[PATCH v4 2/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb332()

From: José Expósito
Date: Mon Jun 20 2022 - 12:07:00 EST

Test the conversion from XRGB8888 to RGB332.

What is tested?

- Different values for the X in XRGB8888 to make sure it is ignored
- Different clip values: Single pixel and full and partial buffer
- Well known colors: White, black, red, green, blue, magenta, yellow
and cyan
- Other colors: Randomly picked
- Destination pitch

How to run the tests?

$ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/tests \
--kconfig_add CONFIG_VIRTIO_UML=y \
--kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y

Suggested-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
---
drivers/gpu/drm/Kconfig | 16 ++
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/tests/.kunitconfig | 3 +
drivers/gpu/drm/tests/Makefile | 3 +
.../gpu/drm/tests/drm_format_helper_test.c | 161 ++++++++++++++++++
5 files changed, 184 insertions(+)
create mode 100644 drivers/gpu/drm/tests/.kunitconfig
create mode 100644 drivers/gpu/drm/tests/Makefile
create mode 100644 drivers/gpu/drm/tests/drm_format_helper_test.c

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 22e7fa48d693..6c2256e8474b 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -70,6 +70,22 @@ config DRM_DEBUG_SELFTEST

If in doubt, say "N".

+config DRM_KUNIT_TEST
+ tristate "KUnit tests for DRM" if !KUNIT_ALL_TESTS
+ depends on DRM && KUNIT=y
+ select DRM_KMS_HELPER
+ default KUNIT_ALL_TESTS
+ help
+ This builds unit tests for DRM. This option is not useful for
+ distributions or general kernels, but only for kernel
+ developers working on DRM and associated drivers.
+
+ For more information on KUnit and unit tests in general,
+ please refer to the KUnit documentation in
+ Documentation/dev-tools/kunit/.
+
+ If in doubt, say "N".
+
config DRM_KMS_HELPER
tristate
depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 13ef240b3d2b..db8ffcf4e048 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
#

obj-$(CONFIG_DRM_DEBUG_SELFTEST) += selftests/
+obj-$(CONFIG_DRM_KUNIT_TEST) += tests/

obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o
obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
diff --git a/drivers/gpu/drm/tests/.kunitconfig b/drivers/gpu/drm/tests/.kunitconfig
new file mode 100644
index 000000000000..6ec04b4c979d
--- /dev/null
+++ b/drivers/gpu/drm/tests/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_DRM=y
+CONFIG_DRM_KUNIT_TEST=y
diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile
new file mode 100644
index 000000000000..2c8273796d9d
--- /dev/null
+++ b/drivers/gpu/drm/tests/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DRM_KUNIT_TEST) += drm_format_helper_test.o
diff --git a/drivers/gpu/drm/tests/drm_format_helper_test.c b/drivers/gpu/drm/tests/drm_format_helper_test.c
new file mode 100644
index 000000000000..98583bf56044
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_format_helper_test.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <kunit/test.h>
+
+#include <drm/drm_device.h>
+#include <drm/drm_file.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_mode.h>
+#include <drm/drm_print.h>
+#include <drm/drm_rect.h>
+
+#include "../drm_crtc_internal.h"
+
+#define TEST_BUF_SIZE 50
+
+struct xrgb8888_to_rgb332_case {
+ const char *name;
+ unsigned int pitch;
+ unsigned int dst_pitch;
+ struct drm_rect clip;
+ const u32 xrgb8888[TEST_BUF_SIZE];
+ const u8 expected[4 * TEST_BUF_SIZE];
+};
+
+static struct xrgb8888_to_rgb332_case xrgb8888_to_rgb332_cases[] = {
+ {
+ .name = "single_pixel_source_buffer",
+ .pitch = 1 * 4,
+ .dst_pitch = 0,
+ .clip = DRM_RECT_INIT(0, 0, 1, 1),
+ .xrgb8888 = { 0x01FF0000 },
+ .expected = { 0xE0 },
+ },
+ {
+ .name = "single_pixel_clip_rectangle",
+ .pitch = 2 * 4,
+ .dst_pitch = 0,
+ .clip = DRM_RECT_INIT(1, 1, 1, 1),
+ .xrgb8888 = {
+ 0x00000000, 0x00000000,
+ 0x00000000, 0x10FF0000,
+ },
+ .expected = { 0xE0 },
+ },
+ {
+ /* Well known colors: White, black, red, green, blue, magenta,
+ * yellow and cyan. Different values for the X in XRGB8888 to
+ * make sure it is ignored. Partial clip area.
+ */
+ .name = "well_known_colors",
+ .pitch = 4 * 4,
+ .dst_pitch = 0,
+ .clip = DRM_RECT_INIT(1, 1, 2, 4),
+ .xrgb8888 = {
+ 0x00000000, 0x00000000, 0x00000000, 0x00000000,
+ 0x00000000, 0x11FFFFFF, 0x22000000, 0x00000000,
+ 0x00000000, 0x33FF0000, 0x4400FF00, 0x00000000,
+ 0x00000000, 0x550000FF, 0x66FF00FF, 0x00000000,
+ 0x00000000, 0x77FFFF00, 0x8800FFFF, 0x00000000,
+ },
+ .expected = {
+ 0xFF, 0x00,
+ 0xE0, 0x1C,
+ 0x03, 0xE3,
+ 0xFC, 0x1F,
+ },
+ },
+ {
+ /* Randomly picked colors. Full buffer within the clip area. */
+ .name = "destination_pitch",
+ .pitch = 3 * 4,
+ .dst_pitch = 5,
+ .clip = DRM_RECT_INIT(0, 0, 3, 3),
+ .xrgb8888 = {
+ 0xA10E449C, 0xB1114D05, 0xC1A80303,
+ 0xD16C7073, 0xA20E449C, 0xB2114D05,
+ 0xC2A80303, 0xD26C7073, 0xA30E449C,
+ },
+ .expected = {
+ 0x0A, 0x08, 0xA0, 0x00, 0x00,
+ 0x6D, 0x0A, 0x08, 0x00, 0x00,
+ 0xA0, 0x6D, 0x0A, 0x00, 0x00,
+ },
+ },
+};
+
+/*
+ * conversion_buf_size - Return the destination buffer size required to convert
+ * between formats.
+ * @dst_format: destination buffer pixel format (DRM_FORMAT_*)
+ * @dst_pitch: Number of bytes between two consecutive scanlines within dst
+ * @clip: Clip rectangle area to convert
+ *
+ * Returns:
+ * The size of the destination buffer or negative value on error.
+ */
+static size_t conversion_buf_size(u32 dst_format, unsigned int dst_pitch,
+ const struct drm_rect *clip)
+{
+ const struct drm_format_info *dst_fi = drm_format_info(dst_format);
+
+ if (!dst_fi)
+ return -EINVAL;
+
+ if (!dst_pitch)
+ dst_pitch = drm_rect_width(clip) * dst_fi->cpp[0];
+
+ return dst_pitch * drm_rect_height(clip);
+}
+
+static void xrgb8888_to_rgb332_case_desc(struct xrgb8888_to_rgb332_case *t,
+ char *desc)
+{
+ strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(xrgb8888_to_rgb332, xrgb8888_to_rgb332_cases,
+ xrgb8888_to_rgb332_case_desc);
+
+static void xrgb8888_to_rgb332_test(struct kunit *test)
+{
+ const struct xrgb8888_to_rgb332_case *params = test->param_value;
+ size_t dst_size;
+ __u8 *dst = NULL;
+
+ struct drm_framebuffer fb = {
+ .format = drm_format_info(DRM_FORMAT_XRGB8888),
+ .pitches = { params->pitch, 0, 0 },
+ };
+
+ dst_size = conversion_buf_size(DRM_FORMAT_RGB332, params->dst_pitch,
+ &params->clip);
+ KUNIT_ASSERT_GT(test, dst_size, 0);
+
+ dst = kunit_kzalloc(test, dst_size, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dst);
+
+ drm_fb_xrgb8888_to_rgb332(dst, params->dst_pitch, params->xrgb8888,
+ &fb, &params->clip);
+ KUNIT_EXPECT_EQ(test, memcmp(dst, params->expected, dst_size), 0);
+}
+
+static struct kunit_case drm_format_helper_test_cases[] = {
+ KUNIT_CASE_PARAM(xrgb8888_to_rgb332_test,
+ xrgb8888_to_rgb332_gen_params),
+ {}
+};
+
+static struct kunit_suite drm_format_helper_test_suite = {
+ .name = "drm_format_helper_test",
+ .test_cases = drm_format_helper_test_cases,
+};
+
+kunit_test_suite(drm_format_helper_test_suite);
+
+MODULE_DESCRIPTION("KUnit tests for the drm_format_helper APIs");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@xxxxxxxxx>");
--
2.25.1