tree 3d6b9d9d6d0eadf4148449ad067ba0cd5eaac183
parent 53b40e8d54fcdb834e10e6538084517524b8401b
author Peter Hoyes <Peter.Hoyes@arm.com> 1629388390 +0100
committer Tom Rini <trini@konsulko.com> 1630592265 -0400

armv8: Ensure EL1&0 VMSA is enabled

On Armv8-R, the EL1&0 memory system architecture is configurable as a
VMSA or PMSA, and resets to an "architecturally unknown" value.

Add code to armv8_switch_to_el1_m which detects whether the MSA at
EL1&0 is configurable using the id_aa64mmfr0_el1 register MSA fields.
If it is we must ensure the VMSA is enabled so that a rich OS can boot.

The MSA and MSA_FRAC fields are described in the Armv8-R architecture
profile supplement (section G1.3.7):
https://developer.arm.com/documentation/ddi0600/latest/

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>