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1da177e4
LT
1/*
2 * lib/bitmap.c
3 * Helper functions for bitmap.h.
4 *
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
7 */
8bc3bcc9
PG
8#include <linux/export.h>
9#include <linux/thread_info.h>
1da177e4
LT
10#include <linux/ctype.h>
11#include <linux/errno.h>
12#include <linux/bitmap.h>
13#include <linux/bitops.h>
50af5ead 14#include <linux/bug.h>
1da177e4
LT
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
43int __bitmap_empty(const unsigned long *bitmap, int bits)
44{
45 int k, lim = bits/BITS_PER_LONG;
46 for (k = 0; k < lim; ++k)
47 if (bitmap[k])
48 return 0;
49
50 if (bits % BITS_PER_LONG)
51 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
52 return 0;
53
54 return 1;
55}
56EXPORT_SYMBOL(__bitmap_empty);
57
58int __bitmap_full(const unsigned long *bitmap, int bits)
59{
60 int k, lim = bits/BITS_PER_LONG;
61 for (k = 0; k < lim; ++k)
62 if (~bitmap[k])
63 return 0;
64
65 if (bits % BITS_PER_LONG)
66 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
67 return 0;
68
69 return 1;
70}
71EXPORT_SYMBOL(__bitmap_full);
72
73int __bitmap_equal(const unsigned long *bitmap1,
74 const unsigned long *bitmap2, int bits)
75{
76 int k, lim = bits/BITS_PER_LONG;
77 for (k = 0; k < lim; ++k)
78 if (bitmap1[k] != bitmap2[k])
79 return 0;
80
81 if (bits % BITS_PER_LONG)
82 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
83 return 0;
84
85 return 1;
86}
87EXPORT_SYMBOL(__bitmap_equal);
88
89void __bitmap_complement(unsigned long *dst, const unsigned long *src, int bits)
90{
91 int k, lim = bits/BITS_PER_LONG;
92 for (k = 0; k < lim; ++k)
93 dst[k] = ~src[k];
94
95 if (bits % BITS_PER_LONG)
96 dst[k] = ~src[k] & BITMAP_LAST_WORD_MASK(bits);
97}
98EXPORT_SYMBOL(__bitmap_complement);
99
72fd4a35 100/**
1da177e4 101 * __bitmap_shift_right - logical right shift of the bits in a bitmap
05fb6bf0
RD
102 * @dst : destination bitmap
103 * @src : source bitmap
104 * @shift : shift by this many bits
105 * @bits : bitmap size, in bits
1da177e4
LT
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 */
111void __bitmap_shift_right(unsigned long *dst,
112 const unsigned long *src, int shift, int bits)
113{
114 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
115 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
116 unsigned long mask = (1UL << left) - 1;
117 for (k = 0; off + k < lim; ++k) {
118 unsigned long upper, lower;
119
120 /*
121 * If shift is not word aligned, take lower rem bits of
122 * word above and make them the top rem bits of result.
123 */
124 if (!rem || off + k + 1 >= lim)
125 upper = 0;
126 else {
127 upper = src[off + k + 1];
128 if (off + k + 1 == lim - 1 && left)
129 upper &= mask;
130 }
131 lower = src[off + k];
132 if (left && off + k == lim - 1)
133 lower &= mask;
134 dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
135 if (left && k == lim - 1)
136 dst[k] &= mask;
137 }
138 if (off)
139 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
140}
141EXPORT_SYMBOL(__bitmap_shift_right);
142
143
72fd4a35 144/**
1da177e4 145 * __bitmap_shift_left - logical left shift of the bits in a bitmap
05fb6bf0
RD
146 * @dst : destination bitmap
147 * @src : source bitmap
148 * @shift : shift by this many bits
149 * @bits : bitmap size, in bits
1da177e4
LT
150 *
151 * Shifting left (multiplying) means moving bits in the LS -> MS
152 * direction. Zeros are fed into the vacated LS bit positions
153 * and those MS bits shifted off the top are lost.
154 */
155
156void __bitmap_shift_left(unsigned long *dst,
157 const unsigned long *src, int shift, int bits)
158{
159 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
160 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
161 for (k = lim - off - 1; k >= 0; --k) {
162 unsigned long upper, lower;
163
164 /*
165 * If shift is not word aligned, take upper rem bits of
166 * word below and make them the bottom rem bits of result.
