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=-17.5 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 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 584B2C636C8 for ; Tue, 20 Jul 2021 22:51:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BD3E61029 for ; Tue, 20 Jul 2021 22:51:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231285AbhGTWJI (ORCPT ); Tue, 20 Jul 2021 18:09:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:35570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231294AbhGTWIu (ORCPT ); Tue, 20 Jul 2021 18:08:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CD333606A5; Tue, 20 Jul 2021 22:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626821367; bh=S0VBkMptMTBMbjlXlL3v3nxSVJbBzwoRLC13STy72fE=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=bpN59brQGPUtdQa9dWrAx0mFd04/ZQnXOjeiwi0mGLgC0s8WSRGtoOrLTT115IalN /CxuTWu6Y+HVfWNSZ2E1nKFyU9iv8L8ZvR/jZhMyRhNJasW9yBzZU2W0U78QVepML8 l8Hcqqd3Jum8OUrYlALzHjbY++rg4nl8wtuHXFISMMSoKihhP+Hz2ycuKQV5+2C7Pp 08mKiYYuDK8sSYHopWnOV2NgTiXoZGGfPtk7mua0V9tf9xzgixbyPqpNYLfC/L81K2 RbwzSswX/sHzc07Rc6Fq7b0W0N1KbJzzQNrea95cps/QzAxhE9OcwEljwLDZNcXbXY YG1vRgnPDrY7A== Date: Tue, 20 Jul 2021 17:49:25 -0500 From: Bjorn Helgaas To: Boqun Feng Cc: Bjorn Helgaas , Arnd Bergmann , Marc Zyngier , Catalin Marinas , Will Deacon , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu , Dexuan Cui , Lorenzo Pieralisi , Rob Herring , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-pci@vger.kernel.org, Sunil Muthuswamy , Mike Rapoport Subject: Re: [RFC v5 1/8] PCI: Introduce domain_nr in pci_host_bridge Message-ID: <20210720224925.GA137627@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210720134429.511541-2-boqun.feng@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 20, 2021 at 09:44:22PM +0800, Boqun Feng wrote: > Currently we retrieve the PCI domain number of the host bridge from the > bus sysdata (or pci_config_window if PCI_DOMAINS_GENERIC=y). Actually > we have the information at PCI host bridge probing time, and it makes > sense that we store it into pci_host_bridge. One benefit of doing so is > the requirement for supporting PCI on Hyper-V for ARM64, because the > host bridge of Hyper-V doesn't have pci_config_window, whereas ARM64 is > a PCI_DOMAINS_GENERIC=y arch, so we cannot retrieve the PCI domain > number from pci_config_window on ARM64 Hyper-V guest. > > As the preparation for ARM64 Hyper-V PCI support, we introduce the > domain_nr in pci_host_bridge and a sentinel value to allow drivers to > set domain numbers properly at probing time. Currently > CONFIG_PCI_DOMAINS_GENERIC=y archs are only users of this > newly-introduced field. > > Signed-off-by: Boqun Feng Once all the issues are ironed out, Lorenzo should probably merge this since it's primarily Hyper-V stuff, but I'm OK with this part: Acked-by: Bjorn Helgaas But fix the comment issue below. > --- > drivers/pci/probe.c | 6 +++++- > include/linux/pci.h | 10 ++++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 79177ac37880..60c50d4f156f 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -594,6 +594,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) > bridge->native_pme = 1; > bridge->native_ltr = 1; > bridge->native_dpc = 1; > + bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; > > device_initialize(&bridge->dev); > } > @@ -898,7 +899,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) > bus->ops = bridge->ops; > bus->number = bus->busn_res.start = bridge->busnr; > #ifdef CONFIG_PCI_DOMAINS_GENERIC > - bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > + if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) > + bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > + else > + bus->domain_nr = bridge->domain_nr; > #endif > > b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 540b377ca8f6..2c413a64d168 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -526,6 +526,15 @@ static inline int pci_channel_offline(struct pci_dev *pdev) > return (pdev->error_state != pci_channel_io_normal); > } > > +/* > +* Currently in ACPI spec, for each PCI host bridge, PCI Segment Group number is > +* limited to a 16-bit value, therefore (int)-1 is not a valid PCI domain number, > +* and can be used as a sentinel value indicating >domain_nr is not set by the > +* driver (and CONFIG_PCI_DOMAINS_GENERIC=y archs will set it with > +* pci_bus_find_domain_nr()). > +*/ Fix comment indentation (follow style of other comments in this file). s/>domain_nr/->domain_nr/ > +#define PCI_DOMAIN_NR_NOT_SET (-1) > + > struct pci_host_bridge { > struct device dev; > struct pci_bus *bus; /* Root bus */ > @@ -533,6 +542,7 @@ struct pci_host_bridge { > struct pci_ops *child_ops; > void *sysdata; > int busnr; > + int domain_nr; > struct list_head windows; /* resource_entry */ > struct list_head dma_ranges; /* dma ranges resource list */ > u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */ > -- > 2.30.2 >