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Linux/lib/bitmap.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * lib/bitmap.c
  4  * Helper functions for bitmap.h.
  5  */
  6 
  7 #include <linux/bitmap.h>
  8 #include <linux/bitops.h>
  9 #include <linux/bug.h>
 10 #include <linux/ctype.h>
 11 #include <linux/device.h>
 12 #include <linux/errno.h>
 13 #include <linux/export.h>
 14 #include <linux/kernel.h>
 15 #include <linux/mm.h>
 16 #include <linux/slab.h>
 17 #include <linux/string.h>
 18 #include <linux/thread_info.h>
 19 #include <linux/uaccess.h>
 20 
 21 #include <asm/page.h>
 22 
 23 #include "kstrtox.h"
 24 
 25 /**
 26  * DOC: bitmap introduction
 27  *
 28  * bitmaps provide an array of bits, implemented using an
 29  * array of unsigned longs.  The number of valid bits in a
 30  * given bitmap does _not_ need to be an exact multiple of
 31  * BITS_PER_LONG.
 32  *
 33  * The possible unused bits in the last, partially used word
 34  * of a bitmap are 'don't care'.  The implementation makes
 35  * no particular effort to keep them zero.  It ensures that
 36  * their value will not affect the results of any operation.
 37  * The bitmap operations that return Boolean (bitmap_empty,
 38  * for example) or scalar (bitmap_weight, for example) results
 39  * carefully filter out these unused bits from impacting their
 40  * results.
 41  *
 42  * The byte ordering of bitmaps is more natural on little
 43  * endian architectures.  See the big-endian headers
 44  * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
 45  * for the best explanations of this ordering.
 46  */
 47 
 48 int __bitmap_equal(const unsigned long *bitmap1,
 49                 const unsigned long *bitmap2, unsigned int bits)
 50 {
 51         unsigned int k, lim = bits/BITS_PER_LONG;
 52         for (k = 0; k < lim; ++k)
 53                 if (bitmap1[k] != bitmap2[k])
 54                         return 0;
 55 
 56         if (bits % BITS_PER_LONG)
 57                 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
 58                         return 0;
 59 
 60         return 1;
 61 }
 62 EXPORT_SYMBOL(__bitmap_equal);
 63 
 64 bool __bitmap_or_equal(const unsigned long *bitmap1,
 65                        const unsigned long *bitmap2,
 66                        const unsigned long *bitmap3,
 67                        unsigned int bits)
 68 {
 69         unsigned int k, lim = bits / BITS_PER_LONG;
 70         unsigned long tmp;
 71 
 72         for (k = 0; k < lim; ++k) {
 73                 if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
 74                         return false;
 75         }
 76 
 77         if (!(bits % BITS_PER_LONG))
 78                 return true;
 79 
 80         tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
 81         return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
 82 }
 83 
 84 void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
 85 {
 86         unsigned int k, lim = BITS_TO_LONGS(bits);
 87         for (k = 0; k < lim; ++k)
 88                 dst[k] = ~src[k];
 89 }
 90 EXPORT_SYMBOL(__bitmap_complement);
 91 
 92 /**
 93  * __bitmap_shift_right - logical right shift of the bits in a bitmap
 94  *   @dst : destination bitmap
 95  *   @src : source bitmap
 96  *   @shift : shift by this many bits
 97  *   @nbits : bitmap size, in bits
 98  *
 99  * Shifting right (dividing) means moving bits in the MS -> LS bit
100  * direction.  Zeros are fed into the vacated MS positions and the
101  * LS bits shifted off the bottom are lost.
102  */
103 void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
104                         unsigned shift, unsigned nbits)
105 {
106         unsigned k, lim = BITS_TO_LONGS(nbits);
107         unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
108         unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
109         for (k = 0; off + k < lim; ++k) {
110                 unsigned long upper, lower;
111 
112                 /*
113                  * If shift is not word aligned, take lower rem bits of
114                  * word above and make them the top rem bits of result.
115                  */
116                 if (!rem || off + k + 1 >= lim)
117                         upper = 0;
118                 else {
119                         upper = src[off + k + 1];
120                         if (off + k + 1 == lim - 1)
121                                 upper &= mask;
122                         upper <<= (BITS_PER_LONG - rem);
123                 }
124                 lower = src[off + k];
125                 if (off + k == lim - 1)
126                         lower &= mask;
127                 lower >>= rem;
128                 dst[k] = lower | upper;
129         }
130         if (off)
131                 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
132 }
133 EXPORT_SYMBOL(__bitmap_shift_right);
134 
135 
136 /**
137  * __bitmap_shift_left - logical left shift of the bits in a bitmap
138  *   @dst : destination bitmap
139  *   @src : source bitmap
140  *   @shift : shift by this many bits
141  *   @nbits : bitmap size, in bits
142  *
143  * Shifting left (multiplying) means moving bits in the LS -> MS
144  * direction.  Zeros are fed into the vacated LS bit positions
145  * and those MS bits shifted off the top are lost.
146  */
147 
148 void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
149                         unsigned int shift, unsigned int nbits)
150 {
151         int k;
152         unsigned int lim = BITS_TO_LONGS(nbits);
153         unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
154         for (k = lim - off - 1; k >= 0; --k) {
155                 unsigned long upper, lower;
156 
157                 /*
158                  * If shift is not word aligned, take upper rem bits of
159                  * word below and make them the bottom rem bits of result.
