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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * lib/bitmap.c
3 * Helper functions for bitmap.h.
4 *
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
7 */
8#include <linux/module.h>
9#include <linux/ctype.h>
10#include <linux/errno.h>
11#include <linux/bitmap.h>
12#include <linux/bitops.h>
13#include <asm/uaccess.h>
14
15/*
16 * bitmaps provide an array of bits, implemented using an an
17 * array of unsigned longs. The number of valid bits in a
18 * given bitmap does _not_ need to be an exact multiple of
19 * BITS_PER_LONG.
20 *
21 * The possible unused bits in the last, partially used word
22 * of a bitmap are 'don't care'. The implementation makes
23 * no particular effort to keep them zero. It ensures that
24 * their value will not affect the results of any operation.
25 * The bitmap operations that return Boolean (bitmap_empty,
26 * for example) or scalar (bitmap_weight, for example) results
27 * carefully filter out these unused bits from impacting their
28 * results.
29 *
30 * These operations actually hold to a slightly stronger rule:
31 * if you don't input any bitmaps to these ops that have some
32 * unused bits set, then they won't output any set unused bits
33 * in output bitmaps.
34 *
35 * The byte ordering of bitmaps is more natural on little
36 * endian architectures. See the big-endian headers
37 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
38 * for the best explanations of this ordering.
39 */
40
41int __bitmap_empty(const unsigned long *bitmap, int bits)
42{
43 int k, lim = bits/BITS_PER_LONG;
44 for (k = 0; k < lim; ++k)
45 if (bitmap[k])
46 return 0;
47
48 if (bits % BITS_PER_LONG)
49 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
50 return 0;
51
52 return 1;
53}
54EXPORT_SYMBOL(__bitmap_empty);
55
56int __bitmap_full(const unsigned long *bitmap, int bits)
57{
58 int k, lim = bits/BITS_PER_LONG;
59 for (k = 0; k < lim; ++k)
60 if (~bitmap[k])
61 return 0;
62
63 if (bits % BITS_PER_LONG)
64 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
65 return 0;
66
67 return 1;
68}
69EXPORT_SYMBOL(__bitmap_full);
70
71int __bitmap_equal(const unsigned long *bitmap1,
72 const unsigned long *bitmap2, int bits)
73{
74 int k, lim = bits/BITS_PER_LONG;
75 for (k = 0; k < lim; ++k)
76 if (bitmap1[k] != bitmap2[k])
77 return 0;
78
79 if (bits % BITS_PER_LONG)
80 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
81 return 0;
82
83 return 1;
84}
85EXPORT_SYMBOL(__bitmap_equal);
86
87void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits)
88{
89 int k, lim = bits/BITS_PER_LONG;
90 for (k = 0; k < lim; ++k)
91 dst[k] = ~src[k];
92
93 if (bits % BITS_PER_LONG)
94 dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
95}
96EXPORT_SYMBOL(__bitmap_complement);
97
Robert P. J. Day72fd4a32007-02-10 01:45:59 -080098/**
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 * __bitmap_shift_right - logical right shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800100 * @dst : destination bitmap
101 * @src : source bitmap
102 * @shift : shift by this many bits
103 * @bits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 *
105 * Shifting right (dividing) means moving bits in the MS -> LS bit
106 * direction. Zeros are fed into the vacated MS positions and the
107 * LS bits shifted off the bottom are lost.
108 */
109void __bitmap_shift_right(unsigned long *dst,
110 const unsigned long *src, int shift, int bits)
111{
112 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
113 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
114 unsigned long mask = (1UL << left) - 1;
115 for (k = 0; off + k < lim; ++k) {
116 unsigned long upper, lower;
117
118 /*
119 * If shift is not word aligned, take lower rem bits of
120 * word above and make them the top rem bits of result.
121 */
122 if (!rem || off + k + 1 >= lim)
123 upper = 0;
124 else {
125 upper = src[off + k + 1];
126 if (off + k + 1 == lim - 1 && left)
127 upper &= mask;
128 }
129 lower = src[off + k];
130 if (left && off + k == lim - 1)
131 lower &= mask;
132 dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
133 if (left && k == lim - 1)
134 dst[k] &= mask;
135 }
136 if (off)
137 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
138}
139EXPORT_SYMBOL(__bitmap_shift_right);
140
141
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800142/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 * __bitmap_shift_left - logical left shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800144 * @dst : destination bitmap
145 * @src : source bitmap
146 * @shift : shift by this many bits
147 * @bits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 *
149 * Shifting left (multiplying) means moving bits in the LS -> MS
150 * direction. Zeros are fed into the vacated LS bit positions
151 * and those MS bits shifted off the top are lost.
