[RFC 1/5] atomics: add test for atomic operations with _relaxed variants

[Boqun Feng <boqun.feng@gmail.com>]

Some atomic operations now have _{relaxed, acquire, release} variants,
this patch then adds some trivial tests for two purpose:

1.	test the behavior of these new operations in single-CPU
	environment.
2.	make their code generated before we actually use them somewhere,
	so that we can examine their assembly code.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 lib/atomic64_test.c | 91 ++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 59 insertions(+), 32 deletions(-)

diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index 83c33a5b..0484437 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -27,6 +27,50 @@ do {								\
 		(unsigned long long)r);				\
 } while (0)
 
+#define TEST_RETURN(bit, op, c_op, val)				\
+do {								\
+	atomic##bit##_set(&v, v0);				\
+	r = v0;							\
+	r c_op val;						\
+	BUG_ON(atomic##bit##_##op(val, &v) != r);		\
+	BUG_ON(atomic##bit##_read(&v) != r);			\
+} while (0)
+
+#define TEST_RETURN_FAMILY(bit, op, c_op, val)			\
+do {								\
+	TEST_RETURN(bit, op, c_op, val);			\
+	TEST_RETURN(bit, op##_acquire, c_op, val);		\
+	TEST_RETURN(bit, op##_release, c_op, val);		\
+	TEST_RETURN(bit, op##_relaxed, c_op, val);		\
+} while (0)
+
+#define TEST_ARGS(bit, op, init, ret, expect, args...)		\
+do {								\
+	atomic##bit##_set(&v, init);				\
+	BUG_ON(atomic##bit##_##op(&v, args) != ret);		\
+	BUG_ON(atomic##bit##_read(&v) != expect);		\
+} while (0)
+
+#define TEST_XCHG_FAMILY(bit, init, new)			\
+do {								\
+	TEST_ARGS(bit, xchg, init, init, new, new);		\
+	TEST_ARGS(bit, xchg_acquire, init, init, new, new);	\
+	TEST_ARGS(bit, xchg_release, init, init, new, new);	\
+	TEST_ARGS(bit, xchg_relaxed, init, init, new, new);	\
+} while (0)
+
+#define TEST_CMPXCHG_FAMILY(bit, init, new, wrong)			\
+do {									\
+	TEST_ARGS(bit, cmpxchg, init, init, new, init, new);		\
+	TEST_ARGS(bit, cmpxchg, init, init, init, wrong, new);		\
+	TEST_ARGS(bit, cmpxchg_acquire, init, init, new, init, new);	\
+	TEST_ARGS(bit, cmpxchg_acquire, init, init, init, wrong, new);	\
+	TEST_ARGS(bit, cmpxchg_release, init, init, new, init, new);	\
+	TEST_ARGS(bit, cmpxchg_release, init, init, init, wrong, new);	\
+	TEST_ARGS(bit, cmpxchg_relaxed, init, init, new, init, new);	\
+	TEST_ARGS(bit, cmpxchg_relaxed, init, init, init, wrong, new);	\
+} while (0)
+
 static __init void test_atomic(void)
 {
 	int v0 = 0xaaa31337;
@@ -45,6 +89,15 @@ static __init void test_atomic(void)
 	TEST(, and, &=, v1);
 	TEST(, xor, ^=, v1);
 	TEST(, andnot, &= ~, v1);
+
+	TEST_RETURN_FAMILY(, add_return, +=, onestwos);
+	TEST_RETURN_FAMILY(, add_return, +=, -one);
+	TEST_RETURN_FAMILY(, sub_return, -=, onestwos);
+	TEST_RETURN_FAMILY(, sub_return, -=, -one);
+
+	TEST_XCHG_FAMILY(, v0, v1);
+	TEST_CMPXCHG_FAMILY(, v0, v1, onestwos);
+
 }
 
 #define INIT(c) do { atomic64_set(&v, c); r = c; } while (0)
@@ -74,25 +127,10 @@ static __init void test_atomic64(void)
 	TEST(64, xor, ^=, v1);
 	TEST(64, andnot, &= ~, v1);
 
-	INIT(v0);
-	r += onestwos;
-	BUG_ON(atomic64_add_return(onestwos, &v) != r);
-	BUG_ON(v.counter != r);
-
-	INIT(v0);
-	r += -one;
-	BUG_ON(atomic64_add_return(-one, &v) != r);
-	BUG_ON(v.counter != r);
-
-	INIT(v0);
-	r -= onestwos;
-	BUG_ON(atomic64_sub_return(onestwos, &v) != r);
-	BUG_ON(v.counter != r);
-
-	INIT(v0);
-	r -= -one;
-	BUG_ON(atomic64_sub_return(-one, &v) != r);
-	BUG_ON(v.counter != r);
+	TEST_RETURN_FAMILY(64, add_return, +=, onestwos);
+	TEST_RETURN_FAMILY(64, add_return, +=, -one);
+	TEST_RETURN_FAMILY(64, sub_return, -=, onestwos);
+	TEST_RETURN_FAMILY(64, sub_return, -=, -one);
 
 	INIT(v0);
 	atomic64_inc(&v);
@@ -114,19 +152,8 @@ static __init void test_atomic64(void)
 	BUG_ON(atomic64_dec_return(&v) != r);
 	BUG_ON(v.counter != r);
 
-	INIT(v0);
-	BUG_ON(atomic64_xchg(&v, v1) != v0);
-	r = v1;
-	BUG_ON(v.counter != r);
-
-	INIT(v0);
-	BUG_ON(atomic64_cmpxchg(&v, v0, v1) != v0);
-	r = v1;
-	BUG_ON(v.counter != r);
-
-	INIT(v0);
-	BUG_ON(atomic64_cmpxchg(&v, v2, v1) != v0);
-	BUG_ON(v.counter != r);
+	TEST_XCHG_FAMILY(64, v0, v1);
+	TEST_CMPXCHG_FAMILY(64, v0, v1, v2);
 
 	INIT(v0);
 	BUG_ON(atomic64_add_unless(&v, one, v0));
-- 
2.5.0