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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 F2C5BC43142 for ; Wed, 3 Mar 2021 00:47:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC62164FC3 for ; Wed, 3 Mar 2021 00:47:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239888AbhCCA3d (ORCPT ); Tue, 2 Mar 2021 19:29:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:52414 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1447025AbhCBMmG (ORCPT ); Tue, 2 Mar 2021 07:42:06 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4D42764F7C; Tue, 2 Mar 2021 11:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614686281; bh=K/seB1ZTNbXTRxaVsRjdXI4F5uY5bqo3gY/KwSsYDZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IeeqihxIC7Jh+s2hJCfLL/lStS6PeJxCjYxnZMkO5BrQQTQ8xhdEY/imSpB/uDqD1 be8W390CHrOwp6ADkY1MvkLaZtB2fIUvA8xs3BRI8dCIFeR6n0m+JLfvVAD56Jr/+n sA/SrwCnY9bPGRvlGJrnQDr6gbiV+KoOgz3EzbkXUgz3gQ5M3mJGRz54uEPmw9D7LL kWBr02uOk2zr1pfAIhXumVzI1ZGsyxk6+045k2rEdlnw+f4zLZ+aJH3B7P8rIiBiNK trpcYfKr+r9OIngDOZ89VLCMct1WyPAk0wvAG8fgBEWn38T6uCm0paL7eP3/7is8Zh 8nA76MEv/aOXA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oliver O'Halloran , kernel test robot , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.4 08/33] powerpc/pci: Add ppc_md.discover_phbs() Date: Tue, 2 Mar 2021 06:57:24 -0500 Message-Id: <20210302115749.62653-8-sashal@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210302115749.62653-1-sashal@kernel.org> References: <20210302115749.62653-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Oliver O'Halloran [ Upstream commit 5537fcb319d016ce387f818dd774179bc03217f5 ] On many powerpc platforms the discovery and initalisation of pci_controllers (PHBs) happens inside of setup_arch(). This is very early in boot (pre-initcalls) and means that we're initialising the PHB long before many basic kernel services (slab allocator, debugfs, a real ioremap) are available. On PowerNV this causes an additional problem since we map the PHB registers with ioremap(). As of commit d538aadc2718 ("powerpc/ioremap: warn on early use of ioremap()") a warning is printed because we're using the "incorrect" API to setup and MMIO mapping in searly boot. The kernel does provide early_ioremap(), but that is not intended to create long-lived MMIO mappings and a seperate warning is printed by generic code if early_ioremap() mappings are "leaked." This is all fixable with dumb hacks like using early_ioremap() to setup the initial mapping then replacing it with a real ioremap later on in boot, but it does raise the question: Why the hell are we setting up the PHB's this early in boot? The old and wise claim it's due to "hysterical rasins." Aside from amused grapes there doesn't appear to be any real reason to maintain the current behaviour. Already most of the newer embedded platforms perform PHB discovery in an arch_initcall and between the end of setup_arch() and the start of initcalls none of the generic kernel code does anything PCI related. On powerpc scanning PHBs occurs in a subsys_initcall so it should be possible to move the PHB discovery to a core, postcore or arch initcall. This patch adds the ppc_md.discover_phbs hook and a core_initcall stub that calls it. The core_initcalls are the earliest to be called so this will any possibly issues with dependency between initcalls. This isn't just an academic issue either since on pseries and PowerNV EEH init occurs in an arch_initcall and depends on the pci_controllers being available, similarly the creation of pci_dns occurs at core_initcall_sync (i.e. between core and postcore initcalls). These problems need to be addressed seperately. Reported-by: kernel test robot Signed-off-by: Oliver O'Halloran [mpe: Make discover_phbs() static] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201103043523.916109-1-oohall@gmail.com Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/machdep.h | 3 +++ arch/powerpc/kernel/pci-common.c | 10 ++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h index 7bcb64444a39..f71c361dc356 100644 --- a/arch/powerpc/include/asm/machdep.h +++ b/arch/powerpc/include/asm/machdep.h @@ -59,6 +59,9 @@ struct machdep_calls { int (*pcibios_root_bridge_prepare)(struct pci_host_bridge *bridge); + /* finds all the pci_controllers present at boot */ + void (*discover_phbs)(void); + /* To setup PHBs when using automatic OF platform driver for PCI */ int (*pci_setup_phb)(struct pci_controller *host); diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c index 1c448cf25506..a2c258a8d736 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1669,3 +1669,13 @@ static void fixup_hide_host_resource_fsl(struct pci_dev *dev) } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MOTOROLA, PCI_ANY_ID, fixup_hide_host_resource_fsl); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID, fixup_hide_host_resource_fsl); + + +static int __init discover_phbs(void) +{ + if (ppc_md.discover_phbs) + ppc_md.discover_phbs(); + + return 0; +} +core_initcall(discover_phbs); -- 2.30.1