drm/virtio: rework resource creation workflow.

This patch moves the virtio_gpu_cmd_create_resource() call (which
notifies the host about the new resource created) into the
virtio_gpu_object_create() function.  That way we can call
virtio_gpu_cmd_create_resource() before ttm_bo_init(), so the host
already knows about the object when ttm initializes the object and calls
our driver callbacks.

Specifically the object is already created when the
virtio_gpu_ttm_tt_bind() callback invokes virtio_gpu_object_attach(),
so the extra virtio_gpu_object_attach() calls done after
virtio_gpu_object_create() are not needed any more.

The fence support for the create ioctl becomes a bit more tricky though.
The code moved into virtio_gpu_object_create() too.  We first submit the
(fenced) virtio_gpu_cmd_create_resource() command, then initialize the
ttm object, and finally attach just created object to the fence for the
command in case it didn't finish yet.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190318113332.10900-6-kraxel@redhat.com

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index ca93ec6ca3c5..e62fe24b1a2e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -376,7 +376,8 @@ retry:
 /* create a basic resource */
 void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 				    struct virtio_gpu_object *bo,
-				    struct virtio_gpu_object_params *params)
+				    struct virtio_gpu_object_params *params,
+				    struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_resource_create_2d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
@@ -390,7 +391,7 @@ void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 	cmd_p->width = cpu_to_le32(params->width);
 	cmd_p->height = cpu_to_le32(params->height);
 
-	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, &cmd_p->hdr, fence);
 	bo->created = true;
 }
 
@@ -826,7 +827,8 @@ void virtio_gpu_cmd_context_detach_resource(struct virtio_gpu_device *vgdev,
 void
 virtio_gpu_cmd_resource_create_3d(struct virtio_gpu_device *vgdev,
 				  struct virtio_gpu_object *bo,
-				  struct virtio_gpu_object_params *params)
+				  struct virtio_gpu_object_params *params,
+				  struct virtio_gpu_fence *fence)
 {
 	struct virtio_gpu_resource_create_3d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
@@ -848,7 +850,7 @@ virtio_gpu_cmd_resource_create_3d(struct virtio_gpu_device *vgdev,
 	cmd_p->nr_samples = cpu_to_le32(params->nr_samples);
 	cmd_p->flags = cpu_to_le32(params->flags);
 
-	virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, &cmd_p->hdr, fence);
 	bo->created = true;
 }
 
@@ -932,8 +934,8 @@ int virtio_gpu_object_attach(struct virtio_gpu_device *vgdev,
 	struct scatterlist *sg;
 	int si, nents;
 
-	if (!obj->created)
-		return 0;
+	if (WARN_ON_ONCE(!obj->created))
+		return -EINVAL;
 
 	if (!obj->pages) {
 		int ret;