152 */
153
154void __bitmap_shift_left(unsigned long *dst,
155 const unsigned long *src, int shift, int bits)
156{
157 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
158 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
159 for (k = lim - off - 1; k >= 0; --k) {
160 unsigned long upper, lower;
161
162 /*
163 * If shift is not word aligned, take upper rem bits of
164 * word below and make them the bottom rem bits of result.
165 */
166 if (rem && k > 0)
167 lower = src[k - 1];
168 else
169 lower = 0;
170 upper = src[k];
171 if (left && k == lim - 1)
172 upper &= (1UL << left) - 1;
173 dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
174 if (left && k + off == lim - 1)
175 dst[k + off] &= (1UL << left) - 1;
176 }
177 if (off)
178 memset(dst, 0, off*sizeof(unsigned long));
179}
180EXPORT_SYMBOL(__bitmap_shift_left);
181
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700182int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 const unsigned long *bitmap2, int bits)
184{
185 int k;
186 int nr = BITS_TO_LONGS(bits);
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700187 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 for (k = 0; k < nr; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700190 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
191 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192}
193EXPORT_SYMBOL(__bitmap_and);
194
195void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
196 const unsigned long *bitmap2, int bits)
197{
198 int k;
199 int nr = BITS_TO_LONGS(bits);
200
201 for (k = 0; k < nr; k++)
202 dst[k] = bitmap1[k] | bitmap2[k];
203}
204EXPORT_SYMBOL(__bitmap_or);
205
206void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
207 const unsigned long *bitmap2, int bits)
208{
209 int k;
210 int nr = BITS_TO_LONGS(bits);
211
212 for (k = 0; k < nr; k++)
213 dst[k] = bitmap1[k] ^ bitmap2[k];
214}
215EXPORT_SYMBOL(__bitmap_xor);
216
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700217int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 const unsigned long *bitmap2, int bits)
219{
220 int k;
221 int nr = BITS_TO_LONGS(bits);
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700222 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
224 for (k = 0; k < nr; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700225 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
226 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228EXPORT_SYMBOL(__bitmap_andnot);
229
230int __bitmap_intersects(const unsigned long *bitmap1,
231 const unsigned long *bitmap2, int bits)
232{
233 int k, lim = bits/BITS_PER_LONG;
234 for (k = 0; k < lim; ++k)
235 if (bitmap1[k] & bitmap2[k])
236 return 1;
237
238 if (bits % BITS_PER_LONG)
239 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
240 return 1;
241 return 0;
242}
243EXPORT_SYMBOL(__bitmap_intersects);
244
245int __bitmap_subset(const unsigned long *bitmap1,
246 const unsigned long *bitmap2, int bits)
247{
248 int k, lim = bits/BITS_PER_LONG;
249 for (k = 0; k < lim; ++k)
250 if (bitmap1[k] & ~bitmap2[k])
251 return 0;
252
253 if (bits % BITS_PER_LONG)
254 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
255 return 0;
256 return 1;
257}
258EXPORT_SYMBOL(__bitmap_subset);
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260int __bitmap_weight(const unsigned long *bitmap, int bits)
261{
262 int k, w = 0, lim = bits/BITS_PER_LONG;
263
264 for (k = 0; k < lim; k++)
Akinobu Mita37d54112006-03-26 01:39:56 -0800265 w += hweight_long(bitmap[k]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267 if (bits % BITS_PER_LONG)
Akinobu Mita37d54112006-03-26 01:39:56 -0800268 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270 return w;
271}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272EXPORT_SYMBOL(__bitmap_weight);
273
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800274#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
275
276void 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}
295EXPORT_SYMBOL(bitmap_set);
296
297void 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}
316EXPORT_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 */
330unsigned 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;
337again:
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}
353EXPORT_SYMBOL(bitmap_find_next_zero_area);
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355/*
356 * Bitmap printing & parsing functions: first version by Bill Irwin,
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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362#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.
