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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, unsigned int bits) |
44 | { |
45 | unsigned 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, unsigned int bits) |
59 | { |
60 | unsigned 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, unsigned int bits) |
75 | { |
76 | unsigned 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, unsigned int bits) |
90 | { |
91 | unsigned 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]; |
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] = lower >> rem; |
135 | if (rem) |
136 | dst[k] |= upper << (BITS_PER_LONG - rem); |
137 | if (left && k == lim - 1) |
138 | dst[k] &= mask; |
139 | } |
140 | if (off) |
141 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); |
142 | } |
143 | EXPORT_SYMBOL(__bitmap_shift_right); |
144 | |
145 | |
146 | /** |
147 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
148 | * @dst : destination bitmap |
149 | * @src : source bitmap |
150 | * @shift : shift by this many bits |
151 | * @bits : bitmap size, in bits |
152 | * |
153 | * Shifting left (multiplying) means moving bits in the LS -> MS |
154 | * direction. Zeros are fed into the vacated LS bit positions |
155 | * and those MS bits shifted off the top are lost. |
156 | */ |
157 | |
158 | void __bitmap_shift_left(unsigned long *dst, |
159 | const unsigned long *src, int shift, int bits) |
160 | { |
161 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; |
162 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
163 | for (k = lim - off - 1; k >= 0; --k) { |
164 | unsigned long upper, lower; |
165 | |
166 | /* |
167 | * If shift is not word aligned, take upper rem bits of |
168 | * word below and make them the bottom rem bits of result. |
169 | */ |
170 | if (rem && k > 0) |
171 | lower = src[k - 1]; |
172 | else |
173 | lower = 0; |
174 | upper = src[k]; |
175 | if (left && k == lim - 1) |
176 | upper &= (1UL << left) - 1; |
177 | dst[k + off] = upper << rem; |
178 | if (rem) |
179 | dst[k + off] |= lower >> (BITS_PER_LONG - rem); |
180 | if (left && k + off == lim - 1) |
181 | dst[k + off] &= (1UL << left) - 1; |
182 | } |
183 | if (off) |
184 | memset(dst, 0, off*sizeof(unsigned long)); |
185 | } |
186 | EXPORT_SYMBOL(__bitmap_shift_left); |
187 | |
188 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
189 | const unsigned long *bitmap2, unsigned int bits) |
190 | { |
191 | unsigned int k; |
192 | unsigned int lim = bits/BITS_PER_LONG; |
193 | unsigned long result = 0; |
194 | |
195 | for (k = 0; k < lim; k++) |
196 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
197 | if (bits % BITS_PER_LONG) |
198 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & |
199 | BITMAP_LAST_WORD_MASK(bits)); |
200 | return result != 0; |
201 | } |
202 | EXPORT_SYMBOL(__bitmap_and); |
203 | |
204 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
205 | const unsigned long *bitmap2, unsigned int bits) |
206 | { |
207 | unsigned int k; |
208 | unsigned 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_or); |
214 | |
215 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
216 | const unsigned long *bitmap2, unsigned int bits) |
217 | { |
218 | unsigned int k; |
219 | unsigned 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_xor); |
225 | |
226 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
227 | const unsigned long *bitmap2, unsigned int bits) |
228 | { |
229 | unsigned int k; |
230 | unsigned int lim = bits/BITS_PER_LONG; |
231 | unsigned long result = 0; |
232 | |
233 | for (k = 0; k < lim; k++) |
234 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
235 | if (bits % BITS_PER_LONG) |
236 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & |
237 | BITMAP_LAST_WORD_MASK(bits)); |
238 | return result != 0; |
239 | } |
240 | EXPORT_SYMBOL(__bitmap_andnot); |
241 | |
242 | int __bitmap_intersects(const unsigned long *bitmap1, |
243 | const unsigned long *bitmap2, unsigned int bits) |
244 | { |
245 | unsigned int k, lim = bits/BITS_PER_LONG; |
246 | for (k = 0; k < lim; ++k) |
247 | if (bitmap1[k] & bitmap2[k]) |
248 | return 1; |
249 | |
250 | if (bits % BITS_PER_LONG) |
251 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
252 | return 1; |
253 | return 0; |
254 | } |
255 | EXPORT_SYMBOL(__bitmap_intersects); |
256 | |
257 | int __bitmap_subset(const unsigned long *bitmap1, |
258 | const unsigned long *bitmap2, unsigned int bits) |
259 | { |
260 | unsigned int k, lim = bits/BITS_PER_LONG; |
261 | for (k = 0; k < lim; ++k) |
262 | if (bitmap1[k] & ~bitmap2[k]) |
263 | return 0; |
264 | |
265 | if (bits % BITS_PER_LONG) |
266 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
267 | return 0; |
268 | return 1; |
269 | } |
270 | EXPORT_SYMBOL(__bitmap_subset); |
271 | |
272 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
