[PATCHv4 4/5] arm64: Emulate CP15 Barrier instructions

[Catalin Marinas]

On Wed, Nov 12, 2014 at 11:44:51AM +0000, Punit Agrawal wrote:
> 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 deprecated in the ARMv7 architecture, superseded by ISB, DSB and DMB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 at arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas at arm.com>