[PATCH 03/29] tools lib: Add for_each_clear_bit macro

Greg Kroah-Hartman
2018-06-03T12:27:41Z

From: Jiri Olsa <jolsa@kernel.org>

commit 02bc11de567273da8ab25c54336ddbb71986f38f upstream.

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@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-cayv2zbqi0nlmg5sjjxs1775@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
tools/include/asm-generic/bitops.h | 1 +
tools/include/asm-generic/bitops/__ffz.h | 12 ++++++++++
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, 72 insertions(+)
create mode 100644 tools/include/asm-generic/bitops/__ffz.h

diff --git a/tools/include/asm-generic/bitops.h b/tools/include/asm-generic/bitops.h
index 653d1bad77de..0304600121da 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/include/asm-generic/bitops/__ffz.h b/tools/include/asm-generic/bitops/__ffz.h
new file mode 100644
index 000000000000..6744bd4cdf46
--- /dev/null
+++ b/tools/include/asm-generic/bitops/__ffz.h
@@ -0,0 +1,12 @@
+#ifndef _ASM_GENERIC_BITOPS_FFZ_H_
+#define _ASM_GENERIC_BITOPS_FFZ_H_
+
+/*
+ * ffz - find first zero in word.
+ * @word: The word to search
+ *
+ * Undefined if no zero exists, so code should check against ~0UL first.
+ */
+#define ffz(x) __ffs(~(x))
+
+#endif /* _ASM_GENERIC_BITOPS_FFZ_H_ */
diff --git a/tools/include/asm-generic/bitops/find.h b/tools/include/asm-generic/bitops/find.h
index 31f51547fcd4..5538ecdc964a 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 49c929a104ee..fc446343ff41 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 9122a9e80046..6d8b8f22cf55 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 0bda2cca2b3a..a511e5f31e36 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
--
2.17.1