273 | { |
274 | unsigned int k, lim = bits/BITS_PER_LONG; |
275 | int w = 0; |
276 | |
277 | for (k = 0; k < lim; k++) |
278 | w += hweight_long(bitmap[k]); |
279 | |
280 | if (bits % BITS_PER_LONG) |
281 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
282 | |
283 | return w; |
284 | } |
285 | EXPORT_SYMBOL(__bitmap_weight); |
286 | |
287 | void bitmap_set(unsigned long *map, unsigned int start, int len) |
288 | { |
289 | unsigned long *p = map + BIT_WORD(start); |
290 | const unsigned int size = start + len; |
291 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
292 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); |
293 | |
294 | while (len - bits_to_set >= 0) { |
295 | *p |= mask_to_set; |
296 | len -= bits_to_set; |
297 | bits_to_set = BITS_PER_LONG; |
298 | mask_to_set = ~0UL; |
299 | p++; |
300 | } |
301 | if (len) { |
302 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
303 | *p |= mask_to_set; |
304 | } |
305 | } |
306 | EXPORT_SYMBOL(bitmap_set); |
307 | |
308 | void bitmap_clear(unsigned long *map, unsigned int start, int len) |
309 | { |
310 | unsigned long *p = map + BIT_WORD(start); |
311 | const unsigned int size = start + len; |
312 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
313 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
314 | |
315 | while (len - bits_to_clear >= 0) { |
316 | *p &= ~mask_to_clear; |
317 | len -= bits_to_clear; |
318 | bits_to_clear = BITS_PER_LONG; |
319 | mask_to_clear = ~0UL; |
320 | p++; |
321 | } |
322 | if (len) { |
323 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
324 | *p &= ~mask_to_clear; |
325 | } |
326 | } |
327 | EXPORT_SYMBOL(bitmap_clear); |
328 | |
329 | /* |
330 | * bitmap_find_next_zero_area - find a contiguous aligned zero area |
331 | * @map: The address to base the search on |
332 | * @size: The bitmap size in bits |
333 | * @start: The bitnumber to start searching at |
334 | * @nr: The number of zeroed bits we're looking for |
335 | * @align_mask: Alignment mask for zero area |
336 | * |
337 | * The @align_mask should be one less than a power of 2; the effect is that |
338 | * the bit offset of all zero areas this function finds is multiples of that |
339 | * power of 2. A @align_mask of 0 means no alignment is required. |
340 | */ |
341 | unsigned long bitmap_find_next_zero_area(unsigned long *map, |
342 | unsigned long size, |
343 | unsigned long start, |
344 | unsigned int nr, |
345 | unsigned long align_mask) |
346 | { |
347 | unsigned long index, end, i; |
348 | again: |
349 | index = find_next_zero_bit(map, size, start); |
350 | |
351 | /* Align allocation */ |
352 | index = __ALIGN_MASK(index, align_mask); |
353 | |
354 | end = index + nr; |
355 | if (end > size) |
356 | return end; |
357 | i = find_next_bit(map, end, index); |
358 | if (i < end) { |
359 | start = i + 1; |
360 | goto again; |
361 | } |
362 | return index; |
363 | } |
364 | EXPORT_SYMBOL(bitmap_find_next_zero_area); |
365 | |
366 | /* |
367 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
368 | * second version by Paul Jackson, third by Joe Korty. |
369 | */ |
370 | |
371 | #define CHUNKSZ 32 |
372 | #define nbits_to_hold_value(val) fls(val) |
373 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
374 | |
375 | /** |
376 | * bitmap_scnprintf - convert bitmap to an ASCII hex string. |
377 | * @buf: byte buffer into which string is placed |
378 | * @buflen: reserved size of @buf, in bytes |
379 | * @maskp: pointer to bitmap to convert |
380 | * @nmaskbits: size of bitmap, in bits |
381 | * |
382 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into |
383 | * comma-separated sets of eight digits per set. Returns the number of |
384 | * characters which were written to *buf, excluding the trailing \0. |
385 | */ |
386 | int bitmap_scnprintf(char *buf, unsigned int buflen, |
387 | const unsigned long *maskp, int nmaskbits) |
388 | { |
389 | int i, word, bit, len = 0; |
390 | unsigned long val; |
391 | const char *sep = ""; |
392 | int chunksz; |
393 | u32 chunkmask; |
394 | |
395 | chunksz = nmaskbits & (CHUNKSZ - 1); |
396 | if (chunksz == 0) |
397 | chunksz = CHUNKSZ; |
398 | |
399 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ; |
400 | for (; i >= 0; i -= CHUNKSZ) { |
401 | chunkmask = ((1ULL << chunksz) - 1); |
402 | word = i / BITS_PER_LONG; |
403 | bit = i % BITS_PER_LONG; |
404 | val = (maskp[word] >> bit) & chunkmask; |
405 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep, |
406 | (chunksz+3)/4, val); |
407 | chunksz = CHUNKSZ; |
408 | sep = ","; |
409 | } |
410 | return len; |
411 | } |
412 | EXPORT_SYMBOL(bitmap_scnprintf); |
413 | |
414 | /** |
415 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
416 | * @buf: pointer to buffer containing string. |
417 | * @buflen: buffer size in bytes. If string is smaller than this |
