blob: 0b66f0e5eb6bb172ae240fe59dd1eec0d9065493
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 <linux/kernel.h> |
16 | #include <linux/string.h> |
17 | #include <linux/uaccess.h> |
18 | |
19 | #include <asm/page.h> |
20 | |
21 | /* |
22 | * bitmaps provide an array of bits, implemented using an an |
23 | * array of unsigned longs. The number of valid bits in a |
24 | * given bitmap does _not_ need to be an exact multiple of |
25 | * BITS_PER_LONG. |
26 | * |
27 | * The possible unused bits in the last, partially used word |
28 | * of a bitmap are 'don't care'. The implementation makes |
29 | * no particular effort to keep them zero. It ensures that |
30 | * their value will not affect the results of any operation. |
31 | * The bitmap operations that return Boolean (bitmap_empty, |
32 | * for example) or scalar (bitmap_weight, for example) results |
33 | * carefully filter out these unused bits from impacting their |
34 | * results. |
35 | * |
36 | * These operations actually hold to a slightly stronger rule: |
37 | * if you don't input any bitmaps to these ops that have some |
38 | * unused bits set, then they won't output any set unused bits |
39 | * in output bitmaps. |
40 | * |
41 | * The byte ordering of bitmaps is more natural on little |
42 | * endian architectures. See the big-endian headers |
43 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h |
44 | * for the best explanations of this ordering. |
45 | */ |
46 | |
47 | int __bitmap_equal(const unsigned long *bitmap1, |
48 | const unsigned long *bitmap2, unsigned int bits) |
49 | { |
50 | unsigned int k, lim = bits/BITS_PER_LONG; |
51 | for (k = 0; k < lim; ++k) |
52 | if (bitmap1[k] != bitmap2[k]) |
53 | return 0; |
54 | |
55 | if (bits % BITS_PER_LONG) |
56 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
57 | return 0; |
58 | |
59 | return 1; |
60 | } |
61 | EXPORT_SYMBOL(__bitmap_equal); |
62 | |
63 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
64 | { |
65 | unsigned int k, lim = bits/BITS_PER_LONG; |
66 | for (k = 0; k < lim; ++k) |
67 | dst[k] = ~src[k]; |
68 | |
69 | if (bits % BITS_PER_LONG) |
70 | dst[k] = ~src[k]; |
71 | } |
72 | EXPORT_SYMBOL(__bitmap_complement); |
73 | |
74 | /** |
75 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
76 | * @dst : destination bitmap |
77 | * @src : source bitmap |
78 | * @shift : shift by this many bits |
79 | * @nbits : bitmap size, in bits |
80 | * |
81 | * Shifting right (dividing) means moving bits in the MS -> LS bit |
82 | * direction. Zeros are fed into the vacated MS positions and the |
83 | * LS bits shifted off the bottom are lost. |
84 | */ |
85 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
86 | unsigned shift, unsigned nbits) |
87 | { |
88 | unsigned k, lim = BITS_TO_LONGS(nbits); |
89 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
90 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
91 | for (k = 0; off + k < lim; ++k) { |
92 | unsigned long upper, lower; |
93 | |
94 | /* |
95 | * If shift is not word aligned, take lower rem bits of |
96 | * word above and make them the top rem bits of result. |
97 | */ |
98 | if (!rem || off + k + 1 >= lim) |
99 | upper = 0; |
100 | else { |
101 | upper = src[off + k + 1]; |
102 | if (off + k + 1 == lim - 1) |
103 | upper &= mask; |
104 | upper <<= (BITS_PER_LONG - rem); |
105 | } |
106 | lower = src[off + k]; |
107 | if (off + k == lim - 1) |
108 | lower &= mask; |
109 | lower >>= rem; |
110 | dst[k] = lower | upper; |
111 | } |
112 | if (off) |
113 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); |
114 | } |
115 | EXPORT_SYMBOL(__bitmap_shift_right); |
116 | |
117 | |
118 | /** |
119 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
120 | * @dst : destination bitmap |
121 | * @src : source bitmap |
122 | * @shift : shift by this many bits |
123 | * @nbits : bitmap size, in bits |
124 | * |
125 | * Shifting left (multiplying) means moving bits in the LS -> MS |
126 | * direction. Zeros are fed into the vacated LS bit positions |
127 | * and those MS bits shifted off the top are lost. |
128 | */ |
129 | |
130 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
131 | unsigned int shift, unsigned int nbits) |
132 | { |
133 | int k; |
134 | unsigned int lim = BITS_TO_LONGS(nbits); |
135 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
136 | for (k = lim - off - 1; k >= 0; --k) { |
137 | unsigned long upper, lower; |
138 | |
139 | /* |
140 | * If shift is not word aligned, take upper rem bits of |
141 | * word below and make them the bottom rem bits of result. |
142 | */ |
143 | if (rem && k > 0) |
144 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
145 | else |
146 | lower = 0; |
147 | upper = src[k] << rem; |
148 | dst[k + off] = lower | upper; |
149 | } |
150 | if (off) |
151 | memset(dst, 0, off*sizeof(unsigned long)); |
152 | } |
153 | EXPORT_SYMBOL(__bitmap_shift_left); |
154 | |
155 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
156 | const unsigned long *bitmap2, unsigned int bits) |
157 | { |
158 | unsigned int k; |
159 | unsigned int lim = bits/BITS_PER_LONG; |
160 | unsigned long result = 0; |
161 | |
162 | for (k = 0; k < lim; k++) |
163 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
164 | if (bits % BITS_PER_LONG) |
165 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & |
166 | BITMAP_LAST_WORD_MASK(bits)); |
167 | return result != 0; |
168 | } |
