Hardware coherence does not replace publication ordering, ownership, access control or architecture rules for changing memory attributes. For DMA mapping, remapping and boot-stage handoff, follow the platform interfaces and transition sequence; some coherent paths need no explicit data-cache maintenance for ordinary transfers, while other transitions do.
Document which memory regions are hardware-coherent vs software-managed.
DMA allocation/mapping must satisfy the platform's granule, alignment, attribute and ownership requirements.
Bootloader-to-kernel handoff must define visibility, attributes and required maintenance/synchronisation for each region.