160                  */
161                 if (rem && k > 0)
162                         lower = src[k - 1] >> (BITS_PER_LONG - rem);
163                 else
164                         lower = 0;
165                 upper = src[k] << rem;
166                 dst[k + off] = lower | upper;
167         }
168         if (off)
169                 memset(dst, 0, off*sizeof(unsigned long));
170 }
171 EXPORT_SYMBOL(__bitmap_shift_left);
172 
173 /**
174  * bitmap_cut() - remove bit region from bitmap and right shift remaining bits
175  * @dst: destination bitmap, might overlap with src
176  * @src: source bitmap
177  * @first: start bit of region to be removed
178  * @cut: number of bits to remove
179  * @nbits: bitmap size, in bits
180  *
181  * Set the n-th bit of @dst iff the n-th bit of @src is set and
182  * n is less than @first, or the m-th bit of @src is set for any
183  * m such that @first <= n < nbits, and m = n + @cut.
184  *
185  * In pictures, example for a big-endian 32-bit architecture:
186  *
187  * The @src bitmap is::
188  *
189  *   31                                   63
190  *   |                                    |
191  *   10000000 11000001 11110010 00010101  10000000 11000001 01110010 00010101
192  *                   |  |              |                                    |
193  *                  16  14             0                                   32
194  *
195  * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
196  *
197  *   31                                   63
198  *   |                                    |
199  *   10110000 00011000 00110010 00010101  00010000 00011000 00101110 01000010
200  *                      |              |                                    |
201  *                      14 (bit 17     0                                   32
202  *                          from @src)
203  *
204  * Note that @dst and @src might overlap partially or entirely.
205  *
206  * This is implemented in the obvious way, with a shift and carry
207  * step for each moved bit. Optimisation is left as an exercise
208  * for the compiler.
209  */
210 void bitmap_cut(unsigned long *dst, const unsigned long *src,
211                 unsigned int first, unsigned int cut, unsigned int nbits)
212 {
213         unsigned int len = BITS_TO_LONGS(nbits);
214         unsigned long keep = 0, carry;
215         int i;
216 
217         if (first % BITS_PER_LONG) {
218                 keep = src[first / BITS_PER_LONG] &
219                        (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
220         }
221 
222         memmove(dst, src, len * sizeof(*dst));
223 
224         while (cut--) {
225                 for (i = first / BITS_PER_LONG; i < len; i++) {
226                         if (i < len - 1)
227                                 carry = dst[i + 1] & 1UL;
228                         else
229                                 carry = 0;
230 
231                         dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
232                 }
233         }
234 
235         dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
236         dst[first / BITS_PER_LONG] |= keep;
237 }
238 EXPORT_SYMBOL(bitmap_cut);
239 
240 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
241                                 const unsigned long *bitmap2, unsigned int bits)
242 {
243         unsigned int k;
244         unsigned int lim = bits/BITS_PER_LONG;
245         unsigned long result = 0;
246 
247         for (k = 0; k < lim; k++)
248                 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
249         if (bits % BITS_PER_LONG)
250                 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
251                            BITMAP_LAST_WORD_MASK(bits));
252         return result != 0;
253 }
254 EXPORT_SYMBOL(__bitmap_and);
255 
256 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
257                                 const unsigned long *bitmap2, unsigned int bits)
258 {
259         unsigned int k;
260         unsigned int nr = BITS_TO_LONGS(bits);
261 
262         for (k = 0; k < nr; k++)
263                 dst[k] = bitmap1[k] | bitmap2[k];
264 }
265 EXPORT_SYMBOL(__bitmap_or);
266 
267 void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
268                                 const unsigned long *bitmap2, unsigned int bits)
269 {
270         unsigned int k;
271         unsigned int nr = BITS_TO_LONGS(bits);
272 
273         for (k = 0; k < nr; k++)
274                 dst[k] = bitmap1[k] ^ bitmap2[k];
275 }
276 EXPORT_SYMBOL(__bitmap_xor);
277 
278 int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
279                                 const unsigned long *bitmap2, unsigned int bits)
280 {
281         unsigned int k;
282         unsigned int lim = bits/BITS_PER_LONG;
283         unsigned long result = 0;
284 
285         for (k = 0; k < lim; k++)
286                 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
287         if (bits % BITS_PER_LONG)
288                 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
289                            BITMAP_LAST_WORD_MASK(bits));
290         return result != 0;
291 }
292 EXPORT_SYMBOL(__bitmap_andnot);
293 
294 void __bitmap_replace(unsigned long *dst,
295                       const unsigned long *old, const unsigned long *new,
296                       const unsigned long *mask, unsigned int nbits)
297 {
298         unsigned int k;
299         unsigned int nr = BITS_TO_LONGS(nbits);
300 
301         for (k = 0; k < nr; k++)
302                 dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
303 }
304 EXPORT_SYMBOL(__bitmap_replace);
305 
306 int __bitmap_intersects(const unsigned long *bitmap1,
307                         const unsigned long *bitmap2, unsigned int bits)
308 {
309         unsigned int k, lim = bits/BITS_PER_LONG;
310         for (k = 0; k < lim; ++k)
311                 if (bitmap1[k] & bitmap2[k])
312                         return 1;
313 
314         if (bits % BITS_PER_LONG)
315                 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
316                         return 1;
317         return 0;
318 }
319 EXPORT_SYMBOL(__bitmap_intersects);
320 
321 int __bitmap_subset(const unsigned long *bitmap1,
322                     const unsigned long *bitmap2, unsigned int bits)
323 {
324         unsigned int k, lim = bits/BITS_PER_LONG;
325         for (k = 0; k < lim; ++k)
326                 if (bitmap1[k] & ~bitmap2[k])
327                         return 0;
328 
329         if (bits % BITS_PER_LONG)
330                 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
331                         return 0;
332         return 1;
333 }
334 EXPORT_SYMBOL(__bitmap_subset);
335 
336 int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
337 {
338         unsigned int k, lim = bits/BITS_PER_LONG;
339         int w = 0;
340 
341         for (k = 0; k < lim; k++)
342                 w += hweight_long(bitmap[k]);
343 
344         if (bits % BITS_PER_LONG)
345                 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
346 
347         return w;
348 }
349 EXPORT_SYMBOL(__bitmap_weight);
350 
351 void __bitmap_set(unsigned long *map, unsigned int start, int len)
352 {
353         unsigned long *p = map + BIT_WORD(start);
354         const unsigned int size = start + len;
355         int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
356         unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
357 
358         while (len - bits_to_set >= 0) {
359                 *p |= mask_to_set;
360                 len -= bits_to_set;
361                 bits_to_set = BITS_PER_LONG;
362                 mask_to_set = ~0UL;
363                 p++;
364         }
365         if (len) {
366                 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
367                 *p |= mask_to_set;
368         }
369 }
370 EXPORT_SYMBOL(__bitmap_set);
371 
372 void __bitmap_clear(unsigned long *map, unsigned int start, int len)
373 {
374         unsigned long *p = map + BIT_WORD(start);
375         const unsigned int size = start + len;
376         int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
377         unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
378 
379         while (len - bits_to_clear >= 0) {
380                 *p &= ~mask_to_clear;
381                 len -= bits_to_clear;
382                 bits_to_clear = BITS_PER_LONG;
383                 mask_to_clear = ~0UL;
384                 p++;
385         }
386         if (len) {
387                 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
388                 *p &= ~mask_to_clear;
389         }
390 }
391 EXPORT_SYMBOL(__bitmap_clear);
392 
393 /**
394  * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
395  * @map: The address to base the search on
396  * @size: The bitmap size in bits
397  * @start: The bitnumber to start searching at
398  * @nr: The number of zeroed bits we're looking for
399  * @align_mask: Alignment mask for zero area
400  * @align_offset: Alignment offset for zero area.
