LCOV - code coverage report
Current view: top level - lib - bitmap.c (source / functions) Hit Total Coverage
Test: combined.info Lines: 57 395 14.4 %
Date: 2022-03-28 16:04:14 Functions: 7 41 17.1 %
Branches: 19 264 7.2 %

           Branch data     Line data    Source code
       1                 :            : // SPDX-License-Identifier: GPL-2.0-only
       2                 :            : /*
       3                 :            :  * lib/bitmap.c
       4                 :            :  * Helper functions for bitmap.h.
       5                 :            :  */
       6                 :            : #include <linux/export.h>
       7                 :            : #include <linux/thread_info.h>
       8                 :            : #include <linux/ctype.h>
       9                 :            : #include <linux/errno.h>
      10                 :            : #include <linux/bitmap.h>
      11                 :            : #include <linux/bitops.h>
      12                 :            : #include <linux/bug.h>
      13                 :            : #include <linux/kernel.h>
      14                 :            : #include <linux/mm.h>
      15                 :            : #include <linux/slab.h>
      16                 :            : #include <linux/string.h>
      17                 :            : #include <linux/uaccess.h>
      18                 :            : 
      19                 :            : #include <asm/page.h>
      20                 :            : 
      21                 :            : #include "kstrtox.h"
      22                 :            : 
      23                 :            : /**
      24                 :            :  * DOC: bitmap introduction
      25                 :            :  *
      26                 :            :  * bitmaps provide an array of bits, implemented using an an
      27                 :            :  * array of unsigned longs.  The number of valid bits in a
      28                 :            :  * given bitmap does _not_ need to be an exact multiple of
      29                 :            :  * BITS_PER_LONG.
      30                 :            :  *
      31                 :            :  * The possible unused bits in the last, partially used word
      32                 :            :  * of a bitmap are 'don't care'.  The implementation makes
      33                 :            :  * no particular effort to keep them zero.  It ensures that
      34                 :            :  * their value will not affect the results of any operation.
      35                 :            :  * The bitmap operations that return Boolean (bitmap_empty,
      36                 :            :  * for example) or scalar (bitmap_weight, for example) results
      37                 :            :  * carefully filter out these unused bits from impacting their
      38                 :            :  * results.
      39                 :            :  *
      40                 :            :  * The byte ordering of bitmaps is more natural on little
      41                 :            :  * endian architectures.  See the big-endian headers
      42                 :            :  * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
      43                 :            :  * for the best explanations of this ordering.
      44                 :            :  */
      45                 :            : 
      46                 :          0 : int __bitmap_equal(const unsigned long *bitmap1,
      47                 :            :                 const unsigned long *bitmap2, unsigned int bits)
      48                 :            : {
      49                 :          0 :         unsigned int k, lim = bits/BITS_PER_LONG;
      50         [ #  # ]:          0 :         for (k = 0; k < lim; ++k)
      51         [ #  # ]:          0 :                 if (bitmap1[k] != bitmap2[k])
      52                 :            :                         return 0;
      53                 :            : 
      54         [ #  # ]:          0 :         if (bits % BITS_PER_LONG)
      55         [ #  # ]:          0 :                 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
      56                 :          0 :                         return 0;
      57                 :            : 
      58                 :            :         return 1;
      59                 :            : }
      60                 :            : EXPORT_SYMBOL(__bitmap_equal);
      61                 :            : 
      62                 :          0 : bool __bitmap_or_equal(const unsigned long *bitmap1,
      63                 :            :                        const unsigned long *bitmap2,
      64                 :            :                        const unsigned long *bitmap3,
      65                 :            :                        unsigned int bits)
      66                 :            : {
      67                 :          0 :         unsigned int k, lim = bits / BITS_PER_LONG;
      68                 :          0 :         unsigned long tmp;
      69                 :            : 
      70         [ #  # ]:          0 :         for (k = 0; k < lim; ++k) {
      71         [ #  # ]:          0 :                 if ((bitmap1[k] | bitmap2[k]) != bitmap3[k])
      72                 :            :                         return false;
      73                 :            :         }
      74                 :            : 
      75         [ #  # ]:          0 :         if (!(bits % BITS_PER_LONG))
      76                 :            :                 return true;
      77                 :            : 
      78                 :          0 :         tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k];
      79                 :          0 :         return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0;
      80                 :            : }
      81                 :            : 
      82                 :          0 : void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
      83                 :            : {
      84                 :          0 :         unsigned int k, lim = BITS_TO_LONGS(bits);
      85         [ #  # ]:          0 :         for (k = 0; k < lim; ++k)
      86                 :          0 :                 dst[k] = ~src[k];
      87                 :          0 : }
      88                 :            : EXPORT_SYMBOL(__bitmap_complement);
      89                 :            : 
      90                 :            : /**
      91                 :            :  * __bitmap_shift_right - logical right shift of the bits in a bitmap
      92                 :            :  *   @dst : destination bitmap
      93                 :            :  *   @src : source bitmap
      94                 :            :  *   @shift : shift by this many bits
      95                 :            :  *   @nbits : bitmap size, in bits
      96                 :            :  *
      97                 :            :  * Shifting right (dividing) means moving bits in the MS -> LS bit
      98                 :            :  * direction.  Zeros are fed into the vacated MS positions and the
      99                 :            :  * LS bits shifted off the bottom are lost.
     100                 :            :  */
     101                 :          0 : void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
     102                 :            :                         unsigned shift, unsigned nbits)
     103                 :            : {
     104                 :          0 :         unsigned k, lim = BITS_TO_LONGS(nbits);
     105                 :          0 :         unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
     106                 :          0 :         unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
     107         [ #  # ]:          0 :         for (k = 0; off + k < lim; ++k) {
     108                 :          0 :                 unsigned long upper, lower;
     109                 :            : 
     110                 :            :                 /*
     111                 :            :                  * If shift is not word aligned, take lower rem bits of
     112                 :            :                  * word above and make them the top rem bits of result.
     113                 :            :                  */
     114   [ #  #  #  # ]:          0 :                 if (!rem || off + k + 1 >= lim)
     115                 :            :                         upper = 0;
     116                 :            :                 else {
     117                 :          0 :                         upper = src[off + k + 1];
     118         [ #  # ]:          0 :                         if (off + k + 1 == lim - 1)
     119                 :          0 :                                 upper &= mask;
     120                 :          0 :                         upper <<= (BITS_PER_LONG - rem);
     121                 :            :                 }
     122                 :          0 :                 lower = src[off + k];
     123         [ #  # ]:          0 :                 if (off + k == lim - 1)
     124                 :          0 :                         lower &= mask;
     125                 :          0 :                 lower >>= rem;
     126                 :          0 :                 dst[k] = lower | upper;
     127                 :            :         }
     128         [ #  # ]:          0 :         if (off)
     129                 :          0 :                 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
     130                 :          0 : }
     131                 :            : EXPORT_SYMBOL(__bitmap_shift_right);
     132                 :            : 
     133                 :            : 
     134                 :            : /**
     135                 :            :  * __bitmap_shift_left - logical left shift of the bits in a bitmap
     136                 :            :  *   @dst : destination bitmap
     137                 :            :  *   @src : source bitmap
     138                 :            :  *   @shift : shift by this many bits
     139                 :            :  *   @nbits : bitmap size, in bits
     140                 :            :  *
     141                 :            :  * Shifting left (multiplying) means moving bits in the LS -> MS
     142                 :            :  * direction.  Zeros are fed into the vacated LS bit positions
     143                 :            :  * and those MS bits shifted off the top are lost.
     144                 :            :  */
     145                 :            : 
     146                 :          0 : void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
     147                 :            :                         unsigned int shift, unsigned int nbits)
     148                 :            : {
     149                 :          0 :         int k;
     150                 :          0 :         unsigned int lim = BITS_TO_LONGS(nbits);
     151                 :          0 :         unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
     152         [ #  # ]:          0 :         for (k = lim - off - 1; k >= 0; --k) {
     153                 :          0 :                 unsigned long upper, lower;
     154                 :            : 
     155                 :            :                 /*
     156                 :            :                  * If shift is not word aligned, take upper rem bits of
     157                 :            :                  * word below and make them the bottom rem bits of result.
