1 files changed, 17 insertions, 2 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 3fc9f5aab5f..7f070746336 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -44,6 +44,16 @@ extern const char linux_proc_banner[];
 
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 
+/*
+ * This looks more complex than it should be. But we need to
+ * get the type for the ~ right in round_down (it needs to be
+ * as wide as the result!), and we want to evaluate the macro
+ * arguments just once each.
+ */
+#define __round_mask(x, y) ((__typeof__(x))((y)-1))
+#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1)
+#define round_down(x, y) ((x) & ~__round_mask(x, y))
+
 #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))
 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 #define roundup(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
@@ -124,7 +134,7 @@ extern int _cond_resched(void);
 #endif
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
-  void __might_sleep(char *file, int line, int preempt_offset);
+  void __might_sleep(const char *file, int line, int preempt_offset);
 /**
  * might_sleep - annotation for functions that can sleep
  *
@@ -138,7 +148,8 @@ extern int _cond_resched(void);
 # define might_sleep() \
 	do { __might_sleep(__FILE__, __LINE__, 0); might_resched(); } while (0)
 #else
-  static inline void __might_sleep(char *file, int line, int preempt_offset) { }
+  static inline void __might_sleep(const char *file, int line,
+				   int preempt_offset) { }
 # define might_sleep() do { might_resched(); } while (0)
 #endif
 
@@ -734,6 +745,10 @@ struct sysinfo {
 /* Force a compilation error if condition is constant and true */
 #define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
 
+/* Force a compilation error if a constant expression is not a power of 2 */
+#define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
+	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
+
 /* Force a compilation error if condition is true, but also produce a
    result (of value 0 and type size_t), so the expression can be used
    e.g. in a structure initializer (or where-ever else comma expressions