dt-bindings: document PASID property for IOMMU masters

On Arm systems, some platform devices behind an SMMU may support the PASID
feature, which offers multiple address space. Let the firmware tell us
when a device supports PASID.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Jean-Philippe Brucker 2020-01-15 13:52:28 +01:00 committed by Will Deacon
parent 9bb9069cfb
commit 2e981b9468

View File

@ -86,6 +86,12 @@ have a means to turn off translation. But it is invalid in such cases to
disable the IOMMU's device tree node in the first place because it would
prevent any driver from properly setting up the translations.
Optional properties:
--------------------
- pasid-num-bits: Some masters support multiple address spaces for DMA, by
tagging DMA transactions with an address space identifier. By default,
this is 0, which means that the device only has one address space.
Notes:
======