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741c74f55e
Add support to perform logical and on bitmaps. Code taken from kernel's include/linux/bitmap.h. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1470074555-24889-4-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
75 lines
1.7 KiB
C
75 lines
1.7 KiB
C
/*
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* From lib/bitmap.c
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* Helper functions for bitmap.h.
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/bitmap.h>
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int __bitmap_weight(const unsigned long *bitmap, int bits)
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{
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int k, w = 0, lim = bits/BITS_PER_LONG;
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for (k = 0; k < lim; k++)
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w += hweight_long(bitmap[k]);
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if (bits % BITS_PER_LONG)
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w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
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return w;
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}
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void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, int bits)
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{
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int k;
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int nr = BITS_TO_LONGS(bits);
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for (k = 0; k < nr; k++)
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dst[k] = bitmap1[k] | bitmap2[k];
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}
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size_t bitmap_scnprintf(unsigned long *bitmap, int nbits,
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char *buf, size_t size)
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{
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/* current bit is 'cur', most recently seen range is [rbot, rtop] */
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int cur, rbot, rtop;
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bool first = true;
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size_t ret = 0;
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rbot = cur = find_first_bit(bitmap, nbits);
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while (cur < nbits) {
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rtop = cur;
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cur = find_next_bit(bitmap, nbits, cur + 1);
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if (cur < nbits && cur <= rtop + 1)
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continue;
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if (!first)
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ret += scnprintf(buf + ret, size - ret, ",");
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first = false;
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ret += scnprintf(buf + ret, size - ret, "%d", rbot);
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if (rbot < rtop)
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ret += scnprintf(buf + ret, size - ret, "-%d", rtop);
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rbot = cur;
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}
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return ret;
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}
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int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
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const unsigned long *bitmap2, unsigned int bits)
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{
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unsigned int k;
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unsigned int lim = bits/BITS_PER_LONG;
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unsigned long result = 0;
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for (k = 0; k < lim; k++)
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result |= (dst[k] = bitmap1[k] & bitmap2[k]);
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if (bits % BITS_PER_LONG)
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result |= (dst[k] = bitmap1[k] & bitmap2[k] &
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BITMAP_LAST_WORD_MASK(bits));
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return result != 0;
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}
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