373 */
374int bitmap_scnprintf(char *buf, unsigned int buflen,
375 const unsigned long *maskp, int nmaskbits)
376{
377 int i, word, bit, len = 0;
378 unsigned long val;
379 const char *sep = "";
380 int chunksz;
381 u32 chunkmask;
382
383 chunksz = nmaskbits & (CHUNKSZ - 1);
384 if (chunksz == 0)
385 chunksz = CHUNKSZ;
386
Nick Wilson8c0e33c2005-06-25 14:59:00 -0700387 i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 for (; i >= 0; i -= CHUNKSZ) {
389 chunkmask = ((1ULL << chunksz) - 1);
390 word = i / BITS_PER_LONG;
391 bit = i % BITS_PER_LONG;
392 val = (maskp[word] >> bit) & chunkmask;
393 len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
394 (chunksz+3)/4, val);
395 chunksz = CHUNKSZ;
396 sep = ",";
397 }
398 return len;
399}
400EXPORT_SYMBOL(bitmap_scnprintf);
401
402/**
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700403 * __bitmap_parse - convert an ASCII hex string into a bitmap.
404 * @buf: pointer to buffer containing string.
405 * @buflen: buffer size in bytes. If string is smaller than this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 * then it must be terminated with a \0.
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700407 * @is_user: location of buffer, 0 indicates kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 * @maskp: pointer to bitmap array that will contain result.
409 * @nmaskbits: size of bitmap, in bits.
410 *
411 * Commas group hex digits into chunks. Each chunk defines exactly 32
412 * bits of the resultant bitmask. No chunk may specify a value larger
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700413 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
414 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 * characters and for grouping errors such as "1,,5", ",44", "," and "".
416 * Leading and trailing whitespace accepted, but not embedded whitespace.
417 */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700418int __bitmap_parse(const char *buf, unsigned int buflen,
419 int is_user, unsigned long *maskp,
420 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421{
422 int c, old_c, totaldigits, ndigits, nchunks, nbits;
423 u32 chunk;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700424 const char __user *ubuf = buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 bitmap_zero(maskp, nmaskbits);
427
428 nchunks = nbits = totaldigits = c = 0;
429 do {
430 chunk = ndigits = 0;
431
432 /* Get the next chunk of the bitmap */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700433 while (buflen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 old_c = c;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700435 if (is_user) {
436 if (__get_user(c, ubuf++))
437 return -EFAULT;
438 }
439 else
440 c = *buf++;
441 buflen--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (isspace(c))
443 continue;
444
445 /*
446 * If the last character was a space and the current
447 * character isn't '\0', we've got embedded whitespace.
448 * This is a no-no, so throw an error.
449 */
450 if (totaldigits && c && isspace(old_c))
451 return -EINVAL;
452
453 /* A '\0' or a ',' signal the end of the chunk */
454 if (c == '\0' || c == ',')
455 break;
456
457 if (!isxdigit(c))
458 return -EINVAL;
459
460 /*
461 * Make sure there are at least 4 free bits in 'chunk'.
462 * If not, this hexdigit will overflow 'chunk', so
463 * throw an error.
464 */
465 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
466 return -EOVERFLOW;
467
Andy Shevchenko66f19912010-10-26 14:23:03 -0700468 chunk = (chunk << 4) | hex_to_bin(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 ndigits++; totaldigits++;
470 }
471 if (ndigits == 0)
472 return -EINVAL;
473 if (nchunks == 0 && chunk == 0)
474 continue;
475
476 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
477 *maskp |= chunk;
478 nchunks++;
479 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
480 if (nbits > nmaskbits)
481 return -EOVERFLOW;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700482 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
484 return 0;
485}
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700486EXPORT_SYMBOL(__bitmap_parse);
487
488/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800489 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700490 *
491 * @ubuf: pointer to user buffer containing string.
492 * @ulen: buffer size in bytes. If string is smaller than this
493 * then it must be terminated with a \0.
494 * @maskp: pointer to bitmap array that will contain result.
495 * @nmaskbits: size of bitmap, in bits.
496 *
497 * Wrapper for __bitmap_parse(), providing it with user buffer.
498 *
499 * We cannot have this as an inline function in bitmap.h because it needs
500 * linux/uaccess.h to get the access_ok() declaration and this causes
501 * cyclic dependencies.
502 */
503int bitmap_parse_user(const char __user *ubuf,
504 unsigned int ulen, unsigned long *maskp,
505 int nmaskbits)
506{
507 if (!access_ok(VERIFY_READ, ubuf, ulen))
508 return -EFAULT;
509 return __bitmap_parse((const char *)ubuf, ulen, 1, maskp, nmaskbits);
510}
511EXPORT_SYMBOL(bitmap_parse_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
513/*
514 * bscnl_emit(buf, buflen, rbot, rtop, bp)
515 *
516 * Helper routine for bitmap_scnlistprintf(). Write decimal number
517 * or range to buf, suppressing output past buf+buflen, with optional
518 * comma-prefix. Return len of what would be written to buf, if it
519 * all fit.
