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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED115C04AA5 for ; Thu, 25 Aug 2022 07:49:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238542AbiHYHtn (ORCPT ); Thu, 25 Aug 2022 03:49:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233991AbiHYHtk (ORCPT ); Thu, 25 Aug 2022 03:49:40 -0400 Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A271A0333; Thu, 25 Aug 2022 00:49:38 -0700 (PDT) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4MCw8s2Q2rz4xV7; Thu, 25 Aug 2022 17:49:33 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1661413773; bh=k/K7Js7dK6dxOfVTDaXcqeIh7AqfvCWAPYJNJN8qsTQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=DccTqgAEj8cQsbTwecf0Jayd3dBrvqd6U8m1Lt7V86aEL++OLOLr5xIxGu99atBxI 8Op6ppf0sepvXsD0m6OkdhzaHfgImYUmJPGiLiq3nJiq3ntzUck+GTN3FvFJV27GEU 4w0hN5KCHxMDg62pj4Q+gPJPSNhBdDSy7LVx3iHwYtaZaFf76dZGxLlkVEdYTsuVes cPfKQfSYwJCazV/Fwg8Wr1BfDBHuNGe+IzPBEfhXpzHVzAtNwu/5Xk0J6aE7z/Syo7 WRJmfyOLeFBd2IapKcyLn3WNadQqoAlge4tptmNzYmzmPjrBmjIwoZb83LvI3srdMO Qu38O06uVNhzg== From: Michael Ellerman To: Pali =?utf-8?Q?Roh=C3=A1r?= , Benjamin Herrenschmidt , Paul Mackerras Cc: linuxppc-dev@lists.ozlabs.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] powerpc/pci: Enable PCI domains in /proc when PCI bus numbers are not unique In-Reply-To: <20220820115113.30581-1-pali@kernel.org> References: <20220820115113.30581-1-pali@kernel.org> Date: Thu, 25 Aug 2022 17:49:28 +1000 Message-ID: <878rnclq47.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pali Roh=C3=A1r 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=3Dy and CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT=3Dy > 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. cheers > Fixes: 566356813082 ("powerpc/pci: Add config option for using all 256 PC= I buses") > Signed-off-by: Pali Roh=C3=A1r > --- > arch/powerpc/kernel/pci_32.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c > index ffc4e1928c80..8acbc9592ebb 100644 > --- a/arch/powerpc/kernel/pci_32.c > +++ b/arch/powerpc/kernel/pci_32.c > @@ -249,6 +249,15 @@ static int __init pcibios_init(void) >=20=20 > printk(KERN_INFO "PCI: Probing PCI hardware\n"); >=20=20 > +#ifdef CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT > + /* > + * Enable PCI domains in /proc when PCI bus numbers are not unique > + * across all PCI domains to prevent conflicts. And keep PCI domain 0 > + * backward compatible in /proc for video cards. > + */ > + pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0); > +#endif > + > if (pci_has_flag(PCI_REASSIGN_ALL_BUS)) > pci_assign_all_buses =3D 1; >=20=20 > --=20 > 2.20.1