     158                 :            :                  */
     159         [ #  # ]:          0 :                 if (rem && k > 0)
     160                 :          0 :                         lower = src[k - 1] >> (BITS_PER_LONG - rem);
     161                 :            :                 else
     162                 :            :                         lower = 0;
     163                 :          0 :                 upper = src[k] << rem;
     164                 :          0 :                 dst[k + off] = lower | upper;
     165                 :            :         }
     166         [ #  # ]:          0 :         if (off)
     167                 :          0 :                 memset(dst, 0, off*sizeof(unsigned long));
     168                 :          0 : }
     169                 :            : EXPORT_SYMBOL(__bitmap_shift_left);
     170                 :            : 
     171                 :            : /**
     172                 :            :  * bitmap_cut() - remove bit region from bitmap and right shift remaining bits
     173                 :            :  * @dst: destination bitmap, might overlap with src
     174                 :            :  * @src: source bitmap
     175                 :            :  * @first: start bit of region to be removed
     176                 :            :  * @cut: number of bits to remove
     177                 :            :  * @nbits: bitmap size, in bits
     178                 :            :  *
     179                 :            :  * Set the n-th bit of @dst iff the n-th bit of @src is set and
     180                 :            :  * n is less than @first, or the m-th bit of @src is set for any
     181                 :            :  * m such that @first <= n < nbits, and m = n + @cut.
     182                 :            :  *
     183                 :            :  * In pictures, example for a big-endian 32-bit architecture:
     184                 :            :  *
     185                 :            :  * @src:
     186                 :            :  * 31                                   63
     187                 :            :  * |                                    |
     188                 :            :  * 10000000 11000001 11110010 00010101  10000000 11000001 01110010 00010101
     189                 :            :  *                 |  |              |                                    |
     190                 :            :  *                16  14             0                                   32
     191                 :            :  *
     192                 :            :  * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:
     193                 :            :  *
     194                 :            :  * 31                                   63
     195                 :            :  * |                                    |
     196                 :            :  * 10110000 00011000 00110010 00010101  00010000 00011000 00101110 01000010
     197                 :            :  *                    |              |                                    |
     198                 :            :  *                    14 (bit 17     0                                   32
     199                 :            :  *                        from @src)
     200                 :            :  *
     201                 :            :  * Note that @dst and @src might overlap partially or entirely.
     202                 :            :  *
     203                 :            :  * This is implemented in the obvious way, with a shift and carry
     204                 :            :  * step for each moved bit. Optimisation is left as an exercise
     205                 :            :  * for the compiler.
     206                 :            :  */
     207                 :          0 : void bitmap_cut(unsigned long *dst, const unsigned long *src,
     208                 :            :                 unsigned int first, unsigned int cut, unsigned int nbits)
     209                 :            : {
     210                 :          0 :         unsigned int len = BITS_TO_LONGS(nbits);
     211                 :          0 :         unsigned long keep = 0, carry;
     212                 :          0 :         int i;
     213                 :            : 
     214                 :          0 :         memmove(dst, src, len * sizeof(*dst));
     215                 :            : 
     216         [ #  # ]:          0 :         if (first % BITS_PER_LONG) {
     217                 :          0 :                 keep = src[first / BITS_PER_LONG] &
     218                 :          0 :                        (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG));
     219                 :            :         }
     220                 :            : 
     221         [ #  # ]:          0 :         while (cut--) {
     222         [ #  # ]:          0 :                 for (i = first / BITS_PER_LONG; i < len; i++) {
     223         [ #  # ]:          0 :                         if (i < len - 1)
     224                 :          0 :                                 carry = dst[i + 1] & 1UL;
     225                 :            :                         else
     226                 :            :                                 carry = 0;
     227                 :            : 
     228                 :          0 :                         dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1));
     229                 :            :                 }
     230                 :            :         }
     231                 :            : 
     232                 :          0 :         dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG);
     233                 :          0 :         dst[first / BITS_PER_LONG] |= keep;
     234                 :          0 : }
     235                 :            : EXPORT_SYMBOL(bitmap_cut);
     236                 :            : 
     237                 :          0 : int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
     238                 :            :                                 const unsigned long *bitmap2, unsigned int bits)
     239                 :            : {
     240                 :          0 :         unsigned int k;
     241                 :          0 :         unsigned int lim = bits/BITS_PER_LONG;
     242                 :          0 :         unsigned long result = 0;
     243                 :            : 
     244         [ #  # ]:          0 :         for (k = 0; k < lim; k++)
     245                 :          0 :                 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
     246         [ #  # ]:          0 :         if (bits % BITS_PER_LONG)
     247                 :          0 :                 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
     248                 :          0 :                            BITMAP_LAST_WORD_MASK(bits));
     249                 :          0 :         return result != 0;
     250                 :            : }
     251                 :            : EXPORT_SYMBOL(__bitmap_and);
     252                 :            : 
     253                 :        208 : void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
     254                 :            :                                 const unsigned long *bitmap2, unsigned int bits)
     255                 :            : {
     256                 :        208 :         unsigned int k;
     257                 :        208 :         unsigned int nr = BITS_TO_LONGS(bits);
     258                 :            : 
     259         [ +  + ]:       1040 :         for (k = 0; k < nr; k++)
     260                 :        832 :                 dst[k] = bitmap1[k] | bitmap2[k];
     261                 :        208 : }
     262                 :            : EXPORT_SYMBOL(__bitmap_or);
     263                 :            : 
     264                 :          0 : void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
     265                 :            :                                 const unsigned long *bitmap2, unsigned int bits)
     266                 :            : {
     267                 :          0 :         unsigned int k;
     268                 :          0 :         unsigned int nr = BITS_TO_LONGS(bits);
     269                 :            : 
     270         [ #  # ]:          0 :         for (k = 0; k < nr; k++)
     271                 :          0 :                 dst[k] = bitmap1[k] ^ bitmap2[k];
     272                 :          0 : }
     273                 :            : EXPORT_SYMBOL(__bitmap_xor);
     274                 :            : 
     275                 :          0 : int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
     276                 :            :                                 const unsigned long *bitmap2, unsigned int bits)
     277                 :            : {
     278                 :          0 :         unsigned int k;
     279                 :          0 :         unsigned int lim = bits/BITS_PER_LONG;
     280                 :          0 :         unsigned long result = 0;
     281                 :            : 
     282         [ #  # ]:          0 :         for (k = 0; k < lim; k++)
     283                 :          0 :                 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
     284         [ #  # ]:          0 :         if (bits % BITS_PER_LONG)
     285                 :          0 :                 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
     286                 :          0 :                            BITMAP_LAST_WORD_MASK(bits));
     287                 :          0 :         return result != 0;
     288                 :            : }
     289                 :            : EXPORT_SYMBOL(__bitmap_andnot);
     290                 :            : 
     291                 :          0 : void __bitmap_replace(unsigned long *dst,
     292                 :            :                       const unsigned long *old, const unsigned long *new,
     293                 :            :                       const unsigned long *mask, unsigned int nbits)
     294                 :            : {
     295                 :          0 :         unsigned int k;
     296                 :          0 :         unsigned int nr = BITS_TO_LONGS(nbits);
     297                 :            : 
     298         [ #  # ]:          0 :         for (k = 0; k < nr; k++)
     299                 :          0 :                 dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]);
     300                 :          0 : }
     301                 :            : EXPORT_SYMBOL(__bitmap_replace);
     302                 :            : 
     303                 :          0 : int __bitmap_intersects(const unsigned long *bitmap1,
     304                 :            :                         const unsigned long *bitmap2, unsigned int bits)
     305                 :            : {
     306                 :          0 :         unsigned int k, lim = bits/BITS_PER_LONG;
     307         [ #  # ]:          0 :         for (k = 0; k < lim; ++k)
     308         [ #  # ]:          0 :                 if (bitmap1[k] & bitmap2[k])
     309                 :            :                         return 1;
     310                 :            : 
     311         [ #  # ]:          0 :         if (bits % BITS_PER_LONG)
     312         [ #  # ]:          0 :                 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
     313                 :          0 :                         return 1;
     314                 :            :         return 0;
     315                 :            : }
     316                 :            : EXPORT_SYMBOL(__bitmap_intersects);
     317                 :            : 
     318                 :        429 : int __bitmap_subset(const unsigned long *bitmap1,
     319                 :            :                     const unsigned long *bitmap2, unsigned int bits)
     320                 :            : {
     321                 :        429 :         unsigned int k, lim = bits/BITS_PER_LONG;