167 */
168 if (rem && k > 0)
169 lower = src[k - 1];
170 else
171 lower = 0;
172 upper = src[k];
173 if (left && k == lim - 1)
174 upper &= (1UL << left) - 1;
175 dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
176 if (left && k + off == lim - 1)
177 dst[k + off] &= (1UL << left) - 1;
178 }
179 if (off)
180 memset(dst, 0, off*sizeof(unsigned long));
181}
182EXPORT_SYMBOL(__bitmap_shift_left);
183
f4b0373b 184int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
1da177e4
LT
185 const unsigned long *bitmap2, int bits)
186{
187 int k;
188 int nr = BITS_TO_LONGS(bits);
f4b0373b 189 unsigned long result = 0;
1da177e4
LT
190
191 for (k = 0; k < nr; k++)
f4b0373b
LT
192 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
193 return result != 0;
1da177e4
LT
194}
195EXPORT_SYMBOL(__bitmap_and);
196
197void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
198 const unsigned long *bitmap2, int bits)
199{
200 int k;
201 int nr = BITS_TO_LONGS(bits);
202
203 for (k = 0; k < nr; k++)
204 dst[k] = bitmap1[k] | bitmap2[k];
205}
206EXPORT_SYMBOL(__bitmap_or);
207
208void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
209 const unsigned long *bitmap2, int bits)
210{
211 int k;
212 int nr = BITS_TO_LONGS(bits);
213
214 for (k = 0; k < nr; k++)
215 dst[k] = bitmap1[k] ^ bitmap2[k];
216}
217EXPORT_SYMBOL(__bitmap_xor);
218
f4b0373b 219int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
1da177e4
LT
220 const unsigned long *bitmap2, int bits)
221{
222 int k;
223 int nr = BITS_TO_LONGS(bits);
f4b0373b 224 unsigned long result = 0;
1da177e4
LT
225
226 for (k = 0; k < nr; k++)
f4b0373b
LT
227 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
228 return result != 0;
1da177e4
LT
229}
230EXPORT_SYMBOL(__bitmap_andnot);
231
232int __bitmap_intersects(const unsigned long *bitmap1,
233 const unsigned long *bitmap2, int bits)
234{
235 int k, lim = bits/BITS_PER_LONG;
236 for (k = 0; k < lim; ++k)
237 if (bitmap1[k] & bitmap2[k])
238 return 1;
239
240 if (bits % BITS_PER_LONG)
241 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
242 return 1;
243 return 0;
244}
245EXPORT_SYMBOL(__bitmap_intersects);
246
247int __bitmap_subset(const unsigned long *bitmap1,
248 const unsigned long *bitmap2, int bits)
249{
250 int k, lim = bits/BITS_PER_LONG;
251 for (k = 0; k < lim; ++k)
252 if (bitmap1[k] & ~bitmap2[k])
253 return 0;
254
255 if (bits % BITS_PER_LONG)
256 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
257 return 0;
258 return 1;
259}
260EXPORT_SYMBOL(__bitmap_subset);
261
1da177e4
LT
262int __bitmap_weight(const unsigned long *bitmap, int bits)
263{
264 int k, w = 0, lim = bits/BITS_PER_LONG;
265
266 for (k = 0; k < lim; k++)
37d54111 267 w += hweight_long(bitmap[k]);
1da177e4
LT
268
269 if (bits % BITS_PER_LONG)
37d54111 270 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
1da177e4
LT
271
272 return w;
273}
1da177e4
LT
274EXPORT_SYMBOL(__bitmap_weight);
275
c1a2a962
AM
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
1da177e4 355/*
6d49e352 356 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
1da177e4
LT
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)
1da177e4
LT
362#define BASEDEC 10 /* fancier cpuset lists input in decimal */
363
364/**
365 * bitmap_scnprintf - convert bitmap to an ASCII hex string.
366 * @buf: byte buffer into which string is placed
367 * @buflen: reserved size of @buf, in bytes
368 * @maskp: pointer to bitmap to convert
369 * @nmaskbits: size of bitmap, in bits
370 *
371 * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
05a6c8a9
AM
372 * comma-separated sets of eight digits per set. Returns the number of
373 * characters which were written to *buf, excluding the trailing \0.
1da177e4
LT
374 */
375int bitmap_scnprintf(char *buf, unsigned int buflen,
376 const unsigned long *maskp, int nmaskbits)
377{
378 int i, word, bit, len = 0;
379 unsigned long val;
380 const char *sep = "";
381 int chunksz;
382 u32 chunkmask;
383
384 chunksz = nmaskbits & (CHUNKSZ - 1);
385 if (chunksz == 0)
386 chunksz = CHUNKSZ;
387
8c0e33c1 388 i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
1da177e4
LT
389 for (; i >= 0; i -= CHUNKSZ) {
390 chunkmask = ((1ULL << chunksz) - 1);
391 word = i / BITS_PER_LONG;
392 bit = i % BITS_PER_LONG;
393 val = (maskp[word] >> bit) & chunkmask;
394 len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
395 (chunksz+3)/4, val);
396 chunksz = CHUNKSZ;
397 sep = ",";
398 }
399 return len;
400}
401EXPORT_SYMBOL(bitmap_scnprintf);
402
403/**
01a3ee2b
RC
404 * __bitmap_parse - convert an ASCII hex string into a bitmap.
405 * @buf: pointer to buffer containing string.
406 * @buflen: buffer size in bytes. If string is smaller than this
1da177e4 407 * then it must be terminated with a \0.
