyphen-separated |
544 | * decimal numbers, the smallest and largest bit numbers set in |
545 | * the range. Output format is compatible with the format |
546 | * accepted as input by bitmap_parselist(). |
547 | * |
548 | * The return value is the number of characters which were written to *buf |
549 | * excluding the trailing '\0', as per ISO C99's scnprintf. |
550 | */ |
551 | int bitmap_scnlistprintf(char *buf, unsigned int buflen, |
552 | const unsigned long *maskp, int nmaskbits) |
553 | { |
554 | int len = 0; |
555 | /* current bit is 'cur', most recently seen range is [rbot, rtop] */ |
556 | int cur, rbot, rtop; |
557 | |
558 | if (buflen == 0) |
559 | return 0; |
560 | buf[0] = 0; |
561 | |
562 | rbot = cur = find_first_bit(maskp, nmaskbits); |
563 | while (cur < nmaskbits) { |
564 | rtop = cur; |
565 | cur = find_next_bit(maskp, nmaskbits, cur+1); |
566 | if (cur >= nmaskbits || cur > rtop + 1) { |
567 | len = bscnl_emit(buf, buflen, rbot, rtop, len); |
568 | rbot = cur; |
569 | } |
570 | } |
571 | return len; |
572 | } |
573 | EXPORT_SYMBOL(bitmap_scnlistprintf); |
574 | |
575 | /** |
576 | * __bitmap_parselist - convert list format ASCII string to bitmap |
577 | * @buf: read nul-terminated user string from this buffer |
578 | * @buflen: buffer size in bytes. If string is smaller than this |
579 | * then it must be terminated with a \0. |
580 | * @is_user: location of buffer, 0 indicates kernel space |
581 | * @maskp: write resulting mask here |
582 | * @nmaskbits: number of bits in mask to be written |
583 | * |
584 | * Input format is a comma-separated list of decimal numbers and |
585 | * ranges. Consecutively set bits are shown as two hyphen-separated |
586 | * decimal numbers, the smallest and largest bit numbers set in |
587 | * the range. |
588 | * |
589 | * Returns 0 on success, -errno on invalid input strings. |
590 | * Error values: |
591 | * %-EINVAL: second number in range smaller than first |
592 | * %-EINVAL: invalid character in string |
593 | * %-ERANGE: bit number specified too large for mask |
594 | */ |
595 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
596 | int is_user, unsigned long *maskp, |
597 | int nmaskbits) |
598 | { |
599 | unsigned a, b; |
600 | int c, old_c, totaldigits; |
601 | const char __user __force *ubuf = (const char __user __force *)buf; |
602 | int exp_digit, in_range; |
603 | |
604 | totaldigits = c = 0; |
605 | bitmap_zero(maskp, nmaskbits); |
606 | do { |
607 | exp_digit = 1; |
608 | in_range = 0; |
609 | a = b = 0; |
610 | |
611 | /* Get the next cpu# or a range of cpu#'s */ |
612 | while (buflen) { |
613 | old_c = c; |
614 | if (is_user) { |
615 | if (__get_user(c, ubuf++)) |
616 | return -EFAULT; |
617 | } else |
618 | c = *buf++; |
619 | buflen--; |
620 | if (isspace(c)) |
621 | continue; |
622 | |
623 | /* |
624 | * If the last character was a space and the current |
625 | * character isn't '\0', we've got embedded whitespace. |
626 | * This is a no-no, so throw an error. |
627 | */ |
628 | if (totaldigits && c && isspace(old_c)) |
629 | return -EINVAL; |
630 | |
631 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
632 | if (c == '\0' || c == ',') |
633 | break; |
634 | |
635 | if (c == '-') { |
636 | if (exp_digit || in_range) |
637 | return -EINVAL; |
638 | b = 0; |
639 | in_range = 1; |
640 | exp_digit = 1; |
641 | continue; |
642 | } |
643 | |
644 | if (!isdigit(c)) |
645 | return -EINVAL; |
646 | |
647 | b = b * 10 + (c - '0'); |
648 | if (!in_range) |
649 | a = b; |
650 | exp_digit = 0; |
651 | totaldigits++; |
652 | } |
653 | if (!(a <= b)) |
654 | return -EINVAL; |
655 | if (b >= nmaskbits) |
656 | return -ERANGE; |
657 | while (a <= b) { |
658 | set_bit(a, maskp); |
659 | a++; |
660 | } |
661 | } while (buflen && c == ','); |
662 | return 0; |
663 | } |
664 | |
665 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) |
666 | { |
667 | char *nl = strchr(bp, '\n'); |
668 | int len; |
669 | |
670 | if (nl) |
671 | len = nl - bp; |
672 | else |
673 | len = strlen(bp); |
674 | |
675 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); |
