drm/amdgpu: fix waiting for BO moves with CPU based PD/PT updates

Otherwise we open up the possibility to use uninitialized memory.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -1781,13 +1781,18 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
 		if (pages_addr)
 			params.src = ~0;
 
-		/* Wait for PT BOs to be free. PTs share the same resv. object
+		/* Wait for PT BOs to be idle. PTs share the same resv. object
 		 * as the root PD BO
 		 */
 		r = amdgpu_vm_wait_pd(adev, vm, owner);
 		if (unlikely(r))
 			return r;
 
+		/* Wait for any BO move to be completed */
+		r = dma_fence_wait(exclusive, true);
+		if (unlikely(r))
+			return r;
+
 		params.func = amdgpu_vm_cpu_set_ptes;
 		params.pages_addr = pages_addr;
 		return amdgpu_vm_update_ptes(&params, start, last + 1,