| Message ID | 20240226211100.100108-25-harry.wentland@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Color Pipeline API w/ VKMS | expand |
On Mon, 26 Feb 2024 16:10:38 -0500 Harry Wentland <harry.wentland@amd.com> wrote: > While working on the CTM implementation of VKMS I had to ascertain > myself of a few assumptions. One of those is whether drm_fixed.h > treats its numbers using signed-magnitude or twos-complement. It is > twos-complement. > > In order to make someone else's day easier I am adding the > drm_test_int2fixp test that validates the above assumption. > > I am also adding a test for the new sm2fixp function that converts > from a signed-magnitude fixed point to the twos-complement fixed > point. > > Signed-off-by: Harry Wentland <harry.wentland@amd.com> > --- > drivers/gpu/drm/tests/Makefile | 3 +- > drivers/gpu/drm/tests/drm_fixp_test.c | 69 +++++++++++++++++++++++++++ > 2 files changed, 71 insertions(+), 1 deletion(-) > create mode 100644 drivers/gpu/drm/tests/drm_fixp_test.c > > diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile > index d6183b3d7688..98468f7908dd 100644 > --- a/drivers/gpu/drm/tests/Makefile > +++ b/drivers/gpu/drm/tests/Makefile > @@ -19,6 +19,7 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \ > drm_modes_test.o \ > drm_plane_helper_test.o \ > drm_probe_helper_test.o \ > - drm_rect_test.o > + drm_rect_test.o \ > + drm_fixp_test.o > > CFLAGS_drm_mm_test.o := $(DISABLE_STRUCTLEAK_PLUGIN) > diff --git a/drivers/gpu/drm/tests/drm_fixp_test.c b/drivers/gpu/drm/tests/drm_fixp_test.c > new file mode 100644 > index 000000000000..f420f173ff66 > --- /dev/null > +++ b/drivers/gpu/drm/tests/drm_fixp_test.c > @@ -0,0 +1,69 @@ > +// SPDX-License-Identifier: MIT > +/* > + * Copyright 2022 Advanced Micro Devices, Inc. > + */ > + > +#include <kunit/test.h> > +#include <drm/drm_fixed.h> > + > +static void drm_test_sm2fixp(struct kunit *test) > +{ > + KUNIT_EXPECT_EQ(test, 0x7fffffffffffffffll, ((1LL << 63) - 1)); > + > + /* 1 */ > + KUNIT_EXPECT_EQ(test, drm_int2fixp(1), drm_sm2fixp(1ull << DRM_FIXED_POINT)); This sounds like confusing two different APIs. DRM_FIXED_POINT is for the two's complement representation, and sm is not. It does not look like there is a #define for the signed-magnitude UAPI construct, otherwise drm_color_ctm_s31_32_to_qm_n() would be using it. It's just an accident that DRM_FIXED_POINT has the right value for sm. Hm, drm_color_ctm_s31_32_to_qm_n() produces two's complement. Why not use that for implementing drm_sm2fixp()? Thanks, pq > + > + /* -1 */ > + KUNIT_EXPECT_EQ(test, drm_int2fixp(-1), drm_sm2fixp((1ull << 63) | (1ull << DRM_FIXED_POINT))); > + > + /* 0.5 */ > + KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(1, 2), drm_sm2fixp(1ull << (DRM_FIXED_POINT - 1))); > + > + /* -0.5 */ > + KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(-1, 2), drm_sm2fixp((1ull << 63) | (1ull << (DRM_FIXED_POINT - 1)))); > + > +} > + > +static void drm_test_int2fixp(struct kunit *test) > +{ > + /* 1 */ > + KUNIT_EXPECT_EQ(test, 1ll << 32, drm_int2fixp(1)); > + > + /* -1 */ > + KUNIT_EXPECT_EQ(test, -(1ll << 32), drm_int2fixp(-1)); > + > + /* 1 + (-1) = 0 */ > + KUNIT_EXPECT_EQ(test, 0, drm_int2fixp(1) + drm_int2fixp(-1)); > + > + /* 1 / 2 */ > + KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(1, 2)); > + > + /* -0.5 */ > + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(-1, 2)); > + > + /* (1 / 2) + (-1) = 0.5 */ > + KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(-1, 2) + drm_int2fixp(1)); > + > + /* (1 / 2) - 1) = 0.5 */ > + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) + drm_int2fixp(-1)); > + > + /* (1 / 2) - 1) = 0.5 */ > + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) - drm_int2fixp(1)); > + > +} > + > +static struct kunit_case drm_fixp_tests[] = { > + KUNIT_CASE(drm_test_int2fixp), > + KUNIT_CASE(drm_test_sm2fixp), > + { } > +}; > + > +static struct kunit_suite drm_rect_test_suite = { > + .name = "drm_fixp", > + .test_cases = drm_fixp_tests, > +}; > + > +kunit_test_suite(drm_rect_test_suite); > + > +MODULE_AUTHOR("AMD"); > +MODULE_LICENSE("GPL and additional rights"); > \ No newline at end of file
diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile index d6183b3d7688..98468f7908dd 100644 --- a/drivers/gpu/drm/tests/Makefile +++ b/drivers/gpu/drm/tests/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \ drm_modes_test.o \ drm_plane_helper_test.o \ drm_probe_helper_test.o \ - drm_rect_test.o + drm_rect_test.o \ + drm_fixp_test.o CFLAGS_drm_mm_test.o := $(DISABLE_STRUCTLEAK_PLUGIN) diff --git a/drivers/gpu/drm/tests/drm_fixp_test.c b/drivers/gpu/drm/tests/drm_fixp_test.c new file mode 100644 index 000000000000..f420f173ff66 --- /dev/null +++ b/drivers/gpu/drm/tests/drm_fixp_test.c @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright 2022 Advanced Micro Devices, Inc. + */ + +#include <kunit/test.h> +#include <drm/drm_fixed.h> + +static void drm_test_sm2fixp(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 0x7fffffffffffffffll, ((1LL << 63) - 1)); + + /* 1 */ + KUNIT_EXPECT_EQ(test, drm_int2fixp(1), drm_sm2fixp(1ull << DRM_FIXED_POINT)); + + /* -1 */ + KUNIT_EXPECT_EQ(test, drm_int2fixp(-1), drm_sm2fixp((1ull << 63) | (1ull << DRM_FIXED_POINT))); + + /* 0.5 */ + KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(1, 2), drm_sm2fixp(1ull << (DRM_FIXED_POINT - 1))); + + /* -0.5 */ + KUNIT_EXPECT_EQ(test, drm_fixp_from_fraction(-1, 2), drm_sm2fixp((1ull << 63) | (1ull << (DRM_FIXED_POINT - 1)))); + +} + +static void drm_test_int2fixp(struct kunit *test) +{ + /* 1 */ + KUNIT_EXPECT_EQ(test, 1ll << 32, drm_int2fixp(1)); + + /* -1 */ + KUNIT_EXPECT_EQ(test, -(1ll << 32), drm_int2fixp(-1)); + + /* 1 + (-1) = 0 */ + KUNIT_EXPECT_EQ(test, 0, drm_int2fixp(1) + drm_int2fixp(-1)); + + /* 1 / 2 */ + KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(1, 2)); + + /* -0.5 */ + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(-1, 2)); + + /* (1 / 2) + (-1) = 0.5 */ + KUNIT_EXPECT_EQ(test, 1ll << 31, drm_fixp_from_fraction(-1, 2) + drm_int2fixp(1)); + + /* (1 / 2) - 1) = 0.5 */ + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) + drm_int2fixp(-1)); + + /* (1 / 2) - 1) = 0.5 */ + KUNIT_EXPECT_EQ(test, -(1ll << 31), drm_fixp_from_fraction(1, 2) - drm_int2fixp(1)); + +} + +static struct kunit_case drm_fixp_tests[] = { + KUNIT_CASE(drm_test_int2fixp), + KUNIT_CASE(drm_test_sm2fixp), + { } +}; + +static struct kunit_suite drm_rect_test_suite = { + .name = "drm_fixp", + .test_cases = drm_fixp_tests, +}; + +kunit_test_suite(drm_rect_test_suite); + +MODULE_AUTHOR("AMD"); +MODULE_LICENSE("GPL and additional rights"); \ No newline at end of file
While working on the CTM implementation of VKMS I had to ascertain myself of a few assumptions. One of those is whether drm_fixed.h treats its numbers using signed-magnitude or twos-complement. It is twos-complement. In order to make someone else's day easier I am adding the drm_test_int2fixp test that validates the above assumption. I am also adding a test for the new sm2fixp function that converts from a signed-magnitude fixed point to the twos-complement fixed point. Signed-off-by: Harry Wentland <harry.wentland@amd.com> --- drivers/gpu/drm/tests/Makefile | 3 +- drivers/gpu/drm/tests/drm_fixp_test.c | 69 +++++++++++++++++++++++++++ 2 files changed, 71 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/tests/drm_fixp_test.c