169 | EXPORT_SYMBOL(__bitmap_and); |
170 | |
171 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, |
172 | const unsigned long *bitmap2, unsigned int bits) |
173 | { |
174 | unsigned int k; |
175 | unsigned int nr = BITS_TO_LONGS(bits); |
176 | |
177 | for (k = 0; k < nr; k++) |
178 | dst[k] = bitmap1[k] | bitmap2[k]; |
179 | } |
180 | EXPORT_SYMBOL(__bitmap_or); |
181 | |
182 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, |
183 | const unsigned long *bitmap2, unsigned int bits) |
184 | { |
185 | unsigned int k; |
186 | unsigned 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_xor); |
192 | |
193 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
194 | const unsigned long *bitmap2, unsigned int bits) |
195 | { |
196 | unsigned int k; |
197 | unsigned int lim = bits/BITS_PER_LONG; |
198 | unsigned long result = 0; |
199 | |
200 | for (k = 0; k < lim; k++) |
201 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
202 | if (bits % BITS_PER_LONG) |
203 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & |
204 | BITMAP_LAST_WORD_MASK(bits)); |
205 | return result != 0; |
206 | } |
207 | EXPORT_SYMBOL(__bitmap_andnot); |
208 | |
209 | int __bitmap_intersects(const unsigned long *bitmap1, |
210 | const unsigned long *bitmap2, unsigned int bits) |
211 | { |
212 | unsigned int k, lim = bits/BITS_PER_LONG; |
213 | for (k = 0; k < lim; ++k) |
214 | if (bitmap1[k] & bitmap2[k]) |
215 | return 1; |
216 | |
217 | if (bits % BITS_PER_LONG) |
218 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
219 | return 1; |
220 | return 0; |
221 | } |
222 | EXPORT_SYMBOL(__bitmap_intersects); |
223 | |
224 | int __bitmap_subset(const unsigned long *bitmap1, |
225 | const unsigned long *bitmap2, unsigned int bits) |
226 | { |
227 | unsigned int k, lim = bits/BITS_PER_LONG; |
228 | for (k = 0; k < lim; ++k) |
229 | if (bitmap1[k] & ~bitmap2[k]) |
230 | return 0; |
231 | |
232 | if (bits % BITS_PER_LONG) |
233 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) |
234 | return 0; |
235 | return 1; |
236 | } |
237 | EXPORT_SYMBOL(__bitmap_subset); |
238 | |
239 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
240 | { |
241 | unsigned int k, lim = bits/BITS_PER_LONG; |
242 | int w = 0; |
243 | |
244 | for (k = 0; k < lim; k++) |
245 | w += hweight_long(bitmap[k]); |
246 | |
247 | if (bits % BITS_PER_LONG) |
248 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
249 | |
250 | return w; |
251 | } |
252 | EXPORT_SYMBOL(__bitmap_weight); |
253 | |
254 | void bitmap_set(unsigned long *map, unsigned int start, int len) |
255 | { |
256 | unsigned long *p = map + BIT_WORD(start); |
257 | const unsigned int size = start + len; |
258 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
259 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); |
260 | |
261 | while (len - bits_to_set >= 0) { |
262 | *p |= mask_to_set; |
263 | len -= bits_to_set; |
264 | bits_to_set = BITS_PER_LONG; |
265 | mask_to_set = ~0UL; |
266 | p++; |
267 | } |
268 | if (len) { |
269 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
270 | *p |= mask_to_set; |
271 | } |
272 | } |
273 | EXPORT_SYMBOL(bitmap_set); |
274 | |
275 | void bitmap_clear(unsigned long *map, unsigned int start, int len) |
276 | { |
277 | unsigned long *p = map + BIT_WORD(start); |
278 | const unsigned int size = start + len; |
279 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
280 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); |
281 | |
282 | while (len - bits_to_clear >= 0) { |
283 | *p &= ~mask_to_clear; |
284 | len -= bits_to_clear; |
285 | bits_to_clear = BITS_PER_LONG; |
286 | mask_to_clear = ~0UL; |
287 | p++; |
288 | } |
289 | if (len) { |
290 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
291 | *p &= ~mask_to_clear; |
292 | } |
293 | } |
294 | EXPORT_SYMBOL(bitmap_clear); |
295 | |
296 | /** |
297 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area |
298 | * @map: The address to base the search on |
299 | * @size: The bitmap size in bits |
300 | * @start: The bitnumber to start searching at |
301 | * @nr: The number of zeroed bits we're looking for |
302 | * @align_mask: Alignment mask for zero area |
303 | * @align_offset: Alignment offset for zero area. |
304 | * |
305 | * The @align_mask should be one less than a power of 2; the effect is that |
306 | * the bit offset of all zero areas this function finds plus @align_offset |
307 | * is multiple of that power of 2. |
308 | */ |
309 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
310 | unsigned long size, |
311 | unsigned long start, |
312 | unsigned int nr, |
313 | unsigned long align_mask, |
314 | unsigned long align_offset) |
315 | { |
316 | unsigned long index, end, i; |
317 | again: |
318 | index = find_next_zero_bit(map, size, start); |
319 | |
320 | /* Align allocation */ |
321 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
322 | |
323 | end = index + nr; |
324 | if (end > size) |
325 | return end; |
326 | i = find_next_bit(map, end, index); |
327 | if (i < end) { |
328 | start = i + 1; |
329 | goto again; |
330 | } |
331 | return index; |
332 | } |
333 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
334 | |
335 | /* |
336 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
337 | * second version by Paul Jackson, third by Joe Korty. |
338 | */ |
339 | |
340 | #define CHUNKSZ 32 |
341 | #define nbits_to_hold_value(val) fls(val) |
