From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 369EA3009DE; Fri, 31 Oct 2025 08:14:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761898468; cv=none; b=EkP7TlwtxRCP+xJND5+9QAl2VmwcpvbLr1tPSr6jze42w4xgL08PRW3sXzh9VmFuSjEtX7fWD0lNizZ7FkLTcb0CTN6lrUrvsTMBNNYf+IarGPIKsDHf+/7quq2NZ3ML+VEQ+a7B7wsNymhDbKiz3jbSvJrijb09pQw4PeuOu/w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761898468; c=relaxed/simple; bh=T7nI7xvtFl7krfWTdP/qjx1BlQ3XmAzSZCU1Kz/Md9c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=P4O8g6Q0JOWN2XufPa6QGFk2cNx3MYQuUndsqCWvsVKV3mQcO/P6GoKcFP4Y1eey+orRMxjRSBPwV3EgUznQxd6EXVD8FqB2+rJPJajdEjbyx63AO4VvCtI+EbtgD2ftQGPho4DDcrKhQMBtMt7LC7hhBajaIQUw4ClBj0t9czk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LJbKnESF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LJbKnESF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 754F3C4CEFB; Fri, 31 Oct 2025 08:14:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761898468; bh=T7nI7xvtFl7krfWTdP/qjx1BlQ3XmAzSZCU1Kz/Md9c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LJbKnESFg6XyUjYSq7gFteRw1AzLeEOwhq/R1FQ9acELAGb+1lo+BK3K6HG4G/O9k xCbFSxVcLC6lxIA0RrBry1xU4Ny6c2H9iQpJGAXLuYmETlnLIP8hBxSbvlZPayn7P3 pcdWLf2PtvqhAnCGPD2p3hRJ9Lk1gYYEF4knXXJYhNNNRjes5DC7lcoG0kLdNdtV/1 nCEB4VgBWNM6NXS1awmf6VveSzpRC4x8tIriIrbbOk8w5xV8RlXWbSdrKrJV1DsLdn UnSBH3oBfQXE59g/0J4wbD5O4tEdAtNlrTE0qdoi8niaUfHbef0uVckyS7o8sjZq5k qYs5Od5VGpOrQ== Date: Fri, 31 Oct 2025 09:14:25 +0100 From: Krzysztof Kozlowski To: Ashish Mhetre Cc: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, thierry.reding@gmail.com, jonathanh@nvidia.com, jgg@ziepe.ca, nicolinc@nvidia.com, linux-tegra@nvidia.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH 2/3] dt-bindings: iommu: Add NVIDIA Tegra CMDQV support Message-ID: <20251031-witty-sociable-chachalaca-b73dbc@kuoka> References: <20251031062959.1521704-1-amhetre@nvidia.com> <20251031062959.1521704-3-amhetre@nvidia.com> Precedence: bulk X-Mailing-List: linux-tegra@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251031062959.1521704-3-amhetre@nvidia.com> On Fri, Oct 31, 2025 at 06:29:58AM +0000, Ashish Mhetre wrote: > The Command Queue Virtualization (CMDQV) hardware is part of the > SMMUv3 implementation on NVIDIA Tegra SoCs. It assists in > virtualizing the command queue for the SMMU. If this is specific to Nvidia, then I think you need specific front compatible and disallow it for other vendors. > > Add a new device tree binding document for nvidia,tegra264-cmdqv. > > Also update the arm,smmu-v3 binding to include an optional nvidia,cmdqv > property. This property is a phandle to the CMDQV device node, allowing > the SMMU driver to associate with its corresponding CMDQV instance. > > Signed-off-by: Ashish Mhetre > --- > .../bindings/iommu/arm,smmu-v3.yaml | 10 ++++ > .../bindings/iommu/nvidia,tegra264-cmdqv.yaml | 46 +++++++++++++++++++ > 2 files changed, 56 insertions(+) > create mode 100644 Documentation/devicetree/bindings/iommu/nvidia,tegra264-cmdqv.yaml > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > index 75fcf4cb52d9..edc0c20a0c80 100644 > --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > @@ -58,6 +58,15 @@ properties: > > msi-parent: true > > + nvidia,cmdqv: > + description: | > + A phandle to its pairing CMDQV extension for an implementation on NVIDIA > + Tegra SoC. > + > + If this property is absent, CMDQ-Virtualization won't be used and SMMU > + will only use its own CMDQ. > + $ref: /schemas/types.yaml#/definitions/phandle > + > hisilicon,broken-prefetch-cmd: > type: boolean > description: Avoid sending CMD_PREFETCH_* commands to the SMMU. > @@ -92,4 +101,5 @@ examples: > dma-coherent; > #iommu-cells = <1>; > msi-parent = <&its 0xff0000>; > + nvidia,cmdqv = <&cmdqv>; > }; > diff --git a/Documentation/devicetree/bindings/iommu/nvidia,tegra264-cmdqv.yaml b/Documentation/devicetree/bindings/iommu/nvidia,tegra264-cmdqv.yaml > new file mode 100644 > index 000000000000..f22c370278a3 > --- /dev/null > +++ b/Documentation/devicetree/bindings/iommu/nvidia,tegra264-cmdqv.yaml > @@ -0,0 +1,46 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: NVIDIA Tegra264 CMDQV Missing blank line > +description: | Do not need '|' unless you need to preserve formatting. > + The CMDQ-Virtualization hardware block is part of the SMMUv3 implementation > + on Tegra264 SoCs. It assists in virtualizing the command queue for the SMMU. > + > +maintainers: > + - NVIDIA Corporation No. It should be a person. If entire Nvidia cannot find a person, I don't think we are interested in having this in the kernel. > + > +properties: > + compatible: > + const: nvidia,tegra264-cmdqv > + > + reg: > + maxItems: 1 > + > + interrupts: > + maxItems: 1 > + > + interrupt-names: > + items: > + - const: cmdqv Drop interript names, obvious. > + > +required: > + - compatible > + - reg > + - interrupts > + - interrupt-names > + > +additionalProperties: false > + > +examples: > + - | > + #include > + #include > + > + cmdqv: cmdqv@8105200000 { Drop unused label Best regards, Krzysztof