From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1564606A331 for ; Fri, 6 Nov 2026 15:08:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=LwKT488S; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=IVwKxxUh 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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=Sykp4o/+jigFXiA4+ilYlXp+/rgV6/09mQP79j9S/us=; b=LwKT488S9Mpk+VH8+6Sg8VSbpW wgic3WhcL9/K/3m2qg50Hq6hYS1Co0O52oTDKRxuMJjd5Dmic9QwhdK2yWNpNgV9s1HoB0AnMLWaQ mssLXz25GjPUeRaG+4+gxRqXgORVT+tR1+T7BghM6RCZr+p6sPljR+KJpjGZPPsAxWc6dtdeinQj9 Kg7PMCB0IZ2+sXoifXRERbuWIkpYYDmBjnNje+W/XlatsJFtln1L5XjD73tB43EAHm9zQhKWCSU59 umN+h5+VLgbfVUmlf9rABQ7AwnrlFIYOUqqjUcCC2Hq/1bV9uzO+OUdwwQHYbvvv0m6vwAhJOpPWW OLmRz/kA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xPLYI-0000000Cmdo-3hiA; Fri, 06 Nov 2026 15:08:26 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xPLYH-0000000CmdS-0WPP for linux-arm-kernel@lists.infradead.org; Fri, 06 Nov 2026 15:08:25 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id C60AE402F8; Fri, 6 Nov 2026 15:08:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 741CF1F0089F; Fri, 6 Nov 2026 15:08:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793977704; bh=Sykp4o/+jigFXiA4+ilYlXp+/rgV6/09mQP79j9S/us=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=IVwKxxUhudP6RzHQOzDgbAjaH4xylq1CsAsHRSwnkeemBd9LrNTk96sTCoZ0OQFRG lCe0tZHupUyZ/DJCOM2Ce4zDcIQqqQm/4CavmxGdVTsEeSKqIwKAYU/Gqy/meCssCm PhJJGdUeKjGjgZGJTmlgzpPFVzTM63+ZhFnm72DIe9zV/x+zCRKdn9MiZXEPG5gXzg 3naESWWBaOkM+TI7clfa7v9FbFReidls9Ow1vxOEjmBpWrAj/FO3kCAH667gyZHwdm oSC2FU9s5fM9V96o6A9wQnWQlXzFpy8bHTIguBZVPmJ/4lINSP1lZROuW1No/Az6eN HzN8jiNHe3vFw== Date: Fri, 6 Nov 2026 09:08:22 -0600 From: Rob Herring To: Ping Li Cc: yin.li@oss.qualcomm.com, james.morse@arm.com, ben.horgan@arm.com, sdonthineni@nvidia.com, andre.przywara@arm.com, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/6] arm-mpam: Add basic device tree support for resctrl Message-ID: <20261106150822.GA3193214-robh@kernel.org> References: <20261028-mpam-resctrl-dt-knp-support-v4-0-bdda1e445cba@oss.qualcomm.com> <20261104081302.304667-1-leeonion.muyu@gmail.com> <9d370f12-9e4c-4b80-9d28-ff8085ce3aee@oss.qualcomm.com> <20261105055347.947416-1-leeonion.muyu@gmail.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261105055347.947416-1-leeonion.muyu@gmail.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Thu, Nov 05, 2026 at 01:53:47PM +0800, Ping Li wrote: > Hi Yin, > > Sure. Our memory controller MSC is described as a top-level node. > The MPAM register window is mapped independently in the SoC (the > component sits on the DDR egress path rather than being a sub-block > of a memory-controller DT node), so the node is a direct child of > the root: > > ddr_msc: msc@2238000 { > compatible = ",-ddr-qos", > "arm,mpam-memory-controller-msc", > "arm,mpam-msc"; > reg = <0x0 0x02238000 0x0 0x1000>; > arm,not-ready-us = <10>; > }; > > The first compatible in the list is for our platform glue; I have > replaced it with a placeholder here since it is not relevant to the > binding discussion. > > Notes on the properties, in case they matter for the binding: > > - reg: the MPAM register window. Only a subset of the architectural > register space is implemented, so the size is the truncated window. > - single RIS: the component reports HAS_RIS=0, so there are no > ris@N child nodes. > - no interrupts: the component has no MPAM ESR block, so there is > no interrupts property. > - arm,not-ready-us: 10. > > The verified probe path: the node matches via "arm,mpam-msc", and > patch 6/8 in v3 classifies it as MPAM_CLASS_MEMORY and treats it as > accessible from all CPUs, which is exactly the behavior we need. > > One question in return: with the node being a direct child of the > root rather than a child of a memory-controller node, is that a > form the binding should cover? If the binding expects the MSC to > always be a sub-node of a memory controller, we would need the > top-level form to be allowed as well. This would be why we're not upstreaming the binding without users. We need actual h/w to validate the binding works. Rob