342 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
343 | |
344 | /** |
345 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
346 | * @buf: pointer to buffer containing string. |
347 | * @buflen: buffer size in bytes. If string is smaller than this |
348 | * then it must be terminated with a \0. |
349 | * @is_user: location of buffer, 0 indicates kernel space |
350 | * @maskp: pointer to bitmap array that will contain result. |
351 | * @nmaskbits: size of bitmap, in bits. |
352 | * |
353 | * Commas group hex digits into chunks. Each chunk defines exactly 32 |
354 | * bits of the resultant bitmask. No chunk may specify a value larger |
355 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
356 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal |
357 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
358 | * Leading and trailing whitespace accepted, but not embedded whitespace. |
359 | */ |
360 | int __bitmap_parse(const char *buf, unsigned int buflen, |
361 | int is_user, unsigned long *maskp, |
362 | int nmaskbits) |
363 | { |
364 | int c, old_c, totaldigits, ndigits, nchunks, nbits; |
365 | u32 chunk; |
366 | const char __user __force *ubuf = (const char __user __force *)buf; |
367 | |
368 | bitmap_zero(maskp, nmaskbits); |
369 | |
370 | nchunks = nbits = totaldigits = c = 0; |
371 | do { |
372 | chunk = 0; |
373 | ndigits = totaldigits; |
374 | |
375 | /* Get the next chunk of the bitmap */ |
376 | while (buflen) { |
377 | old_c = c; |
378 | if (is_user) { |
379 | if (__get_user(c, ubuf++)) |
380 | return -EFAULT; |
381 | } |
382 | else |
383 | c = *buf++; |
384 | buflen--; |
385 | if (isspace(c)) |
386 | continue; |
387 | |
388 | /* |
389 | * If the last character was a space and the current |
390 | * character isn't '\0', we've got embedded whitespace. |
391 | * This is a no-no, so throw an error. |
392 | */ |
393 | if (totaldigits && c && isspace(old_c)) |
394 | return -EINVAL; |
395 | |
396 | /* A '\0' or a ',' signal the end of the chunk */ |
397 | if (c == '\0' || c == ',') |
398 | break; |
399 | |
400 | if (!isxdigit(c)) |
401 | return -EINVAL; |
402 | |
403 | /* |
404 | * Make sure there are at least 4 free bits in 'chunk'. |
405 | * If not, this hexdigit will overflow 'chunk', so |
406 | * throw an error. |
407 | */ |
408 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) |
409 | return -EOVERFLOW; |
410 | |
411 | chunk = (chunk << 4) | hex_to_bin(c); |
412 | totaldigits++; |
413 | } |
414 | if (ndigits == totaldigits) |
415 | return -EINVAL; |
416 | if (nchunks == 0 && chunk == 0) |
417 | continue; |
418 | |
419 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); |
420 | *maskp |= chunk; |
421 | nchunks++; |
422 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; |
423 | if (nbits > nmaskbits) |
424 | return -EOVERFLOW; |
425 | } while (buflen && c == ','); |
426 | |
427 | return 0; |
428 | } |
429 | EXPORT_SYMBOL(__bitmap_parse); |
430 | |
431 | /** |
432 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
433 | * |
434 | * @ubuf: pointer to user buffer containing string. |
435 | * @ulen: buffer size in bytes. If string is smaller than this |
436 | * then it must be terminated with a \0. |
437 | * @maskp: pointer to bitmap array that will contain result. |
438 | * @nmaskbits: size of bitmap, in bits. |
439 | * |
440 | * Wrapper for __bitmap_parse(), providing it with user buffer. |
441 | * |
442 | * We cannot have this as an inline function in bitmap.h because it needs |
443 | * linux/uaccess.h to get the access_ok() declaration and this causes |
444 | * cyclic dependencies. |
445 | */ |
446 | int bitmap_parse_user(const char __user *ubuf, |
447 | unsigned int ulen, unsigned long *maskp, |
448 | int nmaskbits) |
449 | { |
450 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
451 | return -EFAULT; |
452 | return __bitmap_parse((const char __force *)ubuf, |
453 | ulen, 1, maskp, nmaskbits); |
454 | |
455 | } |
456 | EXPORT_SYMBOL(bitmap_parse_user); |
457 | |
458 | /** |
459 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string |
460 | * @list: indicates whether the bitmap must be list |
461 | * @buf: page aligned buffer into which string is placed |
462 | * @maskp: pointer to bitmap to convert |
463 | * @nmaskbits: size of bitmap, in bits |
464 | * |
465 | * Output format is a comma-separated list of decimal numbers and |
466 | * ranges if list is specified or hex digits grouped into comma-separated |
467 | * sets of 8 digits/set. Returns the number of characters written to buf. |
468 | * |
469 | * It is assumed that @buf is a pointer into a PAGE_SIZE area and that |
470 | * sufficient storage remains at @buf to accommodate the |
471 | * bitmap_print_to_pagebuf() output. |
472 | */ |
473 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, |
474 | int nmaskbits) |
475 | { |
476 | ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf; |
477 | int n = 0; |
478 | |
479 | if (len > 1) |
480 | n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : |
481 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); |
482 | return n; |
483 | } |
484 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); |
485 | |
486 | /** |
487 | * __bitmap_parselist - convert list format ASCII string to bitmap |
488 | * @buf: read nul-terminated user string from this buffer |
489 | * @buflen: buffer size in bytes. If string is smaller than this |
490 | * then it must be terminated with a \0. |