01a3ee2b 408 * @is_user: location of buffer, 0 indicates kernel space
1da177e4
LT
409 * @maskp: pointer to bitmap array that will contain result.
410 * @nmaskbits: size of bitmap, in bits.
411 *
412 * Commas group hex digits into chunks. Each chunk defines exactly 32
413 * bits of the resultant bitmask. No chunk may specify a value larger
6e1907ff
RD
414 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
415 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
1da177e4
LT
416 * characters and for grouping errors such as "1,,5", ",44", "," and "".
417 * Leading and trailing whitespace accepted, but not embedded whitespace.
418 */
01a3ee2b
RC
419int __bitmap_parse(const char *buf, unsigned int buflen,
420 int is_user, unsigned long *maskp,
421 int nmaskbits)
1da177e4
LT
422{
423 int c, old_c, totaldigits, ndigits, nchunks, nbits;
424 u32 chunk;
b9c321fd 425 const char __user __force *ubuf = (const char __user __force *)buf;
1da177e4
LT
426
427 bitmap_zero(maskp, nmaskbits);
428
429 nchunks = nbits = totaldigits = c = 0;
430 do {
431 chunk = ndigits = 0;
432
433 /* Get the next chunk of the bitmap */
01a3ee2b 434 while (buflen) {
1da177e4 435 old_c = c;
01a3ee2b
RC
436 if (is_user) {
437 if (__get_user(c, ubuf++))
438 return -EFAULT;
439 }
440 else
441 c = *buf++;
442 buflen--;
1da177e4
LT
443 if (isspace(c))
444 continue;
445
446 /*
447 * If the last character was a space and the current
448 * character isn't '\0', we've got embedded whitespace.
449 * This is a no-no, so throw an error.
450 */
451 if (totaldigits && c && isspace(old_c))
452 return -EINVAL;
453
454 /* A '\0' or a ',' signal the end of the chunk */
455 if (c == '\0' || c == ',')
456 break;
457
458 if (!isxdigit(c))
459 return -EINVAL;
460
461 /*
462 * Make sure there are at least 4 free bits in 'chunk'.
463 * If not, this hexdigit will overflow 'chunk', so
464 * throw an error.
465 */
466 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
467 return -EOVERFLOW;
468
66f1991b 469 chunk = (chunk << 4) | hex_to_bin(c);
1da177e4
LT
470 ndigits++; totaldigits++;
471 }
472 if (ndigits == 0)
473 return -EINVAL;
474 if (nchunks == 0 && chunk == 0)
475 continue;
476
477 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
478 *maskp |= chunk;
479 nchunks++;
480 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
481 if (nbits > nmaskbits)
482 return -EOVERFLOW;
01a3ee2b 483 } while (buflen && c == ',');
1da177e4
LT
484
485 return 0;
486}
01a3ee2b
RC
487EXPORT_SYMBOL(__bitmap_parse);
488
489/**
9a86e2ba 490 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
01a3ee2b
RC
491 *
492 * @ubuf: pointer to user buffer containing string.
493 * @ulen: buffer size in bytes. If string is smaller than this
494 * then it must be terminated with a \0.
495 * @maskp: pointer to bitmap array that will contain result.
496 * @nmaskbits: size of bitmap, in bits.
497 *
498 * Wrapper for __bitmap_parse(), providing it with user buffer.
499 *
500 * We cannot have this as an inline function in bitmap.h because it needs
501 * linux/uaccess.h to get the access_ok() declaration and this causes
502 * cyclic dependencies.
503 */
504int bitmap_parse_user(const char __user *ubuf,
505 unsigned int ulen, unsigned long *maskp,
506 int nmaskbits)
507{
508 if (!access_ok(VERIFY_READ, ubuf, ulen))
509 return -EFAULT;
b9c321fd
HS
510 return __bitmap_parse((const char __force *)ubuf,
511 ulen, 1, maskp, nmaskbits);
512
01a3ee2b
RC
513}
514EXPORT_SYMBOL(bitmap_parse_user);
1da177e4
LT
515
516/*
517 * bscnl_emit(buf, buflen, rbot, rtop, bp)
518 *
519 * Helper routine for bitmap_scnlistprintf(). Write decimal number
520 * or range to buf, suppressing output past buf+buflen, with optional
05a6c8a9
AM
521 * comma-prefix. Return len of what was written to *buf, excluding the
522 * trailing \0.
1da177e4
LT
523 */
524static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
525{
526 if (len > 0)
527 len += scnprintf(buf + len, buflen - len, ",");
528 if (rbot == rtop)
529 len += scnprintf(buf + len, buflen - len, "%d", rbot);
530 else
531 len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
532 return len;
533}
534
535/**
536 * bitmap_scnlistprintf - convert bitmap to list format ASCII string
537 * @buf: byte buffer into which string is placed
538 * @buflen: reserved size of @buf, in bytes
539 * @maskp: pointer to bitmap to convert
540 * @nmaskbits: size of bitmap, in bits
541 *
542 * Output format is a comma-separated list of decimal numbers and
543 * ranges. Consecutively set bits are shown as two hyphen-separated
544 * decimal numbers, the smallest and largest bit numbers set in
545 * the range. Output format is compatible with the format
546 * accepted as input by bitmap_parselist().