676 | } |
677 | EXPORT_SYMBOL(bitmap_parselist); |
678 | |
679 | |
680 | /** |
681 | * bitmap_parselist_user() |
682 | * |
683 | * @ubuf: pointer to user buffer containing string. |
684 | * @ulen: buffer size in bytes. If string is smaller than this |
685 | * then it must be terminated with a \0. |
686 | * @maskp: pointer to bitmap array that will contain result. |
687 | * @nmaskbits: size of bitmap, in bits. |
688 | * |
689 | * Wrapper for bitmap_parselist(), providing it with user buffer. |
690 | * |
691 | * We cannot have this as an inline function in bitmap.h because it needs |
692 | * linux/uaccess.h to get the access_ok() declaration and this causes |
693 | * cyclic dependencies. |
694 | */ |
695 | int bitmap_parselist_user(const char __user *ubuf, |
696 | unsigned int ulen, unsigned long *maskp, |
697 | int nmaskbits) |
698 | { |
699 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
700 | return -EFAULT; |
701 | return __bitmap_parselist((const char __force *)ubuf, |
702 | ulen, 1, maskp, nmaskbits); |
703 | } |
704 | EXPORT_SYMBOL(bitmap_parselist_user); |
705 | |
706 | |
707 | /** |
708 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
709 | * @buf: pointer to a bitmap |
710 | * @pos: a bit position in @buf (0 <= @pos < @bits) |
711 | * @bits: number of valid bit positions in @buf |
712 | * |
713 | * Map the bit at position @pos in @buf (of length @bits) to the |
714 | * ordinal of which set bit it is. If it is not set or if @pos |
715 | * is not a valid bit position, map to -1. |
716 | * |
717 | * If for example, just bits 4 through 7 are set in @buf, then @pos |
718 | * values 4 through 7 will get mapped to 0 through 3, respectively, |
719 | * and other @pos values will get mapped to 0. When @pos value 7 |
720 | * gets mapped to (returns) @ord value 3 in this example, that means |
721 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. |
722 | * |
723 | * The bit positions 0 through @bits are valid positions in @buf. |
724 | */ |
725 | static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) |
726 | { |
727 | int i, ord; |
728 | |
729 | if (pos < 0 || pos >= bits || !test_bit(pos, buf)) |
730 | return -1; |
731 | |
732 | i = find_first_bit(buf, bits); |
733 | ord = 0; |
734 | while (i < pos) { |
735 | i = find_next_bit(buf, bits, i + 1); |
736 | ord++; |
737 | } |
738 | BUG_ON(i != pos); |
739 | |
740 | return ord; |
741 | } |
742 | |
743 | /** |
744 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
745 | * @buf: pointer to bitmap |
746 | * @ord: ordinal bit position (n-th set bit, n >= 0) |
747 | * @bits: number of valid bit positions in @buf |
748 | * |
749 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. |
750 | * Value of @ord should be in range 0 <= @ord < weight(buf), else |
751 | * results are undefined. |
752 | * |
753 | * If for example, just bits 4 through 7 are set in @buf, then @ord |
754 | * values 0 through 3 will get mapped to 4 through 7, respectively, |
755 | * and all other @ord values return undefined values. When @ord value 3 |
756 | * gets mapped to (returns) @pos value 7 in this example, that means |
757 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. |
758 | * |
759 | * The bit positions 0 through @bits are valid positions in @buf. |
760 | */ |
761 | int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) |
762 | { |
763 | int pos = 0; |
764 | |
765 | if (ord >= 0 && ord < bits) { |
766 | int i; |
767 | |
768 | for (i = find_first_bit(buf, bits); |
769 | i < bits && ord > 0; |
770 | i = find_next_bit(buf, bits, i + 1)) |
771 | ord--; |
772 | if (i < bits && ord == 0) |
773 | pos = i; |
774 | } |
775 | |
776 | return pos; |
777 | } |
778 | |
779 | /** |
780 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap |
781 | * @dst: remapped result |
782 | * @src: subset to be remapped |
783 | * @old: defines domain of map |
784 | * @new: defines range of map |
785 | * @bits: number of bits in each of these bitmaps |
786 | * |
787 | * Let @old and @new define a mapping of bit positions, such that |
788 | * whatever position is held by the n-th set bit in @old is mapped |
