[RFC 1/3] drm/amd/display: Introduce KUnit to DML

["Maíra Canal" <maira.canal@usp.br>]

KUnit unifies the test structure and provides helper tools that simplify
the development. Basic use case allows running tests as regular
processes, which makes easier to run unit tests on a development machine
and to integrate the tests in a CI system.

This commit introduce a basic unit test to one part of the Display Mode
Library: display_mode_lib, in order to introduce the basic structure of the
tests on the DML.

Signed-off-by: Maíra Canal <maira.canal@usp.br>
---
 drivers/gpu/drm/amd/display/Kconfig           |  1 +
 .../gpu/drm/amd/display/amdgpu_dm/Makefile    |  5 ++
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  3 +
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  3 +
 .../drm/amd/display/amdgpu_dm/tests/Kconfig   | 29 +++++++
 .../drm/amd/display/amdgpu_dm/tests/Makefile  | 14 ++++
 .../amdgpu_dm/tests/display_mode_lib_test.c   | 83 +++++++++++++++++++
 .../amd/display/amdgpu_dm/tests/dml_test.c    | 23 +++++
 .../amd/display/amdgpu_dm/tests/dml_test.h    | 13 +++
 9 files changed, 174 insertions(+)
 create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig
 create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile
 create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c
 create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c
 create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index 127667e549c1..83042e2e4d22 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -53,5 +53,6 @@ config DRM_AMD_SECURE_DISPLAY
             of crc of specific region via debugfs.
             Cooperate with specific DMCU FW.
 
+source "drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig"
 
 endmenu
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
index 718e123a3230..d25b63566640 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/Makefile
@@ -24,6 +24,11 @@
 # It provides the control and status of dm blocks.
 
 
+AMDGPU_DM_LIBS = tests
+
+AMD_DM = $(addsuffix /Makefile, $(addprefix $(FULL_AMD_DISPLAY_PATH)/amdgpu_dm/,$(AMDGPU_DM_LIBS)))
+
+include $(AMD_DM)
 
 AMDGPUDM = amdgpu_dm.o amdgpu_dm_irq.o amdgpu_dm_mst_types.o amdgpu_dm_color.o
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index cb1e9bb60db2..f73da1e0088f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1655,6 +1655,7 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 		goto error;
 	}
 
+	amdgpu_dml_test_init();
 
 	DRM_DEBUG_DRIVER("KMS initialized.\n");
 
@@ -1678,6 +1679,8 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev)
 {
 	int i;
 
