drm/vkms: add rotate-90 property

Currently, vkms only supports the rotate-180, reflect-x and reflect-y
properties. Therefore, improve the vkms IGT test coverage by adding the
rotate-90 property to vkms. The rotation was implement by software: rotate
the way the blending occurs by making the source x axis be the destination
y axis and the source y axis be the destination x axis.

Tested with igt@kms_rotation_crc@primary-rotation-90 [1],
igt@kms_rotation_crc@sprite-rotation-90 [1], and
igt@kms_rotation_crc@sprite-rotation-90-pos-100-0 [1].

[1] https://patchwork.freedesktop.org/series/116025/Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20230418130525.128733-5-mcanal@igalia.com

drivers/gpu/drm/vkms/vkms_composer.c

@@ -57,13 +57,24 @@ static int get_y_pos(struct vkms_frame_info *frame_info, int y)
 {
 	if (frame_info->rotation & DRM_MODE_REFLECT_Y)
 		return drm_rect_height(&frame_info->rotated) - y - 1;
-	return y;
+
+	switch (frame_info->rotation & DRM_MODE_ROTATE_MASK) {
+	case DRM_MODE_ROTATE_90:
+		return frame_info->rotated.x2 - y - 1;
+	default:
+		return y;
+	}
 }
 
-static bool check_y_limit(struct vkms_frame_info *frame_info, int y)
+static bool check_limit(struct vkms_frame_info *frame_info, int pos)
 {
-	if (y >= frame_info->rotated.y1 && y < frame_info->rotated.y2)
-		return true;
+	if (frame_info->rotation & DRM_MODE_ROTATE_90) {
+		if (pos >= 0 && pos < drm_rect_width(&frame_info->rotated))
+			return true;
+	} else {
+		if (pos >= frame_info->rotated.y1 && pos < frame_info->rotated.y2)
+			return true;
+	}
 
 	return false;
 }
@@ -106,7 +117,7 @@ static void blend(struct vkms_writeback_job *wb,
 		for (size_t i = 0; i < n_active_planes; i++) {
 			y_pos = get_y_pos(plane[i]->frame_info, y);
 
-			if (!check_y_limit(plane[i]->frame_info, y_pos))
+			if (!check_limit(plane[i]->frame_info, y_pos))
 				continue;
 
 			vkms_compose_row(stage_buffer, plane[i], y_pos);

drivers/gpu/drm/vkms/vkms_formats.c

@@ -119,6 +119,10 @@ void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state
 	for (size_t x = 0; x < limit; x++, src_pixels += frame_info->cpp) {
 		int x_pos = get_x_position(frame_info, limit, x);
 
+		if (frame_info->rotation & DRM_MODE_ROTATE_90)
+			src_pixels = get_packed_src_addr(frame_info, x + frame_info->rotated.y1)
+				+ frame_info->cpp * y;
+
 		plane->pixel_read(src_pixels, &out_pixels[x_pos]);
 	}
 }

drivers/gpu/drm/vkms/vkms_plane.c

@@ -117,6 +117,7 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
 	memcpy(&frame_info->map, &shadow_plane_state->data, sizeof(frame_info->map));
 	drm_framebuffer_get(frame_info->fb);
 	frame_info->rotation = drm_rotation_simplify(new_state->rotation, DRM_MODE_ROTATE_0 |
+						     DRM_MODE_ROTATE_90 |
 						     DRM_MODE_REFLECT_X |
 						     DRM_MODE_REFLECT_Y);
 
@@ -212,6 +213,7 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
 
 	drm_plane_create_rotation_property(&plane->base, DRM_MODE_ROTATE_0,
 					   DRM_MODE_ROTATE_0 |
+					   DRM_MODE_ROTATE_90 |
 					   DRM_MODE_ROTATE_180 |
 					   DRM_MODE_REFLECT_X |
 					   DRM_MODE_REFLECT_Y);