789 | * to the n-th set bit in @new. In the more general case, allowing |
790 | * for the possibility that the weight 'w' of @new is less than the |
791 | * weight of @old, map the position of the n-th set bit in @old to |
792 | * the position of the m-th set bit in @new, where m == n % w. |
793 | * |
794 | * If either of the @old and @new bitmaps are empty, or if @src and |
795 | * @dst point to the same location, then this routine copies @src |
796 | * to @dst. |
797 | * |
798 | * The positions of unset bits in @old are mapped to themselves |
799 | * (the identify map). |
800 | * |
801 | * Apply the above specified mapping to @src, placing the result in |
802 | * @dst, clearing any bits previously set in @dst. |
803 | * |
804 | * For example, lets say that @old has bits 4 through 7 set, and |
805 | * @new has bits 12 through 15 set. This defines the mapping of bit |
806 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
807 | * bit positions unchanged. So if say @src comes into this routine |
808 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, |
809 | * 13 and 15 set. |
810 | */ |
811 | void bitmap_remap(unsigned long *dst, const unsigned long *src, |
812 | const unsigned long *old, const unsigned long *new, |
813 | int bits) |
814 | { |
815 | int oldbit, w; |
816 | |
817 | if (dst == src) /* following doesn't handle inplace remaps */ |
818 | return; |
819 | bitmap_zero(dst, bits); |
820 | |
821 | w = bitmap_weight(new, bits); |
822 | for_each_set_bit(oldbit, src, bits) { |
823 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
824 | |
825 | if (n < 0 || w == 0) |
826 | set_bit(oldbit, dst); /* identity map */ |
827 | else |
828 | set_bit(bitmap_ord_to_pos(new, n % w, bits), dst); |
829 | } |
830 | } |
831 | EXPORT_SYMBOL(bitmap_remap); |
832 | |
833 | /** |
834 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit |
835 | * @oldbit: bit position to be mapped |
836 | * @old: defines domain of map |
837 | * @new: defines range of map |
838 | * @bits: number of bits in each of these bitmaps |
839 | * |
840 | * Let @old and @new define a mapping of bit positions, such that |
841 | * whatever position is held by the n-th set bit in @old is mapped |
842 | * to the n-th set bit in @new. In the more general case, allowing |
843 | * for the possibility that the weight 'w' of @new is less than the |
844 | * weight of @old, map the position of the n-th set bit in @old to |
845 | * the position of the m-th set bit in @new, where m == n % w. |
846 | * |
847 | * The positions of unset bits in @old are mapped to themselves |
848 | * (the identify map). |
849 | * |
850 | * Apply the above specified mapping to bit position @oldbit, returning |
851 | * the new bit position. |
852 | * |
853 | * For example, lets say that @old has bits 4 through 7 set, and |
854 | * @new has bits 12 through 15 set. This defines the mapping of bit |
855 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
856 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
857 | * returns 13. |
858 | */ |
859 | int bitmap_bitremap(int oldbit, const unsigned long *old, |
860 | const unsigned long *new, int bits) |
861 | { |
862 | int w = bitmap_weight(new, bits); |
863 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
864 | if (n < 0 || w == 0) |
865 | return oldbit; |
866 | else |
867 | return bitmap_ord_to_pos(new, n % w, bits); |
868 | } |
869 | EXPORT_SYMBOL(bitmap_bitremap); |
870 | |
871 | /** |
872 | * bitmap_onto - translate one bitmap relative to another |
873 | * @dst: resulting translated bitmap |
874 | * @orig: original untranslated bitmap |
875 | * @relmap: bitmap relative to which translated |
876 | * @bits: number of bits in each of these bitmaps |
877 | * |
878 | * Set the n-th bit of @dst iff there exists some m such that the |
879 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and |
880 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. |
881 | * (If you understood the previous sentence the first time your |
882 | * read it, you're overqualified for your current job.) |
883 | * |