520 */
521static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
522{
523 if (len > 0)
524 len += scnprintf(buf + len, buflen - len, ",");
525 if (rbot == rtop)
526 len += scnprintf(buf + len, buflen - len, "%d", rbot);
527 else
528 len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
529 return len;
530}
531
532/**
533 * bitmap_scnlistprintf - convert bitmap to list format ASCII string
534 * @buf: byte buffer into which string is placed
535 * @buflen: reserved size of @buf, in bytes
536 * @maskp: pointer to bitmap to convert
537 * @nmaskbits: size of bitmap, in bits
538 *
539 * Output format is a comma-separated list of decimal numbers and
540 * ranges. Consecutively set bits are shown as two hyphen-separated
541 * decimal numbers, the smallest and largest bit numbers set in
542 * the range. Output format is compatible with the format
543 * accepted as input by bitmap_parselist().
544 *
545 * The return value is the number of characters which would be
546 * generated for the given input, excluding the trailing '\0', as
547 * per ISO C99.
548 */
549int bitmap_scnlistprintf(char *buf, unsigned int buflen,
550 const unsigned long *maskp, int nmaskbits)
551{
552 int len = 0;
553 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
554 int cur, rbot, rtop;
555
Andi Kleen0b030c22007-11-05 14:50:56 -0800556 if (buflen == 0)
557 return 0;
558 buf[0] = 0;
559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 rbot = cur = find_first_bit(maskp, nmaskbits);
561 while (cur < nmaskbits) {
562 rtop = cur;
563 cur = find_next_bit(maskp, nmaskbits, cur+1);
564 if (cur >= nmaskbits || cur > rtop + 1) {
565 len = bscnl_emit(buf, buflen, rbot, rtop, len);
566 rbot = cur;
567 }
568 }
569 return len;
570}
571EXPORT_SYMBOL(bitmap_scnlistprintf);
572
573/**
574 * bitmap_parselist - convert list format ASCII string to bitmap
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700575 * @bp: read nul-terminated user string from this buffer
576 * @maskp: write resulting mask here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 * @nmaskbits: number of bits in mask to be written
578 *
579 * Input format is a comma-separated list of decimal numbers and
580 * ranges. Consecutively set bits are shown as two hyphen-separated
581 * decimal numbers, the smallest and largest bit numbers set in
582 * the range.
583 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700584 * Returns 0 on success, -errno on invalid input strings.
585 * Error values:
586 * %-EINVAL: second number in range smaller than first
587 * %-EINVAL: invalid character in string
588 * %-ERANGE: bit number specified too large for mask
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 */
590int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
591{
592 unsigned a, b;
593
594 bitmap_zero(maskp, nmaskbits);
595 do {
596 if (!isdigit(*bp))
597 return -EINVAL;
598 b = a = simple_strtoul(bp, (char **)&bp, BASEDEC);
599 if (*bp == '-') {
600 bp++;
601 if (!isdigit(*bp))
602 return -EINVAL;
603 b = simple_strtoul(bp, (char **)&bp, BASEDEC);
604 }
605 if (!(a <= b))
606 return -EINVAL;
607 if (b >= nmaskbits)
608 return -ERANGE;
609 while (a <= b) {
610 set_bit(a, maskp);
611 a++;
612 }
613 if (*bp == ',')
614 bp++;
615 } while (*bp != '\0' && *bp != '\n');
616 return 0;
617}
618EXPORT_SYMBOL(bitmap_parselist);
619
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800620/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800621 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800622 * @buf: pointer to a bitmap
623 * @pos: a bit position in @buf (0 <= @pos < @bits)
624 * @bits: number of valid bit positions in @buf
625 *
626 * Map the bit at position @pos in @buf (of length @bits) to the
627 * ordinal of which set bit it is. If it is not set or if @pos
Paul Jackson96b7f342006-01-08 01:01:46 -0800628 * is not a valid bit position, map to -1.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800629 *
630 * If for example, just bits 4 through 7 are set in @buf, then @pos
631 * values 4 through 7 will get mapped to 0 through 3, respectively,
632 * and other @pos values will get mapped to 0. When @pos value 7
633 * gets mapped to (returns) @ord value 3 in this example, that means
634 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
635 *
636 * The bit positions 0 through @bits are valid positions in @buf.
