Re: [PATCH V4 0/8] PCI: ACPI: Setting up DMA coherency for PCI device from _CCA attribute

[Bjorn Helgaas <helgaas@kernel.org>]

Hi Suravee,

On Wed, Oct 21, 2015 at 08:52:03AM -0700, Suravee Suthikulpanit wrote:
> This patch series adds support to setup DMA coherency for PCI device using
> the ACPI _CCA attribute. According to the ACPI spec, the _CCA attribute
> is required for ARM64. Therefore, this patch is a pre-req for ACPI PCI
> support for ARM64 which is currently in development.  Also, this should
> not affect other architectures that does not define 
> CONFIG_ACPI_CCA_REQUIRED, since the default value is coherent.
> 
> In the process, this series also introduces enum dev_dma_attr and a set
> of APIs to query device DMA attribute. These APIs replace the obsolete
> device_dma_is_coherent(), and acpi_check_dma().
> 
> I have also included a patch from Jeremy posted here:
>     http://www.spinics.net/lists/linux-usb/msg128582.html
> 
> This patch series  has been tested on AMD Seattle RevB platform.
> The git tree containing tested code and pre-req patches are posted here:
> 
>     http://github.com/ssuthiku/linux.git pci-cca-v4
> 
> Changes from V3: (https://lkml.org/lkml/2015/8/26/389)
>     * Clean up suggested by Bjorn
>     * Introduce enum dev_dma_attr
>     * Replace device_dma_is_coherent() and acpi_check_dma() with
>       new APIs.
> 
> Changes from V2: (https://lkml.org/lkml/2015/8/25/549)
>     * Return -ENOSUPP instead of -1 (per Rafael's suggestion)
>     * Add WARN() when fail to setup DMA for PCI device when booting
>       ACPI (per Arnd's suggestion)
>     * Added Acked-by from Rob.
>     * Minor clean up
> 
> Changes from V1: (https://lkml.org/lkml/2015/8/13/182)
>     * Include patch 1 from Jeremy to enable support for _CCA=0
>     * Clean up acpi_check_dma() per Bjorn suggestions
>     * Split the original V1 patch into two patches (patch 3 and 4)
> 
> Jeremy Linton (1):
>   Honor ACPI _CCA attribute setting
> 
> Suravee Suthikulpanit (7):
>   device property: Introducing enum dev_dma_attr
>   acpi: Adding DMA Attribute APIs for ACPI Device
>   device property: Adding DMA Attribute APIs for Generic Devices
>   device property: acpi: Make use of the new DMA Attribute APIs
>   device property: acpi: Remove unused DMA APIs
>   PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()
>   PCI: ACPI: Add support for PCI device DMA coherency
> 
>  drivers/acpi/acpi_platform.c              |  7 +++++-
>  drivers/acpi/glue.c                       |  8 +++---
>  drivers/acpi/scan.c                       | 42 +++++++++++++++++++++++++++++++
>  drivers/base/property.c                   | 32 +++++++++++++++++------
>  drivers/crypto/ccp/ccp-platform.c         |  9 ++++++-
>  drivers/net/ethernet/amd/xgbe/xgbe-main.c |  9 ++++++-
>  drivers/of/of_pci.c                       | 20 ---------------
>  drivers/pci/probe.c                       | 36 ++++++++++++++++++++++++--
>  include/acpi/acpi_bus.h                   | 36 +++-----------------------
>  include/linux/acpi.h                      |  7 +++++-
>  include/linux/of_pci.h                    |  3 ---
>  include/linux/property.h                  | 10 +++++++-
>  12 files changed, 145 insertions(+), 74 deletions(-)

I had a couple minor comments.  It's sort of a toss-up, but this feels
more ACPI-flavored than PCI, so I assume Rafael will take this whole
series unless I hear otherwise.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>