Re: [PATCH v8 11/21] ARM64 / ACPI: Get PSCI flags in FADT for PSCI init

[Hanjun Guo]

On 2015å02æ05æ 00:43, Lorenzo Pieralisi wrote:
> On Mon, Feb 02, 2015 at 12:45:39PM +0000, Hanjun Guo wrote:
> > From: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> >
> > There are two flags: PSCI_COMPLIANT and PSCI_USE_HVC. When set,
> > the former signals to the OS that the firmware is PSCI compliant.
> > The latter selects the appropriate conduit for PSCI calls by
> > toggling between Hypervisor Calls (HVC) and Secure Monitor Calls
> > (SMC).
> >
> > FADT table contains such information in ACPI 5.1, FADT table was
> > parsed in ACPI table init and copy to struct acpi_gbl_FADT, so
> > use the flags in struct acpi_gbl_FADT for PSCI init.
>
> So you do rely on a global FADT being available, if you use it for PSCI
> detection you can use it for ACPI revision detection too, right ?

Yes, I think so.

> Point is, either we should not use the global FADT table, or we use
> it consistently, or there is something I am unaware of that prevents
> you from using in some code paths and I would like to understand
> why.

global FADT table is initialized when parsing the tables from RSDP in
ACPICA core, and it should be work on ARM64 too.

Thanks
Hanjun
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