401  *
402  * The @align_mask should be one less than a power of 2; the effect is that
403  * the bit offset of all zero areas this function finds plus @align_offset
404  * is multiple of that power of 2.
405  */
406 unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
407                                              unsigned long size,
408                                              unsigned long start,
409                                              unsigned int nr,
410                                              unsigned long align_mask,
411                                              unsigned long align_offset)
412 {
413         unsigned long index, end, i;
414 again:
415         index = find_next_zero_bit(map, size, start);
416 
417         /* Align allocation */
418         index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
419 
420         end = index + nr;
421         if (end > size)
422                 return end;
423         i = find_next_bit(map, end, index);
424         if (i < end) {
425                 start = i + 1;
426                 goto again;
427         }
428         return index;
429 }
430 EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
431 
432 /*
433  * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
434  * second version by Paul Jackson, third by Joe Korty.
435  */
436 
437 /**
438  * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
439  *
440  * @ubuf: pointer to user buffer containing string.
441  * @ulen: buffer size in bytes.  If string is smaller than this
442  *    then it must be terminated with a \0.
443  * @maskp: pointer to bitmap array that will contain result.
444  * @nmaskbits: size of bitmap, in bits.
445  */
446 int bitmap_parse_user(const char __user *ubuf,
447                         unsigned int ulen, unsigned long *maskp,
448                         int nmaskbits)
449 {
450         char *buf;
451         int ret;
452 
453         buf = memdup_user_nul(ubuf, ulen);
454         if (IS_ERR(buf))
455                 return PTR_ERR(buf);
456 
457         ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits);
458 
459         kfree(buf);
460         return ret;
461 }
462 EXPORT_SYMBOL(bitmap_parse_user);
463 
464 /**
465  * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
466  * @list: indicates whether the bitmap must be list
467  * @buf: page aligned buffer into which string is placed
468  * @maskp: pointer to bitmap to convert
469  * @nmaskbits: size of bitmap, in bits
470  *
471  * Output format is a comma-separated list of decimal numbers and
472  * ranges if list is specified or hex digits grouped into comma-separated
473  * sets of 8 digits/set. Returns the number of characters written to buf.
474  *
475  * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
476  * area and that sufficient storage remains at @buf to accommodate the
477  * bitmap_print_to_pagebuf() output. Returns the number of characters
478  * actually printed to @buf, excluding terminating '\0'.
479  */
480 int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
481                             int nmaskbits)
482 {
483         ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
484 
485         return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
486                       scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
487 }
488 EXPORT_SYMBOL(bitmap_print_to_pagebuf);
489 
490 /*
491  * Region 9-38:4/10 describes the following bitmap structure:
492  * 0       9  12    18                  38           N
493  * .........****......****......****..................
494  *          ^  ^     ^                   ^           ^
495  *      start  off   group_len         end       nbits
496  */
497 struct region {
498         unsigned int start;
499         unsigned int off;
500         unsigned int group_len;
501         unsigned int end;
502         unsigned int nbits;
503 };
504 
505 static void bitmap_set_region(const struct region *r, unsigned long *bitmap)
506 {
507         unsigned int start;
508 
509         for (start = r->start; start <= r->end; start += r->group_len)
510                 bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
511 }
512 
513 static int bitmap_check_region(const struct region *r)
514 {
515         if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
516                 return -EINVAL;
517 
518         if (r->end >= r->nbits)
519                 return -ERANGE;
520 
521         return 0;
522 }
523 
524 static const char *bitmap_getnum(const char *str, unsigned int *num,
525                                  unsigned int lastbit)
526 {
527         unsigned long long n;
528         unsigned int len;
529 
530         if (str[0] == 'N') {
531                 *num = lastbit;
532                 return str + 1;
533         }
534 
535         len = _parse_integer(str, 10, &n);
536         if (!len)
537                 return ERR_PTR(-EINVAL);
538         if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
539                 return ERR_PTR(-EOVERFLOW);
540 
541         *num = n;
542         return str + len;
543 }
544 
545 static inline bool end_of_str(char c)
546 {
547         return c == '\0' || c == '\n';
548 }
549 
550 static inline bool __end_of_region(char c)
551 {
552         return isspace(c) || c == ',';
553 }
554 
555 static inline bool end_of_region(char c)
556 {
557         return __end_of_region(c) || end_of_str(c);
558 }
559 
560 /*
561  * The format allows commas and whitespaces at the beginning
562  * of the region.
