From mboxrd@z Thu Jan 1 00:00:00 1970 From: hanjun.guo@linaro.org (Hanjun Guo) Date: Thu, 30 Apr 2015 21:47:13 +0800 Subject: [PATCH 1/2] arm/arm64: ACPI: Introduce CONFIG_ACPI_MUST_HAVE_CCA In-Reply-To: <20150429144232.GC18867@e104818-lin.cambridge.arm.com> References: <1430315049-4663-1-git-send-email-Suravee.Suthikulpanit@amd.com> <1430315049-4663-2-git-send-email-Suravee.Suthikulpanit@amd.com> <20150429140445.GA18867@e104818-lin.cambridge.arm.com> <5540EB27.8060507@amd.com> <20150429144232.GC18867@e104818-lin.cambridge.arm.com> Message-ID: <55423261.4050008@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2015?04?29? 22:42, Catalin Marinas wrote: > On Wed, Apr 29, 2015 at 09:31:03AM -0500, Suravee Suthikulpanit wrote: >> >> >> 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 >>>> Signed-off-by: Suravee Suthikulpanit >>>> --- >>>> 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. > > I think it should be removed (as long as ACPI cannot be selected on > arm32). I agree. Now there is no plan for ARM32 ACPI as I know, ACPI for ARM targets for ARM64 based enterprise system at now. Thanks Hanjun