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 6308CCAC582 for ; Fri, 12 Sep 2025 10:15:16 +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=vee/TLMNG6EI8Cz9DnAPyhQqR0gceHv7S+20tpt4Xgk=; b=b/Dgx68jVpsmDm82ZZJdFW0YGN YBb/y3ZhLnTh1rFroRoQwjpUqX8Iq075Qn5K6arhlsjBieSurzVcHnl2B+zAgm7Z9e43yICQb+6YW 4tgorvGln5fRUhaPMy/7aUBMmxv7BCoieWSCNJShseGgVEbh4pQtXwkD/9ic3U0h6fjNDwI6TpIhH pRufgKvrplbJNdQcUg3szzYfopo+fJew2EqTmEnwIbnMZdeAf348N3aaROJlwUMUrGAl5QjV8gng3 GGsTQ8EpeAJ0TUt+/C1d1D0eSeemwBi08eGJkt4xw3WIulhSfkGsLkBjTdJ57UMn47xk6Y7A7LK0X eUBsEkBQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1ux0o9-00000008Vmk-15sE; Fri, 12 Sep 2025 10:15:09 +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 1ux0o7-00000008Vko-0h1T for linux-arm-kernel@lists.infradead.org; Fri, 12 Sep 2025 10:15:08 +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 7973916A3; Fri, 12 Sep 2025 03:14:57 -0700 (PDT) Received: from [10.1.196.46] (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 563A93F66E; Fri, 12 Sep 2025 03:15:01 -0700 (PDT) Message-ID: <3a93f4f3-cafc-40f5-b405-d42d5f5c9525@arm.com> Date: Fri, 12 Sep 2025 11:14:59 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 05/29] arm64: kconfig: Add Kconfig entry for MPAM To: James Morse , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: 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 , 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 , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich References: <20250910204309.20751-1-james.morse@arm.com> <20250910204309.20751-6-james.morse@arm.com> From: Ben Horgan Content-Language: en-US In-Reply-To: <20250910204309.20751-6-james.morse@arm.com> 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-20250912_031507_326796_6B8C2B0B X-CRM114-Status: GOOD ( 24.84 ) 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 James, On 9/10/25 21:42, James Morse wrote: > The bulk of the MPAM driver lives outside the arch code because it > largely manages MMIO devices that generate interrupts. The driver > needs a Kconfig symbol to enable it. As MPAM is only found on arm64 > platforms, the arm64 tree is the most natural home for the Kconfig > option. > > This Kconfig option will later be used by the arch code to enable > or disable the MPAM context-switch code, and to register properties > of CPUs with the MPAM driver. > > Signed-off-by: James Morse > Reviewed-by: Jonathan Cameron > CC: Dave Martin > --- > Changes since v1: > * Help text rewritten by Dave. > --- > arch/arm64/Kconfig | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index e9bbfacc35a6..4be8a13505bf 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -2060,6 +2060,29 @@ config ARM64_TLB_RANGE > ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a > range of input addresses. > > +config ARM64_MPAM > + bool "Enable support for MPAM" > + help > + Memory System Resource Partitioning and Monitoring (MPAM) is an > + optional extension to the Arm architecture that allows each > + transaction issued to the memory system to be labelled with a > + Partition identifier (PARTID) and Performance Monitoring Group > + identifier (PMG). > + > + Memory system components, such as the caches, can be configured with > + policies to control how much of various physical resources (such as > + memory bandwidth or cache memory) the transactions labelled with each > + PARTID can consume. Depending on the capabilities of the hardware, > + the PARTID and PMG can also be used as filtering criteria to measure > + the memory system resource consumption of different parts of a > + workload. > + > + Use of this extension requires CPU support, support in the > + Memory System Components (MSC), and a description from firmware > + of where the MSCs are in the address space. > + > + MPAM is exposed to user-space via the resctrl pseudo filesystem. > + > endmenu # "ARMv8.4 architectural features" > > menu "ARMv8.5 architectural features" Seems good to me. I guess we can consider separately whether we want this to be default or not. Reviewed-by: Ben Horgan Thanks, Ben