drm/selftests: Add drm_rect selftests

Add selftests for drm_rect. A few basic ones for clipped and unclipped
cases, and a few special ones for specific bugs we had in the code.

I'm too lazy to think of more corner cases to check at this time.
Maybe later.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191122175623.13565-5-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@st.com>

1 files changed, 223 insertions, 0 deletions

diff --git a/drivers/gpu/drm/selftests/test-drm_rect.c b/drivers/gpu/drm/selftests/test-drm_rect.c
new file mode 100644
index 000000000000..3a5ff38321f4
--- /dev/null
+++ b/drivers/gpu/drm/selftests/test-drm_rect.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test cases for the drm_rect functions
+ */
+
+#define pr_fmt(fmt) "drm_rect: " fmt
+
+#include <linux/limits.h>
+
+#include <drm/drm_rect.h>
+
+#include "test-drm_modeset_common.h"
+
+int igt_drm_rect_clip_scaled_div_by_zero(void *ignored)
+{
+	struct drm_rect src, dst, clip;
+	bool visible;
+
+	/*
+	 * Make sure we don't divide by zero when dst
+	 * width/height is zero and dst and clip do not intersect.
+	 */
+	drm_rect_init(&src, 0, 0, 0, 0);
+	drm_rect_init(&dst, 0, 0, 0, 0);
+	drm_rect_init(&clip, 1, 1, 1, 1);
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+	FAIL(visible, "Destination not be visible\n");
+	FAIL(drm_rect_visible(&src), "Source should not be visible\n");
+
+	drm_rect_init(&src, 0, 0, 0, 0);
+	drm_rect_init(&dst, 3, 3, 0, 0);
+	drm_rect_init(&clip, 1, 1, 1, 1);
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+	FAIL(visible, "Destination not be visible\n");
+	FAIL(drm_rect_visible(&src), "Source should not be visible\n");
+
+	return 0;
+}
+
+int igt_drm_rect_clip_scaled_not_clipped(void *ignored)
+{
+	struct drm_rect src, dst, clip;
+	bool visible;
+
+	/* 1:1 scaling */
+	drm_rect_init(&src, 0, 0, 1 << 16, 1 << 16);
+	drm_rect_init(&dst, 0, 0, 1, 1);
+	drm_rect_init(&clip, 0, 0, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 1 << 16 ||
+	     src.y1 != 0 || src.y2 != 1 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 1 ||
+	     dst.y1 != 0 || dst.y2 != 1,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 2:1 scaling */
+	drm_rect_init(&src, 0, 0, 2 << 16, 2 << 16);
+	drm_rect_init(&dst, 0, 0, 1, 1);
+	drm_rect_init(&clip, 0, 0, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 2 << 16 ||
+	     src.y1 != 0 || src.y2 != 2 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 1 ||
+	     dst.y1 != 0 || dst.y2 != 1,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 1:2 scaling */
+	drm_rect_init(&src, 0, 0, 1 << 16, 1 << 16);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 0, 0, 2, 2);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 1 << 16 ||
+	     src.y1 != 0 || src.y2 != 1 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 2 ||
+	     dst.y1 != 0 || dst.y2 != 2,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	return 0;
+}
+
+int igt_drm_rect_clip_scaled_clipped(void *ignored)
+{
+	struct drm_rect src, dst, clip;
+	bool visible;
+
+	/* 1:1 scaling top/left clip */
+	drm_rect_init(&src, 0, 0, 2 << 16, 2 << 16);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 0, 0, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 1 << 16 ||
+	     src.y1 != 0 || src.y2 != 1 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 1 ||
+	     dst.y1 != 0 || dst.y2 != 1,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 1:1 scaling bottom/right clip */
+	drm_rect_init(&src, 0, 0, 2 << 16, 2 << 16);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 1, 1, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 1 << 16 || src.x2 != 2 << 16 ||
+	     src.y1 != 1 << 16 || src.y2 != 2 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 1 || dst.x2 != 2 ||
+	     dst.y1 != 1 || dst.y2 != 2,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 2:1 scaling top/left clip */
+	drm_rect_init(&src, 0, 0, 4 << 16, 4 << 16);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 0, 0, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 2 << 16 ||
+	     src.y1 != 0 || src.y2 != 2 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 1 ||
+	     dst.y1 != 0 || dst.y2 != 1,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 2:1 scaling bottom/right clip */
+	drm_rect_init(&src, 0, 0, 4 << 16, 4 << 16);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 1, 1, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 2 << 16 || src.x2 != 4 << 16 ||
+	     src.y1 != 2 << 16 || src.y2 != 4 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 1 || dst.x2 != 2 ||
+	     dst.y1 != 1 || dst.y2 != 2,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 1:2 scaling top/left clip */
+	drm_rect_init(&src, 0, 0, 2 << 16, 2 << 16);
+	drm_rect_init(&dst, 0, 0, 4, 4);
+	drm_rect_init(&clip, 0, 0, 2, 2);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 0 || src.x2 != 1 << 16 ||
+	     src.y1 != 0 || src.y2 != 1 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 0 || dst.x2 != 2 ||
+	     dst.y1 != 0 || dst.y2 != 2,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	/* 1:2 scaling bottom/right clip */
+	drm_rect_init(&src, 0, 0, 2 << 16, 2 << 16);
+	drm_rect_init(&dst, 0, 0, 4, 4);
+	drm_rect_init(&clip, 2, 2, 2, 2);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(src.x1 != 1 << 16 || src.x2 != 2 << 16 ||
+	     src.y1 != 1 << 16 || src.y2 != 2 << 16,
+	     "Source badly clipped\n");
+	FAIL(dst.x1 != 2 || dst.x2 != 4 ||
+	     dst.y1 != 2 || dst.y2 != 4,
+	     "Destination badly clipped\n");
+	FAIL(!visible, "Destination should be visible\n");
+	FAIL(!drm_rect_visible(&src), "Source should be visible\n");
+
+	return 0;
+}
+
+int igt_drm_rect_clip_scaled_signed_vs_unsigned(void *ignored)
+{
+	struct drm_rect src, dst, clip;
+	bool visible;
+
+	/*
+	 * 'clip.x2 - dst.x1 >= dst width' could result a negative
+	 * src rectangle width which is no longer expected by the
+	 * code as it's using unsigned types. This could lead to
+	 * the clipped source rectangle appering visible when it
+	 * should have been fully clipped. Make sure both rectangles
+	 * end up invisible.
+	 */
+	drm_rect_init(&src, 0, 0, INT_MAX, INT_MAX);
+	drm_rect_init(&dst, 0, 0, 2, 2);
+	drm_rect_init(&clip, 3, 3, 1, 1);
+
+	visible = drm_rect_clip_scaled(&src, &dst, &clip);
+
+	FAIL(visible, "Destination should not be visible\n");
+	FAIL(drm_rect_visible(&src), "Source should not be visible\n");
+
+	return 0;
+}