LXR linux/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
  10int __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
  23void __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
  33size_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
  62int __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}
  76