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 5F98DD6ACDC for ; Thu, 18 Dec 2025 10:38:56 +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:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lZD14hx6Q84bvnu6zDw0ForMMp+V0B0wC7tel4GpwgA=; b=jqWNssmL8CMeSrp+SA3zrCTsyZ Z6X7mRJ8Go0bEQOZtt73KAHGeNCHsFvVDqITR09tAtJBWsLsqAsxpZ4f7z3n6SeXiCS7TZRp9SM5S QmeN8S5VinxJMgiiNd6u6/hbvSGX8eKAqYnUbqT1ISOQ5i77++enCmXJqtdZoywGmpbvJ77iQ9/x5 IPSj4aSC7ke04oFSczjv4uZ5TNcqeP8Bva/iMUaY9BXkDRWb0zV6iMYqN5GiY72I2vPYbMjsliu78 n3Hhqb3ZL3KfXYIWOIWopYMPbhSld9Asq15aLox+hoEdJU7NdGaiRn5EUk1ZfrXbNd8RcGY5Uy3MI M+YE3caQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWBPI-00000008FCJ-3sZu; Thu, 18 Dec 2025 10:38:52 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vWBPG-00000008FBt-1hlp for linux-arm-kernel@lists.infradead.org; Thu, 18 Dec 2025 10:38:51 +0000 Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dX6Zc758kzJ46CP; Thu, 18 Dec 2025 18:38:16 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id CC6DC40539; Thu, 18 Dec 2025 18:38:47 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Thu, 18 Dec 2025 10:38:46 +0000 Date: Thu, 18 Dec 2025 10:38:45 +0000 From: Jonathan Cameron To: James Morse CC: , , D Scott Phillips OS , , , , , , Jamie Iles , "Xin Hao" , , , , David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , , , Gavin Shan , Ben Horgan , , , Punit Agrawal Subject: Re: [RFC PATCH 03/38] arm64: mpam: Advertise the CPUs MPAM limits to the driver Message-ID: <20251218103845.000053b3@huawei.com> In-Reply-To: <20251205215901.17772-4-james.morse@arm.com> References: <20251205215901.17772-1-james.morse@arm.com> <20251205215901.17772-4-james.morse@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml100011.china.huawei.com (7.191.174.247) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251218_023850_612453_4DF8508F X-CRM114-Status: GOOD ( 12.98 ) 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 On Fri, 5 Dec 2025 21:58:26 +0000 James Morse wrote: > Requestors need to populate the MPAM fields for any traffic they send > on the interconnect. For the CPUs these values are taken from the > corresponding MPAMy_ELx register. Each requestor may have a limit on > the largest PARTID or PMG value that can be used. The MPAM driver has > to determine the system-wide minimum supported PARTID and PMG values. > > To do this, the driver needs to be told what each requestor's > limit is. Trivial but this commit message line wrap isn't very consistent. > > CPUs are special, but this infrastructure is also needed for the > SMMU and GIC ITS. Call the helper to tell the MPAM driver what the > CPUs can do. > > The return value can be ignored by the arch code as it runs well > before the MPAM driver starts probing. > > Signed-off-by: James Morse