Re: [PATCH] arm64: Disallow combination of ARCH_XGENE and 16K page size

From: Will Deacon
Date: Thu Jan 28 2016 - 06:08:34 EST


On Thu, Jan 28, 2016 at 10:34:41AM +0000, Catalin Marinas wrote:
> On Wed, Jan 27, 2016 at 04:10:30PM -0700, dann frazier wrote:
> > 16K page size is an optional feature of the architecture, and is not
> > supported by the X-Gene SoC family.
> >
> > Signed-off-by: dann frazier <dann.frazier@xxxxxxxxxxxxx>
> > ---
> > arch/arm64/Kconfig.platforms | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> > index 21074f6..b241290 100644
> > --- a/arch/arm64/Kconfig.platforms
> > +++ b/arch/arm64/Kconfig.platforms
> > @@ -133,6 +133,7 @@ config ARCH_VEXPRESS
> >
> > config ARCH_XGENE
> > bool "AppliedMicro X-Gene SOC Family"
> > + depends on !ARM64_16K_PAGES
> > help
> > This enables support for AppliedMicro X-Gene SOC Family
>
> This would be the case on Juno as well. But maybe at some point the
> X-Gene family would gain a CPU with such support.
>
> Anyway, I would rather make 16K pages depend on EXPERT, make it a bit
> harder to enable. We've had a few questions recently about enabling it
> on CPUs that don't have such feature.

I thought there was also a suggestion that we could fail gracefully in
the EFI stub if we detected an unsupported page size?

Will