418 | * then it must be terminated with a \0. |
419 | * @is_user: location of buffer, 0 indicates kernel space |
420 | * @maskp: pointer to bitmap array that will contain result. |
421 | * @nmaskbits: size of bitmap, in bits. |
422 | * |
423 | * Commas group hex digits into chunks. Each chunk defines exactly 32 |
424 | * bits of the resultant bitmask. No chunk may specify a value larger |
425 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
426 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal |
427 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
428 | * Leading and trailing whitespace accepted, but not embedded whitespace. |
429 | */ |
430 | int __bitmap_parse(const char *buf, unsigned int buflen, |
431 | int is_user, unsigned long *maskp, |
432 | int nmaskbits) |
433 | { |
434 | int c, old_c, totaldigits, ndigits, nchunks, nbits; |
435 | u32 chunk; |
436 | const char __user __force *ubuf = (const char __user __force *)buf; |
437 | |
438 | bitmap_zero(maskp, nmaskbits); |
439 | |
440 | nchunks = nbits = totaldigits = c = 0; |
441 | do { |
442 | chunk = ndigits = 0; |
443 | |
444 | /* Get the next chunk of the bitmap */ |
445 | while (buflen) { |
446 | old_c = c; |
447 | if (is_user) { |
448 | if (__get_user(c, ubuf++)) |
449 | return -EFAULT; |
450 | } |
451 | else |
452 | c = *buf++; |
453 | buflen--; |
454 | if (isspace(c)) |
455 | continue; |
456 | |
457 | /* |
458 | * If the last character was a space and the current |
459 | * character isn't '\0', we've got embedded whitespace. |
460 | * This is a no-no, so throw an error. |
461 | */ |
462 | if (totaldigits && c && isspace(old_c)) |
463 | return -EINVAL; |
464 | |
465 | /* A '\0' or a ',' signal the end of the chunk */ |
466 | if (c == '\0' || c == ',') |
467 | break; |
468 | |
469 | if (!isxdigit(c)) |
470 | return -EINVAL; |
471 | |
472 | /* |
473 | * Make sure there are at least 4 free bits in 'chunk'. |
474 | * If not, this hexdigit will overflow 'chunk', so |
475 | * throw an error. |
476 | */ |
477 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) |
478 | return -EOVERFLOW; |
479 | |
480 | chunk = (chunk << 4) | hex_to_bin(c); |
481 | ndigits++; totaldigits++; |
482 | } |
483 | if (ndigits == 0) |
484 | return -EINVAL; |
485 | if (nchunks == 0 && chunk == 0) |
486 | continue; |
487 | |
488 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); |
489 | *maskp |= chunk; |
490 | nchunks++; |
491 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; |
492 | if (nbits > nmaskbits) |
493 | return -EOVERFLOW; |
494 | } while (buflen && c == ','); |
495 | |
496 | return 0; |
497 | } |
498 | EXPORT_SYMBOL(__bitmap_parse); |
499 | |
500 | /** |
501 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
502 | * |
503 | * @ubuf: pointer to user buffer containing string. |
504 | * @ulen: buffer size in bytes. If string is smaller than this |
505 | * then it must be terminated with a \0. |
506 | * @maskp: pointer to bitmap array that will contain result. |
507 | * @nmaskbits: size of bitmap, in bits. |
508 | * |
509 | * Wrapper for __bitmap_parse(), providing it with user buffer. |
510 | * |
511 | * We cannot have this as an inline function in bitmap.h because it needs |
512 | * linux/uaccess.h to get the access_ok() declaration and this causes |
513 | * cyclic dependencies. |
514 | */ |
515 | int bitmap_parse_user(const char __user *ubuf, |
516 | unsigned int ulen, unsigned long *maskp, |
517 | int nmaskbits) |
518 | { |
519 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
520 | return -EFAULT; |
521 | return __bitmap_parse((const char __force *)ubuf, |
522 | ulen, 1, maskp, nmaskbits); |
523 | |
524 | } |
525 | EXPORT_SYMBOL(bitmap_parse_user); |
526 | |
527 | /* |
528 | * bscnl_emit(buf, buflen, rbot, rtop, bp) |
529 | * |
530 | * Helper routine for bitmap_scnlistprintf(). Write decimal number |
531 | * or range to buf, suppressing output past buf+buflen, with optional |
532 | * comma-prefix. Return len of what was written to *buf, excluding the |
533 | * trailing \0. |
534 | */ |
535 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) |
536 | { |
537 | if (len > 0) |
538 | len += scnprintf(buf + len, buflen - len, ","); |
539 | if (rbot == rtop) |
540 | len += scnprintf(buf + len, buflen - len, "%d", rbot); |
541 | else |
542 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop); |
543 | return len; |
544 | } |
545 | |
546 | /** |
547 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string |
548 | * @buf: byte buffer into which string is placed |
549 | * @buflen: reserved size of @buf, in bytes |
550 | * @maskp: pointer to bitmap to convert |
551 | * @nmaskbits: size of bitmap, in bits |
552 | * |
553 | * Output format is a comma-separated list of decimal numbers and |
554 | * ranges. Consecutively set bits are shown as two hyphen-separated |
555 | * decimal numbers, the smallest and largest bit numbers set in |
