Re: [PATCH v2 1/9] dt-bindings: dma: nvidia,tegra186-gpc-dma: Add iommu-map property
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2026-03-03 06:40:01
Also in:
dmaengine, linux-tegra, lkml
On Mon, Mar 02, 2026 at 06:02:31PM +0530, Akhil R wrote:
quoted hunk ↗ jump to hunk
Add iommu-map property to specify separate stream IDs for each DMA channel. This enables each channel to be in its own IOMMU domain, keeping memory isolated from other devices sharing the same DMA controller. Signed-off-by: Akhil R <akhilrajeev@nvidia.com> --- .../devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml b/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml index 0dabe9bbb219..1e7b5ddd4658 100644 --- a/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml +++ b/Documentation/devicetree/bindings/dma/nvidia,tegra186-gpc-dma.yaml@@ -14,6 +14,7 @@ description: | maintainers: - Jon Hunter <jonathanh@nvidia.com> - Rajesh Gumasta <rgumasta@nvidia.com> + - Akhil R <akhilrajeev@nvidia.com> allOf: - $ref: dma-controller.yaml#@@ -51,6 +52,10 @@ properties: iommus: maxItems: 1 + iommu-map: + minItems: 1 + maxItems: 32
Why is this flexible? If it is, means usually items are distinctive, so I would expect defining/listing them. If they are not distinctive, commit msg is incorrect. If the list is as simple as 1-to-1 channel mapping, just add it in the description how they are ordered.
+ dma-coherent: true dma-channel-mask: -- 2.50.1