This patch series introduce support for _CCA object, which is currently used mainly by ARM64 platform to specify DMA coherency attribute for devices when booting with ACPI.
A copy of ACPIv6 can be found here: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
This has been tested on AMD-Seattle platform, which implements _CCA object as described in the AMD Opteron A1100 Series Processor ACPI Porting Guide:
http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2012/10/Seattle_ACPI_...
Changes From RFC: (https://lkml.org/lkml/2015/4/1/389) * New logic for deriving and propagating coherent attribute from parent devices. (by Mark) * Introducing acpi_dma_is_coherent() API (Per Tom suggestion) * Introducing CONFIG_ACPI_MUST_HAVE_CCA kernel configuration. * Rebased to linux-4.1-rc1
Suravee Suthikulpanit (2): arm/arm64: ACPI: Introduce CONFIG_ACPI_MUST_HAVE_CCA ACPI / scan: Parse _CCA and setup device coherency
arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 + drivers/acpi/Kconfig | 3 +++ drivers/acpi/acpi_platform.c | 5 ++++- drivers/acpi/scan.c | 45 ++++++++++++++++++++++++++++++++++++++++++++ include/acpi/acpi_bus.h | 9 ++++++++- 6 files changed, 62 insertions(+), 2 deletions(-)