Re: [PATCH v2 0/5] ACPI: DMA ranges management

From: Rafael J. Wysocki
Date: Mon Jul 31 2017 - 14:57:28 EST


On Mon, Jul 31, 2017 at 5:23 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@xxxxxxx> wrote:
> This patch series is v2 of a previous posting:
>
> v1: http://lkml.kernel.org/r/20170720144517.32529-1-lorenzo.pieralisi@xxxxxxx
>
> v1->v2:
> - Reworked acpi_dma_get_range() flow and logs
> - Added IORT named component address limits
> - Renamed acpi_dev_get_resources() helper function
> - Rebased against v4.13-rc3
>
> -- Original cover letter --
>
> As reported in:
>
> http://lkml.kernel.org/r/CAL85gmA_SSCwM80TKdkZqEe+S1beWzDEvdki1kpkmUTDRmSP7g@xxxxxxxxxxxxxx
>
> the bus connecting devices to an IOMMU bus can be smaller in size than
> the IOMMU input address bits which results in devices DMA HW bugs in
> particular related to IOVA allocation (ie chopping of higher address
> bits owing to system bus HW capabilities mismatch with the IOMMU).
>
> Fortunately this problem can be solved through an already present but never
> used ACPI 6.2 firmware bindings (ie _DMA object) allowing to define the DMA
> window for a specific bus in ACPI and therefore all upstream devices
> connected to it.
>
> This small patch series enables _DMA parsing in ACPI core code and
> use it in ACPI IORT code in order to detect DMA ranges for devices and
> update their data structures to make them work with their related DMA
> addressing restrictions.
>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Cc: Feng Kan <fkan@xxxxxxx>
> Cc: Jon Masters <jcm@xxxxxxxxxx>
> Cc: Robert Moore <robert.moore@xxxxxxxxx>
> Cc: Robin Murphy <robin.murphy@xxxxxxx>
> Cc: Zhang Rui <rui.zhang@xxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
>
> Lorenzo Pieralisi (5):
> ACPICA: resource_mgr: Allow _DMA method in walk resources
> ACPI: Make acpi_dev_get_resources() method agnostic
> ACPI: Introduce DMA ranges parsing
> ACPI: Make acpi_dma_configure() DMA regions aware
> ACPI/IORT: Add IORT named component memory address limits

Patches [1-3/5] are fine by me, but I need ACKs from the ARM side on
the last two ones.

Thanks,
Rafael