637 */
638static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
639{
Paul Jackson96b7f342006-01-08 01:01:46 -0800640 int i, ord;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800641
Paul Jackson96b7f342006-01-08 01:01:46 -0800642 if (pos < 0 || pos >= bits || !test_bit(pos, buf))
643 return -1;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800644
Paul Jackson96b7f342006-01-08 01:01:46 -0800645 i = find_first_bit(buf, bits);
646 ord = 0;
647 while (i < pos) {
648 i = find_next_bit(buf, bits, i + 1);
649 ord++;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800650 }
Paul Jackson96b7f342006-01-08 01:01:46 -0800651 BUG_ON(i != pos);
652
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800653 return ord;
654}
655
656/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800657 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800658 * @buf: pointer to bitmap
659 * @ord: ordinal bit position (n-th set bit, n >= 0)
660 * @bits: number of valid bit positions in @buf
661 *
662 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
Paul Jackson96b7f342006-01-08 01:01:46 -0800663 * Value of @ord should be in range 0 <= @ord < weight(buf), else
664 * results are undefined.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800665 *
666 * If for example, just bits 4 through 7 are set in @buf, then @ord
667 * values 0 through 3 will get mapped to 4 through 7, respectively,
Paul Jackson96b7f342006-01-08 01:01:46 -0800668 * and all other @ord values return undefined values. When @ord value 3
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800669 * gets mapped to (returns) @pos value 7 in this example, that means
670 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
671 *
672 * The bit positions 0 through @bits are valid positions in @buf.
673 */
Linus Torvalds35926ff2010-05-30 09:00:03 -0700674static int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800675{
676 int pos = 0;
677
678 if (ord >= 0 && ord < bits) {
679 int i;
680
681 for (i = find_first_bit(buf, bits);
682 i < bits && ord > 0;
683 i = find_next_bit(buf, bits, i + 1))
684 ord--;
685 if (i < bits && ord == 0)
686 pos = i;
687 }
688
689 return pos;
690}
691
692/**
693 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800694 * @dst: remapped result
Paul Jackson96b7f342006-01-08 01:01:46 -0800695 * @src: subset to be remapped
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800696 * @old: defines domain of map
697 * @new: defines range of map
698 * @bits: number of bits in each of these bitmaps
699 *
700 * Let @old and @new define a mapping of bit positions, such that
701 * whatever position is held by the n-th set bit in @old is mapped
702 * to the n-th set bit in @new. In the more general case, allowing
703 * for the possibility that the weight 'w' of @new is less than the
704 * weight of @old, map the position of the n-th set bit in @old to
705 * the position of the m-th set bit in @new, where m == n % w.
706 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800707 * If either of the @old and @new bitmaps are empty, or if @src and
708 * @dst point to the same location, then this routine copies @src
709 * to @dst.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800710 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800711 * The positions of unset bits in @old are mapped to themselves
712 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800713 *
714 * Apply the above specified mapping to @src, placing the result in
715 * @dst, clearing any bits previously set in @dst.
716 *
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800717 * For example, lets say that @old has bits 4 through 7 set, and
718 * @new has bits 12 through 15 set. This defines the mapping of bit
719 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
Paul Jackson96b7f342006-01-08 01:01:46 -0800720 * bit positions unchanged. So if say @src comes into this routine
721 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
722 * 13 and 15 set.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800723 */
724void bitmap_remap(unsigned long *dst, const unsigned long *src,
725 const unsigned long *old, const unsigned long *new,
726 int bits)
727{
Paul Jackson96b7f342006-01-08 01:01:46 -0800728 int oldbit, w;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800729
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800730 if (dst == src) /* following doesn't handle inplace remaps */
731 return;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800732 bitmap_zero(dst, bits);
Paul Jackson96b7f342006-01-08 01:01:46 -0800733
734 w = bitmap_weight(new, bits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800735 for_each_set_bit(oldbit, src, bits) {
Paul Jackson96b7f342006-01-08 01:01:46 -0800736 int n = bitmap_pos_to_ord(old, oldbit, bits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800737
Paul Jackson96b7f342006-01-08 01:01:46 -0800738 if (n < 0 || w == 0)
739 set_bit(oldbit, dst); /* identity map */
740 else
741 set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800742 }
743}
744EXPORT_SYMBOL(bitmap_remap);
745
746/**
747 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700748 * @oldbit: bit position to be mapped
749 * @old: defines domain of map
750 * @new: defines range of map
751 * @bits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800752 *
753 * Let @old and @new define a mapping of bit positions, such that
754 * whatever position is held by the n-th set bit in @old is mapped
755 * to the n-th set bit in @new. In the more general case, allowing
756 * for the possibility that the weight 'w' of @new is less than the
757 * weight of @old, map the position of the n-th set bit in @old to
758 * the position of the m-th set bit in @new, where m == n % w.
