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,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 0D4D4C433DB for ; Mon, 15 Mar 2021 14:29:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D18BF64D9A for ; Mon, 15 Mar 2021 14:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234821AbhCOO3R (ORCPT ); Mon, 15 Mar 2021 10:29:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:37522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231975AbhCOOAX (ORCPT ); Mon, 15 Mar 2021 10:00:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 55F9F64EFD; Mon, 15 Mar 2021 14:00:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816806; bh=6OhngbGwqvsnATk/KIC5F1A9jZo516TfcwsKiUsPGBI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UcltqmveBYHeUFDksWWFILrF6VESZCnr7e0JYp6s6ud1juLXmQffAAXvGgf8iTh1Z DktiNRuF/R2zL5vaeE3db+Dbg/yW+pKrp9AinAORypOkx5zAsPIG/L9xtxWirUU3pv vWH2NO3CN42sOXBhvXPFgmCgQtolihNxaqcdJc3w= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , Oliver OHalloran , Michael Ellerman , Sasha Levin Subject: [PATCH 5.11 136/306] powerpc/pci: Add ppc_md.discover_phbs() Date: Mon, 15 Mar 2021 14:53:19 +0100 Message-Id: <20210315135512.246764515@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135507.611436477@linuxfoundation.org> References: <20210315135507.611436477@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman 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 cf6ebbc16cb4..764f2732a821 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 2b555997b295..001e90cd8948 100644 --- a/arch/powerpc/kernel/pci-common.c +++ b/arch/powerpc/kernel/pci-common.c @@ -1699,3 +1699,13 @@ 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