547 *
05a6c8a9
AM
548 * The return value is the number of characters which were written to *buf
549 * excluding the trailing '\0', as per ISO C99's scnprintf.
1da177e4
LT
550 */
551int bitmap_scnlistprintf(char *buf, unsigned int buflen,
552 const unsigned long *maskp, int nmaskbits)
553{
554 int len = 0;
555 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
556 int cur, rbot, rtop;
557
0b030c2c
AK
558 if (buflen == 0)
559 return 0;
560 buf[0] = 0;
561
1da177e4
LT
562 rbot = cur = find_first_bit(maskp, nmaskbits);
563 while (cur < nmaskbits) {
564 rtop = cur;
565 cur = find_next_bit(maskp, nmaskbits, cur+1);
566 if (cur >= nmaskbits || cur > rtop + 1) {
567 len = bscnl_emit(buf, buflen, rbot, rtop, len);
568 rbot = cur;
569 }
570 }
571 return len;
572}
573EXPORT_SYMBOL(bitmap_scnlistprintf);
574
575/**
4b060420 576 * __bitmap_parselist - convert list format ASCII string to bitmap
b0825ee3 577 * @buf: read nul-terminated user string from this buffer
4b060420
MT
578 * @buflen: buffer size in bytes. If string is smaller than this
579 * then it must be terminated with a \0.
580 * @is_user: location of buffer, 0 indicates kernel space
6e1907ff 581 * @maskp: write resulting mask here
1da177e4
LT
582 * @nmaskbits: number of bits in mask to be written
583 *
584 * Input format is a comma-separated list of decimal numbers and
585 * ranges. Consecutively set bits are shown as two hyphen-separated
586 * decimal numbers, the smallest and largest bit numbers set in
587 * the range.
588 *
6e1907ff
RD
589 * Returns 0 on success, -errno on invalid input strings.
590 * Error values:
591 * %-EINVAL: second number in range smaller than first
592 * %-EINVAL: invalid character in string
593 * %-ERANGE: bit number specified too large for mask
1da177e4 594 */
4b060420
MT
595static int __bitmap_parselist(const char *buf, unsigned int buflen,
596 int is_user, unsigned long *maskp,
597 int nmaskbits)
1da177e4
LT
598{
599 unsigned a, b;
4b060420 600 int c, old_c, totaldigits;
b9c321fd 601 const char __user __force *ubuf = (const char __user __force *)buf;
4b060420 602 int exp_digit, in_range;
1da177e4 603
4b060420 604 totaldigits = c = 0;
1da177e4
LT
605 bitmap_zero(maskp, nmaskbits);
606 do {
4b060420
MT
607 exp_digit = 1;
608 in_range = 0;
609 a = b = 0;
610
611 /* Get the next cpu# or a range of cpu#'s */
612 while (buflen) {
613 old_c = c;
614 if (is_user) {
615 if (__get_user(c, ubuf++))
616 return -EFAULT;
617 } else
618 c = *buf++;
619 buflen--;
620 if (isspace(c))
621 continue;
622
623 /*
624 * If the last character was a space and the current
625 * character isn't '\0', we've got embedded whitespace.
626 * This is a no-no, so throw an error.
627 */
628 if (totaldigits && c && isspace(old_c))
629 return -EINVAL;
630
631 /* A '\0' or a ',' signal the end of a cpu# or range */
632 if (c == '\0' || c == ',')
633 break;
634
635 if (c == '-') {
636 if (exp_digit || in_range)
637 return -EINVAL;
638 b = 0;
639 in_range = 1;
640 exp_digit = 1;
641 continue;
642 }
643
644 if (!isdigit(c))
1da177e4 645 return -EINVAL;
4b060420
MT
646
647 b = b * 10 + (c - '0');
648 if (!in_range)
649 a = b;
650 exp_digit = 0;
651 totaldigits++;
1da177e4
LT
652 }
653 if (!(a <= b))
654 return -EINVAL;
655 if (b >= nmaskbits)
656 return -ERANGE;
657 while (a <= b) {
658 set_bit(a, maskp);
659 a++;
660 }
4b060420 661 } while (buflen && c == ',');
1da177e4
LT
662 return 0;
663}
4b060420
MT
664
665int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
666{
667 char *nl = strchr(bp, '\n');
668 int len;
669
670 if (nl)
671 len = nl - bp;
672 else
673 len = strlen(bp);
674
675 return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
676}
1da177e4
LT
677EXPORT_SYMBOL(bitmap_parselist);
678
4b060420
MT
679
680/**
681 * bitmap_parselist_user()
682 *
683 * @ubuf: pointer to user buffer containing string.
684 * @ulen: buffer size in bytes. If string is smaller than this
685 * then it must be terminated with a \0.
