diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 423bb6b..10b8f23 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -308,11 +308,35 @@
 #ifndef __compiletime_error
 # define __compiletime_error(message)
 # define __compiletime_error_fallback(condition) \
-	do { ((void)sizeof(char[1 - 2*!!(condition)])); } while (0)
+	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
 #else
 # define __compiletime_error_fallback(condition) do { } while (0)
 #endif
 
+#define __compiletime_assert(condition, msg, prefix, suffix)		\
+	do {								\
+		bool __cond = !(condition);				\
+		extern void prefix ## suffix(void) __compiletime_error(msg); \
+		if (__cond)						\
+			prefix ## suffix();				\
+		__compiletime_error_fallback(__cond);			\
+	} while (0)
+
+#define _compiletime_assert(condition, msg, prefix, suffix) \
+	__compiletime_assert(condition, msg, prefix, suffix)
+
+/**
+ * compiletime_assert - break build and emit msg if condition is false
+ * @condition: a compile-time constant condition to check
+ * @msg:       a message to emit if condition is false
+ *
+ * In tradition of POSIX assert, this macro will break the build if the
+ * supplied condition is *false*, emitting the supplied error message if the
+ * compiler has support to do so.
+ */
+#define compiletime_assert(condition, msg) \
+	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
+
 /*
  * Prevent the compiler from merging or refetching accesses.  The compiler
  * is also forbidden from reordering successive instances of ACCESS_ONCE(),