491 | * @is_user: location of buffer, 0 indicates kernel space |
492 | * @maskp: write resulting mask here |
493 | * @nmaskbits: number of bits in mask to be written |
494 | * |
495 | * Input format is a comma-separated list of decimal numbers and |
496 | * ranges. Consecutively set bits are shown as two hyphen-separated |
497 | * decimal numbers, the smallest and largest bit numbers set in |
498 | * the range. |
499 | * Optionally each range can be postfixed to denote that only parts of it |
500 | * should be set. The range will divided to groups of specific size. |
501 | * From each group will be used only defined amount of bits. |
502 | * Syntax: range:used_size/group_size |
503 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 |
504 | * |
505 | * Returns 0 on success, -errno on invalid input strings. |
506 | * Error values: |
507 | * %-EINVAL: second number in range smaller than first |
508 | * %-EINVAL: invalid character in string |
509 | * %-ERANGE: bit number specified too large for mask |
510 | */ |
511 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
512 | int is_user, unsigned long *maskp, |
513 | int nmaskbits) |
514 | { |
515 | unsigned int a, b, old_a, old_b; |
516 | unsigned int group_size, used_size; |
517 | int c, old_c, totaldigits, ndigits; |
518 | const char __user __force *ubuf = (const char __user __force *)buf; |
519 | int at_start, in_range, in_partial_range; |
520 | |
521 | totaldigits = c = 0; |
522 | old_a = old_b = 0; |
523 | group_size = used_size = 0; |
524 | bitmap_zero(maskp, nmaskbits); |
525 | do { |
526 | at_start = 1; |
527 | in_range = 0; |
528 | in_partial_range = 0; |
529 | a = b = 0; |
530 | ndigits = totaldigits; |
531 | |
532 | /* Get the next cpu# or a range of cpu#'s */ |
533 | while (buflen) { |
534 | old_c = c; |
535 | if (is_user) { |
536 | if (__get_user(c, ubuf++)) |
537 | return -EFAULT; |
538 | } else |
539 | c = *buf++; |
540 | buflen--; |
541 | if (isspace(c)) |
542 | continue; |
543 | |
544 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
545 | if (c == '\0' || c == ',') |
546 | break; |
547 | /* |
548 | * whitespaces between digits are not allowed, |
549 | * but it's ok if whitespaces are on head or tail. |
550 | * when old_c is whilespace, |
551 | * if totaldigits == ndigits, whitespace is on head. |
552 | * if whitespace is on tail, it should not run here. |
553 | * as c was ',' or '\0', |
554 | * the last code line has broken the current loop. |
555 | */ |
556 | if ((totaldigits != ndigits) && isspace(old_c)) |
557 | return -EINVAL; |
558 | |
559 | if (c == '/') { |
560 | used_size = a; |
561 | at_start = 1; |
562 | in_range = 0; |
563 | a = b = 0; |
564 | continue; |
565 | } |
566 | |
567 | if (c == ':') { |
568 | old_a = a; |
569 | old_b = b; |
570 | at_start = 1; |
571 | in_range = 0; |
572 | in_partial_range = 1; |
573 | a = b = 0; |
574 | continue; |
575 | } |
576 | |
577 | if (c == '-') { |
578 | if (at_start || in_range) |
579 | return -EINVAL; |
580 | b = 0; |
581 | in_range = 1; |
582 | at_start = 1; |
583 | continue; |
584 | } |
585 | |
586 | if (!isdigit(c)) |
587 | return -EINVAL; |
588 | |
589 | b = b * 10 + (c - '0'); |
590 | if (!in_range) |
591 | a = b; |
592 | at_start = 0; |
593 | totaldigits++; |
594 | } |
595 | if (ndigits == totaldigits) |
596 | continue; |
597 | if (in_partial_range) { |
598 | group_size = a; |
599 | a = old_a; |
600 | b = old_b; |
601 | old_a = old_b = 0; |
602 | } |
603 | /* if no digit is after '-', it's wrong*/ |
604 | if (at_start && in_range) |
605 | return -EINVAL; |
606 | if (!(a <= b) || !(used_size <= group_size)) |
607 | return -EINVAL; |
608 | if (b >= nmaskbits) |
609 | return -ERANGE; |
610 | while (a <= b) { |
611 | if (in_partial_range) { |
612 | static int pos_in_group = 1; |
613 | |
614 | if (pos_in_group <= used_size) |
615 | set_bit(a, maskp); |
616 | |
617 | if (a == b || ++pos_in_group > group_size) |
618 | pos_in_group = 1; |
619 | } else |
620 | set_bit(a, maskp); |
621 | a++; |
622 | } |
623 | } while (buflen && c == ','); |
624 | return 0; |
625 | } |
626 | |
627 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) |
628 | { |
629 | char *nl = strchrnul(bp, '\n'); |
630 | int len = nl - bp; |
631 | |
632 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); |
633 | } |
634 | EXPORT_SYMBOL(bitmap_parselist); |
635 | |
636 | |
637 | /** |
638 | * bitmap_parselist_user() |
639 | * |
640 | * @ubuf: pointer to user buffer containing string. |
641 | * @ulen: buffer size in bytes. If string is smaller than this |
642 | * then it must be terminated with a \0. |
643 | * @maskp: pointer to bitmap array that will contain result. |
644 | * @nmaskbits: size of bitmap, in bits. |
645 | * |
646 | * Wrapper for bitmap_parselist(), providing it with user buffer. |
647 | * |
648 | * We cannot have this as an inline function in bitmap.h because it needs |
649 | * linux/uaccess.h to get the access_ok() declaration and this causes |
650 | * cyclic dependencies. |
651 | */ |
652 | int bitmap_parselist_user(const char __user *ubuf, |
653 | unsigned int ulen, unsigned long *maskp, |
654 | int nmaskbits) |
655 | { |
656 | if (!access_ok(VERIFY_READ, ubuf, ulen)) |
657 | return -EFAULT; |
658 | return __bitmap_parselist((const char __force *)ubuf, |
659 | ulen, 1, maskp, nmaskbits); |
660 | } |
661 | EXPORT_SYMBOL(bitmap_parselist_user); |
662 | |
663 | |
664 | /** |
