In root port mode, incoming PCIe traffic to the CCI ACE-Lite port goes through the SMMU TBU3. In this situation, traffic from any source (e.g., PS, PL) to the CPM must go directly to the CPM without passing through a TBU. This restriction is shown in the following figure.
Figure 1. Restriction on PCIe Root Port Mode I/O Coherent
Traffic
