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 AACC0362087; Tue, 9 Sep 2025 16:57:40 +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=1757437062; cv=none; b=TmkBorBOOCrDiyyiKrL6hcE00cjlDakkkso57a6xzNFGEcXj/Ztjwmrj5YS+MSxKdVMMoeVCFNM38o1R6nf/+ABWtXA+0HBw5yqv/8gyX1vwlxqg8/kETxZIA2guol1beFiI2ODMuph7mgxYR3om9sgeSM9cn6ORGV/wUy+jcJk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757437062; c=relaxed/simple; bh=4dSZ165qmpGFOYD4MEJwykS+T7jpCQJECJirqZzh1lA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=p7t3flQB8qZW71WvUS0DRJxpx9sUxgyInrLLwL+ljO+Ts71z4Yf1o9a7b3KJGccEPZALlUyruSC/FRj+RqIV2i/Ehe7hZDbe+l2BlPcX3BjSyKmttRvQm0GDo3Fc4I1xtpY1T57X6uCm5EMsigiv+DpZoqsUGZkGfiS0qsJMriE= 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 BB5762008; Tue, 9 Sep 2025 09:57:31 -0700 (PDT) Received: from [10.1.197.69] (eglon.cambridge.arm.com [10.1.197.69]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C76363F694; Tue, 9 Sep 2025 09:57:33 -0700 (PDT) Message-ID: Date: Tue, 9 Sep 2025 17:57:25 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 18/33] arm_mpam: Merge supported features during mpam_enable() into mpam_class To: Ben Horgan , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, devicetree@vger.kernel.org Cc: shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Rex Nie , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Krzysztof Kozlowski , Conor Dooley , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich References: <20250822153048.2287-1-james.morse@arm.com> <20250822153048.2287-19-james.morse@arm.com> Content-Language: en-GB From: James Morse In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Ben, On 29/08/2025 14:54, Ben Horgan wrote: > On 8/22/25 16:29, James Morse wrote: >> To make a decision about whether to expose an mpam class as >> a resctrl resource we need to know its overall supported >> features and properties. >> >> Once we've probed all the resources, we can walk the tree >> and produce overall values by merging the bitmaps. This >> eliminates features that are only supported by some MSC >> that make up a component or class. >> >> If bitmap properties are mismatched within a component we >> cannot support the mismatched feature. >> >> Care has to be taken as vMSC may hold mismatched RIS. > Intricate but, as far as I can tell, all correct. Yeah - its cpufeature.c all over again. > Reviewed-by: Ben Horgan Thanks! James