665 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
666 | * @buf: pointer to a bitmap |
667 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
668 | * @nbits: number of valid bit positions in @buf |
669 | * |
670 | * Map the bit at position @pos in @buf (of length @nbits) to the |
671 | * ordinal of which set bit it is. If it is not set or if @pos |
672 | * is not a valid bit position, map to -1. |
673 | * |
674 | * If for example, just bits 4 through 7 are set in @buf, then @pos |
675 | * values 4 through 7 will get mapped to 0 through 3, respectively, |
676 | * and other @pos values will get mapped to -1. When @pos value 7 |
677 | * gets mapped to (returns) @ord value 3 in this example, that means |
678 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. |
679 | * |
680 | * The bit positions 0 through @bits are valid positions in @buf. |
681 | */ |
682 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
683 | { |
684 | if (pos >= nbits || !test_bit(pos, buf)) |
685 | return -1; |
686 | |
687 | return __bitmap_weight(buf, pos); |
688 | } |
689 | |
690 | /** |
691 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
692 | * @buf: pointer to bitmap |
693 | * @ord: ordinal bit position (n-th set bit, n >= 0) |
694 | * @nbits: number of valid bit positions in @buf |
695 | * |
696 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. |
697 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
698 | * >= weight(buf), returns @nbits. |
699 | * |
700 | * If for example, just bits 4 through 7 are set in @buf, then @ord |
701 | * values 0 through 3 will get mapped to 4 through 7, respectively, |
702 | * and all other @ord values returns @nbits. When @ord value 3 |
703 | * gets mapped to (returns) @pos value 7 in this example, that means |
704 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. |
705 | * |
706 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
707 | */ |
708 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
709 | { |
710 | unsigned int pos; |
711 | |
712 | for (pos = find_first_bit(buf, nbits); |
713 | pos < nbits && ord; |
714 | pos = find_next_bit(buf, nbits, pos + 1)) |
715 | ord--; |
716 | |
717 | return pos; |
718 | } |
719 | |
720 | /** |
721 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap |
722 | * @dst: remapped result |
723 | * @src: subset to be remapped |
724 | * @old: defines domain of map |
725 | * @new: defines range of map |
726 | * @nbits: number of bits in each of these bitmaps |
727 | * |
728 | * Let @old and @new define a mapping of bit positions, such that |
729 | * whatever position is held by the n-th set bit in @old is mapped |
730 | * to the n-th set bit in @new. In the more general case, allowing |
731 | * for the possibility that the weight 'w' of @new is less than the |
732 | * weight of @old, map the position of the n-th set bit in @old to |
733 | * the position of the m-th set bit in @new, where m == n % w. |
734 | * |
735 | * If either of the @old and @new bitmaps are empty, or if @src and |
736 | * @dst point to the same location, then this routine copies @src |
737 | * to @dst. |
738 | * |
739 | * The positions of unset bits in @old are mapped to themselves |
740 | * (the identify map). |
741 | * |
742 | * Apply the above specified mapping to @src, placing the result in |
743 | * @dst, clearing any bits previously set in @dst. |
744 | * |
745 | * For example, lets say that @old has bits 4 through 7 set, and |
746 | * @new has bits 12 through 15 set. This defines the mapping of bit |
747 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
748 | * bit positions unchanged. So if say @src comes into this routine |
749 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, |
750 | * 13 and 15 set. |
751 | */ |
752 | void bitmap_remap(unsigned long *dst, const unsigned long *src, |
753 | const unsigned long *old, const unsigned long *new, |
754 | unsigned int nbits) |
755 | { |
756 | unsigned int oldbit, w; |
757 | |
758 | if (dst == src) /* following doesn't handle inplace remaps */ |
759 | return; |
760 | bitmap_zero(dst, nbits); |
761 | |
762 | w = bitmap_weight(new, nbits); |
763 | for_each_set_bit(oldbit, src, nbits) { |
764 | int n = bitmap_pos_to_ord(old, oldbit, nbits); |
765 | |
766 | if (n < 0 || w == 0) |
767 | set_bit(oldbit, dst); /* identity map */ |
768 | else |
769 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
770 | } |
771 | } |
772 | EXPORT_SYMBOL(bitmap_remap); |
773 | |
774 | /** |
775 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit |
776 | * @oldbit: bit position to be mapped |
777 | * @old: defines domain of map |
778 | * @new: defines range of map |
779 | * @bits: number of bits in each of these bitmaps |
780 | * |
781 | * Let @old and @new define a mapping of bit positions, such that |
782 | * whatever position is held by the n-th set bit in @old is mapped |
783 | * to the n-th set bit in @new. In the more general case, allowing |
784 | * for the possibility that the weight 'w' of @new is less than the |
785 | * weight of @old, map the position of the n-th set bit in @old to |
786 | * the position of the m-th set bit in @new, where m == n % w. |
787 | * |
788 | * The positions of unset bits in @old are mapped to themselves |
789 | * (the identify map). |
790 | * |
791 | * Apply the above specified mapping to bit position @oldbit, returning |
792 | * the new bit position. |
793 | * |
