drm/amdgpu: sync bo and shadow V3

Use shadow flag to judge which direction to sync.
V2:
Don't need bo pin, so remove it.

V3:
1. Split to two functions, one is backup_to_shadow, another is
restore_from_shadow.
2. Clean up previous shadow direction difinitions.

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
index d650b42..b6a2739 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
@@ -155,6 +155,18 @@
 void amdgpu_bo_fence(struct amdgpu_bo *bo, struct fence *fence,
 		     bool shared);
 u64 amdgpu_bo_gpu_offset(struct amdgpu_bo *bo);
+int amdgpu_bo_backup_to_shadow(struct amdgpu_device *adev,
+			       struct amdgpu_ring *ring,
+			       struct amdgpu_bo *bo,
+			       struct reservation_object *resv,
+			       struct fence **fence, bool direct);
+int amdgpu_bo_restore_from_shadow(struct amdgpu_device *adev,
+				  struct amdgpu_ring *ring,
+				  struct amdgpu_bo *bo,
+				  struct reservation_object *resv,
+				  struct fence **fence,
+				  bool direct);
+
 
 /*
  * sub allocation