556 | * the range. Output format is compatible with the format |
557 | * accepted as input by bitmap_parselist(). |
558 | * |
559 | * The return value is the number of characters which were written to *buf |
560 | * excluding the trailing '\0', as per ISO C99's scnprintf. |
561 | */ |
562 | int bitmap_scnlistprintf(char *buf, unsigned int buflen, |
563 | const unsigned long *maskp, int nmaskbits) |
564 | { |
565 | int len = 0; |
566 | /* current bit is 'cur', most recently seen range is [rbot, rtop] */ |
567 | int cur, rbot, rtop; |
568 | |
569 | if (buflen == 0) |
570 | return 0; |
571 | buf[0] = 0; |
572 | |
573 | rbot = cur = find_first_bit(maskp, nmaskbits); |
574 | while (cur < nmaskbits) { |
575 | rtop = cur; |
576 | cur = find_next_bit(maskp, nmaskbits, cur+1); |
577 | if (cur >= nmaskbits || cur > rtop + 1) { |
578 | len = bscnl_emit(buf, buflen, rbot, rtop, len); |
579 | rbot = cur; |
580 | } |
581 | } |
582 | return len; |
583 | } |
584 | EXPORT_SYMBOL(bitmap_scnlistprintf); |
585 | |
586 | /** |
587 | * __bitmap_parselist - convert list format ASCII string to bitmap |
588 | * @buf: read nul-terminated user string from this buffer |
589 | * @buflen: buffer size in bytes. If string is smaller than this |
590 | * then it must be terminated with a \0. |
591 | * @is_user: location of buffer, 0 indicates kernel space |
592 | * @maskp: write resulting mask here |
593 | * @nmaskbits: number of bits in mask to be written |
594 | * |
595 | * Input format is a comma-separated list of decimal numbers and |
596 | * ranges. Consecutively set bits are shown as two hyphen-separated |
597 | * decimal numbers, the smallest and largest bit numbers set in |
598 | * the range. |
599 | * |
600 | * Returns 0 on success, -errno on invalid input strings. |
601 | * Error values: |
602 | * %-EINVAL: second number in range smaller than first |
603 | * %-EINVAL: invalid character in string |
604 | * %-ERANGE: bit number specified too large for mask |
605 | */ |
606 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
607 | int is_user, unsigned long *maskp, |
608 | int nmaskbits) |
609 | { |
610 | unsigned a, b; |
611 | int c, old_c, totaldigits; |
612 | const char __user __force *ubuf = (const char __user __force *)buf; |
613 | int exp_digit, in_range; |
614 | |
615 | totaldigits = c = 0; |
616 | bitmap_zero(maskp, nmaskbits); |
617 | do { |
618 | exp_digit = 1; |
619 | in_range = 0; |
620 | a = b = 0; |
621 | |
622 | /* Get the next cpu# or a range of cpu#'s */ |
623 | while (buflen) { |
624 | old_c = c; |
625 | if (is_user) { |
626 | if (__get_user(c, ubuf++)) |
627 | return -EFAULT; |
628 | } else |
629 | c = *buf++; |
630 | buflen--; |
631 | if (isspace(c)) |
632 | continue; |
633 | |
634 | /* |
635 | * If the last character was a space and the current |
636 | * character isn't '\0', we've got embedded whitespace. |
637 | * This is a no-no, so throw an error. |
638 | */ |
639 | if (totaldigits && c && isspace(old_c)) |
640 | return -EINVAL; |
641 | |
642 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
643 | if (c == '\0' || c == ',') |
644 | break; |
645 | |
646 | if (c == '-') { |
647 | if (exp_digit || in_range) |
648 | return -EINVAL; |
649 | b = 0; |
650 | in_range = 1; |
651 | exp_digit = 1; |
652 | continue; |
653 | } |
654 | |
655 | if (!isdigit(c)) |
656 | return -EINVAL; |
657 | |
658 | b = b * 10 + (c - '0'); |
659 | if (!in_range) |
660 | a = b; |
661 | exp_digit = 0; |
662 | totaldigits++; |
663 | } |
664 | if (!(a <= b)) |
665 | return -EINVAL; |
666 | if (b >= nmaskbits) |
667 | return -ERANGE; |
668 | while (a <= b) { |
669 | set_bit(a, maskp); |
670 | a++; |
671 | } |
672 | } while (buflen && c == ','); |
673 | return 0; |
674 | } |
675 | |
676 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) |
677 | { |
678 | char *nl = strchrnul(bp, '\n'); |
679 | int len = nl - bp; |
680 | |
681 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); |
682 | } |
683 | EXPORT_SYMBOL(bitmap_parselist); |
684 | |
685 | |
686 | /** |
687 | * bitmap_parselist_user() |
688 | * |
689 | * @ubuf: pointer to user buffer containing string. |
690 | * @ulen: buffer size in bytes. If string is smaller than this |
691 | * then it must be terminated with a \0. |
692 | * @maskp: pointer to bitmap array that will contain result. |
693 | * @nmaskbits: size of bitmap, in bits. |
694 | * |
695 | * Wrapper for bitmap_parselist(), providing it with user buffer. |
696 | * |
697 | * We cannot have this as an inline function in bitmap.h because it needs |
698 | * linux/uaccess.h to get the access_ok() declaration and this causes |
699 | * cyclic dependencies. |
700 | */ |
701 | int bitmap_parselist_user(const char __user *ubuf, |
702 | unsigned int ulen, unsigned long *maskp, |
703 | int nmaskbits) |
704 | { |
705 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
