From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 37BB481723; Tue, 19 Mar 2024 13:53:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710856420; cv=none; b=E37sCljsOah45leqNovwdv6x+8dpgCkbz/nc5ISD47HlocfA4esK4sURQ2iYt0OH3fEbQZeubCnSOVYFcjZ7mw6GKZf0d3XuoKcPdFMVlTJqR/cUa3saVKfyjUX9CcRLg0xtRDALYKAkSe7yxhVVUM56hJcVzBKxKC0g7ZFnG2M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710856420; c=relaxed/simple; bh=l1tlpDCQ2bSEpQZ9E3s9/g28w3A6nWny3ZLXbyWSsDQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uVW/jqh8yCp3N6/zeAq+ViFeDeB6lziP/yAcVEz8QwKlQ35zOSJgGXbPVgSHcpx2LCfLdCoIXjkTS9XDEKjl9o8ulpj4IxQOefUlTqIgM/ghuhYtC55LrCw88VWrnTOz70sFEGsn2C5AYT5IZ1aK9/XKQx8pj1I7ycoWcSJ0VOs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5F600106F; Tue, 19 Mar 2024 06:54:12 -0700 (PDT) Received: from [10.57.52.192] (unknown [10.57.52.192]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 123473F762; Tue, 19 Mar 2024 06:53:34 -0700 (PDT) Message-ID: <9b2a681e-1191-4cf7-8da7-14aa2c1fa455@arm.com> Date: Tue, 19 Mar 2024 13:53:32 +0000 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/2] dt-bindings: iommu: arm,smmu-v3: Add SC8280XP compatible Content-Language: en-GB To: Konrad Dybcio , Bjorn Andersson , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Will Deacon , Joerg Roedel , Rob Herring Cc: Marijn Suijten , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, Johan Hovold References: <20231219-topic-8280_smmuv3-v2-0-c67bd3226687@linaro.org> <20231219-topic-8280_smmuv3-v2-1-c67bd3226687@linaro.org> From: Robin Murphy In-Reply-To: <20231219-topic-8280_smmuv3-v2-1-c67bd3226687@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2024-03-09 1:31 pm, Konrad Dybcio wrote: > The smmu-v3 binding currently doesn't differentiate the SoCs it's > implemented on. This is a poor design choice that may bite in the future, > should any quirks surface. That doesn't seem entirely fair to say - the vast majority of bindings don't have separate compatibles for every known integration of the same implementation in different SoCs. And in this case we don't have per-implementation compatibles for quirks and errata because the implementation is architecturally discoverable from the SMMU_IIDR register. We have the whole mess for QCom SMMUv2 because the effective *implementation* is a mix of hardware and hypervisor, whose behaviour does seem to vary on almost a per-SoC basis. I'm not at all keen to start repeating that here without very good reason, and that of "documenting" a device which we typically expect to not even be accessible isn't really convincing me... Thanks, Robin. > > Add a compatible for the instance found on Qualcomm SC8280XP. > > Signed-off-by: Konrad Dybcio > --- > Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > index 75fcf4cb52d9..f284f7b0c1d8 100644 > --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.yaml > @@ -20,7 +20,11 @@ properties: > $nodename: > pattern: "^iommu@[0-9a-f]*" > compatible: > - const: arm,smmu-v3 > + oneOf: > + - items: > + - const: qcom,sc8280xp-smmu-v3 > + - const: arm,smmu-v3 > + - const: arm,smmu-v3 > > reg: > maxItems: 1 >