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Subject[tip:perf/core] perf tools: Add test_and_set_bit function
Commit-ID:  416c419cc3799ddf7ea467c9adcb4cd038bd94a4
Gitweb: http://git.kernel.org/tip/416c419cc3799ddf7ea467c9adcb4cd038bd94a4
Author: Jiri Olsa <jolsa@kernel.org>
AuthorDate: Sun, 26 Oct 2014 23:44:03 +0100
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 6 Nov 2014 17:42:13 -0300

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>
---
tools/perf/util/include/linux/bitmap.h | 17 +++++++++++++++++
tools/perf/util/include/linux/bitops.h | 2 ++
2 files changed, 19 insertions(+)

diff --git a/tools/perf/util/include/linux/bitmap.h b/tools/perf/util/include/linux/bitmap.h
index 01ffd12..40bd214 100644
--- a/tools/perf/util/include/linux/bitmap.h
+++ b/tools/perf/util/include/linux/bitmap.h
@@ -46,4 +46,21 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
__bitmap_or(dst, src1, src2, nbits);
}

+/**
+ * test_and_set_bit - Set a bit and return its old value
+ * @nr: Bit to set
+ * @addr: Address to count from
+ */
+static inline int test_and_set_bit(int nr, unsigned long *addr)
+{
+ unsigned long mask = BIT_MASK(nr);
+ unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+ unsigned long old;
+
+ old = *p;
+ *p = old | mask;
+
+ return (old & mask) != 0;
+}
+
#endif /* _PERF_BITOPS_H */
diff --git a/tools/perf/util/include/linux/bitops.h b/tools/perf/util/include/linux/bitops.h
index dadfa7e..c329416 100644
--- a/tools/perf/util/include/linux/bitops.h
+++ b/tools/perf/util/include/linux/bitops.h
@@ -15,6 +15,8 @@
#define BITS_TO_U64(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
#define BITS_TO_U32(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
#define BITS_TO_BYTES(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE)
+#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
+#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))

#define for_each_set_bit(bit, addr, size) \
for ((bit) = find_first_bit((addr), (size)); \

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