[PATCH v5 3/8] drm/amd/display: Introduce KUnit tests to display_rq_dlg_calc_20

[Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>]

From: Isabella Basso <isabbasso@riseup.net>

This adds tests to the bit encoding format verification functions on the
file. They're meant to be simpler so as to provide a proof of concept on
testing DML code.

Change since v4:
- Use DRM_AMD_DC_FP guard for FPU tests

Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
---
 drivers/gpu/drm/amd/display/Kconfig           |  13 ++
 .../dc/dml/dcn20/display_rq_dlg_calc_20.c     |   4 +
 .../drm/amd/display/test/kunit/.kunitconfig   |   1 +
 .../dml/dcn20/display_rq_dlg_calc_20_test.c   | 124 ++++++++++++++++++
 4 files changed, 142 insertions(+)
 create mode 100644 drivers/gpu/drm/amd/display/test/kunit/dc/dml/dcn20/display_rq_dlg_calc_20_test.c

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index d54036dcac78..ab52b135db85 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -64,6 +64,19 @@ config DCE_KUNIT_TEST
 
 		If unsure, say N.
 
+config DML_KUNIT_TEST
+	bool "Run all KUnit tests for DML" if !KUNIT_ALL_TESTS
+	depends on DRM_AMD_DC_FP && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+		Enables unit tests for the Display Controller Engine. 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 AMD_DC_BASICS_KUNIT_TEST
 	bool "Enable KUnit tests for the 'basics' sub-component of DAL" if !KUNIT_ALL_TESTS
 	depends on DRM_AMD_DC && KUNIT
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
index 548cdef8a8ad..45f75a7f84c7 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c
@@ -1683,3 +1683,7 @@ static void calculate_ttu_cursor(struct display_mode_lib *mode_lib,
 		ASSERT(*refcyc_per_req_delivery_cur < dml_pow(2, 13));
 	}
 }
+
+#if IS_ENABLED(CONFIG_DML_KUNIT_TEST)
+#include "../../../test/kunit/dc/dml/dcn20/display_rq_dlg_calc_20_test.c"
+#endif
diff --git a/drivers/gpu/drm/amd/display/test/kunit/.kunitconfig b/drivers/gpu/drm/amd/display/test/kunit/.kunitconfig
index 7a58f75a8dfc..eb6f81601757 100644
--- a/drivers/gpu/drm/amd/display/test/kunit/.kunitconfig
+++ b/drivers/gpu/drm/amd/display/test/kunit/.kunitconfig
@@ -5,3 +5,4 @@ CONFIG_DRM_AMDGPU=y
 CONFIG_DRM_AMD_DC=y
 CONFIG_AMD_DC_BASICS_KUNIT_TEST=y
 CONFIG_DCE_KUNIT_TEST=y
+CONFIG_DML_KUNIT_TEST=y
diff --git a/drivers/gpu/drm/amd/display/test/kunit/dc/dml/dcn20/display_rq_dlg_calc_20_test.c b/drivers/gpu/drm/amd/display/test/kunit/dc/dml/dcn20/display_rq_dlg_calc_20_test.c
new file mode 100644
index 000000000000..e6d3e356205c
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/test/kunit/dc/dml/dcn20/display_rq_dlg_calc_20_test.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: MIT
+/*
+ * KUnit tests for dml/dcn20/display_rq_dlg_calc_20.c
+ *
+ * Copyright (c) 2022, Isabella Basso <isabbasso@riseup.net>
+ */
+
+#include <kunit/test.h>
+#include "dml/display_mode_lib.h"
+
+/**
+ * get_bytes_per_element_test - KUnit test for get_bytes_per_element
+ * @test: represents a running instance of a test.
+ */
+static void get_bytes_per_element_test(struct kunit *test)
+{
+	/* last numbers should tell us the horizontal 4-element region binary
+	 * size N used for subsampling, thus giving us N/8 bytes per element
+	 */
+	/* note that 4:4:4 is not subsampled */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_16, false), 2);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_32, false), 4);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_64, false), 8);
+
+	/* dcn20 doesn't support bit depths over 10b */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_12, false), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_12, true), 0);
+