706 | return -EFAULT; |
707 | return __bitmap_parselist((const char __force *)ubuf, |
708 | ulen, 1, maskp, nmaskbits); |
709 | } |
710 | EXPORT_SYMBOL(bitmap_parselist_user); |
711 | |
712 | |
713 | /** |
714 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
715 | * @buf: pointer to a bitmap |
716 | * @pos: a bit position in @buf (0 <= @pos < @bits) |
717 | * @bits: number of valid bit positions in @buf |
718 | * |
719 | * Map the bit at position @pos in @buf (of length @bits) to the |
720 | * ordinal of which set bit it is. If it is not set or if @pos |
721 | * is not a valid bit position, map to -1. |
722 | * |
723 | * If for example, just bits 4 through 7 are set in @buf, then @pos |
724 | * values 4 through 7 will get mapped to 0 through 3, respectively, |
725 | * and other @pos values will get mapped to -1. When @pos value 7 |
726 | * gets mapped to (returns) @ord value 3 in this example, that means |
727 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. |
728 | * |
729 | * The bit positions 0 through @bits are valid positions in @buf. |
730 | */ |
731 | static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits) |
732 | { |
733 | int i, ord; |
734 | |
735 | if (pos < 0 || pos >= bits || !test_bit(pos, buf)) |
736 | return -1; |
737 | |
738 | i = find_first_bit(buf, bits); |
739 | ord = 0; |
740 | while (i < pos) { |
741 | i = find_next_bit(buf, bits, i + 1); |
742 | ord++; |
743 | } |
744 | BUG_ON(i != pos); |
745 | |
746 | return ord; |
747 | } |
748 | |
749 | /** |
750 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
751 | * @buf: pointer to bitmap |
752 | * @ord: ordinal bit position (n-th set bit, n >= 0) |
753 | * @bits: number of valid bit positions in @buf |
754 | * |
755 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. |
756 | * Value of @ord should be in range 0 <= @ord < weight(buf), else |
757 | * results are undefined. |
758 | * |
759 | * If for example, just bits 4 through 7 are set in @buf, then @ord |
760 | * values 0 through 3 will get mapped to 4 through 7, respectively, |
761 | * and all other @ord values return undefined values. When @ord value 3 |
762 | * gets mapped to (returns) @pos value 7 in this example, that means |
763 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. |
764 | * |
765 | * The bit positions 0 through @bits are valid positions in @buf. |
766 | */ |
767 | int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits) |
768 | { |
769 | int pos = 0; |
770 | |
771 | if (ord >= 0 && ord < bits) { |
772 | int i; |
773 | |
774 | for (i = find_first_bit(buf, bits); |
775 | i < bits && ord > 0; |
776 | i = find_next_bit(buf, bits, i + 1)) |
777 | ord--; |
778 | if (i < bits && ord == 0) |
779 | pos = i; |
780 | } |
781 | |
782 | return pos; |
783 | } |
784 | |
785 | /** |
786 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap |
787 | * @dst: remapped result |
788 | * @src: subset to be remapped |
789 | * @old: defines domain of map |
790 | * @new: defines range of map |
791 | * @bits: number of bits in each of these bitmaps |
792 | * |
793 | * Let @old and @new define a mapping of bit positions, such that |
794 | * whatever position is held by the n-th set bit in @old is mapped |
795 | * to the n-th set bit in @new. In the more general case, allowing |
796 | * for the possibility that the weight 'w' of @new is less than the |
797 | * weight of @old, map the position of the n-th set bit in @old to |
798 | * the position of the m-th set bit in @new, where m == n % w. |
799 | * |
800 | * If either of the @old and @new bitmaps are empty, or if @src and |
801 | * @dst point to the same location, then this routine copies @src |
802 | * to @dst. |
803 | * |
804 | * The positions of unset bits in @old are mapped to themselves |
805 | * (the identify map). |
806 | * |
807 | * Apply the above specified mapping to @src, placing the result in |
808 | * @dst, clearing any bits previously set in @dst. |
809 | * |
810 | * For example, lets say that @old has bits 4 through 7 set, and |
811 | * @new has bits 12 through 15 set. This defines the mapping of bit |
812 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
813 | * bit positions unchanged. So if say @src comes into this routine |
814 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, |
815 | * 13 and 15 set. |
816 | */ |
817 | void bitmap_remap(unsigned long *dst, const unsigned long *src, |
818 | const unsigned long *old, const unsigned long *new, |
819 | int bits) |
820 | { |
821 | int oldbit, w; |
822 | |
823 | if (dst == src) /* following doesn't handle inplace remaps */ |
824 | return; |
825 | bitmap_zero(dst, bits); |
826 | |
827 | w = bitmap_weight(new, bits); |
828 | for_each_set_bit(oldbit, src, bits) { |
829 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
830 | |
831 | if (n < 0 || w == 0) |
832 | set_bit(oldbit, dst); /* identity map */ |
