Re: [PATCH v3 0/5] ACPI: DMA ranges management

From: Hanjun Guo
Date: Thu Aug 03 2017 - 09:26:03 EST

On 2017/8/3 20:32, Lorenzo Pieralisi wrote:
> This patch series is v3 of a previous posting:
> v2->v3:
> - Fixed DMA masks computation
> - Fixed size computation overflow in acpi_dma_get_range()
> 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
> v2:
> v1:
> -- Original cover letter --
> As reported in:
> 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>

with the whole patch set:

Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>

I tested this patch set with no _DMA in DSDT but with named
component in IORT table, seeing no regressions on D05.