+	/* dm_444_XX are not dual plane */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_16, true), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_32, true), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_64, true), 0);
+
+	/* in the dm_42* values, last numbers specify bit depth, demanding we
+	 * treat chroma and luma channels separately
+	 */
+	/* thus we'll now have ceil(N/8) bytes for luma */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_8, false), 1);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_10, false), 2);
+	/* and double the luma value for accommodating blue and red chroma
+	 * channels
+	 */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_8, true), 2);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_420_10, true), 4);
+
+	/* monochrome encodings should mirror non-subsampled variants */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_mono_8, false),
+			get_bytes_per_element(dm_444_8, false));
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_mono_16, false),
+			get_bytes_per_element(dm_444_16, false));
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_mono_16, true), 0);
+
+	/* dcn20 doesn't support 4:2:2 chroma subsampling */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_422_8, false), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_422_8, true), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_422_10, false), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_422_10, true), 0);
+
+	/* dcn20 doesn't support RGBE encodings */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_rgbe, false), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_rgbe, true), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_rgbe_alpha, false), 0);
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_rgbe_alpha, true), 0);
+
+	/* as in the first values, _8 here represents horizontal binary length */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_8, false), 1);
+	/* in a non-subsampled monochrome encoding chroma and luma should be the
+	 * same length
+	 */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_444_8, false),
+			get_bytes_per_element(dm_444_8, true));
+
+	/* as dm_mono_8 == dm_444_8, it must behave the same way */
+	KUNIT_ASSERT_EQ(test, get_bytes_per_element(dm_mono_8, false),
+			get_bytes_per_element(dm_mono_8, true));
+}
+
+/**
+ * is_dual_plane_test - KUnit test for is_dual_plane
+ * @test: represents a running instance of a test.
+ */
+static void is_dual_plane_test(struct kunit *test)
+{
+	/* strictly speaking monochrome formats are not dual plane, but they're
+	 * included here for completeness
+	 */
+	int source_format_count = 11;
+
+	for (int i = 0; i < source_format_count; i++) {
+		/* dcn20 doesn't support other dual plane formats */
+		if (i == 3 || i == 4)
+			KUNIT_ASSERT_TRUE(test, is_dual_plane(i));
+		else
+			KUNIT_ASSERT_FALSE(test, is_dual_plane(i));
+	}
+}
+
+/**
+ * get_blk_size_bytes_test - KUnit test for get_blk_size_bytes
+ * @test: represents a running instance of a test.
+ */
+static void get_blk_size_bytes_test(struct kunit *test)
+{
+	/* corresponds to 4^4 kB tiles */
+	KUNIT_ASSERT_EQ(test, get_blk_size_bytes(dm_256k_tile), 256 * 1024);
+	/* corresponds to 4^3 kB tiles */
+	KUNIT_ASSERT_EQ(test, get_blk_size_bytes(dm_64k_tile), 64 * 1024);
+	/* corresponds to 4^1 kB tiles */
+	KUNIT_ASSERT_EQ(test, get_blk_size_bytes(dm_4k_tile), 4 * 1024);
+}
+
+static struct kunit_case dcn20_rq_dlg_calc_20_test_cases[] = {
+	KUNIT_CASE(get_bytes_per_element_test),
+	KUNIT_CASE(is_dual_plane_test),
+	KUNIT_CASE(get_blk_size_bytes_test),
+	{  }
+};
+
+static struct kunit_suite dcn20_rq_dlg_calc_20_test_suite = {
+	.name = "display_rq_dlg_calc_20",
+	.test_cases = dcn20_rq_dlg_calc_20_test_cases,
+};
+
+kunit_test_suites(&dcn20_rq_dlg_calc_20_test_suite);
-- 
2.43.0