686 * @maskp: pointer to bitmap array that will contain result.
687 * @nmaskbits: size of bitmap, in bits.
688 *
689 * Wrapper for bitmap_parselist(), providing it with user buffer.
690 *
691 * We cannot have this as an inline function in bitmap.h because it needs
692 * linux/uaccess.h to get the access_ok() declaration and this causes
693 * cyclic dependencies.
694 */
695int bitmap_parselist_user(const char __user *ubuf,
696 unsigned int ulen, unsigned long *maskp,
697 int nmaskbits)
698{
699 if (!access_ok(VERIFY_READ, ubuf, ulen))
700 return -EFAULT;
b9c321fd 701 return __bitmap_parselist((const char __force *)ubuf,
4b060420
MT
702 ulen, 1, maskp, nmaskbits);
703}
704EXPORT_SYMBOL(bitmap_parselist_user);
705
706
72fd4a35 707/**
9a86e2ba 708 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
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709 * @buf: pointer to a bitmap
710 * @pos: a bit position in @buf (0 <= @pos < @bits)
711 * @bits: number of valid bit positions in @buf
712 *
713 * Map the bit at position @pos in @buf (of length @bits) to the
714 * ordinal of which set bit it is. If it is not set or if @pos
96b7f341 715 * is not a valid bit position, map to -1.
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716 *
717 * If for example, just bits 4 through 7 are set in @buf, then @pos
718 * values 4 through 7 will get mapped to 0 through 3, respectively,
719 * and other @pos values will get mapped to 0. When @pos value 7
720 * gets mapped to (returns) @ord value 3 in this example, that means
721 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
722 *
723 * The bit positions 0 through @bits are valid positions in @buf.
724 */
725static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
726{
96b7f341 727 int i, ord;
fb5eeeee 728
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729 if (pos < 0 || pos >= bits || !test_bit(pos, buf))
730 return -1;
fb5eeeee 731
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732 i = find_first_bit(buf, bits);
733 ord = 0;
734 while (i < pos) {
735 i = find_next_bit(buf, bits, i + 1);
736 ord++;
fb5eeeee 737 }
96b7f341
PJ
738 BUG_ON(i != pos);
739
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740 return ord;
741}
742
743/**
9a86e2ba 744 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
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745 * @buf: pointer to bitmap
746 * @ord: ordinal bit position (n-th set bit, n >= 0)
747 * @bits: number of valid bit positions in @buf
748 *
749 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
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750 * Value of @ord should be in range 0 <= @ord < weight(buf), else
751 * results are undefined.
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752 *
753 * If for example, just bits 4 through 7 are set in @buf, then @ord
754 * values 0 through 3 will get mapped to 4 through 7, respectively,
96b7f341 755 * and all other @ord values return undefined values. When @ord value 3
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756 * gets mapped to (returns) @pos value 7 in this example, that means
757 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
758 *
759 * The bit positions 0 through @bits are valid positions in @buf.
760 */
778d3b0f 761int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
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762{
763 int pos = 0;
764
765 if (ord >= 0 && ord < bits) {
766 int i;
767
768 for (i = find_first_bit(buf, bits);
769 i < bits && ord > 0;
770 i = find_next_bit(buf, bits, i + 1))
771 ord--;
772 if (i < bits && ord == 0)
773 pos = i;
774 }
775
776 return pos;
777}
778
779/**
780 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
fb5eeeee 781 * @dst: remapped result
96b7f341 782 * @src: subset to be remapped
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783 * @old: defines domain of map
784 * @new: defines range of map
785 * @bits: number of bits in each of these bitmaps
786 *
787 * Let @old and @new define a mapping of bit positions, such that
788 * whatever position is held by the n-th set bit in @old is mapped
789 * to the n-th set bit in @new. In the more general case, allowing
790 * for the possibility that the weight 'w' of @new is less than the
791 * weight of @old, map the position of the n-th set bit in @old to
792 * the position of the m-th set bit in @new, where m == n % w.
793 *
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794 * If either of the @old and @new bitmaps are empty, or if @src and
795 * @dst point to the same location, then this routine copies @src
796 * to @dst.
fb5eeeee 797 *
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798 * The positions of unset bits in @old are mapped to themselves
799 * (the identify map).
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800 *
801 * Apply the above specified mapping to @src, placing the result in
802 * @dst, clearing any bits previously set in @dst.
803 *
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804 * For example, lets say that @old has bits 4 through 7 set, and
805 * @new has bits 12 through 15 set. This defines the mapping of bit
806 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
96b7f341
PJ
807 * bit positions unchanged. So if say @src comes into this routine
808 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
809 * 13 and 15 set.