833 | else |
834 | set_bit(bitmap_ord_to_pos(new, n % w, bits), dst); |
835 | } |
836 | } |
837 | EXPORT_SYMBOL(bitmap_remap); |
838 | |
839 | /** |
840 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit |
841 | * @oldbit: bit position to be mapped |
842 | * @old: defines domain of map |
843 | * @new: defines range of map |
844 | * @bits: number of bits in each of these bitmaps |
845 | * |
846 | * Let @old and @new define a mapping of bit positions, such that |
847 | * whatever position is held by the n-th set bit in @old is mapped |
848 | * to the n-th set bit in @new. In the more general case, allowing |
849 | * for the possibility that the weight 'w' of @new is less than the |
850 | * weight of @old, map the position of the n-th set bit in @old to |
851 | * the position of the m-th set bit in @new, where m == n % w. |
852 | * |
853 | * The positions of unset bits in @old are mapped to themselves |
854 | * (the identify map). |
855 | * |
856 | * Apply the above specified mapping to bit position @oldbit, returning |
857 | * the new bit position. |
858 | * |
859 | * For example, lets say that @old has bits 4 through 7 set, and |
860 | * @new has bits 12 through 15 set. This defines the mapping of bit |
861 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
862 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
863 | * returns 13. |
864 | */ |
865 | int bitmap_bitremap(int oldbit, const unsigned long *old, |
866 | const unsigned long *new, int bits) |
867 | { |
868 | int w = bitmap_weight(new, bits); |
869 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
870 | if (n < 0 || w == 0) |
871 | return oldbit; |
872 | else |
873 | return bitmap_ord_to_pos(new, n % w, bits); |
874 | } |
875 | EXPORT_SYMBOL(bitmap_bitremap); |
876 | |
877 | /** |
878 | * bitmap_onto - translate one bitmap relative to another |
879 | * @dst: resulting translated bitmap |
880 | * @orig: original untranslated bitmap |
881 | * @relmap: bitmap relative to which translated |
882 | * @bits: number of bits in each of these bitmaps |
883 | * |
884 | * Set the n-th bit of @dst iff there exists some m such that the |
885 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and |
886 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. |
887 | * (If you understood the previous sentence the first time your |
888 | * read it, you're overqualified for your current job.) |
889 | * |
890 | * In other words, @orig is mapped onto (surjectively) @dst, |
891 | * using the map { <n, m> | the n-th bit of @relmap is the |
892 | * m-th set bit of @relmap }. |
893 | * |
894 | * Any set bits in @orig above bit number W, where W is the |
895 | * weight of (number of set bits in) @relmap are mapped nowhere. |
896 | * In particular, if for all bits m set in @orig, m >= W, then |
897 | * @dst will end up empty. In situations where the possibility |
898 | * of such an empty result is not desired, one way to avoid it is |
899 | * to use the bitmap_fold() operator, below, to first fold the |
900 | * @orig bitmap over itself so that all its set bits x are in the |
901 | * range 0 <= x < W. The bitmap_fold() operator does this by |
902 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. |
903 | * |
904 | * Example [1] for bitmap_onto(): |
905 | * Let's say @relmap has bits 30-39 set, and @orig has bits |
906 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, |
907 | * @dst will have bits 31, 33, 35, 37 and 39 set. |
908 | * |
909 | * When bit 0 is set in @orig, it means turn on the bit in |
910 | * @dst corresponding to whatever is the first bit (if any) |
911 | * that is turned on in @relmap. Since bit 0 was off in the |
912 | * above example, we leave off that bit (bit 30) in @dst. |
913 | * |
914 | * When bit 1 is set in @orig (as in the above example), it |
915 | * means turn on the bit in @dst corresponding to whatever |
916 | * is the second bit that is turned on in @relmap. The second |
917 | * bit in @relmap that was turned on in the above example was |
918 | * bit 31, so we turned on bit 31 in @dst. |
919 | * |
920 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, |
921 | * because they were the 4th, 6th, 8th and 10th set bits |
922 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of |
923 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. |
924 | * |
925 | * When bit 11 is set in @orig, it means turn on the bit in |
926 | * @dst corresponding to whatever is the twelfth bit that is |
927 | * turned on in @relmap. In the above example, there were |
928 | * only ten bits turned on in @relmap (30..39), so that bit |
929 | * 11 was set in @orig had no affect on @dst. |
930 | * |
931 | * Example [2] for bitmap_fold() + bitmap_onto(): |
932 | * Let's say @relmap has these ten bits set: |
933 | * 40 41 42 43 45 48 53 61 74 95 |
