drm/tests: helpers: Create the device in another function

We'll need in some tests to control when the device needs to be added
and removed, so let's split the device creation from the DRM device
creation function.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-7-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/tests/drm_client_modeset_test.c

@@ -15,6 +15,7 @@
 
 struct drm_client_modeset_test_priv {
 	struct drm_device *drm;
+	struct device *dev;
 	struct drm_connector connector;
 };
 
@@ -59,7 +60,10 @@ static int drm_client_modeset_test_init(struct kunit *test)
 
 	test->priv = priv;
 
-	priv->drm = drm_kunit_helper_alloc_drm_device(test, DRIVER_MODESET);
+	priv->dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
+
+	priv->drm = drm_kunit_helper_alloc_drm_device(test, priv->dev, DRIVER_MODESET);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
 
 	ret = drmm_connector_init(priv->drm, &priv->connector,
@@ -76,6 +80,13 @@ static int drm_client_modeset_test_init(struct kunit *test)
 	return 0;
 }
 
+static void drm_client_modeset_test_exit(struct kunit *test)
+{
+	struct drm_client_modeset_test_priv *priv = test->priv;
+
+	drm_kunit_helper_free_device(test, priv->dev);
+}
+
 static void drm_test_pick_cmdline_res_1920_1080_60(struct kunit *test)
 {
 	struct drm_client_modeset_test_priv *priv = test->priv;
@@ -175,6 +186,7 @@ static struct kunit_case drm_test_pick_cmdline_tests[] = {
 static struct kunit_suite drm_test_pick_cmdline_test_suite = {
 	.name = "drm_test_pick_cmdline",
 	.init = drm_client_modeset_test_init,
+	.exit = drm_client_modeset_test_exit,
 	.test_cases = drm_test_pick_cmdline_tests
 };
 

drivers/gpu/drm/tests/drm_kunit_helpers.c

@@ -17,36 +17,51 @@ struct kunit_dev {
 static const struct drm_mode_config_funcs drm_mode_config_funcs = {
 };
 
-static int dev_init(struct kunit_resource *res, void *ptr)
+/**
+ * drm_kunit_helper_alloc_device - Allocate a mock device for a KUnit test
+ * @test: The test context object
+ *
+ * This allocates a fake struct &device to create a mock for a KUnit
+ * test.
+ *
+ * Callers need to make sure drm_kunit_helper_free_device() on the
+ * device when done.
+ *
+ * Returns:
+ * A pointer to the new device, or an ERR_PTR() otherwise.
+ */
+struct device *drm_kunit_helper_alloc_device(struct kunit *test)
 {
-	char *name = ptr;
-	struct device *dev;
-
-	dev = root_device_register(name);
-	if (IS_ERR(dev))
-		return PTR_ERR(dev);
-
-	res->data = dev;
-	return 0;
+	return root_device_register(KUNIT_DEVICE_NAME);
 }
+EXPORT_SYMBOL_GPL(drm_kunit_helper_alloc_device);
 
-static void dev_free(struct kunit_resource *res)
+/**
+ * drm_kunit_helper_free_device - Frees a mock device
+ * @test: The test context object
+ * @dev: The device to free
+ *
+ * Frees a device allocated with drm_kunit_helper_alloc_device().
+ */
+void drm_kunit_helper_free_device(struct kunit *test, struct device *dev)
 {
-	struct device *dev = res->data;
-
 	root_device_unregister(dev);
 }
+EXPORT_SYMBOL_GPL(drm_kunit_helper_free_device);
 
 /**
  * drm_kunit_helper_alloc_drm_device - Allocates a mock DRM device for KUnit tests
  * @test: The test context object
+ * @dev: The parent device object
  * @features: Mocked DRM device driver features
  *
- * This function allocates a new struct &device, creates a struct
- * &drm_driver and will create a struct &drm_device using both.
+ * This function creates a struct &drm_driver and will create a struct
+ * &drm_device from @dev and that driver.
  *
- * The device and driver are tied to the @test context and will get
- * cleaned at the end of the test. The drm_device is allocated through
+ * @dev should be allocated using drm_kunit_helper_alloc_device().
+ *
+ * The driver is tied to the @test context and will get cleaned at the
+ * end of the test. The drm_device is allocated through
  * devm_drm_dev_alloc() and will thus be freed through a device-managed
  * resource.
  *
@@ -54,19 +69,14 @@ static void dev_free(struct kunit_resource *res)
  * A pointer to the new drm_device, or an ERR_PTR() otherwise.
  */
 struct drm_device *
-drm_kunit_helper_alloc_drm_device(struct kunit *test,
+drm_kunit_helper_alloc_drm_device(struct kunit *test, struct device *dev,
 				  u32 features)
 {
 	struct kunit_dev *kdev;
 	struct drm_device *drm;
 	struct drm_driver *driver;
-	struct device *dev;
 	int ret;
 