759 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800760 * The positions of unset bits in @old are mapped to themselves
761 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800762 *
763 * Apply the above specified mapping to bit position @oldbit, returning
764 * the new bit position.
765 *
766 * For example, lets say that @old has bits 4 through 7 set, and
767 * @new has bits 12 through 15 set. This defines the mapping of bit
768 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
Paul Jackson96b7f342006-01-08 01:01:46 -0800769 * bit positions unchanged. So if say @oldbit is 5, then this routine
770 * returns 13.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800771 */
772int bitmap_bitremap(int oldbit, const unsigned long *old,
773 const unsigned long *new, int bits)
774{
Paul Jackson96b7f342006-01-08 01:01:46 -0800775 int w = bitmap_weight(new, bits);
776 int n = bitmap_pos_to_ord(old, oldbit, bits);
777 if (n < 0 || w == 0)
778 return oldbit;
779 else
780 return bitmap_ord_to_pos(new, n % w, bits);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800781}
782EXPORT_SYMBOL(bitmap_bitremap);
783
Paul Jackson7ea931c2008-04-28 02:12:29 -0700784/**
785 * bitmap_onto - translate one bitmap relative to another
786 * @dst: resulting translated bitmap
787 * @orig: original untranslated bitmap
788 * @relmap: bitmap relative to which translated
789 * @bits: number of bits in each of these bitmaps
790 *
791 * Set the n-th bit of @dst iff there exists some m such that the
792 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
793 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
794 * (If you understood the previous sentence the first time your
795 * read it, you're overqualified for your current job.)
796 *
797 * In other words, @orig is mapped onto (surjectively) @dst,
798 * using the the map { <n, m> | the n-th bit of @relmap is the
799 * m-th set bit of @relmap }.
800 *
801 * Any set bits in @orig above bit number W, where W is the
802 * weight of (number of set bits in) @relmap are mapped nowhere.
803 * In particular, if for all bits m set in @orig, m >= W, then
804 * @dst will end up empty. In situations where the possibility
805 * of such an empty result is not desired, one way to avoid it is
806 * to use the bitmap_fold() operator, below, to first fold the
807 * @orig bitmap over itself so that all its set bits x are in the
808 * range 0 <= x < W. The bitmap_fold() operator does this by
809 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
810 *
811 * Example [1] for bitmap_onto():
812 * Let's say @relmap has bits 30-39 set, and @orig has bits
813 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
814 * @dst will have bits 31, 33, 35, 37 and 39 set.
815 *
816 * When bit 0 is set in @orig, it means turn on the bit in
817 * @dst corresponding to whatever is the first bit (if any)
818 * that is turned on in @relmap. Since bit 0 was off in the
819 * above example, we leave off that bit (bit 30) in @dst.
820 *
821 * When bit 1 is set in @orig (as in the above example), it
822 * means turn on the bit in @dst corresponding to whatever
823 * is the second bit that is turned on in @relmap. The second
824 * bit in @relmap that was turned on in the above example was
825 * bit 31, so we turned on bit 31 in @dst.
826 *
827 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
828 * because they were the 4th, 6th, 8th and 10th set bits
829 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
830 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
831 *
832 * When bit 11 is set in @orig, it means turn on the bit in
833 * @dst corresponding to whatever is the twelth bit that is
834 * turned on in @relmap. In the above example, there were
835 * only ten bits turned on in @relmap (30..39), so that bit
836 * 11 was set in @orig had no affect on @dst.
837 *
838 * Example [2] for bitmap_fold() + bitmap_onto():
839 * Let's say @relmap has these ten bits set:
840 * 40 41 42 43 45 48 53 61 74 95
841 * (for the curious, that's 40 plus the first ten terms of the
842 * Fibonacci sequence.)
843 *
844 * Further lets say we use the following code, invoking
845 * bitmap_fold() then bitmap_onto, as suggested above to
846 * avoid the possitility of an empty @dst result:
847 *
848 * unsigned long *tmp; // a temporary bitmap's bits
849 *
850 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
851 * bitmap_onto(dst, tmp, relmap, bits);
852 *
853 * Then this table shows what various values of @dst would be, for
854 * various @orig's. I list the zero-based positions of each set bit.
