Re: [PATCH V2] ARM: DRA7/OMAP5: Enable ACTLR[0] (Enable invalidates of BTB) for secondary cores

From: Tony Lindgren
Date: Wed Jul 11 2018 - 09:24:36 EST


* Nishanth Menon <nm@xxxxxx> [180710 12:50]:
> Call secure services to enable ACTLR[0] (Enable invalidates of BTB with
> ICIALLU) when branch hardening is enabled for kernel.
>
> On GP devices OMAP5/DRA7, there is no possibility to update secure
> side since "secure world" is ROM and there are no override mechanisms
> possible. On HS devices, appropriate PPA should do the workarounds as
> well.
>
> However, the configuration is only done for secondary core, since it is
> expected that firmware/bootloader will have enabled the required
> configuration for the primary boot core (note: bootloaders typically
> will NOT enable secondary processors, since it has no need to do so).

Thanks for updating this. Seems like we should merge this into v4.18-rc
cycle as without this the already merged fixes are incomplete.
So if no objections, I'm planning to apply this tomorrow.

Regards,

Tony