LXR linux/tools/lib/bitmap.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * From lib/bitmap.c
   4 * Helper functions for bitmap.h.
   5 */
   6#include <linux/bitmap.h>
   7
   8int __bitmap_weight(const unsigned long *bitmap, int bits)
   9{
  10        int k, w = 0, lim = bits/BITS_PER_LONG;
  11
  12        for (k = 0; k < lim; k++)
  13                w += hweight_long(bitmap[k]);
  14
  15        if (bits % BITS_PER_LONG)
  16                w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
  17
  18        return w;
  19}
  20
  21void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
  22                 const unsigned long *bitmap2, int bits)
  23{
  24        int k;
  25        int nr = BITS_TO_LONGS(bits);
  26
  27        for (k = 0; k < nr; k++)
  28                dst[k] = bitmap1[k] | bitmap2[k];
  29}
  30
  31size_t bitmap_scnprintf(unsigned long *bitmap, unsigned int nbits,
  32                        char *buf, size_t size)
  33{
  34        /* current bit is 'cur', most recently seen range is [rbot, rtop] */
  35        unsigned int cur, rbot, rtop;
  36        bool first = true;
  37        size_t ret = 0;
  38
  39        rbot = cur = find_first_bit(bitmap, nbits);
  40        while (cur < nbits) {
  41                rtop = cur;
  42                cur = find_next_bit(bitmap, nbits, cur + 1);
  43                if (cur < nbits && cur <= rtop + 1)
  44                        continue;
  45
  46                if (!first)
  47                        ret += scnprintf(buf + ret, size - ret, ",");
  48
  49                first = false;
  50
  51                ret += scnprintf(buf + ret, size - ret, "%d", rbot);
  52                if (rbot < rtop)
  53                        ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
  54
  55                rbot = cur;
  56        }
  57        return ret;
  58}
  59
  60int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
  61                 const unsigned long *bitmap2, unsigned int bits)
  62{
  63        unsigned int k;
  64        unsigned int lim = bits/BITS_PER_LONG;
  65        unsigned long result = 0;
  66
  67        for (k = 0; k < lim; k++)
  68                result |= (dst[k] = bitmap1[k] & bitmap2[k]);
  69        if (bits % BITS_PER_LONG)
  70                result |= (dst[k] = bitmap1[k] & bitmap2[k] &
  71                           BITMAP_LAST_WORD_MASK(bits));
  72        return result != 0;
  73}
  74
  75int __bitmap_equal(const unsigned long *bitmap1,
  76                const unsigned long *bitmap2, unsigned int bits)
  77{
  78        unsigned int k, lim = bits/BITS_PER_LONG;
  79        for (k = 0; k < lim; ++k)
  80                if (bitmap1[k] != bitmap2[k])
  81                        return 0;
  82
  83        if (bits % BITS_PER_LONG)
  84                if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
  85                        return 0;
  86
  87        return 1;
  88}
  89
  90int __bitmap_intersects(const unsigned long *bitmap1,
  91                        const unsigned long *bitmap2, unsigned int bits)
  92{
  93        unsigned int k, lim = bits/BITS_PER_LONG;
  94        for (k = 0; k < lim; ++k)
  95                if (bitmap1[k] & bitmap2[k])
  96                        return 1;
  97
  98        if (bits % BITS_PER_LONG)
  99                if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
 100                        return 1;
 101        return 0;
 102}
 103