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 44262C83F07 for ; Mon, 7 Jul 2025 09:56:15 +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=CicbBdC208vKhBivE60UBC2n+cr2IO5c+q2qDbrd2Ig=; b=Kh57OTAlJowkWloI2chv+Vdw2/ BsZg/EQfcSM3yoO3ALB598me81jJ1TqlaVZSxqrfuEP5/5z/i+fvNDAce7PD6/kbGT9Eaheb+/wfH 42q0MuJx6TCJ+ZjwRiT0Z3yEaKF9qp0zvn72z2BHn/rx3rj5ZQiN03TgIkbvBRCeoKkKfoPl/0a2Q 2l1wr4HrY1v5kinw9+HEFiH681ee/KwL/Xw0u/QsVpb6vVc5e/IWpHA4K6AVQH0Txdks5+EVVXP5K SrDyX57m8xrj6nbIXewbaxTTtJmLNvw8n41ie+PZ0bOA+P180HIOt4kDnqwsg/iHO6KyeP/qdAGSb bp/pwLng==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uYia1-0000000246C-1TBd; Mon, 07 Jul 2025 09:56:09 +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 1uYiFQ-00000001zri-0rtq for linux-arm-kernel@lists.infradead.org; Mon, 07 Jul 2025 09:34:54 +0000 Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4bbJsM5F1Wz6L5H5; Mon, 7 Jul 2025 17:31:35 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 15D311402F0; Mon, 7 Jul 2025 17:34:42 +0800 (CST) Received: from localhost (10.203.177.66) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Mon, 7 Jul 2025 11:34:41 +0200 Date: Mon, 7 Jul 2025 10:34:40 +0100 From: Jonathan Cameron To: James Morse CC: , , Greg Kroah-Hartman , "Rafael J . Wysocki" , , Rob Herring , Ben Horgan , Catalin Marinas , Subject: Re: [PATCH v2 1/3] cacheinfo: Set cache 'id' based on DT data Message-ID: <20250707103440.000048ff@huawei.com> In-Reply-To: <20250704173826.13025-2-james.morse@arm.com> References: <20250704173826.13025-1-james.morse@arm.com> <20250704173826.13025-2-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: [10.203.177.66] X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To frapeml500008.china.huawei.com (7.182.85.71) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250707_023452_393618_2175F821 X-CRM114-Status: GOOD ( 14.16 ) 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, 4 Jul 2025 17:38:24 +0000 James Morse wrote: > From: Rob Herring > > Use the minimum CPU h/w id of the CPUs associated with the cache for the > cache 'id'. This will provide a stable id value for a given system. As > we need to check all possible CPUs, we can't use the shared_cpu_map > which is just online CPUs. As there's not a cache to CPUs mapping in DT, > we have to walk all CPU nodes and then walk cache levels. > > The cache_id exposed to user-space has historically been 32 bits, and > is too late to change. This value is parsed into a u32 by user-space > libraries such as libvirt: > https://github.com/libvirt/libvirt/blob/master/src/util/virresctrl.c#L1588 > > Give up on assigning cache-id's if a CPU h/w id greater than 32 bits > is found. > > Cc: Greg Kroah-Hartman > Cc: "Rafael J. Wysocki" > Signed-off-by: Rob Herring > [ ben: converted to use the __free cleanup idiom ] > Signed-off-by: Ben Horgan > [ morse: Add checks to give up if a value larger than 32 bits is seen. ] > Signed-off-by: James Morse Reviewed-by: Jonathan Cameron