[PATCH v2 0/3] KUnit tests for drm_format_helper

[PATCH v2 0/3] KUnit tests for drm_format_helper

[José Expósito]

Hello everyone,

Here is the v2 of the series, including the documentation, previously
sent as a standalone patch [1], and changes suggested during review.

Thanks a lot,
José Expósito

RFC -> v1: https://lore.kernel.org/dri-devel/20220530102017.471865-1-jose.exposito89@gmail.com/T/

 - Add .kunitconfig (Maxime Ripard)
 - Fix memory leak (Daniel Latypov)
 - Make config option generic (Javier Martinez Canillas):
   DRM_FORMAR_HELPER_TEST -> DRM_KUNIT_TEST
 - Remove DISABLE_STRUCTLEAK_PLUGIN (Daniel Latypov)

v1 -> v2: https://lore.kernel.org/dri-devel/20220606095516.938934-1-jose.exposito89@gmail.com/T/

 Thomas Zimmermann:
 - Add DRM_RECT_INIT() macro
 - Move tests to drivers/gpu/drm/kunit
 - Improve test documentation

[1] https://lore.kernel.org/dri-devel/20220606180940.43371-1-jose.exposito89@gmail.com/T/

José Expósito (3):
  drm/rect: Add DRM_RECT_INIT() macro
  drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb332()
  drm/doc: Add KUnit documentation

 Documentation/gpu/drm-internals.rst           |  32 ++++
 drivers/gpu/drm/Kconfig                       |  16 ++
 drivers/gpu/drm/Makefile                      |   1 +
 drivers/gpu/drm/kunit/.kunitconfig            |   3 +
 drivers/gpu/drm/kunit/Makefile                |   3 +
 .../gpu/drm/kunit/drm_format_helper_test.c    | 169 ++++++++++++++++++
 include/drm/drm_rect.h                        |  12 ++
 7 files changed, 236 insertions(+)
 create mode 100644 drivers/gpu/drm/kunit/.kunitconfig
 create mode 100644 drivers/gpu/drm/kunit/Makefile
 create mode 100644 drivers/gpu/drm/kunit/drm_format_helper_test.c

-- 
2.25.1

[PATCH v2 1/3] drm/rect: Add DRM_RECT_INIT() macro

[José Expósito]

Add a helper macro to initialize a rectangle from x, y, width and
height information.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 include/drm/drm_rect.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
index 6f6e19bd4dac..945696323c69 100644
--- a/include/drm/drm_rect.h
+++ b/include/drm/drm_rect.h
@@ -47,6 +47,18 @@ struct drm_rect {
 	int x1, y1, x2, y2;
 };
 
+/**
+ * DRM_RECT_INIT - initialize a rectangle from x/y/w/h
+ * @x: x coordinate
+ * @y: y coordinate
+ * @w: width
+ * @h: height
+ *
+ * RETURNS:
+ * A new rectangle of the specified size.
+ */
+#define DRM_RECT_INIT(x, y, w, h) { (x), (y), (x) + (w), (y) + (h) }
+
 /**
  * DRM_RECT_FMT - printf string for &struct drm_rect
  */
-- 
2.25.1

[PATCH v2 2/3] drm/format-helper: Add KUnit tests for drm_fb_xrgb8888_to_rgb332()

[José Expósito]

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/kunit \
         --kconfig_add CONFIG_VIRTIO_UML=y \
         --kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y

Suggested-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 drivers/gpu/drm/Kconfig                       |  16 ++
 drivers/gpu/drm/Makefile                      |   1 +
 drivers/gpu/drm/kunit/.kunitconfig            |   3 +
 drivers/gpu/drm/kunit/Makefile                |   3 +
 .../gpu/drm/kunit/drm_format_helper_test.c    | 169 ++++++++++++++++++
 5 files changed, 192 insertions(+)
 create mode 100644 drivers/gpu/drm/kunit/.kunitconfig
 create mode 100644 drivers/gpu/drm/kunit/Makefile
 create mode 100644 drivers/gpu/drm/kunit/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..3171437d74f8 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) += kunit/
 
 obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o
 obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
diff --git a/drivers/gpu/drm/kunit/.kunitconfig b/drivers/gpu/drm/kunit/.kunitconfig
new file mode 100644
index 000000000000..6ec04b4c979d
--- /dev/null
+++ b/drivers/gpu/drm/kunit/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_DRM=y
+CONFIG_DRM_KUNIT_TEST=y
diff --git a/drivers/gpu/drm/kunit/Makefile b/drivers/gpu/drm/kunit/Makefile
new file mode 100644
index 000000000000..2c8273796d9d
--- /dev/null
+++ b/drivers/gpu/drm/kunit/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/kunit/drm_format_helper_test.c b/drivers/gpu/drm/kunit/drm_format_helper_test.c
new file mode 100644
index 000000000000..c87e7ab69184
--- /dev/null
+++ b/drivers/gpu/drm/kunit/drm_format_helper_test.c
@@ -0,0 +1,169 @@
+// 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, different values for the X in XRGB8888 to
+		 * make sure it is ignored. Partial clip area.
+		 */
+		.name = "White, black, red, green, blue, magenta, yellow, cyan",
+		.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.
+ * @src_format: source buffer pixel format (DRM_FORMAT_*)
+ * @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 src_format, u32 dst_format,
+				  unsigned int dst_pitch,
+				  const struct drm_rect *clip)
+{
+	const struct drm_format_info *src_fi = drm_format_info(src_format);
+	const struct drm_format_info *dst_fi = drm_format_info(dst_format);
+	size_t width = drm_rect_width(clip);
+	size_t src_nbytes;
+
+	if (!src_fi || !dst_fi)
+		return -EINVAL;
+
+	if (dst_pitch)
+		width = dst_pitch;
+
+	src_nbytes = width * drm_rect_height(clip) * src_fi->cpp[0];
+	if (!src_nbytes)
+		return 0;
+
+	return (src_nbytes * dst_fi->cpp[0]) / src_fi->cpp[0];
+}
+
+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_XRGB8888, 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@gmail.com>");
-- 
2.25.1

[PATCH v2 3/3] drm/doc: Add KUnit documentation

[José Expósito]

Explain how to run the KUnit tests present in the DRM subsystem and
clarify why the UML-only options were not added to the configuration
file present in drivers/gpu/drm/.kunitconfig [1] [2].

