refactor(plat/allwinner): map SRAM as device memory by default

The SRAM on Allwinner platforms is shared between BL31 and coprocessor
firmware. Previously, SRAM was mapped as normal memory by default.
This scheme requires carveouts and cache maintenance code for proper
synchronization with the coprocessor.

A better scheme is to only map pages owned by BL31 as normal memory,
and leave everything else as device memory. This removes the need for
cache maintenance, and it makes the mapping for BL31 RW data explicit
instead of magic.

Signed-off-by: Samuel Holland <>
Change-Id: I820ddeba2dfa2396361c2322308c0db51b55c348
4 files changed