[NETFILTER]: nf_conntrack: optimize __nf_conntrack_find()

[linux-2.6-omap-h63xx.git] / include / linux / log2.h

diff --git a/include/linux/log2.h b/include/linux/log2.h
index 99922bedfcc90acaef644369aee3d5e126b7d46d..c8cf5e8ef1717d40cde2768fd0608f29924b1545 100644 (file)
--- 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_long(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
@@ -152,17 +161,33 @@ unsigned long __roundup_pow_of_two(unsigned long n)
  * roundup_pow_of_two - round the given value up to nearest power of two
  * @n - parameter
  *
- * round the given balue up to the nearest power of two
+ * round the given value up to the nearest power of two
  * - the result is undefined when n == 0
  * - this can be used to initialise global variables from constant data
  */
 #define roundup_pow_of_two(n)                  \
 (                                              \
        __builtin_constant_p(n) ? (             \
-               (n == 1) ? 0 :                  \
+               (n == 1) ? 1 :                  \
                (1UL << (ilog2((n) - 1) + 1))   \
                                   ) :          \
        __roundup_pow_of_two(n)                 \
  )
 
+/**
+ * rounddown_pow_of_two - round the given value down to nearest power of two
+ * @n - parameter
+ *
+ * round the given value down to the nearest power of two
+ * - the result is undefined when n == 0
+ * - this can be used to initialise global variables from constant data
+ */
+#define rounddown_pow_of_two(n)                        \
+(                                              \
+       __builtin_constant_p(n) ? (             \
+               (n == 1) ? 0 :                  \
+               (1UL << ilog2(n))) :            \
+       __rounddown_pow_of_two(n)               \
+ )
+
 #endif /* _LINUX_LOG2_H */