+	amdgpu_dml_test_exit();
+
 	if (adev->dm.vblank_control_workqueue) {
 		destroy_workqueue(adev->dm.vblank_control_workqueue);
 		adev->dm.vblank_control_workqueue = NULL;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 3cc5c15303e6..e586d3a3d2f0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -749,4 +749,7 @@ int dm_atomic_get_state(struct drm_atomic_state *state,
 struct amdgpu_dm_connector *
 amdgpu_dm_find_first_crtc_matching_connector(struct drm_atomic_state *state,
 					     struct drm_crtc *crtc);
+
+int amdgpu_dml_test_init(void);
+void amdgpu_dml_test_exit(void);
 #endif /* __AMDGPU_DM_H__ */
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig
new file mode 100644
index 000000000000..bd1d971d4452
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: MIT
+menu "DML Unit Tests"
+	depends on DRM_AMD_DC && KUNIT=m
+
+config DISPLAY_MODE_LIB_KUNIT_TEST
+	bool "Enable unit tests for dml/display_mode_lib" if !DML_KUNIT_TEST
+	default y if DML_KUNIT_TEST
+	help
+		Enables unit tests for the dml/display_mode_lib. Only useful for kernel
+		devs running KUnit.
+
+		For more information on KUnit and unit tests in general please refer to
+		the KUnit documentation in Documentation/dev-tools/kunit/.
+
+		If unsure, say N.
+
+config DML_KUNIT_TEST
+	bool "Run all unit tests for DML" if !KUNIT_ALL_TESTS
+	default KUNIT_ALL_TESTS
+	help
+		Enables unit tests for the Display Mode Library. Only useful for kernel
+		devs running KUnit.
+
+		For more information on KUnit and unit tests in general please refer to
+		the KUnit documentation in Documentation/dev-tools/kunit/.
+
+		If unsure, say N.
+
+endmenu
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile
new file mode 100644
index 000000000000..53b38e340564
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/Makefile
@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the KUnit Tests for DML
+#
+
+DML_TESTS = dml_test.o
+
+ifdef CONFIG_DISPLAY_MODE_LIB_KUNIT_TEST
+DML_TESTS += display_mode_lib_test.o
+endif
+
+AMD_DAL_DML_TESTS = $(addprefix $(AMDDALPATH)/amdgpu_dm/tests/,$(DML_TESTS))
+
+AMD_DISPLAY_FILES += $(AMD_DAL_DML_TESTS)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c
new file mode 100644
index 000000000000..3ea0e7fb13e3
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/display_mode_lib_test.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: MIT
+/*
+ * KUnit tests for dml/display_mode_lib.h
+ *
+ * Copyright (C) 2022, Maíra Canal <mairacanal@riseup.net>
+ */
+
+#include <kunit/test.h>
+#include "../../dc/dml/display_mode_lib.h"
+#include "../../dc/dml/display_mode_enums.h"
+#include "dml_test.h"
+
+/**
+ * DOC: Unit tests for AMDGPU DML display_mode_lib.h
+ *
+ * The display_mode_lib.h holds the functions responsible for the instantiation
+ * and logging of the Display Mode Library (DML).
+ *
+ * These KUnit tests were implemented with the intention of assuring the proper
+ * logging of the DML.
+ *
+ */
+
+static void dml_get_status_message_test(struct kunit *test)
+{
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_VALIDATION_OK), "Validation OK");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_SCALE_RATIO_TAP), "Scale ratio/tap");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_SOURCE_PIXEL_FORMAT), "Source pixel format");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_VIEWPORT_SIZE), "Viewport size");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_TOTAL_V_ACTIVE_BW), "Total vertical active bandwidth");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DIO_SUPPORT), "DIO support");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_NOT_ENOUGH_DSC), "Not enough DSC Units");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DSC_CLK_REQUIRED), "DSC clock required");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_URGENT_LATENCY), "Urgent latency");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_REORDERING_BUFFER), "Re-ordering buffer");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DISPCLK_DPPCLK), "Dispclk and Dppclk");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_TOTAL_AVAILABLE_PIPES), "Total available pipes");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_NUM_OTG), "Number of OTG");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_MODE), "Writeback mode");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_LATENCY), "Writeback latency");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_WRITEBACK_SCALE_RATIO_TAP), "Writeback scale ratio/tap");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_CURSOR_SUPPORT), "Cursor support");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PITCH_SUPPORT), "Pitch support");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PTE_BUFFER_SIZE), "PTE buffer size");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_DSC_INPUT_BPC), "DSC input bpc");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_PREFETCH_SUPPORT), "Prefetch support");
+	KUNIT_EXPECT_STREQ(test, dml_get_status_message(DML_FAIL_V_RATIO_PREFETCH), "Vertical ratio prefetch");
+}
+
+static struct kunit_case display_mode_library_test_cases[] = {
+	KUNIT_CASE(dml_get_status_message_test),
+	{  }
+};
+
+static struct kunit_suite display_mode_lib_test_suite = {
+	.name = "dml-display-mode-lib",
+	.test_cases = display_mode_library_test_cases,
+};
+
+static struct kunit_suite *display_mode_lib_test_suites[] = { &display_mode_lib_test_suite, NULL };
+
+int display_mode_lib_test_init(void)
+{
+	pr_info("===> Running display_mode_lib KUnit Tests");
+	pr_info("**********************************************************");
+	pr_info("**   NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE   **");
+	pr_info("**                                                      **");
+	pr_info("** display_mode_lib KUnit Tests are being run. This     **");
+	pr_info("** means that this is a TEST kernel and should not be   **");
+	pr_info("** used for production.                                 **");
+	pr_info("**                                                      **");
+	pr_info("** If you see this message and you are not debugging    **");
+	pr_info("** the kernel, report this immediately to your vendor!  **");
+	pr_info("**                                                      **");
+	pr_info("**********************************************************");
+
+	return __kunit_test_suites_init(display_mode_lib_test_suites);
+}
+
+void display_mode_lib_test_exit(void)
+{
+	return __kunit_test_suites_exit(display_mode_lib_test_suites);
+}
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c
new file mode 100644
index 000000000000..9a5d47597c10
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "dml_test.h"
+
+/**
+ * amdgpu_dml_test_init() - Initialise KUnit Tests for DML
+ *
+ * It aggregates all KUnit Tests related to the Display Mode Library (DML).
+ * The DML contains multiple modules, and to assure the modularity of the
+ * tests, the KUnit Tests for a DML module are also gathered in a separated
+ * module. Each KUnit Tests module is initiated in this function.
+ *
+ */
+int amdgpu_dml_test_init(void)
+{
+	display_mode_lib_test_init();
+	return 0;
+}
+
+void amdgpu_dml_test_exit(void)
+{
+	display_mode_lib_test_exit();
+}
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h
new file mode 100644
index 000000000000..2786db9d0e87
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/tests/dml_test.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DML_TEST_H_
+#define DML_TEST_H_
+
+#if defined (CONFIG_DISPLAY_MODE_LIB_KUNIT_TEST)
+int display_mode_lib_test_init(void);
+void display_mode_lib_test_exit(void);
+#else
+static inline int display_mode_lib_test_init(void) { return 0; }
+static inline void display_mode_lib_test_exit(void) { }
+#endif
+
+#endif
-- 
2.36.1