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

[pandora-kernel.git] / include / linux / log2.h

diff --git a/include/linux/log2.h b/include/linux/log2.h
index d02e1a5..99922be 100644 (file)
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -43,6 +43,17 @@ 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
  */