563  */
564 static const char *bitmap_find_region(const char *str)
565 {
566         while (__end_of_region(*str))
567                 str++;
568 
569         return end_of_str(*str) ? NULL : str;
570 }
571 
572 static const char *bitmap_find_region_reverse(const char *start, const char *end)
573 {
574         while (start <= end && __end_of_region(*end))
575                 end--;
576 
577         return end;
578 }
579 
580 static const char *bitmap_parse_region(const char *str, struct region *r)
581 {
582         unsigned int lastbit = r->nbits - 1;
583 
584         str = bitmap_getnum(str, &r->start, lastbit);
585         if (IS_ERR(str))
586                 return str;
587 
588         if (end_of_region(*str))
589                 goto no_end;
590 
591         if (*str != '-')
592                 return ERR_PTR(-EINVAL);
593 
594         str = bitmap_getnum(str + 1, &r->end, lastbit);
595         if (IS_ERR(str))
596                 return str;
597 
598         if (end_of_region(*str))
599                 goto no_pattern;
600 
601         if (*str != ':')
602                 return ERR_PTR(-EINVAL);
603 
604         str = bitmap_getnum(str + 1, &r->off, lastbit);
605         if (IS_ERR(str))
606                 return str;
607 
608         if (*str != '/')
609                 return ERR_PTR(-EINVAL);
610 
611         return bitmap_getnum(str + 1, &r->group_len, lastbit);
612 
613 no_end:
614         r->end = r->start;
615 no_pattern:
616         r->off = r->end + 1;
617         r->group_len = r->end + 1;
618 
619         return end_of_str(*str) ? NULL : str;
620 }
621 
622 /**
623  * bitmap_parselist - convert list format ASCII string to bitmap
624  * @buf: read user string from this buffer; must be terminated
625  *    with a \0 or \n.
626  * @maskp: write resulting mask here
627  * @nmaskbits: number of bits in mask to be written
628  *
629  * Input format is a comma-separated list of decimal numbers and
630  * ranges.  Consecutively set bits are shown as two hyphen-separated
631  * decimal numbers, the smallest and largest bit numbers set in
632  * the range.
633  * Optionally each range can be postfixed to denote that only parts of it
634  * should be set. The range will divided to groups of specific size.
635  * From each group will be used only defined amount of bits.
636  * Syntax: range:used_size/group_size
637  * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
638  * The value 'N' can be used as a dynamically substituted token for the
639  * maximum allowed value; i.e (nmaskbits - 1).  Keep in mind that it is
640  * dynamic, so if system changes cause the bitmap width to change, such
641  * as more cores in a CPU list, then any ranges using N will also change.
642  *
643  * Returns: 0 on success, -errno on invalid input strings. Error values:
644  *
645  *   - ``-EINVAL``: wrong region format
646  *   - ``-EINVAL``: invalid character in string
647  *   - ``-ERANGE``: bit number specified too large for mask
648  *   - ``-EOVERFLOW``: integer overflow in the input parameters
649  */
650 int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
651 {
652         struct region r;
653         long ret;
654 
655         r.nbits = nmaskbits;
656         bitmap_zero(maskp, r.nbits);
657 
658         while (buf) {
659                 buf = bitmap_find_region(buf);
660                 if (buf == NULL)
661                         return 0;
662 
663                 buf = bitmap_parse_region(buf, &r);
664                 if (IS_ERR(buf))
665                         return PTR_ERR(buf);
666 
667                 ret = bitmap_check_region(&r);
668                 if (ret)
669                         return ret;
670 
671                 bitmap_set_region(&r, maskp);
672         }
673 
674         return 0;
675 }
676 EXPORT_SYMBOL(bitmap_parselist);
677 
678 
679 /**
680  * bitmap_parselist_user()
681  *
682  * @ubuf: pointer to user buffer containing string.
683  * @ulen: buffer size in bytes.  If string is smaller than this
684  *    then it must be terminated with a \0.
685  * @maskp: pointer to bitmap array that will contain result.
686  * @nmaskbits: size of bitmap, in bits.
687  *
688  * Wrapper for bitmap_parselist(), providing it with user buffer.
689  */
690 int bitmap_parselist_user(const char __user *ubuf,
691                         unsigned int ulen, unsigned long *maskp,
692                         int nmaskbits)
693 {
694         char *buf;
695         int ret;
696 
697         buf = memdup_user_nul(ubuf, ulen);
698         if (IS_ERR(buf))
699                 return PTR_ERR(buf);
700 
701         ret = bitmap_parselist(buf, maskp, nmaskbits);
702 
703         kfree(buf);
704         return ret;
705 }
706 EXPORT_SYMBOL(bitmap_parselist_user);
707 
708 static const char *bitmap_get_x32_reverse(const char *start,
709                                         const char *end, u32 *num)
710 {
711         u32 ret = 0;
712         int c, i;
713 
714         for (i = 0; i < 32; i += 4) {
715                 c = hex_to_bin(*end--);
716                 if (c < 0)
717                         return ERR_PTR(-EINVAL);
718 
719                 ret |= c << i;
720 
721                 if (start > end || __end_of_region(*end))
722                         goto out;
723         }
724 
725         if (hex_to_bin(*end--) >= 0)
726                 return ERR_PTR(-EOVERFLOW);
727 out:
728         *num = ret;
729         return end;
730 }
731 
732 /**
733  * bitmap_parse - convert an ASCII hex string into a bitmap.
734  * @start: pointer to buffer containing string.
735  * @buflen: buffer size in bytes.  If string is smaller than this
736  *    then it must be terminated with a \0 or \n. In that case,
737  *    UINT_MAX may be provided instead of string length.
