From patchwork Wed Jul 6 10:21:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 1652906 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=txmb5oAo; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by bilbo.ozlabs.org (Postfix) with ESMTP id 4LdFwn1d60z9sGg for ; Wed, 6 Jul 2022 20:22:49 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232641AbiGFKWq (ORCPT ); Wed, 6 Jul 2022 06:22:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233147AbiGFKWW (ORCPT ); Wed, 6 Jul 2022 06:22:22 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B93F326124; Wed, 6 Jul 2022 03:22:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 552BB61DFA; Wed, 6 Jul 2022 10:22:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56115C3411C; Wed, 6 Jul 2022 10:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657102939; bh=SMQcYq8ni/D8jrt39kIE8+5UERyv9ocsQz7ZXYAUkIc=; h=From:To:Cc:Subject:Date:From; b=txmb5oAobChslywtvbJ+gpAXqasBVWhd6fmlE51OsCkOYpAIPcblocnnezSWIrZCA LmFXulu9mSy9W6fxEZTIiFiBYLAxpx4VQTG5BG7N++VYgmAPWq499lxsP2E+gadJg/ U7VJVjLZ2p2yylClQFtvinkB3mYF8fukQ9TAgp0aTPChyscJ9YH0F+o/LiayPDyhRS 7sDelXC3ceihiXBqc4dnA4Ex6lutvhNvKcuZ+l+FFhXDh1+HhlAxmBnoVdOCU92Yq0 ZdTRaEPN1YoAvu9tyl3Fp0KTwR3e1s/DRFbdr3mIHDOabZ6HbAg2nP5fR3CIyose/3 uecTIOhge4t3g== Received: by pali.im (Postfix) id D5CD77BA; Wed, 6 Jul 2022 12:22:16 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , "Guilherme G. Piccoli" , Bjorn Helgaas , Guowen Shan , Tyrel Datwyler Cc: linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] powerpc/pci: Add config option for using OF 'reg' for PCI domain Date: Wed, 6 Jul 2022 12:21:47 +0200 Message-Id: <20220706102148.5060-1-pali@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Spam-Status: No, score=-7.8 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Since commit 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties"), powerpc kernel always fallback to PCI domain assignment from OF / Device Tree 'reg' property of the PCI controller. In most cases 'reg' property is not zero and therefore there it cause that PCI domain zero is not present in system anymore. PCI code for other Linux architectures use increasing assignment of the PCI domain for individual controllers (assign the first free number), like it was also for powerpc prior mentioned commit. Also it starts numbering domains from zero. Upgrading powerpc kernels from LTS 4.4 version (which does not contain mentioned commit) to new LTS versions brings a change in domain assignment. It can be problematic for embedded machines with single PCIe controller where it is expected that PCIe card is connected on the domain zero. Also it can be problematic as that commit changes PCIe domains in multi-controller setup with fixed number of controller (without hotplug support). Originally that change was intended for powernv and pservers and specially server machines with more PCI domains or hot plug support. Fix this issue and introduce a new option CONFIG_PPC_PCI_DOMAIN_FROM_OF_REG. When this option is disabled then powerpc kernel would assign PCI domains in the similar way like it is doing kernel for other architectures, starting from zero and also how it was done prior that commit. This option is by default enabled for powernv and pseries platform for which was that commit originally intended. With this change upgrading kernels from LTS 4.4 version does not change PCI domain on smaller embedded platforms with fixed number of PCIe controllers. And also ensure that PCI domain zero is present as before that commit. Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties") Signed-off-by: Pali Rohár Reviewed-by: Guilherme G. Piccoli --- Changes in v2: * Enable CONFIG_PPC_PCI_DOMAIN_FROM_OF_REG by default on powernv and pseries --- arch/powerpc/Kconfig | 11 +++++++++++ arch/powerpc/kernel/pci-common.c | 4 ++-- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index f66084bc1dfe..053a88e84049 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -386,6 +386,17 @@ config PPC_OF_PLATFORM_PCI depends on PCI depends on PPC64 # not supported on 32 bits yet +config PPC_PCI_DOMAIN_FROM_OF_REG + bool "Use OF reg property for PCI domain" + depends on PCI + default y if PPC_PSERIES || PPC_POWERNV + help + By default PCI domain for host bridge during its registration is + chosen as the lowest unused PCI domain number. + + When this option is enabled then PCI domain can be determined + also from lower bits of the OF / Device Tree 'reg' property. + config ARCH_SUPPORTS_UPROBES def_bool y diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 068410cd54a3..7f959df34833 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -74,7 +74,6 @@ void __init set_pci_dma_ops(const struct dma_map_ops *dma_ops) static int get_phb_number(struct device_node *dn) { int ret, phb_id = -1; - u32 prop_32; u64 prop; /* @@ -83,7 +82,8 @@ static int get_phb_number(struct device_node *dn) * reading "ibm,opal-phbid", only present in OPAL environment. */ ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop); - if (ret) { + if (ret && IS_ENABLED(CONFIG_PPC_PCI_DOMAIN_FROM_OF_REG)) { + u32 prop_32; ret = of_property_read_u32_index(dn, "reg", 1, &prop_32); prop = prop_32; }