[PATCH 2/9] log2: Add missing __rounddown_pow_of_two()

Markus Pargmann mpa at pengutronix.de
Wed Dec 2 05:48:44 PST 2015


Signed-off-by: Markus Pargmann <mpa at pengutronix.de>
---
 include/linux/log2.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/log2.h b/include/linux/log2.h
index d9913f06bd09..36519e3aa38b 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -63,6 +63,15 @@ unsigned long __roundup_pow_of_two(unsigned long n)
 	return 1UL << fls(n - 1);
 }
 
+/*
+ * round down to nearest power of two
+ */
+static inline __attribute__((const))
+unsigned long __rounddown_pow_of_two(unsigned long n)
+{
+	return 1UL << (fls_long(n) - 1);
+}
+
 /**
  * ilog2 - log of base 2 of 32-bit or a 64-bit unsigned value
  * @n - parameter
-- 
2.6.2




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