     322         [ +  + ]:       2262 :         for (k = 0; k < lim; ++k)
     323         [ +  + ]:       2054 :                 if (bitmap1[k] & ~bitmap2[k])
     324                 :            :                         return 0;
     325                 :            : 
     326         [ +  - ]:        208 :         if (bits % BITS_PER_LONG)
     327         [ -  + ]:        208 :                 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
     328                 :          0 :                         return 0;
     329                 :            :         return 1;
     330                 :            : }
     331                 :            : EXPORT_SYMBOL(__bitmap_subset);
     332                 :            : 
     333                 :          0 : int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
     334                 :            : {
     335                 :          0 :         unsigned int k, lim = bits/BITS_PER_LONG;
     336                 :          0 :         int w = 0;
     337                 :            : 
     338         [ #  # ]:          0 :         for (k = 0; k < lim; k++)
     339         [ #  # ]:          0 :                 w += hweight_long(bitmap[k]);
     340                 :            : 
     341         [ #  # ]:          0 :         if (bits % BITS_PER_LONG)
     342         [ #  # ]:          0 :                 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
     343                 :            : 
     344                 :          0 :         return w;
     345                 :            : }
     346                 :            : EXPORT_SYMBOL(__bitmap_weight);
     347                 :            : 
     348                 :      13117 : void __bitmap_set(unsigned long *map, unsigned int start, int len)
     349                 :            : {
     350                 :      13117 :         unsigned long *p = map + BIT_WORD(start);
     351                 :      13117 :         const unsigned int size = start + len;
     352                 :      13117 :         int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
     353                 :      13117 :         unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
     354                 :            : 
     355         [ +  + ]:      15431 :         while (len - bits_to_set >= 0) {
     356                 :       2314 :                 *p |= mask_to_set;
     357                 :       2314 :                 len -= bits_to_set;
     358                 :       2314 :                 bits_to_set = BITS_PER_LONG;
     359                 :       2314 :                 mask_to_set = ~0UL;
     360                 :       2314 :                 p++;
     361                 :            :         }
     362         [ +  + ]:      13117 :         if (len) {
     363                 :      12103 :                 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
     364                 :      12103 :                 *p |= mask_to_set;
     365                 :            :         }
     366                 :      13117 : }
     367                 :            : EXPORT_SYMBOL(__bitmap_set);
     368                 :            : 
     369                 :      13949 : void __bitmap_clear(unsigned long *map, unsigned int start, int len)
     370                 :            : {
     371                 :      13949 :         unsigned long *p = map + BIT_WORD(start);
     372                 :      13949 :         const unsigned int size = start + len;
     373                 :      13949 :         int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
     374                 :      13949 :         unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
     375                 :            : 
     376         [ +  + ]:      15853 :         while (len - bits_to_clear >= 0) {
     377                 :       1904 :                 *p &= ~mask_to_clear;
     378                 :       1904 :                 len -= bits_to_clear;
     379                 :       1904 :                 bits_to_clear = BITS_PER_LONG;
     380                 :       1904 :                 mask_to_clear = ~0UL;
     381                 :       1904 :                 p++;
     382                 :            :         }
     383         [ +  + ]:      13949 :         if (len) {
     384                 :       9321 :                 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
     385                 :       9321 :                 *p &= ~mask_to_clear;
     386                 :            :         }
     387                 :      13949 : }
     388                 :            : EXPORT_SYMBOL(__bitmap_clear);
     389                 :            : 
     390                 :            : /**
     391                 :            :  * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
     392                 :            :  * @map: The address to base the search on
     393                 :            :  * @size: The bitmap size in bits
     394                 :            :  * @start: The bitnumber to start searching at
     395                 :            :  * @nr: The number of zeroed bits we're looking for
     396                 :            :  * @align_mask: Alignment mask for zero area
     397                 :            :  * @align_offset: Alignment offset for zero area.
     398                 :            :  *
     399                 :            :  * The @align_mask should be one less than a power of 2; the effect is that
     400                 :            :  * the bit offset of all zero areas this function finds plus @align_offset
     401                 :            :  * is multiple of that power of 2.
     402                 :            :  */
     403                 :        104 : unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
     404                 :            :                                              unsigned long size,
     405                 :            :                                              unsigned long start,
     406                 :            :                                              unsigned int nr,
     407                 :            :                                              unsigned long align_mask,
     408                 :            :                                              unsigned long align_offset)
     409                 :            : {
     410                 :        104 :         unsigned long index, end, i;
     411                 :        104 : again:
     412                 :        104 :         index = find_next_zero_bit(map, size, start);
     413                 :            : 
     414                 :            :         /* Align allocation */
     415                 :        104 :         index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
     416                 :            : 
     417                 :        104 :         end = index + nr;
     418         [ -  + ]:        104 :         if (end > size)
     419                 :          0 :                 return end;
     420                 :        104 :         i = find_next_bit(map, end, index);
     421         [ -  + ]:        104 :         if (i < end) {
     422                 :          0 :                 start = i + 1;
     423                 :          0 :                 goto again;
     424                 :            :         }
     425                 :            :         return index;
     426                 :            : }
     427                 :            : EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
     428                 :            : 
     429                 :            : /*
     430                 :            :  * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
     431                 :            :  * second version by Paul Jackson, third by Joe Korty.
     432                 :            :  */
     433                 :            : 
     434                 :            : /**
     435                 :            :  * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
     436                 :            :  *
     437                 :            :  * @ubuf: pointer to user buffer containing string.
     438                 :            :  * @ulen: buffer size in bytes.  If string is smaller than this
     439                 :            :  *    then it must be terminated with a \0.
     440                 :            :  * @maskp: pointer to bitmap array that will contain result.
     441                 :            :  * @nmaskbits: size of bitmap, in bits.
     442                 :            :  */
     443                 :          0 : int bitmap_parse_user(const char __user *ubuf,
     444                 :            :                         unsigned int ulen, unsigned long *maskp,
     445                 :            :                         int nmaskbits)
     446                 :            : {
     447                 :          0 :         char *buf;
     448                 :          0 :         int ret;
     449                 :            : 
     450                 :          0 :         buf = memdup_user_nul(ubuf, ulen);
     451         [ #  # ]:          0 :         if (IS_ERR(buf))
     452                 :          0 :                 return PTR_ERR(buf);
     453                 :            : 
     454                 :          0 :         ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits);
     455                 :            : 
     456                 :          0 :         kfree(buf);
     457                 :          0 :         return ret;
     458                 :            : }
     459                 :            : EXPORT_SYMBOL(bitmap_parse_user);
     460                 :            : 
     461                 :            : /**
     462                 :            :  * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
     463                 :            :  * @list: indicates whether the bitmap must be list
     464                 :            :  * @buf: page aligned buffer into which string is placed
     465                 :            :  * @maskp: pointer to bitmap to convert
     466                 :            :  * @nmaskbits: size of bitmap, in bits
     467                 :            :  *
     468                 :            :  * Output format is a comma-separated list of decimal numbers and
     469                 :            :  * ranges if list is specified or hex digits grouped into comma-separated
     470                 :            :  * sets of 8 digits/set. Returns the number of characters written to buf.
     471                 :            :  *
     472                 :            :  * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned
     473                 :            :  * area and that sufficient storage remains at @buf to accommodate the
     474                 :            :  * bitmap_print_to_pagebuf() output. Returns the number of characters
     475                 :            :  * actually printed to @buf, excluding terminating '\0'.
     476                 :            :  */
     477                 :         26 : int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
     478                 :            :                             int nmaskbits)
     479                 :            : {
     480                 :         26 :         ptrdiff_t len = PAGE_SIZE - offset_in_page(buf);
     481                 :            : 
     482         [ +  - ]:         26 :         return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
     483                 :          0 :                       scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
     484                 :            : }
     485                 :            : EXPORT_SYMBOL(bitmap_print_to_pagebuf);
     486                 :            : 
     487                 :            : /*
     488                 :            :  * Region 9-38:4/10 describes the following bitmap structure:
     489                 :            :  * 0       9  12    18                  38
     490                 :            :  * .........****......****......****......