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810 */
811void bitmap_remap(unsigned long *dst, const unsigned long *src,
812 const unsigned long *old, const unsigned long *new,
813 int bits)
814{
96b7f341 815 int oldbit, w;
fb5eeeee 816
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817 if (dst == src) /* following doesn't handle inplace remaps */
818 return;
fb5eeeee 819 bitmap_zero(dst, bits);
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PJ
820
821 w = bitmap_weight(new, bits);
08564fb7 822 for_each_set_bit(oldbit, src, bits) {
96b7f341 823 int n = bitmap_pos_to_ord(old, oldbit, bits);
08564fb7 824
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PJ
825 if (n < 0 || w == 0)
826 set_bit(oldbit, dst); /* identity map */
827 else
828 set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
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PJ
829 }
830}
831EXPORT_SYMBOL(bitmap_remap);
832
833/**
834 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
6e1907ff
RD
835 * @oldbit: bit position to be mapped
836 * @old: defines domain of map
837 * @new: defines range of map
838 * @bits: number of bits in each of these bitmaps
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PJ
839 *
840 * Let @old and @new define a mapping of bit positions, such that
841 * whatever position is held by the n-th set bit in @old is mapped
842 * to the n-th set bit in @new. In the more general case, allowing
843 * for the possibility that the weight 'w' of @new is less than the
844 * weight of @old, map the position of the n-th set bit in @old to
845 * the position of the m-th set bit in @new, where m == n % w.
846 *
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PJ
847 * The positions of unset bits in @old are mapped to themselves
848 * (the identify map).
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849 *
850 * Apply the above specified mapping to bit position @oldbit, returning
851 * the new bit position.
852 *
853 * For example, lets say that @old has bits 4 through 7 set, and
854 * @new has bits 12 through 15 set. This defines the mapping of bit
855 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
96b7f341
PJ
856 * bit positions unchanged. So if say @oldbit is 5, then this routine
857 * returns 13.
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858 */
859int bitmap_bitremap(int oldbit, const unsigned long *old,
860 const unsigned long *new, int bits)
861{
96b7f341
PJ
862 int w = bitmap_weight(new, bits);
863 int n = bitmap_pos_to_ord(old, oldbit, bits);
864 if (n < 0 || w == 0)
865 return oldbit;
866 else
867 return bitmap_ord_to_pos(new, n % w, bits);
fb5eeeee
PJ
868}
869EXPORT_SYMBOL(bitmap_bitremap);
870
7ea931c9
PJ
871/**
872 * bitmap_onto - translate one bitmap relative to another
873 * @dst: resulting translated bitmap
874 * @orig: original untranslated bitmap
875 * @relmap: bitmap relative to which translated
876 * @bits: number of bits in each of these bitmaps
877 *
878 * Set the n-th bit of @dst iff there exists some m such that the
879 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
880 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
881 * (If you understood the previous sentence the first time your
882 * read it, you're overqualified for your current job.)
883 *
884 * In other words, @orig is mapped onto (surjectively) @dst,
885 * using the the map { <n, m> | the n-th bit of @relmap is the
886 * m-th set bit of @relmap }.
887 *
888 * Any set bits in @orig above bit number W, where W is the
889 * weight of (number of set bits in) @relmap are mapped nowhere.
890 * In particular, if for all bits m set in @orig, m >= W, then
891 * @dst will end up empty. In situations where the possibility
892 * of such an empty result is not desired, one way to avoid it is
893 * to use the bitmap_fold() operator, below, to first fold the
894 * @orig bitmap over itself so that all its set bits x are in the
895 * range 0 <= x < W. The bitmap_fold() operator does this by
896 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
897 *
898 * Example [1] for bitmap_onto():
899 * Let's say @relmap has bits 30-39 set, and @orig has bits
900 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
901 * @dst will have bits 31, 33, 35, 37 and 39 set.
902 *
903 * When bit 0 is set in @orig, it means turn on the bit in
904 * @dst corresponding to whatever is the first bit (if any)
905 * that is turned on in @relmap. Since bit 0 was off in the
906 * above example, we leave off that bit (bit 30) in @dst.
907 *
908 * When bit 1 is set in @orig (as in the above example), it
909 * means turn on the bit in @dst corresponding to whatever
910 * is the second bit that is turned on in @relmap. The second
911 * bit in @relmap that was turned on in the above example was
912 * bit 31, so we turned on bit 31 in @dst.
913 *
914 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
915 * because they were the 4th, 6th, 8th and 10th set bits
916 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
917 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
918 *
919 * When bit 11 is set in @orig, it means turn on the bit in
25985edc 920 * @dst corresponding to whatever is the twelfth bit that is
7ea931c9
PJ
921 * turned on in @relmap. In the above example, there were
922 * only ten bits turned on in @relmap (30..39), so that bit
923 * 11 was set in @orig had no affect on @dst.
924 *
925 * Example [2] for bitmap_fold() + bitmap_onto():
926 * Let's say @relmap has these ten bits set:
927 * 40 41 42 43 45 48 53 61 74 95
928 * (for the curious, that's 40 plus the first ten terms of the
929 * Fibonacci sequence.)