855 * The tmp column shows the intermediate result, as computed by
856 * using bitmap_fold() to fold the @orig bitmap modulo ten
857 * (the weight of @relmap).
858 *
859 * @orig tmp @dst
860 * 0 0 40
861 * 1 1 41
862 * 9 9 95
863 * 10 0 40 (*)
864 * 1 3 5 7 1 3 5 7 41 43 48 61
865 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
866 * 0 9 18 27 0 9 8 7 40 61 74 95
867 * 0 10 20 30 0 40
868 * 0 11 22 33 0 1 2 3 40 41 42 43
869 * 0 12 24 36 0 2 4 6 40 42 45 53
870 * 78 102 211 1 2 8 41 42 74 (*)
871 *
872 * (*) For these marked lines, if we hadn't first done bitmap_fold()
873 * into tmp, then the @dst result would have been empty.
874 *
875 * If either of @orig or @relmap is empty (no set bits), then @dst
876 * will be returned empty.
877 *
878 * If (as explained above) the only set bits in @orig are in positions
879 * m where m >= W, (where W is the weight of @relmap) then @dst will
880 * once again be returned empty.
881 *
882 * All bits in @dst not set by the above rule are cleared.
883 */
884void bitmap_onto(unsigned long *dst, const unsigned long *orig,
885 const unsigned long *relmap, int bits)
886{
887 int n, m; /* same meaning as in above comment */
888
889 if (dst == orig) /* following doesn't handle inplace mappings */
890 return;
891 bitmap_zero(dst, bits);
892
893 /*
894 * The following code is a more efficient, but less
895 * obvious, equivalent to the loop:
896 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
897 * n = bitmap_ord_to_pos(orig, m, bits);
898 * if (test_bit(m, orig))
899 * set_bit(n, dst);
900 * }
901 */
902
903 m = 0;
Akinobu Mita08564fb2010-03-05 13:43:18 -0800904 for_each_set_bit(n, relmap, bits) {
Paul Jackson7ea931c2008-04-28 02:12:29 -0700905 /* m == bitmap_pos_to_ord(relmap, n, bits) */
906 if (test_bit(m, orig))
907 set_bit(n, dst);
908 m++;
909 }
910}
911EXPORT_SYMBOL(bitmap_onto);
912
913/**
914 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
915 * @dst: resulting smaller bitmap
916 * @orig: original larger bitmap
917 * @sz: specified size
918 * @bits: number of bits in each of these bitmaps
919 *
920 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
921 * Clear all other bits in @dst. See further the comment and
922 * Example [2] for bitmap_onto() for why and how to use this.
923 */
924void bitmap_fold(unsigned long *dst, const unsigned long *orig,
925 int sz, int bits)
926{
927 int oldbit;
928
929 if (dst == orig) /* following doesn't handle inplace mappings */
930 return;
931 bitmap_zero(dst, bits);
932
Akinobu Mita08564fb2010-03-05 13:43:18 -0800933 for_each_set_bit(oldbit, orig, bits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700934 set_bit(oldbit % sz, dst);
935}
936EXPORT_SYMBOL(bitmap_fold);
937
Paul Jackson3cf64b92006-03-24 03:15:46 -0800938/*
939 * Common code for bitmap_*_region() routines.
940 * bitmap: array of unsigned longs corresponding to the bitmap
941 * pos: the beginning of the region
942 * order: region size (log base 2 of number of bits)
943 * reg_op: operation(s) to perform on that region of bitmap
944 *
945 * Can set, verify and/or release a region of bits in a bitmap,
946 * depending on which combination of REG_OP_* flag bits is set.
947 *
948 * A region of a bitmap is a sequence of bits in the bitmap, of
949 * some size '1 << order' (a power of two), aligned to that same
950 * '1 << order' power of two.
951 *
952 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
953 * Returns 0 in all other cases and reg_ops.
954 */
955
956enum {
957 REG_OP_ISFREE, /* true if region is all zero bits */
958 REG_OP_ALLOC, /* set all bits in region */
959 REG_OP_RELEASE, /* clear all bits in region */
960};
961
962static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
963{
964 int nbits_reg; /* number of bits in region */
965 int index; /* index first long of region in bitmap */
966 int offset; /* bit offset region in bitmap[index] */
967 int nlongs_reg; /* num longs spanned by region in bitmap */
968 int nbitsinlong; /* num bits of region in each spanned long */
969 unsigned long mask; /* bitmask for one long of region */
970 int i; /* scans bitmap by longs */
971 int ret = 0; /* return value */
972
973 /*
974 * Either nlongs_reg == 1 (for small orders that fit in one long)
975 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
976 */
977 nbits_reg = 1 << order;
978 index = pos / BITS_PER_LONG;
979 offset = pos - (index * BITS_PER_LONG);
980 nlongs_reg = BITS_TO_LONGS(nbits_reg);
981 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
982
983 /*
984 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
985 * overflows if nbitsinlong == BITS_PER_LONG.