934 | * (for the curious, that's 40 plus the first ten terms of the |
935 | * Fibonacci sequence.) |
936 | * |
937 | * Further lets say we use the following code, invoking |
938 | * bitmap_fold() then bitmap_onto, as suggested above to |
939 | * avoid the possibility of an empty @dst result: |
940 | * |
941 | * unsigned long *tmp; // a temporary bitmap's bits |
942 | * |
943 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); |
944 | * bitmap_onto(dst, tmp, relmap, bits); |
945 | * |
946 | * Then this table shows what various values of @dst would be, for |
947 | * various @orig's. I list the zero-based positions of each set bit. |
948 | * The tmp column shows the intermediate result, as computed by |
949 | * using bitmap_fold() to fold the @orig bitmap modulo ten |
950 | * (the weight of @relmap). |
951 | * |
952 | * @orig tmp @dst |
953 | * 0 0 40 |
954 | * 1 1 41 |
955 | * 9 9 95 |
956 | * 10 0 40 (*) |
957 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
958 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 |
959 | * 0 9 18 27 0 9 8 7 40 61 74 95 |
960 | * 0 10 20 30 0 40 |
961 | * 0 11 22 33 0 1 2 3 40 41 42 43 |
962 | * 0 12 24 36 0 2 4 6 40 42 45 53 |
963 | * 78 102 211 1 2 8 41 42 74 (*) |
964 | * |
965 | * (*) For these marked lines, if we hadn't first done bitmap_fold() |
966 | * into tmp, then the @dst result would have been empty. |
967 | * |
968 | * If either of @orig or @relmap is empty (no set bits), then @dst |
969 | * will be returned empty. |
970 | * |
971 | * If (as explained above) the only set bits in @orig are in positions |
972 | * m where m >= W, (where W is the weight of @relmap) then @dst will |
973 | * once again be returned empty. |
974 | * |
975 | * All bits in @dst not set by the above rule are cleared. |
976 | */ |
977 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, |
978 | const unsigned long *relmap, int bits) |
979 | { |
980 | int n, m; /* same meaning as in above comment */ |
981 | |
982 | if (dst == orig) /* following doesn't handle inplace mappings */ |
983 | return; |
984 | bitmap_zero(dst, bits); |
985 | |
986 | /* |
987 | * The following code is a more efficient, but less |
988 | * obvious, equivalent to the loop: |
989 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { |
990 | * n = bitmap_ord_to_pos(orig, m, bits); |
991 | * if (test_bit(m, orig)) |
992 | * set_bit(n, dst); |
993 | * } |
994 | */ |
995 | |
996 | m = 0; |
997 | for_each_set_bit(n, relmap, bits) { |
998 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
999 | if (test_bit(m, orig)) |
1000 | set_bit(n, dst); |
1001 | m++; |
1002 | } |
1003 | } |
1004 | EXPORT_SYMBOL(bitmap_onto); |
1005 | |
1006 | /** |
1007 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size |
1008 | * @dst: resulting smaller bitmap |
1009 | * @orig: original larger bitmap |
1010 | * @sz: specified size |
1011 | * @bits: number of bits in each of these bitmaps |
1012 | * |
1013 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. |
1014 | * Clear all other bits in @dst. See further the comment and |
1015 | * Example [2] for bitmap_onto() for why and how to use this. |
1016 | */ |
1017 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, |
1018 | int sz, int bits) |
1019 | { |
1020 | int oldbit; |
1021 | |
1022 | if (dst == orig) /* following doesn't handle inplace mappings */ |
1023 | return; |
1024 | bitmap_zero(dst, bits); |
1025 | |
1026 | for_each_set_bit(oldbit, orig, bits) |
1027 | set_bit(oldbit % sz, dst); |
1028 | } |
1029 | EXPORT_SYMBOL(bitmap_fold); |
1030 | |
1031 | /* |
1032 | * Common code for bitmap_*_region() routines. |
1033 | * bitmap: array of unsigned longs corresponding to the bitmap |
1034 | * pos: the beginning of the region |
1035 | * order: region size (log base 2 of number of bits) |
1036 | * reg_op: operation(s) to perform on that region of bitmap |
1037 | * |
1038 | * Can set, verify and/or release a region of bits in a bitmap, |
1039 | * depending on which combination of REG_OP_* flag bits is set. |
1040 | * |
1041 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1042 | * some size '1 << order' (a power of two), aligned to that same |
1043 | * '1 << order' power of two. |
1044 | * |
1045 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). |
1046 | * Returns 0 in all other cases and reg_ops. |
1047 | */ |
1048 | |
1049 | enum { |
1050 | REG_OP_ISFREE, /* true if region is all zero bits */ |
1051 | REG_OP_ALLOC, /* set all bits in region */ |
1052 | REG_OP_RELEASE, /* clear all bits in region */ |
1053 | }; |
1054 | |
1055 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1056 | { |
1057 | int nbits_reg; /* number of bits in region */ |
1058 | int index; /* index first long of region in bitmap */ |
1059 | int offset; /* bit offset region in bitmap[index] */ |
1060 | int nlongs_reg; /* num longs spanned by region in bitmap */ |