     491                 :            :  *          ^  ^     ^                   ^
     492                 :            :  *      start  off   group_len         end
     493                 :            :  */
     494                 :            : struct region {
     495                 :            :         unsigned int start;
     496                 :            :         unsigned int off;
     497                 :            :         unsigned int group_len;
     498                 :            :         unsigned int end;
     499                 :            : };
     500                 :            : 
     501                 :          0 : static int bitmap_set_region(const struct region *r,
     502                 :            :                                 unsigned long *bitmap, int nbits)
     503                 :            : {
     504                 :          0 :         unsigned int start;
     505                 :            : 
     506         [ #  # ]:          0 :         if (r->end >= nbits)
     507                 :            :                 return -ERANGE;
     508                 :            : 
     509         [ #  # ]:          0 :         for (start = r->start; start <= r->end; start += r->group_len)
     510         [ #  # ]:          0 :                 bitmap_set(bitmap, start, min(r->end - start + 1, r->off));
     511                 :            : 
     512                 :            :         return 0;
     513                 :            : }
     514                 :            : 
     515                 :          0 : static int bitmap_check_region(const struct region *r)
     516                 :            : {
     517   [ #  #  #  # ]:          0 :         if (r->start > r->end || r->group_len == 0 || r->off > r->group_len)
     518                 :          0 :                 return -EINVAL;
     519                 :            : 
     520                 :            :         return 0;
     521                 :            : }
     522                 :            : 
     523                 :          0 : static const char *bitmap_getnum(const char *str, unsigned int *num)
     524                 :            : {
     525                 :          0 :         unsigned long long n;
     526                 :          0 :         unsigned int len;
     527                 :            : 
     528                 :          0 :         len = _parse_integer(str, 10, &n);
     529         [ #  # ]:          0 :         if (!len)
     530                 :            :                 return ERR_PTR(-EINVAL);
     531   [ #  #  #  # ]:          0 :         if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n)
     532                 :            :                 return ERR_PTR(-EOVERFLOW);
     533                 :            : 
     534                 :          0 :         *num = n;
     535                 :          0 :         return str + len;
     536                 :            : }
     537                 :            : 
     538                 :          0 : static inline bool end_of_str(char c)
     539                 :            : {
     540                 :          0 :         return c == '\0' || c == '\n';
     541                 :            : }
     542                 :            : 
     543                 :          0 : static inline bool __end_of_region(char c)
     544                 :            : {
     545   [ #  #  #  #  :          0 :         return isspace(c) || c == ',';
          #  #  #  #  #  
                      # ]
     546                 :            : }
     547                 :            : 
     548                 :          0 : static inline bool end_of_region(char c)
     549                 :            : {
     550   [ #  #  #  #  :          0 :         return __end_of_region(c) || end_of_str(c);
             #  #  #  # ]
     551                 :            : }
     552                 :            : 
     553                 :            : /*
     554                 :            :  * The format allows commas and whitespases at the beginning
     555                 :            :  * of the region.
     556                 :            :  */
     557                 :            : static const char *bitmap_find_region(const char *str)
     558                 :            : {
     559   [ #  #  #  # ]:          0 :         while (__end_of_region(*str))
     560                 :          0 :                 str++;
     561                 :            : 
     562         [ #  # ]:          0 :         return end_of_str(*str) ? NULL : str;
     563                 :            : }
     564                 :            : 
     565                 :          0 : static const char *bitmap_find_region_reverse(const char *start, const char *end)
     566                 :            : {
     567   [ #  #  #  #  :          0 :         while (start <= end && __end_of_region(*end))
                   #  # ]
     568                 :          0 :                 end--;
     569                 :            : 
     570                 :          0 :         return end;
     571                 :            : }
     572                 :            : 
     573                 :          0 : static const char *bitmap_parse_region(const char *str, struct region *r)
     574                 :            : {
     575                 :          0 :         str = bitmap_getnum(str, &r->start);
     576         [ #  # ]:          0 :         if (IS_ERR(str))
     577                 :            :                 return str;
     578                 :            : 
     579   [ #  #  #  # ]:          0 :         if (end_of_region(*str))
     580                 :          0 :                 goto no_end;
     581                 :            : 
     582         [ #  # ]:          0 :         if (*str != '-')
     583                 :            :                 return ERR_PTR(-EINVAL);
     584                 :            : 
     585                 :          0 :         str = bitmap_getnum(str + 1, &r->end);
     586         [ #  # ]:          0 :         if (IS_ERR(str))
     587                 :            :                 return str;
     588                 :            : 
     589   [ #  #  #  # ]:          0 :         if (end_of_region(*str))
     590                 :          0 :                 goto no_pattern;
     591                 :            : 
     592         [ #  # ]:          0 :         if (*str != ':')
     593                 :            :                 return ERR_PTR(-EINVAL);
     594                 :            : 
     595                 :          0 :         str = bitmap_getnum(str + 1, &r->off);
     596         [ #  # ]:          0 :         if (IS_ERR(str))
     597                 :            :                 return str;
     598                 :            : 
     599         [ #  # ]:          0 :         if (*str != '/')
     600                 :            :                 return ERR_PTR(-EINVAL);
     601                 :            : 
     602                 :          0 :         return bitmap_getnum(str + 1, &r->group_len);
     603                 :            : 
     604                 :            : no_end:
     605                 :          0 :         r->end = r->start;
     606                 :          0 : no_pattern:
     607                 :          0 :         r->off = r->end + 1;
     608                 :          0 :         r->group_len = r->end + 1;
     609                 :            : 
     610         [ #  # ]:          0 :         return end_of_str(*str) ? NULL : str;
     611                 :            : }
     612                 :            : 
     613                 :            : /**
     614                 :            :  * bitmap_parselist - convert list format ASCII string to bitmap
     615                 :            :  * @buf: read user string from this buffer; must be terminated
     616                 :            :  *    with a \0 or \n.
     617                 :            :  * @maskp: write resulting mask here
     618                 :            :  * @nmaskbits: number of bits in mask to be written
     619                 :            :  *
     620                 :            :  * Input format is a comma-separated list of decimal numbers and
     621                 :            :  * ranges.  Consecutively set bits are shown as two hyphen-separated
     622                 :            :  * decimal numbers, the smallest and largest bit numbers set in
     623                 :            :  * the range.
     624                 :            :  * Optionally each range can be postfixed to denote that only parts of it
     625                 :            :  * should be set. The range will divided to groups of specific size.
     626                 :            :  * From each group will be used only defined amount of bits.
     627                 :            :  * Syntax: range:used_size/group_size
     628                 :            :  * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769
     629                 :            :  *
     630                 :            :  * Returns: 0 on success, -errno on invalid input strings. Error values:
     631                 :            :  *
     632                 :            :  *   - ``-EINVAL``: wrong region format
     633                 :            :  *   - ``-EINVAL``: invalid character in string
     634                 :            :  *   - ``-ERANGE``: bit number specified too large for mask
     635                 :            :  *   - ``-EOVERFLOW``: integer overflow in the input parameters
     636                 :            :  */
     637                 :          0 : int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits)
     638                 :            : {
     639                 :          0 :         struct region r;
     640                 :          0 :         long ret;
     641                 :            : 
     642                 :          0 :         bitmap_zero(maskp, nmaskbits);
     643                 :            : 
     644         [ #  # ]:          0 :         while (buf) {
     645                 :            :                 buf = bitmap_find_region(buf);
     646         [ #  # ]:          0 :                 if (buf == NULL)
     647                 :            :                         return 0;
     648                 :            : 
     649                 :          0 :                 buf = bitmap_parse_region(buf, &r);
     650         [ #  # ]:          0 :                 if (IS_ERR(buf))
     651                 :          0 :                         return PTR_ERR(buf);
     652                 :            : 
     653         [ #  # ]:          0 :                 ret = bitmap_check_region(&r);
     654         [ #  # ]:          0 :                 if (ret)
     655                 :          0 :                         return ret;
     656                 :            : 
     657                 :          0 :                 ret = bitmap_set_region(&r, maskp, nmaskbits);
     658         [ #  # ]:          0 :                 if (ret)
     659                 :          0 :                         return ret;
     660                 :            :         }
     661                 :            : 
     662                 :            :         return 0;
     663                 :            : }
     664                 :            : EXPORT_SYMBOL(bitmap_parselist);
     665                 :            : 
     666                 :            : 
     667                 :            : /**
     668                 :            :  * bitmap_parselist_user()
     669                 :            :  *
     670                 :            :  * @ubuf: pointer to user buffer containing string.
     671                 :            :  * @ulen: buffer size in bytes.  If string is smaller than this
     672                 :            :  *    then it must be terminated with a \0.
     673                 :            :  * @maskp: pointer to bitmap array that will contain result.
     674                 :            :  * @nmaskbits: size of bitmap, in bits.
     675                 :            :  *
     676                 :            :  * Wrapper for bitmap_parselist(), providing it with user buffer.
