kunit: add example suite to test init suites

Add example_init_test_suite to allow for testing the feature of running
test suites marked as init to indicate they use init data and/or
functions.

This suite should always pass and uses a simple init function.

This suite can also be used to test the is_init attribute introduced in
the next patch.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/kunit-example-test.c

@@ -287,4 +287,41 @@ static struct kunit_suite example_test_suite = {
  */
 kunit_test_suites(&example_test_suite);
 
+static int __init init_add(int x, int y)
+{
+	return (x + y);
+}
+
+/*
+ * This test should always pass. Can be used to test init suites.
+ */
+static void __init example_init_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, init_add(1, 1), 2);
+}
+
+/*
+ * The kunit_case struct cannot be marked as __initdata as this will be
+ * used in debugfs to retrieve results after test has run
+ */
+static struct kunit_case __refdata example_init_test_cases[] = {
+	KUNIT_CASE(example_init_test),
+	{}
+};
+
+/*
+ * The kunit_suite struct cannot be marked as __initdata as this will be
+ * used in debugfs to retrieve results after test has run
+ */
+static struct kunit_suite example_init_test_suite = {
+	.name = "example_init",
+	.test_cases = example_init_test_cases,
+};
+
+/*
+ * This registers the test suite and marks the suite as using init data
+ * and/or functions.
+ */
+kunit_test_init_section_suites(&example_init_test_suite);
+
 MODULE_LICENSE("GPL v2");