[1] https://lore.kernel.org/dri-devel/CABVgOSn8i=LO5p7830h2XU1Jgg0KrN0qTnxkOMhf1oTgxjaKKw@mail.gmail.com/
[2] https://lore.kernel.org/dri-devel/CAGS_qxqpiCim_sy1LDK7PLwVgWf-LKW+uNFTGM=T7ydk-dYcEw@mail.gmail.com/

Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 Documentation/gpu/drm-internals.rst | 32 +++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst
index 38afed24a75c..f1d97e80ca29 100644
--- a/Documentation/gpu/drm-internals.rst
+++ b/Documentation/gpu/drm-internals.rst
@@ -207,6 +207,38 @@ Utilities
    :internal:
 
 
+Unit testing
+============
+
+KUnit
+-----
+
+KUnit (Kernel unit testing framework) provides a common framework for unit tests
+within the Linux kernel.
+
+This section covers the specifics for the DRM subsystem. For general information
+about KUnit, please refer to Documentation/dev-tools/kunit/start.rst.
+
+How to run the tests?
+~~~~~~~~~~~~~~~~~~~~~
+
+In order to facilitate running the test suite, a configuration file is present
+in ``drivers/gpu/drm/kunit/.kunitconfig``. It can be used by ``kunit.py`` as
+follows:
+
+.. code-block:: bash
+
+	$ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/kunit \
+		--kconfig_add CONFIG_VIRTIO_UML=y \
+		--kconfig_add CONFIG_UML_PCI_OVER_VIRTIO=y
+
+.. note::
+	The configuration included in ``.kunitconfig`` should be as generic as
+	possible.
+	``CONFIG_VIRTIO_UML`` and ``CONFIG_UML_PCI_OVER_VIRTIO`` are not
+	included in it because they are only required for User Mode Linux.
+
+
 Legacy Support Code
 ===================
 
-- 
2.25.1

Re: [PATCH v2 1/3] drm/rect: Add DRM_RECT_INIT() macro

[Jani Nikula]

On Sun, 12 Jun 2022, José Expósito <jose.exposito89@gmail.com> wrote:
> Add a helper macro to initialize a rectangle from x, y, width and
> height information.
>
> Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> ---
>  include/drm/drm_rect.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> index 6f6e19bd4dac..945696323c69 100644
> --- a/include/drm/drm_rect.h
> +++ b/include/drm/drm_rect.h
> @@ -47,6 +47,18 @@ struct drm_rect {
>  	int x1, y1, x2, y2;
>  };
>  
> +/**
> + * DRM_RECT_INIT - initialize a rectangle from x/y/w/h
> + * @x: x coordinate
> + * @y: y coordinate
> + * @w: width
> + * @h: height
> + *
> + * RETURNS:
> + * A new rectangle of the specified size.
> + */
> +#define DRM_RECT_INIT(x, y, w, h) { (x), (y), (x) + (w), (y) + (h) }

Please use designated initializers.

It might help type safety if it also contained a (struct drm_rect) cast.

BR,
Jani.


> +
>  /**
>   * DRM_RECT_FMT - printf string for &struct drm_rect
>   */

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH v2 1/3] drm/rect: Add DRM_RECT_INIT() macro

[José Expósito]

On Mon, Jun 13, 2022 at 10:53:57AM +0300, Jani Nikula wrote:
> On Sun, 12 Jun 2022, José Expósito <jose.exposito89@gmail.com> wrote:
> > Add a helper macro to initialize a rectangle from x, y, width and
> > height information.
> >
> > Signed-off-by: José Expósito <jose.exposito89@gmail.com>
> > ---
> >  include/drm/drm_rect.h | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/include/drm/drm_rect.h b/include/drm/drm_rect.h
> > index 6f6e19bd4dac..945696323c69 100644
> > --- a/include/drm/drm_rect.h
> > +++ b/include/drm/drm_rect.h
> > @@ -47,6 +47,18 @@ struct drm_rect {
> >  	int x1, y1, x2, y2;
> >  };
> >  
> > +/**
> > + * DRM_RECT_INIT - initialize a rectangle from x/y/w/h
> > + * @x: x coordinate
> > + * @y: y coordinate
> > + * @w: width
> > + * @h: height
> > + *
> > + * RETURNS:
> > + * A new rectangle of the specified size.
> > + */
> > +#define DRM_RECT_INIT(x, y, w, h) { (x), (y), (x) + (w), (y) + (h) }
> 
> Please use designated initializers.
> 
> It might help type safety if it also contained a (struct drm_rect) cast.

Thanks a lot for your review Jani, just emailed v3 with your suggested
changes.

Jose
 
> BR,
> Jani.
> 
> 
> > +
> >  /**
> >   * DRM_RECT_FMT - printf string for &struct drm_rect
> >   */
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center