     677                 :            :  */
     678                 :          0 : int bitmap_parselist_user(const char __user *ubuf,
     679                 :            :                         unsigned int ulen, unsigned long *maskp,
     680                 :            :                         int nmaskbits)
     681                 :            : {
     682                 :          0 :         char *buf;
     683                 :          0 :         int ret;
     684                 :            : 
     685                 :          0 :         buf = memdup_user_nul(ubuf, ulen);
     686         [ #  # ]:          0 :         if (IS_ERR(buf))
     687                 :          0 :                 return PTR_ERR(buf);
     688                 :            : 
     689                 :          0 :         ret = bitmap_parselist(buf, maskp, nmaskbits);
     690                 :            : 
     691                 :          0 :         kfree(buf);
     692                 :          0 :         return ret;
     693                 :            : }
     694                 :            : EXPORT_SYMBOL(bitmap_parselist_user);
     695                 :            : 
     696                 :          0 : static const char *bitmap_get_x32_reverse(const char *start,
     697                 :            :                                         const char *end, u32 *num)
     698                 :            : {
     699                 :          0 :         u32 ret = 0;
     700                 :          0 :         int c, i;
     701                 :            : 
     702         [ #  # ]:          0 :         for (i = 0; i < 32; i += 4) {
     703                 :          0 :                 c = hex_to_bin(*end--);
     704         [ #  # ]:          0 :                 if (c < 0)
     705                 :            :                         return ERR_PTR(-EINVAL);
     706                 :            : 
     707                 :          0 :                 ret |= c << i;
     708                 :            : 
     709   [ #  #  #  #  :          0 :                 if (start > end || __end_of_region(*end))
                   #  # ]
     710                 :          0 :                         goto out;
     711                 :            :         }
     712                 :            : 
     713         [ #  # ]:          0 :         if (hex_to_bin(*end--) >= 0)
     714                 :            :                 return ERR_PTR(-EOVERFLOW);
     715                 :          0 : out:
     716                 :          0 :         *num = ret;
     717                 :          0 :         return end;
     718                 :            : }
     719                 :            : 
     720                 :            : /**
     721                 :            :  * bitmap_parse - convert an ASCII hex string into a bitmap.
     722                 :            :  * @start: pointer to buffer containing string.
     723                 :            :  * @buflen: buffer size in bytes.  If string is smaller than this
     724                 :            :  *    then it must be terminated with a \0 or \n. In that case,
     725                 :            :  *    UINT_MAX may be provided instead of string length.
     726                 :            :  * @maskp: pointer to bitmap array that will contain result.
     727                 :            :  * @nmaskbits: size of bitmap, in bits.
     728                 :            :  *
     729                 :            :  * Commas group hex digits into chunks.  Each chunk defines exactly 32
     730                 :            :  * bits of the resultant bitmask.  No chunk may specify a value larger
     731                 :            :  * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
     732                 :            :  * then leading 0-bits are prepended.  %-EINVAL is returned for illegal
     733                 :            :  * characters. Grouping such as "1,,5", ",44", "," or "" is allowed.
     734                 :            :  * Leading, embedded and trailing whitespace accepted.
     735                 :            :  */
     736                 :          0 : int bitmap_parse(const char *start, unsigned int buflen,
     737                 :            :                 unsigned long *maskp, int nmaskbits)
     738                 :            : {
     739                 :          0 :         const char *end = strnchrnul(start, buflen, '\n') - 1;
     740                 :          0 :         int chunks = BITS_TO_U32(nmaskbits);
     741                 :          0 :         u32 *bitmap = (u32 *)maskp;
     742                 :          0 :         int unset_bit;
     743                 :            : 
     744                 :          0 :         while (1) {
     745                 :          0 :                 end = bitmap_find_region_reverse(start, end);
     746         [ #  # ]:          0 :                 if (start > end)
     747                 :            :                         break;
     748                 :            : 
     749         [ #  # ]:          0 :                 if (!chunks--)
     750                 :            :                         return -EOVERFLOW;
     751                 :            : 
     752                 :          0 :                 end = bitmap_get_x32_reverse(start, end, bitmap++);
     753         [ #  # ]:          0 :                 if (IS_ERR(end))
     754                 :          0 :                         return PTR_ERR(end);
     755                 :            :         }
     756                 :            : 
     757                 :          0 :         unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32;
     758         [ #  # ]:          0 :         if (unset_bit < nmaskbits) {
     759         [ #  # ]:          0 :                 bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit);
     760                 :          0 :                 return 0;
     761                 :            :         }
     762                 :            : 
     763         [ #  # ]:          0 :         if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit)
     764                 :          0 :                 return -EOVERFLOW;
     765                 :            : 
     766                 :            :         return 0;
     767                 :            : }
     768                 :            : EXPORT_SYMBOL(bitmap_parse);
     769                 :            : 
     770                 :            : 
     771                 :            : #ifdef CONFIG_NUMA
     772                 :            : /**
     773                 :            :  * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
     774                 :            :  *      @buf: pointer to a bitmap
     775                 :            :  *      @pos: a bit position in @buf (0 <= @pos < @nbits)
     776                 :            :  *      @nbits: number of valid bit positions in @buf
     777                 :            :  *
     778                 :            :  * Map the bit at position @pos in @buf (of length @nbits) to the
     779                 :            :  * ordinal of which set bit it is.  If it is not set or if @pos
     780                 :            :  * is not a valid bit position, map to -1.
     781                 :            :  *
     782                 :            :  * If for example, just bits 4 through 7 are set in @buf, then @pos
     783                 :            :  * values 4 through 7 will get mapped to 0 through 3, respectively,
     784                 :            :  * and other @pos values will get mapped to -1.  When @pos value 7
     785                 :            :  * gets mapped to (returns) @ord value 3 in this example, that means
     786                 :            :  * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
     787                 :            :  *
     788                 :            :  * The bit positions 0 through @bits are valid positions in @buf.
     789                 :            :  */
     790                 :          0 : static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
     791                 :            : {
     792   [ #  #  #  # ]:          0 :         if (pos >= nbits || !test_bit(pos, buf))
     793                 :          0 :                 return -1;
     794                 :            : 
     795                 :          0 :         return __bitmap_weight(buf, pos);
     796                 :            : }
     797                 :            : 
     798                 :            : /**
     799                 :            :  * bitmap_ord_to_pos - find position of n-th set bit in bitmap
     800                 :            :  *      @buf: pointer to bitmap
     801                 :            :  *      @ord: ordinal bit position (n-th set bit, n >= 0)
     802                 :            :  *      @nbits: number of valid bit positions in @buf
     803                 :            :  *
     804                 :            :  * Map the ordinal offset of bit @ord in @buf to its position in @buf.
     805                 :            :  * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
     806                 :            :  * >= weight(buf), returns @nbits.
     807                 :            :  *
     808                 :            :  * If for example, just bits 4 through 7 are set in @buf, then @ord
     809                 :            :  * values 0 through 3 will get mapped to 4 through 7, respectively,
     810                 :            :  * and all other @ord values returns @nbits.  When @ord value 3
     811                 :            :  * gets mapped to (returns) @pos value 7 in this example, that means
     812                 :            :  * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
     813                 :            :  *
     814                 :            :  * The bit positions 0 through @nbits-1 are valid positions in @buf.
     815                 :            :  */
     816                 :          0 : unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
     817                 :            : {
     818                 :          0 :         unsigned int pos;
     819                 :            : 
     820                 :          0 :         for (pos = find_first_bit(buf, nbits);
     821         [ #  # ]:          0 :              pos < nbits && ord;
     822                 :          0 :              pos = find_next_bit(buf, nbits, pos + 1))
     823                 :          0 :                 ord--;
     824                 :            : 
     825                 :          0 :         return pos;
     826                 :            : }
     827                 :            : 
     828                 :            : /**
     829                 :            :  * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
     830                 :            :  *      @dst: remapped result
     831                 :            :  *      @src: subset to be remapped
     832                 :            :  *      @old: defines domain of map
     833                 :            :  *      @new: defines range of map
     834                 :            :  *      @nbits: number of bits in each of these bitmaps
     835                 :            :  *
     836                 :            :  * Let @old and @new define a mapping of bit positions, such that
     837                 :            :  * whatever position is held by the n-th set bit in @old is mapped
     838                 :            :  * to the n-th set bit in @new.  In the more general case, allowing
     839                 :            :  * for the possibility that the weight 'w' of @new is less than the
     840                 :            :  * weight of @old, map the position of the n-th set bit in @old to
     841                 :            :  * the position of the m-th set bit in @new, where m == n % w.