794 | * For example, lets say that @old has bits 4 through 7 set, and |
795 | * @new has bits 12 through 15 set. This defines the mapping of bit |
796 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other |
797 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
798 | * returns 13. |
799 | */ |
800 | int bitmap_bitremap(int oldbit, const unsigned long *old, |
801 | const unsigned long *new, int bits) |
802 | { |
803 | int w = bitmap_weight(new, bits); |
804 | int n = bitmap_pos_to_ord(old, oldbit, bits); |
805 | if (n < 0 || w == 0) |
806 | return oldbit; |
807 | else |
808 | return bitmap_ord_to_pos(new, n % w, bits); |
809 | } |
810 | EXPORT_SYMBOL(bitmap_bitremap); |
811 | |
812 | /** |
813 | * bitmap_onto - translate one bitmap relative to another |
814 | * @dst: resulting translated bitmap |
815 | * @orig: original untranslated bitmap |
816 | * @relmap: bitmap relative to which translated |
817 | * @bits: number of bits in each of these bitmaps |
818 | * |
819 | * Set the n-th bit of @dst iff there exists some m such that the |
820 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and |
821 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. |
822 | * (If you understood the previous sentence the first time your |
823 | * read it, you're overqualified for your current job.) |
824 | * |
825 | * In other words, @orig is mapped onto (surjectively) @dst, |
826 | * using the map { <n, m> | the n-th bit of @relmap is the |
827 | * m-th set bit of @relmap }. |
828 | * |
829 | * Any set bits in @orig above bit number W, where W is the |
830 | * weight of (number of set bits in) @relmap are mapped nowhere. |
831 | * In particular, if for all bits m set in @orig, m >= W, then |
832 | * @dst will end up empty. In situations where the possibility |
833 | * of such an empty result is not desired, one way to avoid it is |
834 | * to use the bitmap_fold() operator, below, to first fold the |
835 | * @orig bitmap over itself so that all its set bits x are in the |
836 | * range 0 <= x < W. The bitmap_fold() operator does this by |
837 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. |
838 | * |
839 | * Example [1] for bitmap_onto(): |
840 | * Let's say @relmap has bits 30-39 set, and @orig has bits |
841 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, |
842 | * @dst will have bits 31, 33, 35, 37 and 39 set. |
843 | * |
844 | * When bit 0 is set in @orig, it means turn on the bit in |
845 | * @dst corresponding to whatever is the first bit (if any) |
846 | * that is turned on in @relmap. Since bit 0 was off in the |
847 | * above example, we leave off that bit (bit 30) in @dst. |
848 | * |
849 | * When bit 1 is set in @orig (as in the above example), it |
850 | * means turn on the bit in @dst corresponding to whatever |
851 | * is the second bit that is turned on in @relmap. The second |
852 | * bit in @relmap that was turned on in the above example was |
853 | * bit 31, so we turned on bit 31 in @dst. |
854 | * |
855 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, |
856 | * because they were the 4th, 6th, 8th and 10th set bits |
857 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of |
858 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. |
859 | * |
860 | * When bit 11 is set in @orig, it means turn on the bit in |
861 | * @dst corresponding to whatever is the twelfth bit that is |
862 | * turned on in @relmap. In the above example, there were |
863 | * only ten bits turned on in @relmap (30..39), so that bit |
864 | * 11 was set in @orig had no affect on @dst. |
865 | * |
866 | * Example [2] for bitmap_fold() + bitmap_onto(): |
867 | * Let's say @relmap has these ten bits set: |
868 | * 40 41 42 43 45 48 53 61 74 95 |
869 | * (for the curious, that's 40 plus the first ten terms of the |
870 | * Fibonacci sequence.) |
871 | * |
872 | * Further lets say we use the following code, invoking |
873 | * bitmap_fold() then bitmap_onto, as suggested above to |
874 | * avoid the possibility of an empty @dst result: |
875 | * |
876 | * unsigned long *tmp; // a temporary bitmap's bits |
877 | * |
878 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); |
879 | * bitmap_onto(dst, tmp, relmap, bits); |
880 | * |
881 | * Then this table shows what various values of @dst would be, for |
882 | * various @orig's. I list the zero-based positions of each set bit. |
883 | * The tmp column shows the intermediate result, as computed by |
884 | * using bitmap_fold() to fold the @orig bitmap modulo ten |
885 | * (the weight of @relmap). |
886 | * |
887 | * @orig tmp @dst |
888 | * 0 0 40 |
889 | * 1 1 41 |
890 | * 9 9 95 |
891 | * 10 0 40 (*) |
892 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
893 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 |
894 | * 0 9 18 27 0 9 8 7 40 61 74 95 |
895 | * 0 10 20 30 0 40 |
896 | * 0 11 22 33 0 1 2 3 40 41 42 43 |
897 | * 0 12 24 36 0 2 4 6 40 42 45 53 |
898 | * 78 102 211 1 2 8 41 42 74 (*) |
899 | * |
900 | * (*) For these marked lines, if we hadn't first done bitmap_fold() |
901 | * into tmp, then the @dst result would have been empty. |
902 | * |
903 | * If either of @orig or @relmap is empty (no set bits), then @dst |
904 | * will be returned empty. |
905 | * |
906 | * If (as explained above) the only set bits in @orig are in positions |
907 | * m where m >= W, (where W is the weight of @relmap) then @dst will |
908 | * once again be returned empty. |
