kunit: Add speed attribute

Add speed attribute to the test attribute API. This attribute will allow
users to mark tests with a category of speed.

Currently the categories of speed proposed are: normal, slow, and very_slow
(outlined in enum kunit_speed). These are outlined in the enum kunit_speed.

The assumed default speed for tests is "normal". This indicates that the
test takes a relatively trivial amount of time (less than 1 second),
regardless of the machine it is running on. Any test slower than this could
be marked as "slow" or "very_slow".

Add the macro KUNIT_CASE_SLOW to set a test as slow, as this is likely a
common use of the attributes API.

Add an example of marking a slow test to kunit-example-test.c.

Reviewed-by: David Gow <[e-mail]>
Signed-off-by: Rae Moar <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

include/kunit/test.h

···
 	KUNIT_SKIPPED,
 };
 
+/* Attribute struct/enum definitions */
+
+/*
+ * Speed Attribute is stored as an enum and separated into categories of
+ * speed: very_slowm, slow, and normal. These speeds are relative to
+ * other KUnit tests.
+ *
+ * Note: unset speed attribute acts as default of KUNIT_SPEED_NORMAL.
+ */
+enum kunit_speed {
+	KUNIT_SPEED_UNSET,
+	KUNIT_SPEED_VERY_SLOW,
+	KUNIT_SPEED_SLOW,
+	KUNIT_SPEED_NORMAL,
+	KUNIT_SPEED_MAX = KUNIT_SPEED_NORMAL,
+};
+
 /* Holds attributes for each test case and suite */
-struct kunit_attributes {};
+struct kunit_attributes {
+	enum kunit_speed speed;
+};
 
 /**
  * struct kunit_case - represents an individual test case.
···
 #define KUNIT_CASE_ATTR(test_name, attributes)			\
 		{ .run_case = test_name, .name = #test_name,	\
 		  .attr = attributes }
+
+/**
+ * KUNIT_CASE_SLOW - A helper for creating a &struct kunit_case
+ * with the slow attribute
+ *
+ * @test_name: a reference to a test case function.
+ */
+
+#define KUNIT_CASE_SLOW(test_name)			\
+		{ .run_case = test_name, .name = #test_name,	\
+		  .attr.speed = KUNIT_SPEED_SLOW }
 
 /**
  * KUNIT_CASE_PARAM - A helper for creation a parameterized &struct kunit_case

lib/kunit/attributes.c

···
 	enum print_ops print;
 };
 
+/* String Lists for enum Attributes */
+
+static const char * const speed_str_list[] = {"unset", "very_slow", "slow", "normal"};
+
+/* To String Methods */
+
+static const char *attr_enum_to_string(void *attr, const char * const str_list[], bool *to_free)
+{
+	long val = (long)attr;
+
+	*to_free = false;
+	if (!val)
+		return NULL;
+	return str_list[val];
+}
+
+static const char *attr_speed_to_string(void *attr, bool *to_free)
+{
+	return attr_enum_to_string(attr, speed_str_list, to_free);
+}
+
+/* Get Attribute Methods */
+
+static void *attr_speed_get(void *test_or_suite, bool is_test)
+{
+	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
+	struct kunit_case *test = is_test ? test_or_suite : NULL;
+
+	if (test)
+		return ((void *) test->attr.speed);
+	else
+		return ((void *) suite->attr.speed);
+}
+
 /* List of all Test Attributes */
 
-static struct kunit_attr kunit_attr_list[] = {};
+static struct kunit_attr kunit_attr_list[] = {
+	{
+		.name = "speed",
+		.get_attr = attr_speed_get,
+		.to_string = attr_speed_to_string,
+		.attr_default = (void *)KUNIT_SPEED_NORMAL,
+		.print = PRINT_ALWAYS,
+	},
+};
 
 /* Helper Functions to Access Attributes */
 

lib/kunit/kunit-example-test.c

···
 }
 
 /*
+ * This test should always pass. Can be used to practice filtering attributes.
+ */
+static void example_slow_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1 + 1, 2);
+}
+
+/*
  * Here we make a list of all the test cases we want to add to the test suite
  * below.
  */
···
 	KUNIT_CASE(example_all_expect_macros_test),
 	KUNIT_CASE(example_static_stub_test),
 	KUNIT_CASE_PARAM(example_params_test, example_gen_params),
+	KUNIT_CASE_SLOW(example_slow_test),
 	{}
 };