738  * @maskp: pointer to bitmap array that will contain result.
739  * @nmaskbits: size of bitmap, in bits.
740  *
741  * Commas group hex digits into chunks.  Each chunk defines exactly 32
742  * bits of the resultant bitmask.  No chunk may specify a value larger
743  * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
744  * then leading 0-bits are prepended.  %-EINVAL is returned for illegal
745  * characters. Grouping such as "1,,5", ",44", "," or "" is allowed.
746  * Leading, embedded and trailing whitespace accepted.
747  */
748 int bitmap_parse(const char *start, unsigned int buflen,
749                 unsigned long *maskp, int nmaskbits)
750 {
751         const char *end = strnchrnul(start, buflen, '\n') - 1;
752         int chunks = BITS_TO_U32(nmaskbits);
753         u32 *bitmap = (u32 *)maskp;
754         int unset_bit;
755         int chunk;
756 
757         for (chunk = 0; ; chunk++) {
758                 end = bitmap_find_region_reverse(start, end);
759                 if (start > end)
760                         break;
761 
762                 if (!chunks--)
763                         return -EOVERFLOW;
764 
765 #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN)
766                 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]);
767 #else
768                 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]);
769 #endif
770                 if (IS_ERR(end))
771                         return PTR_ERR(end);
772         }
773 
774         unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
775         if (unset_bit < nmaskbits) {
776                 bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit);
777                 return 0;
778         }
779 
780         if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit)
781                 return -EOVERFLOW;
782 
783         return 0;
784 }
785 EXPORT_SYMBOL(bitmap_parse);
786 
787 
788 #ifdef CONFIG_NUMA
789 /**
790  * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
791  *      @buf: pointer to a bitmap
792  *      @pos: a bit position in @buf (0 <= @pos < @nbits)
793  *      @nbits: number of valid bit positions in @buf
794  *
795  * Map the bit at position @pos in @buf (of length @nbits) to the
796  * ordinal of which set bit it is.  If it is not set or if @pos
797  * is not a valid bit position, map to -1.
798  *
799  * If for example, just bits 4 through 7 are set in @buf, then @pos
800  * values 4 through 7 will get mapped to 0 through 3, respectively,
801  * and other @pos values will get mapped to -1.  When @pos value 7
802  * gets mapped to (returns) @ord value 3 in this example, that means
803  * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
804  *
805  * The bit positions 0 through @bits are valid positions in @buf.
806  */
807 static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
808 {
809         if (pos >= nbits || !test_bit(pos, buf))
810                 return -1;
811 
812         return __bitmap_weight(buf, pos);
813 }
814 
815 /**
816  * bitmap_ord_to_pos - find position of n-th set bit in bitmap
817  *      @buf: pointer to bitmap
818  *      @ord: ordinal bit position (n-th set bit, n >= 0)
819  *      @nbits: number of valid bit positions in @buf
820  *
821  * Map the ordinal offset of bit @ord in @buf to its position in @buf.
822  * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
823  * >= weight(buf), returns @nbits.
824  *
825  * If for example, just bits 4 through 7 are set in @buf, then @ord
826  * values 0 through 3 will get mapped to 4 through 7, respectively,
827  * and all other @ord values returns @nbits.  When @ord value 3
828  * gets mapped to (returns) @pos value 7 in this example, that means
829  * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
830  *
831  * The bit positions 0 through @nbits-1 are valid positions in @buf.
832  */
833 unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
834 {
835         unsigned int pos;
836 
837         for (pos = find_first_bit(buf, nbits);
838              pos < nbits && ord;
839              pos = find_next_bit(buf, nbits, pos + 1))
840                 ord--;
841 
842         return pos;
843 }
844 
845 /**
846  * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
847  *      @dst: remapped result
848  *      @src: subset to be remapped
849  *      @old: defines domain of map
850  *      @new: defines range of map
851  *      @nbits: number of bits in each of these bitmaps
852  *
853  * Let @old and @new define a mapping of bit positions, such that
854  * whatever position is held by the n-th set bit in @old is mapped
855  * to the n-th set bit in @new.  In the more general case, allowing
856  * for the possibility that the weight 'w' of @new is less than the
857  * weight of @old, map the position of the n-th set bit in @old to
858  * the position of the m-th set bit in @new, where m == n % w.
859  *
860  * If either of the @old and @new bitmaps are empty, or if @src and
861  * @dst point to the same location, then this routine copies @src
862  * to @dst.
863  *
864  * The positions of unset bits in @old are mapped to themselves
865  * (the identify map).
866  *
867  * Apply the above specified mapping to @src, placing the result in
868  * @dst, clearing any bits previously set in @dst.
869  *
870  * For example, lets say that @old has bits 4 through 7 set, and
871  * @new has bits 12 through 15 set.  This defines the mapping of bit
872  * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
873  * bit positions unchanged.  So if say @src comes into this routine
874  * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
875  * 13 and 15 set.
876  */
877 void bitmap_remap(unsigned long *dst, const unsigned long *src,
878                 const unsigned long *old, const unsigned long *new,
879                 unsigned int nbits)
880 {
881         unsigned int oldbit, w;
882 
883         if (dst == src)         /* following doesn't handle inplace remaps */
884                 return;
885         bitmap_zero(dst, nbits);
886 
887         w = bitmap_weight(new, nbits);
888         for_each_set_bit(oldbit, src, nbits) {
889                 int n = bitmap_pos_to_ord(old, oldbit, nbits);
890 
891                 if (n < 0 || w == 0)
892                         set_bit(oldbit, dst);   /* identity map */
893                 else
894                         set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
895         }
896 }
897 
898 /**
899  * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
900  *      @oldbit: bit position to be mapped
901  *      @old: defines domain of map
902  *      @new: defines range of map
903  *      @bits: number of bits in each of these bitmaps
904  *
905  * Let @old and @new define a mapping of bit positions, such that
906  * whatever position is held by the n-th set bit in @old is mapped
907  * to the n-th set bit in @new.  In the more general case, allowing
908  * for the possibility that the weight 'w' of @new is less than the
909  * weight of @old, map the position of the n-th set bit in @old to
910  * the position of the m-th set bit in @new, where m == n % w.