-	dev = kunit_alloc_resource(test, dev_init, dev_free, GFP_KERNEL, KUNIT_DEVICE_NAME);
-	if (!dev)
-		return ERR_PTR(-ENOMEM);
-
 	driver = kunit_kzalloc(test, sizeof(*driver), GFP_KERNEL);
 	if (!driver)
 		return ERR_PTR(-ENOMEM);

drivers/gpu/drm/tests/drm_modes_test.c

@@ -13,6 +13,7 @@
 
 struct drm_test_modes_priv {
 	struct drm_device *drm;
+	struct device *dev;
 };
 
 static int drm_test_modes_init(struct kunit *test)
@@ -22,7 +23,11 @@ static int drm_test_modes_init(struct kunit *test)
 	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
 	KUNIT_ASSERT_NOT_NULL(test, priv);
 
-	priv->drm = drm_kunit_helper_alloc_drm_device(test, DRIVER_MODESET);
+	priv->dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
+
+	priv->drm = drm_kunit_helper_alloc_drm_device(test, priv->dev,
+						      DRIVER_MODESET);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
 
 	test->priv = priv;
@@ -30,6 +35,13 @@ static int drm_test_modes_init(struct kunit *test)
 	return 0;
 }
 
+static void drm_test_modes_exit(struct kunit *test)
+{
+	struct drm_test_modes_priv *priv = test->priv;
+
+	drm_kunit_helper_free_device(test, priv->dev);
+}
+
 static void drm_test_modes_analog_tv_ntsc_480i(struct kunit *test)
 {
 	struct drm_test_modes_priv *priv = test->priv;
@@ -135,6 +147,7 @@ static struct kunit_case drm_modes_analog_tv_tests[] = {
 static struct kunit_suite drm_modes_analog_tv_test_suite = {
 	.name = "drm_modes_analog_tv",
 	.init = drm_test_modes_init,
+	.exit = drm_test_modes_exit,
 	.test_cases = drm_modes_analog_tv_tests,
 };
 

drivers/gpu/drm/tests/drm_probe_helper_test.c

@@ -17,6 +17,7 @@
 
 struct drm_probe_helper_test_priv {
 	struct drm_device *drm;
+	struct device *dev;
 	struct drm_connector connector;
 };
 
@@ -39,7 +40,10 @@ static int drm_probe_helper_test_init(struct kunit *test)
 	KUNIT_ASSERT_NOT_NULL(test, priv);
 	test->priv = priv;
 
-	priv->drm = drm_kunit_helper_alloc_drm_device(test,
+	priv->dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
+
+	priv->drm = drm_kunit_helper_alloc_drm_device(test, priv->dev,
 						      DRIVER_MODESET | DRIVER_ATOMIC);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
 
@@ -55,6 +59,13 @@ static int drm_probe_helper_test_init(struct kunit *test)
 	return 0;
 }
 
+static void drm_probe_helper_test_exit(struct kunit *test)
+{
+	struct drm_probe_helper_test_priv *priv = test->priv;
+
+	drm_kunit_helper_free_device(test, priv->dev);
+}
+
 typedef struct drm_display_mode *(*expected_mode_func_t)(struct drm_device *);
 
 struct drm_connector_helper_tv_get_modes_test {
@@ -196,6 +207,7 @@ static struct kunit_case drm_test_connector_helper_tv_get_modes_tests[] = {
 static struct kunit_suite drm_test_connector_helper_tv_get_modes_suite = {
 	.name = "drm_connector_helper_tv_get_modes",
 	.init = drm_probe_helper_test_init,
+	.exit = drm_probe_helper_test_exit,
 	.test_cases = drm_test_connector_helper_tv_get_modes_tests,
 };
 

include/drm/drm_kunit_helpers.h

@@ -6,8 +6,11 @@
 struct drm_device;
 struct kunit;
 
+struct device *drm_kunit_helper_alloc_device(struct kunit *test);
+void drm_kunit_helper_free_device(struct kunit *test, struct device *dev);
+
 struct drm_device *
-drm_kunit_helper_alloc_drm_device(struct kunit *test,
+drm_kunit_helper_alloc_drm_device(struct kunit *test, struct device *dev,
 				  u32 features);
 
 #endif // DRM_KUNIT_HELPERS_H_