nv84_fence_chid
u64 addr = fctx->vma->addr + nv84_fence_chid(prev) * 16;
return nouveau_bo_rd32(priv->bo, nv84_fence_chid(chan) * 16/4);
nouveau_bo_wr32(priv->bo, nv84_fence_chid(chan) * 16 / 4, fctx->base.sequence);
u64 addr = fctx->vma->addr + nv84_fence_chid(chan) * 16;