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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92E8EC072B1 for ; Tue, 28 May 2019 11:32:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75E88206C1 for ; Tue, 28 May 2019 11:32:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726688AbfE1LcW (ORCPT ); Tue, 28 May 2019 07:32:22 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:33632 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726234AbfE1LcW (ORCPT ); Tue, 28 May 2019 07:32:22 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 66B21B82AD9FDEAAE061; Tue, 28 May 2019 19:32:19 +0800 (CST) Received: from localhost (10.202.226.61) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Tue, 28 May 2019 19:32:09 +0800 Date: Tue, 28 May 2019 12:31:58 +0100 From: Jonathan Cameron To: , , , CC: =?ISO-8859-1?Q?J=E9r=F4me?= Glisse , Keith Busch , "Rafael J . Wysocki" , , Andrew Morton Subject: Re: [PATCH 0/4 V3] ACPI: Support generic initiator proximity domains Message-ID: <20190528123158.0000167a@huawei.com> In-Reply-To: <20190415174907.102307-1-Jonathan.Cameron@huawei.com> References: <20190415174907.102307-1-Jonathan.Cameron@huawei.com> Organization: Huawei X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.61] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi All, Anyone had a change to take a look at this? Thanks, Jonathan On Tue, 16 Apr 2019 01:49:03 +0800 Jonathan Cameron wrote: > Changes since RFC V2. > * RFC dropped as now we have x86 support, so the lack of guards in in the > ACPI code etc should now be fine. > * Added x86 support. Note this has only been tested on QEMU as I don't have > a convenient x86 NUMA machine to play with. Note that this fitted together > rather differently form arm64 so I'm particularly interested in feedback > on the two solutions. > > Since RFC V1. > * Fix incorrect interpretation of the ACPI entry noted by Keith Busch > * Use the acpica headers definitions that are now in mmotm. > > It's worth noting that, to safely put a given device in a GI node, may > require changes to the existing drivers as it's not unusual to assume > you have local memory or processor core. There may be futher constraints > not yet covered by this patch. > > Original cover letter... > > ACPI 6.3 introduced a new entity that can be part of a NUMA proximity domain. > It may share such a domain with the existing options (memory, cpu etc) but it > may also exist on it's own. > > The intent is to allow the description of the NUMA properties (particulary > via HMAT) of accelerators and other initiators of memory activity that are not > the host processor running the operating system. > > This patch set introduces 'just enough' to make them work for arm64 and x86. > It should be trivial to support other architectures, I just don't suitable > NUMA systems readily available to test. > > There are a few quirks that need to be considered. > > 1. Fall back nodes > ****************** > > As pre ACPI 6.3 supporting operating systems do not have Generic Initiator > Proximity Domains it is possible to specify, via _PXM in DSDT that another > device is part of such a GI only node. This currently blows up spectacularly. > > Whilst we can obviously 'now' protect against such a situation (see the related > thread on PCI _PXM support and the threadripper board identified there as > also falling into the problem of using non existent nodes > https://patchwork.kernel.org/patch/10723311/ ), there is no way to be sure > we will never have legacy OSes that are not protected against this. It would > also be 'non ideal' to fallback to a default node as there may be a better > (non GI) node to pick if GI nodes aren't available. > > The work around is that we also have a new system wide OSC bit that allows > an operating system to 'annouce' that it supports Generic Initiators. This > allows, the firmware to us DSDT magic to 'move' devices between the nodes > dependent on whether our new nodes are there or not. > > 2. New ways of assigning a proximity domain for devices > ******************************************************* > > Until now, the only way firmware could indicate that a particular device > (outside the 'special' set of cpus etc) was to be found in a particular > Proximity Domain by the use of _PXM in DSDT. > > That is equally valid with GI domains, but we have new options. The SRAT > affinity structure includes a handle (ACPI or PCI) to identify devices > with the system and specify their proximity domain that way. If both _PXM > and this are provided, they should give the same answer. > > For now this patch set completely ignores that feature as we don't need > it to start the discussion. It will form a follow up set at some point > (if no one else fancies doing it). > > Jonathan Cameron (4): > ACPI: Support Generic Initiator only domains > arm64: Support Generic Initiator only domains > x86: Support Generic Initiator only proximity domains > ACPI: Let ACPI know we support Generic Initiator Affinity Structures > > arch/arm64/kernel/smp.c | 8 +++++ > arch/x86/include/asm/numa.h | 2 ++ > arch/x86/kernel/setup.c | 1 + > arch/x86/mm/numa.c | 14 ++++++++ > drivers/acpi/bus.c | 1 + > drivers/acpi/numa.c | 62 +++++++++++++++++++++++++++++++++- > drivers/base/node.c | 3 ++ > include/asm-generic/topology.h | 3 ++ > include/linux/acpi.h | 1 + > include/linux/nodemask.h | 1 + > include/linux/topology.h | 7 ++++ > 11 files changed, 102 insertions(+), 1 deletion(-) >