[POWERPC] Add "is_power_of_2" checking to log2.h.

Add the inline function "is_power_of_2()" to log2.h, where the value
zero is *not* considered to be a power of two.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/log2.h b/include/linux/log2.h
index d02e1a547a7e..99922bedfcc9 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -44,6 +44,17 @@ int __ilog2_u64(u64 n)
 #endif
 
 /*
+ *  Determine whether some value is a power of two, where zero is
+ * *not* considered a power of two.
+ */
+
+static inline __attribute__((const))
+bool is_power_of_2(unsigned long n)
+{
+        return (n != 0 && ((n & (n - 1)) == 0));
+}
+
+/*
  * round up to nearest power of two
  */
 static inline __attribute__((const))