1061 | int nbitsinlong; /* num bits of region in each spanned long */ |
1062 | unsigned long mask; /* bitmask for one long of region */ |
1063 | int i; /* scans bitmap by longs */ |
1064 | int ret = 0; /* return value */ |
1065 | |
1066 | /* |
1067 | * Either nlongs_reg == 1 (for small orders that fit in one long) |
1068 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) |
1069 | */ |
1070 | nbits_reg = 1 << order; |
1071 | index = pos / BITS_PER_LONG; |
1072 | offset = pos - (index * BITS_PER_LONG); |
1073 | nlongs_reg = BITS_TO_LONGS(nbits_reg); |
1074 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); |
1075 | |
1076 | /* |
1077 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that |
1078 | * overflows if nbitsinlong == BITS_PER_LONG. |
1079 | */ |
1080 | mask = (1UL << (nbitsinlong - 1)); |
1081 | mask += mask - 1; |
1082 | mask <<= offset; |
1083 | |
1084 | switch (reg_op) { |
1085 | case REG_OP_ISFREE: |
1086 | for (i = 0; i < nlongs_reg; i++) { |
1087 | if (bitmap[index + i] & mask) |
1088 | goto done; |
1089 | } |
1090 | ret = 1; /* all bits in region free (zero) */ |
1091 | break; |
1092 | |
1093 | case REG_OP_ALLOC: |
1094 | for (i = 0; i < nlongs_reg; i++) |
1095 | bitmap[index + i] |= mask; |
1096 | break; |
1097 | |
1098 | case REG_OP_RELEASE: |
1099 | for (i = 0; i < nlongs_reg; i++) |
1100 | bitmap[index + i] &= ~mask; |
1101 | break; |
1102 | } |
1103 | done: |
1104 | return ret; |
1105 | } |
1106 | |
1107 | /** |
1108 | * bitmap_find_free_region - find a contiguous aligned mem region |
1109 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1110 | * @bits: number of bits in the bitmap |
1111 | * @order: region size (log base 2 of number of bits) to find |
1112 | * |
1113 | * Find a region of free (zero) bits in a @bitmap of @bits bits and |
1114 | * allocate them (set them to one). Only consider regions of length |
1115 | * a power (@order) of two, aligned to that power of two, which |
1116 | * makes the search algorithm much faster. |
1117 | * |
1118 | * Return the bit offset in bitmap of the allocated region, |
1119 | * or -errno on failure. |
1120 | */ |
1121 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
1122 | { |
1123 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
1124 | |
1125 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
1126 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1127 | continue; |
1128 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1129 | return pos; |
1130 | } |
1131 | return -ENOMEM; |
1132 | } |
1133 | EXPORT_SYMBOL(bitmap_find_free_region); |
1134 | |
1135 | /** |
1136 | * bitmap_release_region - release allocated bitmap region |
1137 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1138 | * @pos: beginning of bit region to release |
1139 | * @order: region size (log base 2 of number of bits) to release |
1140 | * |
1141 | * This is the complement to __bitmap_find_free_region() and releases |
1142 | * the found region (by clearing it in the bitmap). |
1143 | * |
1144 | * No return value. |
1145 | */ |
1146 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1147 | { |
1148 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1149 | } |
1150 | EXPORT_SYMBOL(bitmap_release_region); |
1151 | |
1152 | /** |
1153 | * bitmap_allocate_region - allocate bitmap region |
1154 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1155 | * @pos: beginning of bit region to allocate |
1156 | * @order: region size (log base 2 of number of bits) to allocate |
1157 | * |
1158 | * Allocate (set bits in) a specified region of a bitmap. |
1159 | * |
1160 | * Return 0 on success, or %-EBUSY if specified region wasn't |
1161 | * free (not all bits were zero). |
1162 | */ |
1163 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1164 | { |
1165 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1166 | return -EBUSY; |
1167 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1168 | } |
1169 | EXPORT_SYMBOL(bitmap_allocate_region); |
1170 | |
1171 | /** |
1172 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. |
1173 | * @dst: destination buffer |
1174 | * @src: bitmap to copy |
1175 | * @nbits: number of bits in the bitmap |
1176 | * |
1177 | * Require nbits % BITS_PER_LONG == 0. |
1178 | */ |
1179 | void bitmap_copy_le(void *dst, const unsigned long *src, int nbits) |
1180 | { |
1181 | unsigned long *d = dst; |
1182 | int i; |
1183 | |
1184 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { |
1185 | if (BITS_PER_LONG == 64) |
1186 | d[i] = cpu_to_le64(src[i]); |
1187 | else |
1188 | d[i] = cpu_to_le32(src[i]); |
1189 | } |
1190 | } |
1191 | EXPORT_SYMBOL(bitmap_copy_le); |
1192 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
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jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
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