[PATCH v4 10/29] arm64: enable the Permission Overlay Extension for EL0

[Joey Gouly]

On Thu, Jul 25, 2024 at 04:49:08PM +0100, Dave Martin wrote:
> On Fri, May 03, 2024 at 02:01:28PM +0100, Joey Gouly wrote:
> > Expose a HWCAP and ID_AA64MMFR3_EL1_S1POE to userspace, so they can be used to
> > check if the CPU supports the feature.
> > 
> > Signed-off-by: Joey Gouly <joey.gouly at arm.com>
> > Cc: Catalin Marinas <catalin.marinas at arm.com>
> > Cc: Will Deacon <will at kernel.org>
> > ---
> > 
> > This takes the last bit of HWCAP2, is this fine? What can we do about more features in the future?
> > 
> > 
> >  Documentation/arch/arm64/elf_hwcaps.rst |  2 ++
> >  arch/arm64/include/asm/hwcap.h          |  1 +
> >  arch/arm64/include/uapi/asm/hwcap.h     |  1 +
> >  arch/arm64/kernel/cpufeature.c          | 14 ++++++++++++++
> >  arch/arm64/kernel/cpuinfo.c             |  1 +
> >  5 files changed, 19 insertions(+)
> > 
> > diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst
> > index 448c1664879b..694f67fa07d1 100644
> > --- a/Documentation/arch/arm64/elf_hwcaps.rst
> > +++ b/Documentation/arch/arm64/elf_hwcaps.rst
> > @@ -365,6 +365,8 @@ HWCAP2_SME_SF8DP2
> >  HWCAP2_SME_SF8DP4
> >      Functionality implied by ID_AA64SMFR0_EL1.SF8DP4 == 0b1.
> >  
> > +HWCAP2_POE
> > +    Functionality implied by ID_AA64MMFR3_EL1.S1POE == 0b0001.
> 
> Nit: unintentionally dropped blank line before the section heading?

Now there's only one blank line, I think
c1932cac7902a8b0f7355515917dedc5412eb15d unintentionally added 2 blank lines,
before that it was always 1!

> 
> >  
> >  4. Unused AT_HWCAP bits
> >  -----------------------
> 
> [...]
> 
> Cheers
> ---Dave