     842                 :            :  *
     843                 :            :  * If either of the @old and @new bitmaps are empty, or if @src and
     844                 :            :  * @dst point to the same location, then this routine copies @src
     845                 :            :  * to @dst.
     846                 :            :  *
     847                 :            :  * The positions of unset bits in @old are mapped to themselves
     848                 :            :  * (the identify map).
     849                 :            :  *
     850                 :            :  * Apply the above specified mapping to @src, placing the result in
     851                 :            :  * @dst, clearing any bits previously set in @dst.
     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
     856                 :            :  * bit positions unchanged.  So if say @src comes into this routine
     857                 :            :  * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
     858                 :            :  * 13 and 15 set.
     859                 :            :  */
     860                 :          0 : void bitmap_remap(unsigned long *dst, const unsigned long *src,
     861                 :            :                 const unsigned long *old, const unsigned long *new,
     862                 :            :                 unsigned int nbits)
     863                 :            : {
     864                 :          0 :         unsigned int oldbit, w;
     865                 :            : 
     866         [ #  # ]:          0 :         if (dst == src)         /* following doesn't handle inplace remaps */
     867                 :            :                 return;
     868         [ #  # ]:          0 :         bitmap_zero(dst, nbits);
     869                 :            : 
     870         [ #  # ]:          0 :         w = bitmap_weight(new, nbits);
     871         [ #  # ]:          0 :         for_each_set_bit(oldbit, src, nbits) {
     872                 :          0 :                 int n = bitmap_pos_to_ord(old, oldbit, nbits);
     873                 :            : 
     874         [ #  # ]:          0 :                 if (n < 0 || w == 0)
     875                 :          0 :                         set_bit(oldbit, dst);   /* identity map */
     876                 :            :                 else
     877                 :          0 :                         set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
     878                 :            :         }
     879                 :            : }
     880                 :            : 
     881                 :            : /**
     882                 :            :  * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
     883                 :            :  *      @oldbit: bit position to be mapped
     884                 :            :  *      @old: defines domain of map
     885                 :            :  *      @new: defines range of map
     886                 :            :  *      @bits: number of bits in each of these bitmaps
     887                 :            :  *
     888                 :            :  * Let @old and @new define a mapping of bit positions, such that
     889                 :            :  * whatever position is held by the n-th set bit in @old is mapped
     890                 :            :  * to the n-th set bit in @new.  In the more general case, allowing
     891                 :            :  * for the possibility that the weight 'w' of @new is less than the
     892                 :            :  * weight of @old, map the position of the n-th set bit in @old to
     893                 :            :  * the position of the m-th set bit in @new, where m == n % w.
     894                 :            :  *
     895                 :            :  * The positions of unset bits in @old are mapped to themselves
     896                 :            :  * (the identify map).
     897                 :            :  *
     898                 :            :  * Apply the above specified mapping to bit position @oldbit, returning
     899                 :            :  * the new bit position.
     900                 :            :  *
     901                 :            :  * For example, lets say that @old has bits 4 through 7 set, and
     902                 :            :  * @new has bits 12 through 15 set.  This defines the mapping of bit
     903                 :            :  * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
     904                 :            :  * bit positions unchanged.  So if say @oldbit is 5, then this routine
     905                 :            :  * returns 13.
     906                 :            :  */
     907                 :          0 : int bitmap_bitremap(int oldbit, const unsigned long *old,
     908                 :            :                                 const unsigned long *new, int bits)
     909                 :            : {
     910         [ #  # ]:          0 :         int w = bitmap_weight(new, bits);
     911                 :          0 :         int n = bitmap_pos_to_ord(old, oldbit, bits);
     912         [ #  # ]:          0 :         if (n < 0 || w == 0)
     913                 :            :                 return oldbit;
     914                 :            :         else
     915                 :          0 :                 return bitmap_ord_to_pos(new, n % w, bits);
     916                 :            : }
     917                 :            : 
     918                 :            : /**
     919                 :            :  * bitmap_onto - translate one bitmap relative to another
     920                 :            :  *      @dst: resulting translated bitmap
     921                 :            :  *      @orig: original untranslated bitmap
     922                 :            :  *      @relmap: bitmap relative to which translated
     923                 :            :  *      @bits: number of bits in each of these bitmaps
     924                 :            :  *
     925                 :            :  * Set the n-th bit of @dst iff there exists some m such that the
     926                 :            :  * n-th bit of @relmap is set, the m-th bit of @orig is set, and
     927                 :            :  * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
     928                 :            :  * (If you understood the previous sentence the first time your
     929                 :            :  * read it, you're overqualified for your current job.)
     930                 :            :  *
     931                 :            :  * In other words, @orig is mapped onto (surjectively) @dst,
     932                 :            :  * using the map { <n, m> | the n-th bit of @relmap is the
     933                 :            :  * m-th set bit of @relmap }.
     934                 :            :  *
     935                 :            :  * Any set bits in @orig above bit number W, where W is the
     936                 :            :  * weight of (number of set bits in) @relmap are mapped nowhere.
     937                 :            :  * In particular, if for all bits m set in @orig, m >= W, then
     938                 :            :  * @dst will end up empty.  In situations where the possibility
     939                 :            :  * of such an empty result is not desired, one way to avoid it is
     940                 :            :  * to use the bitmap_fold() operator, below, to first fold the
     941                 :            :  * @orig bitmap over itself so that all its set bits x are in the
     942                 :            :  * range 0 <= x < W.  The bitmap_fold() operator does this by
     943                 :            :  * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
     944                 :            :  *
     945                 :            :  * Example [1] for bitmap_onto():
     946                 :            :  *  Let's say @relmap has bits 30-39 set, and @orig has bits
     947                 :            :  *  1, 3, 5, 7, 9 and 11 set.  Then on return from this routine,
     948                 :            :  *  @dst will have bits 31, 33, 35, 37 and 39 set.
     949                 :            :  *
     950                 :            :  *  When bit 0 is set in @orig, it means turn on the bit in
     951                 :            :  *  @dst corresponding to whatever is the first bit (if any)
     952                 :            :  *  that is turned on in @relmap.  Since bit 0 was off in the
     953                 :            :  *  above example, we leave off that bit (bit 30) in @dst.
     954                 :            :  *
     955                 :            :  *  When bit 1 is set in @orig (as in the above example), it
     956                 :            :  *  means turn on the bit in @dst corresponding to whatever
     957                 :            :  *  is the second bit that is turned on in @relmap.  The second
     958                 :            :  *  bit in @relmap that was turned on in the above example was
     959                 :            :  *  bit 31, so we turned on bit 31 in @dst.
     960                 :            :  *
     961                 :            :  *  Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
     962                 :            :  *  because they were the 4th, 6th, 8th and 10th set bits
     963                 :            :  *  set in @relmap, and the 4th, 6th, 8th and 10th bits of
     964                 :            :  *  @orig (i.e. bits 3, 5, 7 and 9) were also set.
     965                 :            :  *
     966                 :            :  *  When bit 11 is set in @orig, it means turn on the bit in
     967                 :            :  *  @dst corresponding to whatever is the twelfth bit that is
     968                 :            :  *  turned on in @relmap.  In the above example, there were
     969                 :            :  *  only ten bits turned on in @relmap (30..39), so that bit
     970                 :            :  *  11 was set in @orig had no affect on @dst.
     971                 :            :  *
     972                 :            :  * Example [2] for bitmap_fold() + bitmap_onto():
     973                 :            :  *  Let's say @relmap has these ten bits set::
     974                 :            :  *
     975                 :            :  *              40 41 42 43 45 48 53 61 74 95
     976                 :            :  *
     977                 :            :  *  (for the curious, that's 40 plus the first ten terms of the
     978                 :            :  *  Fibonacci sequence.)
     979                 :            :  *
     980                 :            :  *  Further lets say we use the following code, invoking
     981                 :            :  *  bitmap_fold() then bitmap_onto, as suggested above to
     982                 :            :  *  avoid the possibility of an empty @dst result::
     983                 :            :  *
     984                 :            :  *      unsigned long *tmp;     // a temporary bitmap's bits
     985                 :            :  *
     986                 :            :  *      bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
     987                 :            :  *      bitmap_onto(dst, tmp, relmap, bits);
     988                 :            :  *
     989                 :            :  *  Then this table shows what various values of @dst would be, for
     990                 :            :  *  various @orig's.  I list the zero-based positions of each set bit.