911  *
912  * The positions of unset bits in @old are mapped to themselves
913  * (the identify map).
914  *
915  * Apply the above specified mapping to bit position @oldbit, returning
916  * the new bit position.
917  *
918  * For example, lets say that @old has bits 4 through 7 set, and
919  * @new has bits 12 through 15 set.  This defines the mapping of bit
920  * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
921  * bit positions unchanged.  So if say @oldbit is 5, then this routine
922  * returns 13.
923  */
924 int bitmap_bitremap(int oldbit, const unsigned long *old,
925                                 const unsigned long *new, int bits)
926 {
927         int w = bitmap_weight(new, bits);
928         int n = bitmap_pos_to_ord(old, oldbit, bits);
929         if (n < 0 || w == 0)
930                 return oldbit;
931         else
932                 return bitmap_ord_to_pos(new, n % w, bits);
933 }
934 
935 /**
936  * bitmap_onto - translate one bitmap relative to another
937  *      @dst: resulting translated bitmap
938  *      @orig: original untranslated bitmap
939  *      @relmap: bitmap relative to which translated
940  *      @bits: number of bits in each of these bitmaps
941  *
942  * Set the n-th bit of @dst iff there exists some m such that the
943  * n-th bit of @relmap is set, the m-th bit of @orig is set, and
944  * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
945  * (If you understood the previous sentence the first time your
946  * read it, you're overqualified for your current job.)
947  *
948  * In other words, @orig is mapped onto (surjectively) @dst,
949  * using the map { <n, m> | the n-th bit of @relmap is the
950  * m-th set bit of @relmap }.
951  *
952  * Any set bits in @orig above bit number W, where W is the
953  * weight of (number of set bits in) @relmap are mapped nowhere.
954  * In particular, if for all bits m set in @orig, m >= W, then
955  * @dst will end up empty.  In situations where the possibility
956  * of such an empty result is not desired, one way to avoid it is
957  * to use the bitmap_fold() operator, below, to first fold the
958  * @orig bitmap over itself so that all its set bits x are in the
959  * range 0 <= x < W.  The bitmap_fold() operator does this by
960  * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
961  *
962  * Example [1] for bitmap_onto():
963  *  Let's say @relmap has bits 30-39 set, and @orig has bits
964  *  1, 3, 5, 7, 9 and 11 set.  Then on return from this routine,
965  *  @dst will have bits 31, 33, 35, 37 and 39 set.
966  *
967  *  When bit 0 is set in @orig, it means turn on the bit in
968  *  @dst corresponding to whatever is the first bit (if any)
969  *  that is turned on in @relmap.  Since bit 0 was off in the
970  *  above example, we leave off that bit (bit 30) in @dst.
971  *
972  *  When bit 1 is set in @orig (as in the above example), it
973  *  means turn on the bit in @dst corresponding to whatever
974  *  is the second bit that is turned on in @relmap.  The second
975  *  bit in @relmap that was turned on in the above example was
976  *  bit 31, so we turned on bit 31 in @dst.
977  *
978  *  Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
979  *  because they were the 4th, 6th, 8th and 10th set bits
980  *  set in @relmap, and the 4th, 6th, 8th and 10th bits of
981  *  @orig (i.e. bits 3, 5, 7 and 9) were also set.
982  *
983  *  When bit 11 is set in @orig, it means turn on the bit in
984  *  @dst corresponding to whatever is the twelfth bit that is
985  *  turned on in @relmap.  In the above example, there were
986  *  only ten bits turned on in @relmap (30..39), so that bit
987  *  11 was set in @orig had no affect on @dst.
988  *
989  * Example [2] for bitmap_fold() + bitmap_onto():
990  *  Let's say @relmap has these ten bits set::
991  *
992  *              40 41 42 43 45 48 53 61 74 95
993  *
994  *  (for the curious, that's 40 plus the first ten terms of the
995  *  Fibonacci sequence.)
996  *
997  *  Further lets say we use the following code, invoking
998  *  bitmap_fold() then bitmap_onto, as suggested above to
999  *  avoid the possibility of an empty @dst result::
1000  *
1001  *      unsigned long *tmp;     // a temporary bitmap's bits
1002  *
1003  *      bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
1004  *      bitmap_onto(dst, tmp, relmap, bits);
1005  *
1006  *  Then this table shows what various values of @dst would be, for
1007  *  various @orig's.  I list the zero-based positions of each set bit.
1008  *  The tmp column shows the intermediate result, as computed by
1009  *  using bitmap_fold() to fold the @orig bitmap modulo ten
1010  *  (the weight of @relmap):
1011  *
1012  *      =============== ============== =================
1013  *      @orig           tmp            @dst
1014  *      0                0             40
1015  *      1                1             41
1016  *      9                9             95
1017  *      10               0             40 [#f1]_
1018  *      1 3 5 7          1 3 5 7       41 43 48 61
1019  *      0 1 2 3 4        0 1 2 3 4     40 41 42 43 45
1020  *      0 9 18 27        0 9 8 7       40 61 74 95
1021  *      0 10 20 30       0             40
1022  *      0 11 22 33       0 1 2 3       40 41 42 43
1023  *      0 12 24 36       0 2 4 6       40 42 45 53
1024  *      78 102 211       1 2 8         41 42 74 [#f1]_
1025  *      =============== ============== =================
1026  *
1027  * .. [#f1]
1028  *
1029  *     For these marked lines, if we hadn't first done bitmap_fold()
1030  *     into tmp, then the @dst result would have been empty.