884 | * In other words, @orig is mapped onto (surjectively) @dst, |
885 | * using the the map { <n, m> | the n-th bit of @relmap is the |
886 | * m-th set bit of @relmap }. |
887 | * |
888 | * Any set bits in @orig above bit number W, where W is the |
889 | * weight of (number of set bits in) @relmap are mapped nowhere. |
890 | * In particular, if for all bits m set in @orig, m >= W, then |
891 | * @dst will end up empty. In situations where the possibility |
892 | * of such an empty result is not desired, one way to avoid it is |
893 | * to use the bitmap_fold() operator, below, to first fold the |
894 | * @orig bitmap over itself so that all its set bits x are in the |
895 | * range 0 <= x < W. The bitmap_fold() operator does this by |
896 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. |
897 | * |
898 | * Example [1] for bitmap_onto(): |
899 | * Let's say @relmap has bits 30-39 set, and @orig has bits |
900 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, |
901 | * @dst will have bits 31, 33, 35, 37 and 39 set. |
902 | * |
903 | * When bit 0 is set in @orig, it means turn on the bit in |
904 | * @dst corresponding to whatever is the first bit (if any) |
905 | * that is turned on in @relmap. Since bit 0 was off in the |
906 | * above example, we leave off that bit (bit 30) in @dst. |
907 | * |
908 | * When bit 1 is set in @orig (as in the above example), it |
909 | * means turn on the bit in @dst corresponding to whatever |
910 | * is the second bit that is turned on in @relmap. The second |
911 | * bit in @relmap that was turned on in the above example was |
912 | * bit 31, so we turned on bit 31 in @dst. |
913 | * |
914 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, |
915 | * because they were the 4th, 6th, 8th and 10th set bits |
916 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of |
917 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. |
918 | * |
919 | * When bit 11 is set in @orig, it means turn on the bit in |
920 | * @dst corresponding to whatever is the twelfth bit that is |
921 | * turned on in @relmap. In the above example, there were |
922 | * only ten bits turned on in @relmap (30..39), so that bit |
923 | * 11 was set in @orig had no affect on @dst. |
924 | * |
925 | * Example [2] for bitmap_fold() + bitmap_onto(): |
926 | * Let's say @relmap has these ten bits set: |
927 | * 40 41 42 43 45 48 53 61 74 95 |
928 | * (for the curious, that's 40 plus the first ten terms of the |
929 | * Fibonacci sequence.) |
930 | * |
931 | * Further lets say we use the following code, invoking |
932 | * bitmap_fold() then bitmap_onto, as suggested above to |
933 | * avoid the possitility of an empty @dst result: |
934 | * |
935 | * unsigned long *tmp; // a temporary bitmap's bits |
936 | * |
937 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); |
938 | * bitmap_onto(dst, tmp, relmap, bits); |
939 | * |
940 | * Then this table shows what various values of @dst would be, for |
941 | * various @orig's. I list the zero-based positions of each set bit. |
942 | * The tmp column shows the intermediate result, as computed by |
943 | * using bitmap_fold() to fold the @orig bitmap modulo ten |
944 | * (the weight of @relmap). |
945 | * |
946 | * @orig tmp @dst |
947 | * 0 0 40 |
948 | * 1 1 41 |
949 | * 9 9 95 |
950 | * 10 0 40 (*) |
951 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
952 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 |
953 | * 0 9 18 27 0 9 8 7 40 61 74 95 |
954 | * 0 10 20 30 0 40 |
955 | * 0 11 22 33 0 1 2 3 40 41 42 43 |
956 | * 0 12 24 36 0 2 4 6 40 42 45 53 |
957 | * 78 102 211 1 2 8 41 42 74 (*) |
958 | * |
959 | * (*) For these marked lines, if we hadn't first done bitmap_fold() |
960 | * into tmp, then the @dst result would have been empty. |
961 | * |
962 | * If either of @orig or @relmap is empty (no set bits), then @dst |
963 | * will be returned empty. |
964 | * |
965 | * If (as explained above) the only set bits in @orig are in positions |
966 | * m where m >= W, (where W is the weight of @relmap) then @dst will |
967 | * once again be returned empty. |
968 | * |