     991                 :            :  *  The tmp column shows the intermediate result, as computed by
     992                 :            :  *  using bitmap_fold() to fold the @orig bitmap modulo ten
     993                 :            :  *  (the weight of @relmap):
     994                 :            :  *
     995                 :            :  *      =============== ============== =================
     996                 :            :  *      @orig           tmp            @dst
     997                 :            :  *      0                0             40
     998                 :            :  *      1                1             41
     999                 :            :  *      9                9             95
    1000                 :            :  *      10               0             40 [#f1]_
    1001                 :            :  *      1 3 5 7          1 3 5 7       41 43 48 61
    1002                 :            :  *      0 1 2 3 4        0 1 2 3 4     40 41 42 43 45
    1003                 :            :  *      0 9 18 27        0 9 8 7       40 61 74 95
    1004                 :            :  *      0 10 20 30       0             40
    1005                 :            :  *      0 11 22 33       0 1 2 3       40 41 42 43
    1006                 :            :  *      0 12 24 36       0 2 4 6       40 42 45 53
    1007                 :            :  *      78 102 211       1 2 8         41 42 74 [#f1]_
    1008                 :            :  *      =============== ============== =================
    1009                 :            :  *
    1010                 :            :  * .. [#f1]
    1011                 :            :  *
    1012                 :            :  *     For these marked lines, if we hadn't first done bitmap_fold()
    1013                 :            :  *     into tmp, then the @dst result would have been empty.
    1014                 :            :  *
    1015                 :            :  * If either of @orig or @relmap is empty (no set bits), then @dst
    1016                 :            :  * will be returned empty.
    1017                 :            :  *
    1018                 :            :  * If (as explained above) the only set bits in @orig are in positions
    1019                 :            :  * m where m >= W, (where W is the weight of @relmap) then @dst will
    1020                 :            :  * once again be returned empty.
    1021                 :            :  *
    1022                 :            :  * All bits in @dst not set by the above rule are cleared.
    1023                 :            :  */
    1024                 :          0 : void bitmap_onto(unsigned long *dst, const unsigned long *orig,
    1025                 :            :                         const unsigned long *relmap, unsigned int bits)
    1026                 :            : {
    1027                 :          0 :         unsigned int n, m;      /* same meaning as in above comment */
    1028                 :            : 
    1029         [ #  # ]:          0 :         if (dst == orig)        /* following doesn't handle inplace mappings */
    1030                 :            :                 return;
    1031                 :          0 :         bitmap_zero(dst, bits);
    1032                 :            : 
    1033                 :            :         /*
    1034                 :            :          * The following code is a more efficient, but less
    1035                 :            :          * obvious, equivalent to the loop:
    1036                 :            :          *      for (m = 0; m < bitmap_weight(relmap, bits); m++) {
    1037                 :            :          *              n = bitmap_ord_to_pos(orig, m, bits);
    1038                 :            :          *              if (test_bit(m, orig))
    1039                 :            :          *                      set_bit(n, dst);
    1040                 :            :          *      }
    1041                 :            :          */
    1042                 :            : 
    1043                 :          0 :         m = 0;
    1044         [ #  # ]:          0 :         for_each_set_bit(n, relmap, bits) {
    1045                 :            :                 /* m == bitmap_pos_to_ord(relmap, n, bits) */
    1046         [ #  # ]:          0 :                 if (test_bit(m, orig))
    1047                 :          0 :                         set_bit(n, dst);
    1048                 :          0 :                 m++;
    1049                 :            :         }
    1050                 :            : }
    1051                 :            : 
    1052                 :            : /**
    1053                 :            :  * bitmap_fold - fold larger bitmap into smaller, modulo specified size
    1054                 :            :  *      @dst: resulting smaller bitmap
    1055                 :            :  *      @orig: original larger bitmap
    1056                 :            :  *      @sz: specified size
    1057                 :            :  *      @nbits: number of bits in each of these bitmaps
    1058                 :            :  *
    1059                 :            :  * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
    1060                 :            :  * Clear all other bits in @dst.  See further the comment and
    1061                 :            :  * Example [2] for bitmap_onto() for why and how to use this.
    1062                 :            :  */
    1063                 :          0 : void bitmap_fold(unsigned long *dst, const unsigned long *orig,
    1064                 :            :                         unsigned int sz, unsigned int nbits)
    1065                 :            : {
    1066                 :          0 :         unsigned int oldbit;
    1067                 :            : 
    1068         [ #  # ]:          0 :         if (dst == orig)        /* following doesn't handle inplace mappings */
    1069                 :            :                 return;
    1070                 :          0 :         bitmap_zero(dst, nbits);
    1071                 :            : 
    1072         [ #  # ]:          0 :         for_each_set_bit(oldbit, orig, nbits)
    1073                 :          0 :                 set_bit(oldbit % sz, dst);
    1074                 :            : }
    1075                 :            : #endif /* CONFIG_NUMA */
    1076                 :            : 
    1077                 :            : /*
    1078                 :            :  * Common code for bitmap_*_region() routines.
    1079                 :            :  *      bitmap: array of unsigned longs corresponding to the bitmap
    1080                 :            :  *      pos: the beginning of the region
    1081                 :            :  *      order: region size (log base 2 of number of bits)
    1082                 :            :  *      reg_op: operation(s) to perform on that region of bitmap
    1083                 :            :  *
    1084                 :            :  * Can set, verify and/or release a region of bits in a bitmap,
    1085                 :            :  * depending on which combination of REG_OP_* flag bits is set.
    1086                 :            :  *
    1087                 :            :  * A region of a bitmap is a sequence of bits in the bitmap, of
    1088                 :            :  * some size '1 << order' (a power of two), aligned to that same
    1089                 :            :  * '1 << order' power of two.
    1090                 :            :  *
    1091                 :            :  * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
    1092                 :            :  * Returns 0 in all other cases and reg_ops.
    1093                 :            :  */
    1094                 :            : 
    1095                 :            : enum {
    1096                 :            :         REG_OP_ISFREE,          /* true if region is all zero bits */
    1097                 :            :         REG_OP_ALLOC,           /* set all bits in region */
    1098                 :            :         REG_OP_RELEASE,         /* clear all bits in region */
    1099                 :            : };
    1100                 :            : 
    1101                 :          0 : static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
    1102                 :            : {
    1103                 :          0 :         int nbits_reg;          /* number of bits in region */
    1104                 :          0 :         int index;              /* index first long of region in bitmap */
    1105                 :          0 :         int offset;             /* bit offset region in bitmap[index] */
    1106                 :          0 :         int nlongs_reg;         /* num longs spanned by region in bitmap */
    1107                 :          0 :         int nbitsinlong;        /* num bits of region in each spanned long */
    1108                 :          0 :         unsigned long mask;     /* bitmask for one long of region */
    1109                 :          0 :         int i;                  /* scans bitmap by longs */
    1110                 :          0 :         int ret = 0;            /* return value */
    1111                 :            : 
    1112                 :            :         /*
    1113                 :            :          * Either nlongs_reg == 1 (for small orders that fit in one long)
    1114                 :            :          * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
    1115                 :            :          */
    1116                 :          0 :         nbits_reg = 1 << order;
    1117                 :          0 :         index = pos / BITS_PER_LONG;
    1118                 :          0 :         offset = pos - (index * BITS_PER_LONG);
    1119                 :          0 :         nlongs_reg = BITS_TO_LONGS(nbits_reg);
    1120                 :          0 :         nbitsinlong = min(nbits_reg,  BITS_PER_LONG);
    1121                 :            : 
    1122                 :            :         /*
    1123                 :            :          * Can't do "mask = (1UL << nbitsinlong) - 1", as that
    1124                 :            :          * overflows if nbitsinlong == BITS_PER_LONG.
