ARM: tegra: add sysfs support for tegra cpuquiet driver
[linux-2.6.git] / include / linux / log2.h
index c8cf5e8..fd7ff3d 100644 (file)
@@ -185,9 +185,24 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
 #define rounddown_pow_of_two(n)                        \
 (                                              \
        __builtin_constant_p(n) ? (             \
-               (n == 1) ? 0 :                  \
                (1UL << ilog2(n))) :            \
        __rounddown_pow_of_two(n)               \
  )
 
+/**
+ * order_base_2 - calculate the (rounded up) base 2 order of the argument
+ * @n: parameter
+ *
+ * The first few values calculated by this routine:
+ *  ob2(0) = 0
+ *  ob2(1) = 0
+ *  ob2(2) = 1
+ *  ob2(3) = 2
+ *  ob2(4) = 2
+ *  ob2(5) = 3
+ *  ... and so on.
+ */
+
+#define order_base_2(n) ilog2(roundup_pow_of_two(n))
+
 #endif /* _LINUX_LOG2_H */