[PATCH] drm/virtio: add overlay plane format support

[Baorui.Liu <baorliu@amd.com>]

From: Sophia Gong <lili.gong@amd.com>

Advertise additional pixel formats for virtio-gpu overlay planes so a
userspace compositor can use KMS overlay composition instead of
falling back to GPU composition.

Handle DRM_PLANE_TYPE_OVERLAY in virtio_gpu_plane_init() with a
dedicated format list, and reuse the primary plane update path for
overlay scanout.

Signed-off-by: Sophia Gong <lili.gong@amd.com>
Signed-off-by: Baorui.Liu <baorliu@amd.com>
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 29e4b458ae57..23ca880692f1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -41,6 +41,21 @@ static const uint32_t virtio_gpu_cursor_formats[] = {
 	DRM_FORMAT_HOST_ARGB8888,
 };
 
+static const uint32_t virtio_gpu_overlay_formats[] = {
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_BGRX8888,
+	DRM_FORMAT_BGRA8888,
+	DRM_FORMAT_RGBX8888,
+	DRM_FORMAT_RGBA8888,
+	DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_ABGR8888,
+	DRM_FORMAT_XRGB2101010,
+	DRM_FORMAT_BGRX1010102,
+	DRM_FORMAT_NV12,
+	DRM_FORMAT_P010,
+};
+
 uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
 {
 	uint32_t format;
@@ -572,6 +587,13 @@ static const struct drm_plane_helper_funcs virtio_gpu_cursor_helper_funcs = {
 	.atomic_update		= virtio_gpu_cursor_plane_update,
 };
 
+static const struct drm_plane_helper_funcs virtio_gpu_overlay_helper_funcs = {
+	.prepare_fb		= virtio_gpu_plane_prepare_fb,
+	.cleanup_fb		= virtio_gpu_plane_cleanup_fb,
+	.atomic_check		= virtio_gpu_plane_atomic_check,
+	.atomic_update		= virtio_gpu_primary_plane_update,
+};
+
 struct drm_plane *virtio_gpu_plane_init(struct virtio_gpu_device *vgdev,
 					enum drm_plane_type type,
 					int index)
@@ -586,6 +608,10 @@ struct drm_plane *virtio_gpu_plane_init(struct virtio_gpu_device *vgdev,
 		formats = virtio_gpu_cursor_formats;
 		nformats = ARRAY_SIZE(virtio_gpu_cursor_formats);
 		funcs = &virtio_gpu_cursor_helper_funcs;
+	} else if (type == DRM_PLANE_TYPE_OVERLAY) {
+		formats = virtio_gpu_overlay_formats;
+		nformats = ARRAY_SIZE(virtio_gpu_overlay_formats);
+		funcs = &virtio_gpu_overlay_helper_funcs;
 	} else {
 		formats = virtio_gpu_formats;
 		nformats = ARRAY_SIZE(virtio_gpu_formats);
-- 
2.25.1