1031  *
1032  * If either of @orig or @relmap is empty (no set bits), then @dst
1033  * will be returned empty.
1034  *
1035  * If (as explained above) the only set bits in @orig are in positions
1036  * m where m >= W, (where W is the weight of @relmap) then @dst will
1037  * once again be returned empty.
1038  *
1039  * All bits in @dst not set by the above rule are cleared.
1040  */
1041 void bitmap_onto(unsigned long *dst, const unsigned long *orig,
1042                         const unsigned long *relmap, unsigned int bits)
1043 {
1044         unsigned int n, m;      /* same meaning as in above comment */
1045 
1046         if (dst == orig)        /* following doesn't handle inplace mappings */
1047                 return;
1048         bitmap_zero(dst, bits);
1049 
1050         /*
1051          * The following code is a more efficient, but less
1052          * obvious, equivalent to the loop:
1053          *      for (m = 0; m < bitmap_weight(relmap, bits); m++) {
1054          *              n = bitmap_ord_to_pos(orig, m, bits);
1055          *              if (test_bit(m, orig))
1056          *                      set_bit(n, dst);
1057          *      }
1058          */
1059 
1060         m = 0;
1061         for_each_set_bit(n, relmap, bits) {
1062                 /* m == bitmap_pos_to_ord(relmap, n, bits) */
1063                 if (test_bit(m, orig))
1064                         set_bit(n, dst);
1065                 m++;
1066         }
1067 }
1068 
1069 /**
1070  * bitmap_fold - fold larger bitmap into smaller, modulo specified size
1071  *      @dst: resulting smaller bitmap
1072  *      @orig: original larger bitmap
1073  *      @sz: specified size
1074  *      @nbits: number of bits in each of these bitmaps
1075  *
1076  * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
1077  * Clear all other bits in @dst.  See further the comment and
1078  * Example [2] for bitmap_onto() for why and how to use this.
1079  */
1080 void bitmap_fold(unsigned long *dst, const unsigned long *orig,
1081                         unsigned int sz, unsigned int nbits)
1082 {
1083         unsigned int oldbit;
1084 
1085         if (dst == orig)        /* following doesn't handle inplace mappings */
1086                 return;
1087         bitmap_zero(dst, nbits);
1088 
1089         for_each_set_bit(oldbit, orig, nbits)
1090                 set_bit(oldbit % sz, dst);
1091 }
1092 #endif /* CONFIG_NUMA */
1093 
1094 /*
1095  * Common code for bitmap_*_region() routines.
1096  *      bitmap: array of unsigned longs corresponding to the bitmap
1097  *      pos: the beginning of the region
1098  *      order: region size (log base 2 of number of bits)
1099  *      reg_op: operation(s) to perform on that region of bitmap
1100  *
1101  * Can set, verify and/or release a region of bits in a bitmap,
1102  * depending on which combination of REG_OP_* flag bits is set.
1103  *
1104  * A region of a bitmap is a sequence of bits in the bitmap, of
1105  * some size '1 << order' (a power of two), aligned to that same
1106  * '1 << order' power of two.
1107  *
1108  * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
1109  * Returns 0 in all other cases and reg_ops.
1110  */
1111 
1112 enum {
1113         REG_OP_ISFREE,          /* true if region is all zero bits */
1114         REG_OP_ALLOC,           /* set all bits in region */
1115         REG_OP_RELEASE,         /* clear all bits in region */
1116 };
1117 
1118 static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
1119 {
1120         int nbits_reg;          /* number of bits in region */
1121         int index;              /* index first long of region in bitmap */
1122         int offset;             /* bit offset region in bitmap[index] */
1123         int nlongs_reg;         /* num longs spanned by region in bitmap */
1124         int nbitsinlong;        /* num bits of region in each spanned long */
1125         unsigned long mask;     /* bitmask for one long of region */
1126         int i;                  /* scans bitmap by longs */
1127         int ret = 0;            /* return value */
1128 
1129         /*
1130          * Either nlongs_reg == 1 (for small orders that fit in one long)
1131          * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
1132          */
1133         nbits_reg = 1 << order;
1134         index = pos / BITS_PER_LONG;
1135         offset = pos - (index * BITS_PER_LONG);
1136         nlongs_reg = BITS_TO_LONGS(nbits_reg);
1137         nbitsinlong = min(nbits_reg,  BITS_PER_LONG);
1138 
1139         /*
1140          * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1141          * overflows if nbitsinlong == BITS_PER_LONG.
1142          */
1143         mask = (1UL << (nbitsinlong - 1));
1144         mask += mask - 1;
1145         mask <<= offset;
1146 
1147         switch (reg_op) {
1148         case REG_OP_ISFREE:
1149                 for (i = 0; i < nlongs_reg; i++) {
1150                         if (bitmap[index + i] & mask)
1151                                 goto done;
1152                 }
1153                 ret = 1;        /* all bits in region free (zero) */
1154                 break;
1155 
1156         case REG_OP_ALLOC:
1157                 for (i = 0; i < nlongs_reg; i++)
1158                         bitmap[index + i] |= mask;
1159                 break;
1160 
1161         case REG_OP_RELEASE:
1162                 for (i = 0; i < nlongs_reg; i++)
1163                         bitmap[index + i] &= ~mask;
1164                 break;
1165         }
1166 done:
1167         return ret;
1168 }
1169 
1170 /**
1171  * bitmap_find_free_region - find a contiguous aligned mem region
1172  *      @bitmap: array of unsigned longs corresponding to the bitmap
1173  *      @bits: number of bits in the bitmap
1174  *      @order: region size (log base 2 of number of bits) to find
1175  *
1176  * Find a region of free (zero) bits in a @bitmap of @bits bits and
1177  * allocate them (set them to one).  Only consider regions of length
1178  * a power (@order) of two, aligned to that power of two, which
1179  * makes the search algorithm much faster.