909 | * |
910 | * All bits in @dst not set by the above rule are cleared. |
911 | */ |
912 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, |
913 | const unsigned long *relmap, unsigned int bits) |
914 | { |
915 | unsigned int n, m; /* same meaning as in above comment */ |
916 | |
917 | if (dst == orig) /* following doesn't handle inplace mappings */ |
918 | return; |
919 | bitmap_zero(dst, bits); |
920 | |
921 | /* |
922 | * The following code is a more efficient, but less |
923 | * obvious, equivalent to the loop: |
924 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { |
925 | * n = bitmap_ord_to_pos(orig, m, bits); |
926 | * if (test_bit(m, orig)) |
927 | * set_bit(n, dst); |
928 | * } |
929 | */ |
930 | |
931 | m = 0; |
932 | for_each_set_bit(n, relmap, bits) { |
933 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
934 | if (test_bit(m, orig)) |
935 | set_bit(n, dst); |
936 | m++; |
937 | } |
938 | } |
939 | EXPORT_SYMBOL(bitmap_onto); |
940 | |
941 | /** |
942 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size |
943 | * @dst: resulting smaller bitmap |
944 | * @orig: original larger bitmap |
945 | * @sz: specified size |
946 | * @nbits: number of bits in each of these bitmaps |
947 | * |
948 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. |
949 | * Clear all other bits in @dst. See further the comment and |
950 | * Example [2] for bitmap_onto() for why and how to use this. |
951 | */ |
952 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, |
953 | unsigned int sz, unsigned int nbits) |
954 | { |
955 | unsigned int oldbit; |
956 | |
957 | if (dst == orig) /* following doesn't handle inplace mappings */ |
958 | return; |
959 | bitmap_zero(dst, nbits); |
960 | |
961 | for_each_set_bit(oldbit, orig, nbits) |
962 | set_bit(oldbit % sz, dst); |
963 | } |
964 | EXPORT_SYMBOL(bitmap_fold); |
965 | |
966 | /* |
967 | * Common code for bitmap_*_region() routines. |
968 | * bitmap: array of unsigned longs corresponding to the bitmap |
969 | * pos: the beginning of the region |
970 | * order: region size (log base 2 of number of bits) |
971 | * reg_op: operation(s) to perform on that region of bitmap |
972 | * |
973 | * Can set, verify and/or release a region of bits in a bitmap, |
974 | * depending on which combination of REG_OP_* flag bits is set. |
975 | * |
976 | * A region of a bitmap is a sequence of bits in the bitmap, of |
977 | * some size '1 << order' (a power of two), aligned to that same |
978 | * '1 << order' power of two. |
979 | * |
980 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). |
981 | * Returns 0 in all other cases and reg_ops. |
982 | */ |
983 | |
984 | enum { |
985 | REG_OP_ISFREE, /* true if region is all zero bits */ |
986 | REG_OP_ALLOC, /* set all bits in region */ |
987 | REG_OP_RELEASE, /* clear all bits in region */ |
988 | }; |
989 | |
990 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
991 | { |
992 | int nbits_reg; /* number of bits in region */ |
993 | int index; /* index first long of region in bitmap */ |
994 | int offset; /* bit offset region in bitmap[index] */ |
995 | int nlongs_reg; /* num longs spanned by region in bitmap */ |
996 | int nbitsinlong; /* num bits of region in each spanned long */ |
997 | unsigned long mask; /* bitmask for one long of region */ |
998 | int i; /* scans bitmap by longs */ |
999 | int ret = 0; /* return value */ |
1000 | |
1001 | /* |
1002 | * Either nlongs_reg == 1 (for small orders that fit in one long) |
1003 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) |
1004 | */ |
1005 | nbits_reg = 1 << order; |
1006 | index = pos / BITS_PER_LONG; |
1007 | offset = pos - (index * BITS_PER_LONG); |
1008 | nlongs_reg = BITS_TO_LONGS(nbits_reg); |
1009 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); |
1010 | |
1011 | /* |
1012 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that |
1013 | * overflows if nbitsinlong == BITS_PER_LONG. |
1014 | */ |
1015 | mask = (1UL << (nbitsinlong - 1)); |
1016 | mask += mask - 1; |
1017 | mask <<= offset; |
1018 | |
1019 | switch (reg_op) { |
1020 | case REG_OP_ISFREE: |
1021 | for (i = 0; i < nlongs_reg; i++) { |
1022 | if (bitmap[index + i] & mask) |
1023 | goto done; |
1024 | } |
1025 | ret = 1; /* all bits in region free (zero) */ |
1026 | break; |
1027 | |
1028 | case REG_OP_ALLOC: |
1029 | for (i = 0; i < nlongs_reg; i++) |
1030 | bitmap[index + i] |= mask; |
1031 | break; |
1032 | |
1033 | case REG_OP_RELEASE: |
1034 | for (i = 0; i < nlongs_reg; i++) |
1035 | bitmap[index + i] &= ~mask; |
1036 | break; |
1037 | } |
1038 | done: |
1039 | return ret; |
1040 | } |
1041 | |
1042 | /** |
1043 | * bitmap_find_free_region - find a contiguous aligned mem region |
1044 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1045 | * @bits: number of bits in the bitmap |
1046 | * @order: region size (log base 2 of number of bits) to find |
1047 | * |
1048 | * Find a region of free (zero) bits in a @bitmap of @bits bits and |
1049 | * allocate them (set them to one). Only consider regions of length |
1050 | * a power (@order) of two, aligned to that power of two, which |
1051 | * makes the search algorithm much faster. |
1052 | * |
1053 | * Return the bit offset in bitmap of the allocated region, |
1054 | * or -errno on failure. |
1055 | */ |
1056 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
1057 | { |
1058 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
