Re: [PATCH 1/2] arm/arm64: ACPI: Introduce CONFIG_ACPI_MUST_HAVE_CCA

[Suravee Suthikulpanit]

On 04/29/2015 09:04 AM, Catalin Marinas wrote:
> On Wed, Apr 29, 2015 at 08:44:08AM -0500, Suravee Suthikulpanit wrote:
> >  From ACPIv6 (http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf),
> > section 6.2.17 _CCA states that ARM platforms require ACPI _CCA object to be
> > specified for DMA-cabpable devices. This patch introduces ACPI_MUST_HAVE_CCA
> > in arm and arm64 Kconfig to specify such requirement.
> >
> > Note that when _CCA is required, if it is missing in the DSDT. ACPI driver
> > will default to setting up devices as non-coherent.
> >
> > Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
> > Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> > ---
> >   arch/arm/Kconfig     | 1 +
> >   arch/arm64/Kconfig   | 1 +
> >   drivers/acpi/Kconfig | 3 +++
> >   3 files changed, 5 insertions(+)
> >
> > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> > index 45df48b..2a0d036 100644
> > --- a/arch/arm/Kconfig
> > +++ b/arch/arm/Kconfig
> > @@ -1,6 +1,7 @@
> >   config ARM
> >   	bool
> >   	default y
> > +	select ACPI_MUST_HAVE_CCA if ACPI
> >   	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> >   	select ARCH_HAS_ELF_RANDOMIZE
> >   	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>
> Any plans for ACPI on 32-bit ARM?

Not that I am aware, but I could be totally wrong. The reason I am 
adding this here for 32-bit ARM is because the ACPI spec mentioned this.

If you think this is not necessary until we introduce ACPI for ARM32, it 
can be removed.

Thanks,

Suravee
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