[tip:perf/core] tools lib: Add for_each_clear_bit macro

[tip-bot for Jiri Olsa]

Commit-ID:  02bc11de567273da8ab25c54336ddbb71986f38f
Gitweb:     http://git.kernel.org/tip/02bc11de567273da8ab25c54336ddbb71986f38f
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Mon, 10 Oct 2016 09:26:33 +0200
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 24 Oct 2016 11:07:33 -0300

tools lib: Add for_each_clear_bit macro

Adding for_each_clear_bit macro plus all its the necessary backbone
functions. Taken from related kernel code. It will be used in following
patch.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-cayv2zbqi0nlmg5sjjxs1775@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/include/asm-generic/bitops.h                 |  1 +
 .../ffz.h => include/asm-generic/bitops/__ffz.h}   |  0
 tools/include/asm-generic/bitops/find.h            | 28 ++++++++++++++++++++++
 tools/include/linux/bitops.h                       |  5 ++++
 tools/lib/find_bit.c                               | 25 +++++++++++++++++++
 tools/perf/MANIFEST                                |  1 +
 6 files changed, 60 insertions(+)

diff --git a/tools/include/asm-generic/bitops.h b/tools/include/asm-generic/bitops.h
index 653d1ba..0304600 100644
--- a/tools/include/asm-generic/bitops.h
+++ b/tools/include/asm-generic/bitops.h
@@ -13,6 +13,7 @@
  */
 
 #include <asm-generic/bitops/__ffs.h>
+#include <asm-generic/bitops/__ffz.h>
 #include <asm-generic/bitops/fls.h>
 #include <asm-generic/bitops/__fls.h>
 #include <asm-generic/bitops/fls64.h>
diff --git a/tools/testing/radix-tree/linux/bitops/ffz.h b/tools/include/asm-generic/bitops/__ffz.h
similarity index 100%
copy from tools/testing/radix-tree/linux/bitops/ffz.h
copy to tools/include/asm-generic/bitops/__ffz.h
diff --git a/tools/include/asm-generic/bitops/find.h b/tools/include/asm-generic/bitops/find.h
index 31f5154..5538ecd 100644
--- a/tools/include/asm-generic/bitops/find.h
+++ b/tools/include/asm-generic/bitops/find.h
@@ -15,6 +15,21 @@ extern unsigned long find_next_bit(const unsigned long *addr, unsigned long
 		size, unsigned long offset);
 #endif
 
+#ifndef find_next_zero_bit
+
+/**
+ * find_next_zero_bit - find the next cleared bit in a memory region
+ * @addr: The address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number of the next zero bit
+ * If no bits are zero, returns @size.
+ */
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+				 unsigned long offset);
+#endif
+
 #ifndef find_first_bit
 
 /**
@@ -30,4 +45,17 @@ extern unsigned long find_first_bit(const unsigned long *addr,
 
 #endif /* find_first_bit */
 
+#ifndef find_first_zero_bit
+
+/**
+ * find_first_zero_bit - find the first cleared bit in a memory region
+ * @addr: The address to start the search at
+ * @size: The maximum number of bits to search
+ *
+ * Returns the bit number of the first cleared bit.
+ * If no bits are zero, returns @size.
+ */
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size);
+#endif
+
 #endif /*_TOOLS_LINUX_ASM_GENERIC_BITOPS_FIND_H_ */
diff --git a/tools/include/linux/bitops.h b/tools/include/linux/bitops.h
index 49c929a..fc446343 100644
--- a/tools/include/linux/bitops.h
+++ b/tools/include/linux/bitops.h
@@ -39,6 +39,11 @@ extern unsigned long __sw_hweight64(__u64 w);
 	     (bit) < (size);					\
 	     (bit) = find_next_bit((addr), (size), (bit) + 1))
 
+#define for_each_clear_bit(bit, addr, size) \
+	for ((bit) = find_first_zero_bit((addr), (size));       \
+	     (bit) < (size);                                    \
+	     (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
+
 /* same as for_each_set_bit() but use bit as value to start with */
 #define for_each_set_bit_from(bit, addr, size) \
 	for ((bit) = find_next_bit((addr), (size), (bit));	\
diff --git a/tools/lib/find_bit.c b/tools/lib/find_bit.c
index 9122a9e..6d8b8f2 100644
--- a/tools/lib/find_bit.c
+++ b/tools/lib/find_bit.c
@@ -82,3 +82,28 @@ unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
 	return size;
 }
 #endif
+
+#ifndef find_first_zero_bit
+/*
+ * Find the first cleared bit in a memory region.
+ */
+unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
+{
+	unsigned long idx;
+
+	for (idx = 0; idx * BITS_PER_LONG < size; idx++) {
+		if (addr[idx] != ~0UL)
+			return min(idx * BITS_PER_LONG + ffz(addr[idx]), size);
+	}
+
+	return size;
+}
+#endif
+
+#ifndef find_next_zero_bit
+unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
+				 unsigned long offset)
+{
+	return _find_next_bit(addr, size, offset, ~0UL);
+}
+#endif
diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST
index 0bda2cc..a511e5f 100644
--- a/tools/perf/MANIFEST
+++ b/tools/perf/MANIFEST
@@ -51,6 +51,7 @@ tools/include/asm-generic/bitops/arch_hweight.h
 tools/include/asm-generic/bitops/atomic.h
 tools/include/asm-generic/bitops/const_hweight.h
 tools/include/asm-generic/bitops/__ffs.h
+tools/include/asm-generic/bitops/__ffz.h
 tools/include/asm-generic/bitops/__fls.h
 tools/include/asm-generic/bitops/find.h
 tools/include/asm-generic/bitops/fls64.h