perf tools: Add test_and_set_bit function
Set a bit and return its old value. Stolen from kernel sources, will be used in next patches. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1414363445-22370-1-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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@ -46,4 +46,21 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
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__bitmap_or(dst, src1, src2, nbits);
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}
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/**
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* test_and_set_bit - Set a bit and return its old value
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* @nr: Bit to set
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* @addr: Address to count from
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*/
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static inline int test_and_set_bit(int nr, unsigned long *addr)
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{
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unsigned long mask = BIT_MASK(nr);
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unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
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unsigned long old;
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old = *p;
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*p = old | mask;
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return (old & mask) != 0;
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}
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#endif /* _PERF_BITOPS_H */
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@ -15,6 +15,8 @@
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#define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
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#define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
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#define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE)
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#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
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#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
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#define for_each_set_bit(bit, addr, size) \
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for ((bit) = find_first_bit((addr), (size)); \
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