From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BF815CA0FED for ; Tue, 9 Sep 2025 17:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=4dSZ165qmpGFOYD4MEJwykS+T7jpCQJECJirqZzh1lA=; b=vSpP/JeKHAlRnPPaDhShL9o+0i YOmV59bC4Slfo9RrRJlxptnAYsFk0KRtNA/2xA1rF8tM7QCVJE9ynaSAPvtMKwX9EWxSxzvQTMkPf jGYtFDxlLBIthRveLt08Qu+rWlc3HjTRLcwCh/BGXStrSB26ZbCuTel9C0X8MB3lgP1VJw9fmHVEk ey9A66J7tL3iwNYyxiXCDMbCSDRg2aEaVYcdxQh7mlPArZWPvWNvbjMSDiudAU1bmIxR9ubBmBTQK YjRJudtpVVXpjTdNNU4PFd6kB9Us5d/03SCHAZTmGVcAzFiG+1ddfN03AIaXf2IEKJF3TTIdrv8iR NrC3HLIw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uw27Q-000000096eu-2FKV; Tue, 09 Sep 2025 17:27:00 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uw1f2-00000008h3C-3BbE for linux-arm-kernel@lists.infradead.org; Tue, 09 Sep 2025 16:57:42 +0000 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 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250909_095740_843500_8C8E8C6C X-CRM114-Status: GOOD ( 10.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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