1059 | |
1060 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
1061 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1062 | continue; |
1063 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1064 | return pos; |
1065 | } |
1066 | return -ENOMEM; |
1067 | } |
1068 | EXPORT_SYMBOL(bitmap_find_free_region); |
1069 | |
1070 | /** |
1071 | * bitmap_release_region - release allocated bitmap region |
1072 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1073 | * @pos: beginning of bit region to release |
1074 | * @order: region size (log base 2 of number of bits) to release |
1075 | * |
1076 | * This is the complement to __bitmap_find_free_region() and releases |
1077 | * the found region (by clearing it in the bitmap). |
1078 | * |
1079 | * No return value. |
1080 | */ |
1081 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1082 | { |
1083 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1084 | } |
1085 | EXPORT_SYMBOL(bitmap_release_region); |
1086 | |
1087 | /** |
1088 | * bitmap_allocate_region - allocate bitmap region |
1089 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1090 | * @pos: beginning of bit region to allocate |
1091 | * @order: region size (log base 2 of number of bits) to allocate |
1092 | * |
1093 | * Allocate (set bits in) a specified region of a bitmap. |
1094 | * |
1095 | * Return 0 on success, or %-EBUSY if specified region wasn't |
1096 | * free (not all bits were zero). |
1097 | */ |
1098 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1099 | { |
1100 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1101 | return -EBUSY; |
1102 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1103 | } |
1104 | EXPORT_SYMBOL(bitmap_allocate_region); |
1105 | |
1106 | /** |
1107 | * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap |
1108 | * @bitmap: array of unsigned longs, the destination bitmap, non NULL |
1109 | * @nbits: number of bits in @bitmap |
1110 | * @buf: array of u32 (in host byte order), the source bitmap, non NULL |
1111 | * @nwords: number of u32 words in @buf |
1112 | * |
1113 | * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining |
1114 | * bits between nword and nbits in @bitmap (if any) are cleared. In |
1115 | * last word of @bitmap, the bits beyond nbits (if any) are kept |
1116 | * unchanged. |
1117 | * |
1118 | * Return the number of bits effectively copied. |
1119 | */ |
1120 | unsigned int |
1121 | bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits, |
1122 | const u32 *buf, unsigned int nwords) |
1123 | { |
1124 | unsigned int dst_idx, src_idx; |
1125 | |
1126 | for (src_idx = dst_idx = 0; dst_idx < BITS_TO_LONGS(nbits); ++dst_idx) { |
1127 | unsigned long part = 0; |
1128 | |
1129 | if (src_idx < nwords) |
1130 | part = buf[src_idx++]; |
1131 | |
1132 | #if BITS_PER_LONG == 64 |
1133 | if (src_idx < nwords) |
1134 | part |= ((unsigned long) buf[src_idx++]) << 32; |
1135 | #endif |
1136 | |
1137 | if (dst_idx < nbits/BITS_PER_LONG) |
1138 | bitmap[dst_idx] = part; |
1139 | else { |
1140 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1141 | |
1142 | bitmap[dst_idx] = (bitmap[dst_idx] & ~mask) |
1143 | | (part & mask); |
1144 | } |
1145 | } |
1146 | |
1147 | return min_t(unsigned int, nbits, 32*nwords); |
1148 | } |
1149 | EXPORT_SYMBOL(bitmap_from_u32array); |
1150 | |
1151 | /** |
1152 | * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits |
1153 | * @buf: array of u32 (in host byte order), the dest bitmap, non NULL |
1154 | * @nwords: number of u32 words in @buf |
1155 | * @bitmap: array of unsigned longs, the source bitmap, non NULL |
1156 | * @nbits: number of bits in @bitmap |
1157 | * |
1158 | * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining |
1159 | * bits after nbits in @buf (if any) are cleared. |
1160 | * |
1161 | * Return the number of bits effectively copied. |
1162 | */ |
1163 | unsigned int |
1164 | bitmap_to_u32array(u32 *buf, unsigned int nwords, |
1165 | const unsigned long *bitmap, unsigned int nbits) |
1166 | { |
1167 | unsigned int dst_idx = 0, src_idx = 0; |
1168 | |
1169 | while (dst_idx < nwords) { |
1170 | unsigned long part = 0; |
1171 | |
1172 | if (src_idx < BITS_TO_LONGS(nbits)) { |
1173 | part = bitmap[src_idx]; |
1174 | if (src_idx >= nbits/BITS_PER_LONG) |
1175 | part &= BITMAP_LAST_WORD_MASK(nbits); |
1176 | src_idx++; |
1177 | } |
1178 | |
1179 | buf[dst_idx++] = part & 0xffffffffUL; |
1180 | |
1181 | #if BITS_PER_LONG == 64 |
1182 | if (dst_idx < nwords) { |
1183 | part >>= 32; |
1184 | buf[dst_idx++] = part & 0xffffffffUL; |
1185 | } |
1186 | #endif |
1187 | } |
1188 | |
1189 | return min_t(unsigned int, nbits, 32*nwords); |
1190 | } |
1191 | EXPORT_SYMBOL(bitmap_to_u32array); |
1192 | |
1193 | /** |
1194 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. |
1195 | * @dst: destination buffer |
1196 | * @src: bitmap to copy |
1197 | * @nbits: number of bits in the bitmap |
1198 | * |
1199 | * Require nbits % BITS_PER_LONG == 0. |
1200 | */ |
1201 | #ifdef __BIG_ENDIAN |
1202 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
1203 | { |
1204 | unsigned int i; |
1205 | |
1206 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { |
1207 | if (BITS_PER_LONG == 64) |
1208 | dst[i] = cpu_to_le64(src[i]); |
1209 | else |
1210 | dst[i] = cpu_to_le32(src[i]); |
1211 | } |
1212 | } |
1213 | EXPORT_SYMBOL(bitmap_copy_le); |
1214 | #endif |
1215 |