986 */
987 mask = (1UL << (nbitsinlong - 1));
988 mask += mask - 1;
989 mask <<= offset;
990
991 switch (reg_op) {
992 case REG_OP_ISFREE:
993 for (i = 0; i < nlongs_reg; i++) {
994 if (bitmap[index + i] & mask)
995 goto done;
996 }
997 ret = 1; /* all bits in region free (zero) */
998 break;
999
1000 case REG_OP_ALLOC:
1001 for (i = 0; i < nlongs_reg; i++)
1002 bitmap[index + i] |= mask;
1003 break;
1004
1005 case REG_OP_RELEASE:
1006 for (i = 0; i < nlongs_reg; i++)
1007 bitmap[index + i] &= ~mask;
1008 break;
1009 }
1010done:
1011 return ret;
1012}
1013
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014/**
Paul Jackson87e24802006-03-24 03:15:44 -08001015 * bitmap_find_free_region - find a contiguous aligned mem region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001016 * @bitmap: array of unsigned longs corresponding to the bitmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 * @bits: number of bits in the bitmap
Paul Jackson3cf64b92006-03-24 03:15:46 -08001018 * @order: region size (log base 2 of number of bits) to find
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001020 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1021 * allocate them (set them to one). Only consider regions of length
1022 * a power (@order) of two, aligned to that power of two, which
Paul Jackson87e24802006-03-24 03:15:44 -08001023 * makes the search algorithm much faster.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001025 * Return the bit offset in bitmap of the allocated region,
Paul Jackson87e24802006-03-24 03:15:44 -08001026 * or -errno on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 */
1028int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
1029{
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001030 int pos, end; /* scans bitmap by regions of size order */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001032 for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
1033 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1034 continue;
1035 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1036 return pos;
1037 }
1038 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039}
1040EXPORT_SYMBOL(bitmap_find_free_region);
1041
1042/**
Paul Jackson87e24802006-03-24 03:15:44 -08001043 * bitmap_release_region - release allocated bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001044 * @bitmap: array of unsigned longs corresponding to the bitmap
1045 * @pos: beginning of bit region to release
1046 * @order: region size (log base 2 of number of bits) to release
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001048 * This is the complement to __bitmap_find_free_region() and releases
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 * the found region (by clearing it in the bitmap).
Paul Jackson3cf64b92006-03-24 03:15:46 -08001050 *
1051 * No return value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 */
1053void bitmap_release_region(unsigned long *bitmap, int pos, int order)
1054{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001055 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056}
1057EXPORT_SYMBOL(bitmap_release_region);
1058
Paul Jackson87e24802006-03-24 03:15:44 -08001059/**
1060 * bitmap_allocate_region - allocate bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001061 * @bitmap: array of unsigned longs corresponding to the bitmap
1062 * @pos: beginning of bit region to allocate
1063 * @order: region size (log base 2 of number of bits) to allocate
Paul Jackson87e24802006-03-24 03:15:44 -08001064 *
1065 * Allocate (set bits in) a specified region of a bitmap.
Paul Jackson3cf64b92006-03-24 03:15:46 -08001066 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -07001067 * Return 0 on success, or %-EBUSY if specified region wasn't
Paul Jackson87e24802006-03-24 03:15:44 -08001068 * free (not all bits were zero).
1069 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
1071{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001072 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1073 return -EBUSY;
1074 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 return 0;
1076}
1077EXPORT_SYMBOL(bitmap_allocate_region);
David Vrabelccbe3292008-09-17 16:34:03 +01001078
1079/**
1080 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1081 * @dst: destination buffer
1082 * @src: bitmap to copy
1083 * @nbits: number of bits in the bitmap
1084 *
1085 * Require nbits % BITS_PER_LONG == 0.
1086 */
1087void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
1088{
1089 unsigned long *d = dst;
1090 int i;
1091
1092 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1093 if (BITS_PER_LONG == 64)
1094 d[i] = cpu_to_le64(src[i]);
1095 else
1096 d[i] = cpu_to_le32(src[i]);
1097 }
1098}
1099EXPORT_SYMBOL(bitmap_copy_le);