930 *
931 * Further lets say we use the following code, invoking
932 * bitmap_fold() then bitmap_onto, as suggested above to
933 * avoid the possitility of an empty @dst result:
934 *
935 * unsigned long *tmp; // a temporary bitmap's bits
936 *
937 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
938 * bitmap_onto(dst, tmp, relmap, bits);
939 *
940 * Then this table shows what various values of @dst would be, for
941 * various @orig's. I list the zero-based positions of each set bit.
942 * The tmp column shows the intermediate result, as computed by
943 * using bitmap_fold() to fold the @orig bitmap modulo ten
944 * (the weight of @relmap).
945 *
946 * @orig tmp @dst
947 * 0 0 40
948 * 1 1 41
949 * 9 9 95
950 * 10 0 40 (*)
951 * 1 3 5 7 1 3 5 7 41 43 48 61
952 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
953 * 0 9 18 27 0 9 8 7 40 61 74 95
954 * 0 10 20 30 0 40
955 * 0 11 22 33 0 1 2 3 40 41 42 43
956 * 0 12 24 36 0 2 4 6 40 42 45 53
957 * 78 102 211 1 2 8 41 42 74 (*)
958 *
959 * (*) For these marked lines, if we hadn't first done bitmap_fold()
960 * into tmp, then the @dst result would have been empty.
961 *
962 * If either of @orig or @relmap is empty (no set bits), then @dst
963 * will be returned empty.
964 *
965 * If (as explained above) the only set bits in @orig are in positions
966 * m where m >= W, (where W is the weight of @relmap) then @dst will
967 * once again be returned empty.
968 *
969 * All bits in @dst not set by the above rule are cleared.
970 */
971void bitmap_onto(unsigned long *dst, const unsigned long *orig,
972 const unsigned long *relmap, int bits)
973{
974 int n, m; /* same meaning as in above comment */
975
976 if (dst == orig) /* following doesn't handle inplace mappings */
977 return;
978 bitmap_zero(dst, bits);
979
980 /*
981 * The following code is a more efficient, but less
982 * obvious, equivalent to the loop:
983 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
984 * n = bitmap_ord_to_pos(orig, m, bits);
985 * if (test_bit(m, orig))
986 * set_bit(n, dst);
987 * }
988 */
989
990 m = 0;
08564fb7 991 for_each_set_bit(n, relmap, bits) {
7ea931c9
PJ
992 /* m == bitmap_pos_to_ord(relmap, n, bits) */
993 if (test_bit(m, orig))
994 set_bit(n, dst);
995 m++;
996 }
997}
998EXPORT_SYMBOL(bitmap_onto);
999
1000/**
1001 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
1002 * @dst: resulting smaller bitmap
1003 * @orig: original larger bitmap
1004 * @sz: specified size
1005 * @bits: number of bits in each of these bitmaps
1006 *
1007 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
1008 * Clear all other bits in @dst. See further the comment and
1009 * Example [2] for bitmap_onto() for why and how to use this.
1010 */
1011void bitmap_fold(unsigned long *dst, const unsigned long *orig,
1012 int sz, int bits)
1013{
1014 int oldbit;
1015
1016 if (dst == orig) /* following doesn't handle inplace mappings */
1017 return;
1018 bitmap_zero(dst, bits);
1019
08564fb7 1020 for_each_set_bit(oldbit, orig, bits)
7ea931c9
PJ
1021 set_bit(oldbit % sz, dst);
1022}
1023EXPORT_SYMBOL(bitmap_fold);
1024
3cf64b93
PJ
1025/*
1026 * Common code for bitmap_*_region() routines.
1027 * bitmap: array of unsigned longs corresponding to the bitmap
1028 * pos: the beginning of the region
1029 * order: region size (log base 2 of number of bits)
1030 * reg_op: operation(s) to perform on that region of bitmap
1da177e4 1031 *
3cf64b93
PJ
1032 * Can set, verify and/or release a region of bits in a bitmap,
1033 * depending on which combination of REG_OP_* flag bits is set.
1da177e4 1034 *
3cf64b93
PJ
1035 * A region of a bitmap is a sequence of bits in the bitmap, of
1036 * some size '1 << order' (a power of two), aligned to that same
1037 * '1 << order' power of two.
1038 *
1039 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
1040 * Returns 0 in all other cases and reg_ops.
1da177e4 1041 */
3cf64b93
PJ
1042
1043enum {
1044 REG_OP_ISFREE, /* true if region is all zero bits */
1045 REG_OP_ALLOC, /* set all bits in region */
1046 REG_OP_RELEASE, /* clear all bits in region */
1047};
1048
1049static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op)
1da177e4 1050{
3cf64b93
PJ
1051 int nbits_reg; /* number of bits in region */
1052 int index; /* index first long of region in bitmap */
1053 int offset; /* bit offset region in bitmap[index] */
1054 int nlongs_reg; /* num longs spanned by region in bitmap */
74373c6a 1055 int nbitsinlong; /* num bits of region in each spanned long */
3cf64b93 1056 unsigned long mask; /* bitmask for one long of region */
74373c6a 1057 int i; /* scans bitmap by longs */
3cf64b93 1058 int ret = 0; /* return value */
74373c6a 1059
3cf64b93
PJ
1060 /*
1061 * Either nlongs_reg == 1 (for small orders that fit in one long)
1062 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
1063 */
1064 nbits_reg = 1 << order;
1065 index = pos / BITS_PER_LONG;
1066 offset = pos - (index * BITS_PER_LONG);
1067 nlongs_reg = BITS_TO_LONGS(nbits_reg);
1068 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
1da177e4 1069
3cf64b93
PJ
1070 /*
1071 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1072 * overflows if nbitsinlong == BITS_PER_LONG.
