tree 7ac24b05487d66d95e70c0cd631e8c0a35ab0ac1
parent c77f625b65ec6548108a2fd091c88f807c17c96a
author Arvind Ram Prakash <arvind.ramprakash@arm.com> 1740439321 -0600
committer Govindraj Raja <govindraj.raja@arm.com> 1745359036 -0500

fix(errata-abi): add support for handling split workarounds

Certain erratum workarounds like Neoverse N1 1542419, need a part
of their mitigation done in EL3 and the rest in lower EL. But currently
such workarounds return HIGHER_EL_MITIGATION which indicates that the
erratum has already been mitigated by a higher EL(EL3 in this case)
which causes the lower EL to not apply it's part of the mitigation.

This patch fixes this issue by adding support for split workarounds
so that on certain errata we return AFFECTED even though EL3 has
applied it's workaround. This is done by reusing the chosen field of
erratum_entry structure into a bitfield that has two bitfields -
Bit 0 indicates that the erratum has been enabled in build,
Bit 1 indicates that the erratum is a split workaround and should
return AFFECTED instead of HIGHER_EL_MITIGATION.

SDEN documentation:
https://developer.arm.com/documentation/SDEN885747/latest

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: Iec94d665b5f55609507a219a7d1771eb75e7f4a7
(cherry picked from commit bbff267b6f2777483a37781850dd1be01c16b937)