drm/virtio: add in/out fence support for explicit synchronization

When the execbuf call receives an in-fence it will get the dma_fence
related to that fence fd and wait on it before submitting the draw call.

On the out-fence side we get fence returned by the submitted draw call
and attach it to a sync_file and send the sync_file fd to userspace. On
error -1 is returned to userspace.

VIRTGPU_EXECBUF_FENCE_FD_IN & VIRTGPU_EXECBUF_FENCE_FD_OUT
are supported at the simultaneously and can be flagged
for simultaneously.

Signed-off-by: Gustavo Padovan <[email protected]>
Signed-off-by: Robert Foss <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Suggested-by: Rob Herring <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>
Signed-off-by: Gerd Hoffmann <[email protected]>

0 files changed, 0 insertions, 0 deletions