1073 */
74373c6a 1074 mask = (1UL << (nbitsinlong - 1));
1da177e4 1075 mask += mask - 1;
3cf64b93 1076 mask <<= offset;
1da177e4 1077
3cf64b93
PJ
1078 switch (reg_op) {
1079 case REG_OP_ISFREE:
1080 for (i = 0; i < nlongs_reg; i++) {
1081 if (bitmap[index + i] & mask)
1082 goto done;
1083 }
1084 ret = 1; /* all bits in region free (zero) */
1085 break;
1086
1087 case REG_OP_ALLOC:
1088 for (i = 0; i < nlongs_reg; i++)
1089 bitmap[index + i] |= mask;
1090 break;
1091
1092 case REG_OP_RELEASE:
1093 for (i = 0; i < nlongs_reg; i++)
1094 bitmap[index + i] &= ~mask;
1095 break;
1da177e4 1096 }
3cf64b93
PJ
1097done:
1098 return ret;
1099}
1100
1101/**
1102 * bitmap_find_free_region - find a contiguous aligned mem region
1103 * @bitmap: array of unsigned longs corresponding to the bitmap
1104 * @bits: number of bits in the bitmap
1105 * @order: region size (log base 2 of number of bits) to find
1106 *
1107 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1108 * allocate them (set them to one). Only consider regions of length
1109 * a power (@order) of two, aligned to that power of two, which
1110 * makes the search algorithm much faster.
1111 *
1112 * Return the bit offset in bitmap of the allocated region,
1113 * or -errno on failure.
1114 */
1115int bitmap_find_free_region(unsigned long *bitmap, int bits, int order)
1116{
aa8e4fc6
LT
1117 int pos, end; /* scans bitmap by regions of size order */
1118
1119 for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) {
1120 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1121 continue;
1122 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1123 return pos;
1124 }
1125 return -ENOMEM;
1da177e4
LT
1126}
1127EXPORT_SYMBOL(bitmap_find_free_region);
1128
1129/**
87e24802 1130 * bitmap_release_region - release allocated bitmap region
3cf64b93
PJ
1131 * @bitmap: array of unsigned longs corresponding to the bitmap
1132 * @pos: beginning of bit region to release
1133 * @order: region size (log base 2 of number of bits) to release
1da177e4 1134 *
72fd4a35 1135 * This is the complement to __bitmap_find_free_region() and releases
1da177e4 1136 * the found region (by clearing it in the bitmap).
3cf64b93
PJ
1137 *
1138 * No return value.
1da177e4
LT
1139 */
1140void bitmap_release_region(unsigned long *bitmap, int pos, int order)
1141{
3cf64b93 1142 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
1da177e4
LT
1143}
1144EXPORT_SYMBOL(bitmap_release_region);
1145
87e24802
PJ
1146/**
1147 * bitmap_allocate_region - allocate bitmap region
3cf64b93
PJ
1148 * @bitmap: array of unsigned longs corresponding to the bitmap
1149 * @pos: beginning of bit region to allocate
1150 * @order: region size (log base 2 of number of bits) to allocate
87e24802
PJ
1151 *
1152 * Allocate (set bits in) a specified region of a bitmap.
3cf64b93 1153 *
6e1907ff 1154 * Return 0 on success, or %-EBUSY if specified region wasn't
87e24802
PJ
1155 * free (not all bits were zero).
1156 */
1da177e4
LT
1157int bitmap_allocate_region(unsigned long *bitmap, int pos, int order)
1158{
3cf64b93
PJ
1159 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1160 return -EBUSY;
1161 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1da177e4
LT
1162 return 0;
1163}
1164EXPORT_SYMBOL(bitmap_allocate_region);
ccbe329b
DV
1165
1166/**
1167 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1168 * @dst: destination buffer
1169 * @src: bitmap to copy
1170 * @nbits: number of bits in the bitmap
1171 *
1172 * Require nbits % BITS_PER_LONG == 0.
1173 */
1174void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
1175{
1176 unsigned long *d = dst;
1177 int i;
1178
1179 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1180 if (BITS_PER_LONG == 64)
1181 d[i] = cpu_to_le64(src[i]);
1182 else
1183 d[i] = cpu_to_le32(src[i]);
1184 }
1185}
1186EXPORT_SYMBOL(bitmap_copy_le);