tree 57f88ee08e59727db2ac8d305ad89f15990b4ecd
parent bd35a4adc4131c530ec7d90242555eac7b3dbe3f
author Punit Agrawal <punit.agrawal@arm.com> 1416310886 +0000
committer Will Deacon <will.deacon@arm.com> 1416501288 +0000

arm64: Emulate CP15 Barrier instructions

The CP15 barrier instructions (CP15ISB, CP15DSB and CP15DMB) are
deprecated in the ARMv7 architecture, superseded by ISB, DSB and DMB
instructions respectively. Some implementations may provide the
ability to disable the CP15 barriers by disabling the CP15BEN bit in
SCTLR_EL1. If not enabled, the encodings for these instructions become
undefined.

To support legacy software using these instructions, this patch
register hooks to -
* emulate CP15 barriers and warn the user about their use
* toggle CP15BEN in SCTLR_EL1

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>