1180  *
1181  * Return the bit offset in bitmap of the allocated region,
1182  * or -errno on failure.
1183  */
1184 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
1185 {
1186         unsigned int pos, end;          /* scans bitmap by regions of size order */
1187 
1188         for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
1189                 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1190                         continue;
1191                 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1192                 return pos;
1193         }
1194         return -ENOMEM;
1195 }
1196 EXPORT_SYMBOL(bitmap_find_free_region);
1197 
1198 /**
1199  * bitmap_release_region - release allocated bitmap region
1200  *      @bitmap: array of unsigned longs corresponding to the bitmap
1201  *      @pos: beginning of bit region to release
1202  *      @order: region size (log base 2 of number of bits) to release
1203  *
1204  * This is the complement to __bitmap_find_free_region() and releases
1205  * the found region (by clearing it in the bitmap).
1206  *
1207  * No return value.
1208  */
1209 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
1210 {
1211         __reg_op(bitmap, pos, order, REG_OP_RELEASE);
1212 }
1213 EXPORT_SYMBOL(bitmap_release_region);
1214 
1215 /**
1216  * bitmap_allocate_region - allocate bitmap region
1217  *      @bitmap: array of unsigned longs corresponding to the bitmap
1218  *      @pos: beginning of bit region to allocate
1219  *      @order: region size (log base 2 of number of bits) to allocate
1220  *
1221  * Allocate (set bits in) a specified region of a bitmap.
1222  *
1223  * Return 0 on success, or %-EBUSY if specified region wasn't
1224  * free (not all bits were zero).
1225  */
1226 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
1227 {
1228         if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1229                 return -EBUSY;
1230         return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1231 }
1232 EXPORT_SYMBOL(bitmap_allocate_region);
1233 
1234 /**
1235  * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1236  * @dst:   destination buffer
1237  * @src:   bitmap to copy
1238  * @nbits: number of bits in the bitmap
1239  *
1240  * Require nbits % BITS_PER_LONG == 0.
1241  */
1242 #ifdef __BIG_ENDIAN
1243 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
1244 {
1245         unsigned int i;
1246 
1247         for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1248                 if (BITS_PER_LONG == 64)
1249                         dst[i] = cpu_to_le64(src[i]);
1250                 else
1251                         dst[i] = cpu_to_le32(src[i]);
1252         }
1253 }
1254 EXPORT_SYMBOL(bitmap_copy_le);
1255 #endif
1256 
1257 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
1258 {
1259         return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
1260                              flags);
1261 }
1262 EXPORT_SYMBOL(bitmap_alloc);
1263 
1264 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
1265 {
1266         return bitmap_alloc(nbits, flags | __GFP_ZERO);
1267 }
1268 EXPORT_SYMBOL(bitmap_zalloc);
1269 
1270 void bitmap_free(const unsigned long *bitmap)
1271 {
1272         kfree(bitmap);
1273 }
1274 EXPORT_SYMBOL(bitmap_free);
1275 
1276 static void devm_bitmap_free(void *data)
1277 {
1278         unsigned long *bitmap = data;
1279 
1280         bitmap_free(bitmap);
1281 }
1282 
1283 unsigned long *devm_bitmap_alloc(struct device *dev,
1284                                  unsigned int nbits, gfp_t flags)
1285 {
1286         unsigned long *bitmap;
1287         int ret;
1288 
1289         bitmap = bitmap_alloc(nbits, flags);
1290         if (!bitmap)
1291                 return NULL;
1292 
1293         ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap);
1294         if (ret)
1295                 return NULL;
1296 
1297         return bitmap;
1298 }
1299 EXPORT_SYMBOL_GPL(devm_bitmap_alloc);
1300 
1301 unsigned long *devm_bitmap_zalloc(struct device *dev,
1302                                   unsigned int nbits, gfp_t flags)
1303 {
1304         return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO);
1305 }
1306 EXPORT_SYMBOL_GPL(devm_bitmap_zalloc);
1307 
1308 #if BITS_PER_LONG == 64
1309 /**
1310  * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
1311  *      @bitmap: array of unsigned longs, the destination bitmap
1312  *      @buf: array of u32 (in host byte order), the source bitmap
1313  *      @nbits: number of bits in @bitmap
1314  */
1315 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
1316 {
1317         unsigned int i, halfwords;
1318 
1319         halfwords = DIV_ROUND_UP(nbits, 32);
1320         for (i = 0; i < halfwords; i++) {
1321                 bitmap[i/2] = (unsigned long) buf[i];
1322                 if (++i < halfwords)
1323                         bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
1324         }
1325 
1326         /* Clear tail bits in last word beyond nbits. */
1327         if (nbits % BITS_PER_LONG)
1328                 bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
1329 }
1330 EXPORT_SYMBOL(bitmap_from_arr32);
1331 
1332 /**
1333  * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
1334  *      @buf: array of u32 (in host byte order), the dest bitmap
1335  *      @bitmap: array of unsigned longs, the source bitmap
1336  *      @nbits: number of bits in @bitmap
1337  */
1338 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
1339 {
1340         unsigned int i, halfwords;
1341 
1342         halfwords = DIV_ROUND_UP(nbits, 32);
1343         for (i = 0; i < halfwords; i++) {
1344                 buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
1345                 if (++i < halfwords)
1346                         buf[i] = (u32) (bitmap[i/2] >> 32);
1347         }
1348 
1349         /* Clear tail bits in last element of array beyond nbits. */
1350         if (nbits % BITS_PER_LONG)
1351                 buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
1352 }
1353 EXPORT_SYMBOL(bitmap_to_arr32);
1354 
1355 #endif
1356 

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