tools/lib/bitmap.c

   1 /*
   2  * From lib/bitmap.c
   3  * Helper functions for bitmap.h.
   4  *
   5  * This source code is licensed under the GNU General Public License,
   6  * Version 2.  See the file COPYING for more details.
   7  */
   8 #include <linux/bitmap.h>
   9
  10 int __bitmap_weight(const unsigned long *bitmap, int bits)
  11 {
  12         int k, w = 0, lim = bits/BITS_PER_LONG;
  13
  14         for (k = 0; k < lim; k++)
  15                 w += hweight_long(bitmap[k]);
  16
  17         if (bits % BITS_PER_LONG)
  18                 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
  19
  20         return w;
  21 }
  22
  23 void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  24                  const unsigned long *bitmap2, int bits)
  25 {
  26         int k;
  27         int nr = BITS_TO_LONGS(bits);
  28
  29         for (k = 0; k < nr; k++)
  30                 dst[k] = bitmap1[k] | bitmap2[k];
  31 }
  32
  33 size_t bitmap_scnprintf(unsigned long *bitmap, int nbits,
  34                         char *buf, size_t size)
  35 {
  36         /* current bit is 'cur', most recently seen range is [rbot, rtop] */
  37         int cur, rbot, rtop;
  38         bool first = true;
  39         size_t ret = 0;
  40
  41         rbot = cur = find_first_bit(bitmap, nbits);
  42         while (cur < nbits) {
  43                 rtop = cur;
  44                 cur = find_next_bit(bitmap, nbits, cur + 1);
  45                 if (cur < nbits && cur <= rtop + 1)
  46                         continue;
  47
  48                 if (!first)
  49                         ret += scnprintf(buf + ret, size - ret, ",");
  50
  51                 first = false;
  52
  53                 ret += scnprintf(buf + ret, size - ret, "%d", rbot);
  54                 if (rbot < rtop)
  55                         ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
  56
  57                 rbot = cur;
  58         }
  59         return ret;
  60 }
  61
  62 int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  63                  const unsigned long *bitmap2, unsigned int bits)
  64 {
  65         unsigned int k;
  66         unsigned int lim = bits/BITS_PER_LONG;
  67         unsigned long result = 0;
  68
  69         for (k = 0; k < lim; k++)
  70                 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
  71         if (bits % BITS_PER_LONG)
  72                 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
  73                            BITMAP_LAST_WORD_MASK(bits));
  74         return result != 0;
  75 }