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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 3E044ECAAD1 for ; Thu, 1 Sep 2022 07:25:34 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4MJCHw4wkzz2xkn for ; Thu, 1 Sep 2022 17:25:32 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=Deo+YD+Q; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=145.40.73.55; helo=sin.source.kernel.org; envelope-from=pali@kernel.org; receiver=) Authentication-Results: lists.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=Deo+YD+Q; dkim-atps=neutral Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4MJCHG20PJz2xGR for ; Thu, 1 Sep 2022 17:24:58 +1000 (AEST) 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 sin.source.kernel.org (Postfix) with ESMTPS id 1F0F7CE246D; Thu, 1 Sep 2022 07:24:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC12FC433D6; Thu, 1 Sep 2022 07:24:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662017093; bh=stL9+yzK0zgdLie5xf0hjyraAlajedBKEBb65rMMvRw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Deo+YD+Qtg4Ei+JHnT2yXSe+uKnWw8TmyJIetCBkvgsk1Q7LlzsyoYoLTsOfoIi9H OwhDTSuHW6wmK1UEXZdoB3V1y6jPaa6Gnl+RYAHD8O9Y3LVX5IfL7CRFiOeksw36Wm EYmdTybxXyum1jTy27Dch3Ul5cE/l8TcGSQ6IV0XZkNiYbEcW7Nus1P8ePSG+R584J ytYy7VQ/lm2hstwOzR4PGDiapbPxiRVClotXRc2TZgKCgbQB6oL7YeI8VElF+RKMDD D5IhD/lqXpNx9SApSSGxj9pQdWDifYzzwY17Ei+NamHJpcHkmogcZb4K3wswvbiX13 GO2I5M6b6Bowg== Received: by pali.im (Postfix) id E3E127B8; Thu, 1 Sep 2022 09:24:49 +0200 (CEST) Date: Thu, 1 Sep 2022 09:24:49 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Michael Ellerman Subject: Re: [PATCH] powerpc/pci: Enable PCI domains in /proc when PCI bus numbers are not unique Message-ID: <20220901072449.hswlq5fpnqrhgvcf@pali> References: <20220820115113.30581-1-pali@kernel.org> <878rnclq47.fsf@mpe.ellerman.id.au> <20220825083713.4glfivegmodluiun@pali> <87wnanu4vf.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87wnanu4vf.fsf@mpe.ellerman.id.au> User-Agent: NeoMutt/20180716 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thursday 01 September 2022 13:53:56 Michael Ellerman wrote: > Pali Rohár writes: > > On Thursday 25 August 2022 17:49:28 Michael Ellerman wrote: > >> Pali Rohár writes: > >> > On 32-bit powerpc systems with more PCIe controllers and more PCI domains, > >> > where on more PCI domains are same PCI numbers, when kernel is compiled > >> > with CONFIG_PROC_FS=y and CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT=y > >> > options, kernel prints "proc_dir_entry 'pci/01' already registered" error > >> > message. > >> > >> Thanks, I'll pick this up. > >> > >> > This regression started appearing after commit 566356813082 ("powerpc/pci: > >> > Add config option for using all 256 PCI buses") in case in each mPCIe slot > >> > is connected PCIe card and therefore PCI bus 1 is populated in for every > >> > PCIe controller / PCI domain. > >> > > >> > The reason is that PCI procfs code expects that when PCI bus numbers are > >> > not unique across all PCI domains, function pci_proc_domain() returns true > >> > for domain dependent buses. > >> > > >> > Fix this issue by setting PCI_ENABLE_PROC_DOMAINS and PCI_COMPAT_DOMAIN_0 > >> > flags for 32-bit powerpc code when CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT > >> > is enabled. Same approach is already implemented for 64-bit powerpc code > >> > (where PCI bus numbers are always domain dependent). > >> > >> We also have the same in ppc4xx_pci_find_bridges(). > >> > >> And if we can eventually make CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT > >> the standard behaviour on 32-bit then everything would behave the same > >> and we could simplify pci_proc_domain() to match what other arches do. > > > > I sent two patches which do another steps to achieve it: > > https://lore.kernel.org/linuxppc-dev/20220817163927.24453-1-pali@kernel.org/t/#u > > > > Main blocker is pci-OF-bus-map which is in direct conflict with > > CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT and which used on chrp and pmac. > > And I have no idea if pci-OF-bus-map is still needed or not. > > Yeah thanks, I saw those patches. > > I can't find any code that refers to pci-OF-bus-map, so I'm inclined to > remove it entirely. > > But I'll do some more searching to see if I can find any references to > it in old code. > > cheers >From the code itself I have feeling that some external programs or maybe some firmware can access or use this property. But I have really no idea.