    1125                 :            :          */
    1126                 :          0 :         mask = (1UL << (nbitsinlong - 1));
    1127                 :          0 :         mask += mask - 1;
    1128                 :          0 :         mask <<= offset;
    1129                 :            : 
    1130   [ #  #  #  # ]:          0 :         switch (reg_op) {
    1131                 :            :         case REG_OP_ISFREE:
    1132         [ #  # ]:          0 :                 for (i = 0; i < nlongs_reg; i++) {
    1133         [ #  # ]:          0 :                         if (bitmap[index + i] & mask)
    1134                 :          0 :                                 goto done;
    1135                 :            :                 }
    1136                 :            :                 ret = 1;        /* all bits in region free (zero) */
    1137                 :            :                 break;
    1138                 :            : 
    1139                 :            :         case REG_OP_ALLOC:
    1140   [ #  #  #  # ]:          0 :                 for (i = 0; i < nlongs_reg; i++)
    1141                 :          0 :                         bitmap[index + i] |= mask;
    1142                 :            :                 break;
    1143                 :            : 
    1144                 :            :         case REG_OP_RELEASE:
    1145         [ #  # ]:          0 :                 for (i = 0; i < nlongs_reg; i++)
    1146                 :          0 :                         bitmap[index + i] &= ~mask;
    1147                 :            :                 break;
    1148                 :            :         }
    1149                 :          0 : done:
    1150                 :          0 :         return ret;
    1151                 :            : }
    1152                 :            : 
    1153                 :            : /**
    1154                 :            :  * bitmap_find_free_region - find a contiguous aligned mem region
    1155                 :            :  *      @bitmap: array of unsigned longs corresponding to the bitmap
    1156                 :            :  *      @bits: number of bits in the bitmap
    1157                 :            :  *      @order: region size (log base 2 of number of bits) to find
    1158                 :            :  *
    1159                 :            :  * Find a region of free (zero) bits in a @bitmap of @bits bits and
    1160                 :            :  * allocate them (set them to one).  Only consider regions of length
    1161                 :            :  * a power (@order) of two, aligned to that power of two, which
    1162                 :            :  * makes the search algorithm much faster.
    1163                 :            :  *
    1164                 :            :  * Return the bit offset in bitmap of the allocated region,
    1165                 :            :  * or -errno on failure.
    1166                 :            :  */
    1167                 :          0 : int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
    1168                 :            : {
    1169                 :          0 :         unsigned int pos, end;          /* scans bitmap by regions of size order */
    1170                 :            : 
    1171         [ #  # ]:          0 :         for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
    1172         [ #  # ]:          0 :                 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
    1173                 :          0 :                         continue;
    1174                 :          0 :                 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
    1175                 :          0 :                 return pos;
    1176                 :            :         }
    1177                 :            :         return -ENOMEM;
    1178                 :            : }
    1179                 :            : EXPORT_SYMBOL(bitmap_find_free_region);
    1180                 :            : 
    1181                 :            : /**
    1182                 :            :  * bitmap_release_region - release allocated bitmap region
    1183                 :            :  *      @bitmap: array of unsigned longs corresponding to the bitmap
    1184                 :            :  *      @pos: beginning of bit region to release
    1185                 :            :  *      @order: region size (log base 2 of number of bits) to release
    1186                 :            :  *
    1187                 :            :  * This is the complement to __bitmap_find_free_region() and releases
    1188                 :            :  * the found region (by clearing it in the bitmap).
    1189                 :            :  *
    1190                 :            :  * No return value.
    1191                 :            :  */
    1192                 :          0 : void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
    1193                 :            : {
    1194                 :          0 :         __reg_op(bitmap, pos, order, REG_OP_RELEASE);
    1195                 :          0 : }
    1196                 :            : EXPORT_SYMBOL(bitmap_release_region);
    1197                 :            : 
    1198                 :            : /**
    1199                 :            :  * bitmap_allocate_region - allocate bitmap region
    1200                 :            :  *      @bitmap: array of unsigned longs corresponding to the bitmap
    1201                 :            :  *      @pos: beginning of bit region to allocate
    1202                 :            :  *      @order: region size (log base 2 of number of bits) to allocate
    1203                 :            :  *
    1204                 :            :  * Allocate (set bits in) a specified region of a bitmap.
    1205                 :            :  *
    1206                 :            :  * Return 0 on success, or %-EBUSY if specified region wasn't
    1207                 :            :  * free (not all bits were zero).
    1208                 :            :  */
    1209                 :          0 : int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
    1210                 :            : {
    1211         [ #  # ]:          0 :         if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
    1212                 :            :                 return -EBUSY;
    1213                 :          0 :         return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
    1214                 :            : }
    1215                 :            : EXPORT_SYMBOL(bitmap_allocate_region);
    1216                 :            : 
    1217                 :            : /**
    1218                 :            :  * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
    1219                 :            :  * @dst:   destination buffer
    1220                 :            :  * @src:   bitmap to copy
    1221                 :            :  * @nbits: number of bits in the bitmap
    1222                 :            :  *
    1223                 :            :  * Require nbits % BITS_PER_LONG == 0.
    1224                 :            :  */
    1225                 :            : #ifdef __BIG_ENDIAN
    1226                 :            : void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
    1227                 :            : {
    1228                 :            :         unsigned int i;
    1229                 :            : 
    1230                 :            :         for (i = 0; i < nbits/BITS_PER_LONG; i++) {
    1231                 :            :                 if (BITS_PER_LONG == 64)
    1232                 :            :                         dst[i] = cpu_to_le64(src[i]);
    1233                 :            :                 else
    1234                 :            :                         dst[i] = cpu_to_le32(src[i]);
    1235                 :            :         }
    1236                 :            : }
    1237                 :            : EXPORT_SYMBOL(bitmap_copy_le);
    1238                 :            : #endif
    1239                 :            : 
    1240                 :          0 : unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags)
    1241                 :            : {
    1242                 :          0 :         return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long),
    1243                 :            :                              flags);
    1244                 :            : }
    1245                 :            : EXPORT_SYMBOL(bitmap_alloc);
    1246                 :            : 
    1247                 :          0 : unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags)
    1248                 :            : {
    1249                 :          0 :         return bitmap_alloc(nbits, flags | __GFP_ZERO);
    1250                 :            : }
    1251                 :            : EXPORT_SYMBOL(bitmap_zalloc);
    1252                 :            : 
    1253                 :       1248 : void bitmap_free(const unsigned long *bitmap)
    1254                 :            : {
    1255                 :       1248 :         kfree(bitmap);
    1256                 :       1248 : }
    1257                 :            : EXPORT_SYMBOL(bitmap_free);
    1258                 :            : 
    1259                 :            : #if BITS_PER_LONG == 64
    1260                 :            : /**
    1261                 :            :  * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap
    1262                 :            :  *      @bitmap: array of unsigned longs, the destination bitmap
    1263                 :            :  *      @buf: array of u32 (in host byte order), the source bitmap
    1264                 :            :  *      @nbits: number of bits in @bitmap
    1265                 :            :  */
    1266                 :          0 : void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits)
    1267                 :            : {
    1268                 :          0 :         unsigned int i, halfwords;
    1269                 :            : 
    1270                 :          0 :         halfwords = DIV_ROUND_UP(nbits, 32);
    1271         [ #  # ]:          0 :         for (i = 0; i < halfwords; i++) {
    1272                 :          0 :                 bitmap[i/2] = (unsigned long) buf[i];
    1273         [ #  # ]:          0 :                 if (++i < halfwords)
    1274                 :          0 :                         bitmap[i/2] |= ((unsigned long) buf[i]) << 32;
    1275                 :            :         }
    1276                 :            : 
    1277                 :            :         /* Clear tail bits in last word beyond nbits. */
    1278         [ #  # ]:          0 :         if (nbits % BITS_PER_LONG)
    1279                 :          0 :                 bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits);
    1280                 :          0 : }
    1281                 :            : EXPORT_SYMBOL(bitmap_from_arr32);
    1282                 :            : 
    1283                 :            : /**
    1284                 :            :  * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits
    1285                 :            :  *      @buf: array of u32 (in host byte order), the dest bitmap
    1286                 :            :  *      @bitmap: array of unsigned longs, the source bitmap
    1287                 :            :  *      @nbits: number of bits in @bitmap
    1288                 :            :  */
    1289                 :          0 : void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits)
    1290                 :            : {
    1291                 :          0 :         unsigned int i, halfwords;
    1292                 :            : 
    1293                 :          0 :         halfwords = DIV_ROUND_UP(nbits, 32);
    1294         [ #  # ]:          0 :         for (i = 0; i < halfwords; i++) {
    1295                 :          0 :                 buf[i] = (u32) (bitmap[i/2] & UINT_MAX);
    1296         [ #  # ]:          0 :                 if (++i < halfwords)
    1297                 :          0 :                         buf[i] = (u32) (bitmap[i/2] >> 32);
    1298                 :            :         }
    1299                 :            : 
    1300                 :            :         /* Clear tail bits in last element of array beyond nbits. */
    1301         [ #  # ]:          0 :         if (nbits % BITS_PER_LONG)
    1302                 :          0 :                 buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31));
    1303                 :          0 : }
    1304                 :            : EXPORT_SYMBOL(bitmap_to_arr32);
    1305                 :            : 
    1306                 :            : #endif

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