[RFC v2 2/7] drm/virtio: support async cursor updates

[Gustavo Padovan]

From: Gustavo Padovan <gustavo.padovan at collabora.com>

Short circuit the update path for cursors and use the drm async update
infrastructure.

v2: move fb setting to core and use new state (Eric Anholt)

Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.com>

---
I wrote this mostly for testing purposes, not sure if its something that
we actually need for virtio.
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 42 ++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 76d5fed..783f146 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -260,6 +260,46 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 	virtio_gpu_cursor_ping(vgdev, output);
 }
 
+static int virtio_gpu_cursor_plane_async_check(struct drm_plane *plane,
+					       struct drm_plane_state *new_state)
+{
+	struct virtio_gpu_output *output;
+
+	if (!plane->state->crtc)
+		return -EINVAL;
+
+	output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
+	if (!output)
+		return -EINVAL;
+
+	if (plane->state->fb != new_state->fb)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void virtio_gpu_cursor_plane_async_update(struct drm_plane *plane,
+						 struct drm_plane_state *new_state)
+{
+	struct drm_device *dev = plane->dev;
+	struct virtio_gpu_device *vgdev = dev->dev_private;
+	struct virtio_gpu_output *output = NULL;
+
+	output = drm_crtc_to_virtio_gpu_output(plane->state->crtc);
+	if (WARN_ON(!output))
+		return;
+
+	if (plane->state->fb != new_state->fb)
+		return;
+
+	DRM_DEBUG("move +%d+%d\n", new_state->crtc_x, new_state->crtc_y);
+
+	output->cursor.hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_MOVE_CURSOR);
+	output->cursor.pos.x = cpu_to_le32(new_state->crtc_x);
+	output->cursor.pos.y = cpu_to_le32(new_state->crtc_y);
+	virtio_gpu_cursor_ping(vgdev, output);
+}
+
 static const struct drm_plane_helper_funcs virtio_gpu_primary_helper_funcs = {
 	.atomic_check		= virtio_gpu_plane_atomic_check,
 	.atomic_update		= virtio_gpu_primary_plane_update,
@@ -268,6 +308,8 @@ static const struct drm_plane_helper_funcs virtio_gpu_primary_helper_funcs = {
 static const struct drm_plane_helper_funcs virtio_gpu_cursor_helper_funcs = {
 	.atomic_check		= virtio_gpu_plane_atomic_check,
 	.atomic_update		= virtio_gpu_cursor_plane_update,
+	.atomic_async_check	= virtio_gpu_cursor_plane_async_check,
+	.atomic_async_update	= virtio_gpu_cursor_plane_async_update,
 };
 
 struct drm_plane *virtio_gpu_plane_init(struct virtio_gpu_device *vgdev,
-- 
2.9.3