969 | * All bits in @dst not set by the above rule are cleared. |
970 | */ |
971 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, |
972 | const unsigned long *relmap, int bits) |
973 | { |
974 | int n, m; /* same meaning as in above comment */ |
975 | |
976 | if (dst == orig) /* following doesn't handle inplace mappings */ |
977 | return; |
978 | bitmap_zero(dst, bits); |
979 | |
980 | /* |
981 | * The following code is a more efficient, but less |
982 | * obvious, equivalent to the loop: |
983 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { |
984 | * n = bitmap_ord_to_pos(orig, m, bits); |
985 | * if (test_bit(m, orig)) |
986 | * set_bit(n, dst); |
987 | * } |
988 | */ |
989 | |
990 | m = 0; |
991 | for_each_set_bit(n, relmap, bits) { |
992 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
993 | if (test_bit(m, orig)) |
994 | set_bit(n, dst); |
995 | m++; |
996 | } |
997 | } |
998 | EXPORT_SYMBOL(bitmap_onto); |
999 | |
1000 | /** |
1001 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size |
1002 | * @dst: resulting smaller bitmap |
1003 | * @orig: original larger bitmap |
1004 | * @sz: specified size |
1005 | * @bits: number of bits in each of these bitmaps |
1006 | * |
1007 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. |
1008 | * Clear all other bits in @dst. See further the comment and |
1009 | * Example [2] for bitmap_onto() for why and how to use this. |
1010 | */ |
1011 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, |
1012 | int sz, int bits) |
1013 | { |
1014 | int oldbit; |
1015 | |
1016 | if (dst == orig) /* following doesn't handle inplace mappings */ |
1017 | return; |
1018 | bitmap_zero(dst, bits); |
1019 | |
1020 | for_each_set_bit(oldbit, orig, bits) |
1021 | set_bit(oldbit % sz, dst); |
1022 | } |
1023 | EXPORT_SYMBOL(bitmap_fold); |
1024 | |
1025 | /* |
1026 | * Common code for bitmap_*_region() routines. |
1027 | * bitmap: array of unsigned longs corresponding to the bitmap |
1028 | * pos: the beginning of the region |
1029 | * order: region size (log base 2 of number of bits) |
1030 | * reg_op: operation(s) to perform on that region of bitmap |
1031 | * |
1032 | * Can set, verify and/or release a region of bits in a bitmap, |
1033 | * depending on which combination of REG_OP_* flag bits is set. |
1034 | * |
1035 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1036 | * some size '1 << order' (a power of two), aligned to that same |
1037 | * '1 << order' power of two. |
1038 | * |
1039 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). |
1040 | * Returns 0 in all other cases and reg_ops. |
1041 | */ |
1042 | |
1043 | enum { |
1044 | REG_OP_ISFREE, /* true if region is all zero bits */ |
1045 | REG_OP_ALLOC, /* set all bits in region */ |
1046 | REG_OP_RELEASE, /* clear all bits in region */ |
1047 | }; |
1048 | |
1049 | static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) |
1050 | { |
1051 | int nbits_reg; /* number of bits in region */ |
1052 | int index; /* index first long of region in bitmap */ |
1053 | int offset; /* bit offset region in bitmap[index] */ |
1054 | int nlongs_reg; /* num longs spanned by region in bitmap */ |
1055 | int nbitsinlong; /* num bits of region in each spanned long */ |
1056 | unsigned long mask; /* bitmask for one long of region */ |
1057 | int i; /* scans bitmap by longs */ |
1058 | int ret = 0; /* return value */ |
1059 | |
1060 | /* |
1061 | * Either nlongs_reg == 1 (for small orders that fit in one long) |
1062 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) |
1063 | */ |
1064 | nbits_reg = 1 << order; |
1065 | index = pos / BITS_PER_LONG; |
1066 | offset = pos - (index * BITS_PER_LONG); |
1067 | nlongs_reg = BITS_TO_LONGS(nbits_reg); |
1068 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); |
1069 | |
1070 | /* |
1071 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that |
1072 | * overflows if nbitsinlong == BITS_PER_LONG. |
1073 | */ |
1074 | mask = (1UL << (nbitsinlong - 1)); |
1075 | mask += mask - 1; |
1076 | mask <<= offset; |
1077 | |
1078 | switch (reg_op) { |
1079 | case REG_OP_ISFREE: |
