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 71CE1C433EF for ; Fri, 7 Jan 2022 18:18:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348801AbiAGSSY (ORCPT ); Fri, 7 Jan 2022 13:18:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348834AbiAGSSX (ORCPT ); Fri, 7 Jan 2022 13:18:23 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 838A8C061574; Fri, 7 Jan 2022 10:18:23 -0800 (PST) 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 D537761F8C; Fri, 7 Jan 2022 18:18:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F5C8C36AE0; Fri, 7 Jan 2022 18:18:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641579502; bh=uOEOl/NwRA3PkSryb0Xx+c1DctY6qveaChGe30yKiWs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lAXkRk1kurXScMSVF1vdjDUZa6d6WKgp/GPeEcCR7b8nS6Xclc6WhWjpiAxlIoBhh Ssx0jlaZnsFYcx0JMHq34YsKtwSXjaarpEbTWBFm25j4Rl6NjJKGa4Vrs6OLtNNHTc Y+b57HMpGS0yeAD1J2HJP8KeUtF/HkdW2ANosLzVOjuANsUEXhr5i0VzVpxD9OMmH8 iL3h1XxZTNia6orD1ZH6NsAjCvuiTdvTDkgOuMI63XzIfREwEtPgx4zYCj2cOFMcNy jsfFJkEUlpdyJdj9cd+kFovuV0V1hcEY7d0vjnYJ9Cd03rF6bsJOizaxAcYMC0InfV 62N4Sjr3oi5Ig== Received: by pali.im (Postfix) id 7AF42B22; Fri, 7 Jan 2022 19:18:19 +0100 (CET) Date: Fri, 7 Jan 2022 19:18:19 +0100 From: Pali =?utf-8?B?Um9ow6Fy?= To: Bjorn Helgaas Cc: Thomas Petazzoni , Lorenzo Pieralisi , Rob Herring , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Bjorn Helgaas , Marek =?utf-8?B?QmVow7pu?= , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/15] PCI: mvebu: Check that PCI bridge specified in DT has function number zero Message-ID: <20220107181819.yiya3mxhtfsnubg4@pali> References: <20211125124605.25915-4-pali@kernel.org> <20220107181512.GA390598@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220107181512.GA390598@bhelgaas> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Friday 07 January 2022 12:15:12 Bjorn Helgaas wrote: > On Thu, Nov 25, 2021 at 01:45:53PM +0100, Pali Rohár wrote: > > Driver cannot handle PCI bridges at non-zero function address. So add > > appropriate check. Currently all in-tree kernel DTS files set PCI bridge > > function to zero. > > Why can the driver not handle bridges at non-zero function addresses? > The PCI spec allows that, doesn't it? Is this a hardware limitation? It is software / kernel limitation. Because this bridge is virtual, emulated by pci-bridge-emul.c driver and this driver can emulate only single function PCI-to-PCI bridge device. > > Signed-off-by: Pali Rohár > > Cc: stable@vger.kernel.org > > --- > > drivers/pci/controller/pci-mvebu.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c > > index 6197f7e7c317..08274132cdfb 100644 > > --- a/drivers/pci/controller/pci-mvebu.c > > +++ b/drivers/pci/controller/pci-mvebu.c > > @@ -864,6 +864,11 @@ static int mvebu_pcie_parse_port(struct mvebu_pcie *pcie, > > port->devfn = of_pci_get_devfn(child); > > if (port->devfn < 0) > > goto skip; > > + if (PCI_FUNC(port->devfn) != 0) { > > + dev_err(dev, "%s: invalid function number, must be zero\n", > > + port->name); > > + goto skip; > > + } > > > > ret = mvebu_get_tgt_attr(dev->of_node, port->devfn, IORESOURCE_MEM, > > &port->mem_target, &port->mem_attr); > > -- > > 2.20.1 > >