1080 | for (i = 0; i < nlongs_reg; i++) { |
1081 | if (bitmap[index + i] & mask) |
1082 | goto done; |
1083 | } |
1084 | ret = 1; /* all bits in region free (zero) */ |
1085 | break; |
1086 | |
1087 | case REG_OP_ALLOC: |
1088 | for (i = 0; i < nlongs_reg; i++) |
1089 | bitmap[index + i] |= mask; |
1090 | break; |
1091 | |
1092 | case REG_OP_RELEASE: |
1093 | for (i = 0; i < nlongs_reg; i++) |
1094 | bitmap[index + i] &= ~mask; |
1095 | break; |
1096 | } |
1097 | done: |
1098 | return ret; |
1099 | } |
1100 | |
1101 | /** |
1102 | * bitmap_find_free_region - find a contiguous aligned mem region |
1103 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1104 | * @bits: number of bits in the bitmap |
1105 | * @order: region size (log base 2 of number of bits) to find |
1106 | * |
1107 | * Find a region of free (zero) bits in a @bitmap of @bits bits and |
1108 | * allocate them (set them to one). Only consider regions of length |
1109 | * a power (@order) of two, aligned to that power of two, which |
1110 | * makes the search algorithm much faster. |
1111 | * |
1112 | * Return the bit offset in bitmap of the allocated region, |
1113 | * or -errno on failure. |
1114 | */ |
1115 | int bitmap_find_free_region(unsigned long *bitmap, int bits, int order) |
1116 | { |
1117 | int pos, end; /* scans bitmap by regions of size order */ |
1118 | |
1119 | for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) { |
1120 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1121 | continue; |
1122 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1123 | return pos; |
1124 | } |
1125 | return -ENOMEM; |
1126 | } |
1127 | EXPORT_SYMBOL(bitmap_find_free_region); |
1128 | |
1129 | /** |
1130 | * bitmap_release_region - release allocated bitmap region |
1131 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1132 | * @pos: beginning of bit region to release |
1133 | * @order: region size (log base 2 of number of bits) to release |
1134 | * |
1135 | * This is the complement to __bitmap_find_free_region() and releases |
1136 | * the found region (by clearing it in the bitmap). |
1137 | * |
1138 | * No return value. |
1139 | */ |
1140 | void bitmap_release_region(unsigned long *bitmap, int pos, int order) |
1141 | { |
1142 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1143 | } |
1144 | EXPORT_SYMBOL(bitmap_release_region); |
1145 | |
1146 | /** |
1147 | * bitmap_allocate_region - allocate bitmap region |
1148 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1149 | * @pos: beginning of bit region to allocate |
1150 | * @order: region size (log base 2 of number of bits) to allocate |
1151 | * |
1152 | * Allocate (set bits in) a specified region of a bitmap. |
1153 | * |
1154 | * Return 0 on success, or %-EBUSY if specified region wasn't |
1155 | * free (not all bits were zero). |
1156 | */ |
1157 | int bitmap_allocate_region(unsigned long *bitmap, int pos, int order) |
1158 | { |
1159 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1160 | return -EBUSY; |
1161 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1162 | return 0; |
1163 | } |
1164 | EXPORT_SYMBOL(bitmap_allocate_region); |
1165 | |
1166 | /** |
1167 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. |
1168 | * @dst: destination buffer |
1169 | * @src: bitmap to copy |
1170 | * @nbits: number of bits in the bitmap |
1171 | * |
1172 | * Require nbits % BITS_PER_LONG == 0. |
1173 | */ |
1174 | void bitmap_copy_le(void *dst, const unsigned long *src, int nbits) |
1175 | { |
1176 | unsigned long *d = dst; |
1177 | int i; |
1178 | |
1179 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { |
1180 | if (BITS_PER_LONG == 64) |
1181 | d[i] = cpu_to_le64(src[i]); |
1182 | else |
1183 | d[i] = cpu_to_le32(src[i]); |
1184 | } |
1185 | } |
1186 | EXPORT_SYMBOL(bitmap_copy_le); |
1187 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
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jz-3.3
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jz-3.6-rc2-pwm
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jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9