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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 6FBFEC43381 for ; Tue, 26 Mar 2019 21:01:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A93C208E4 for ; Tue, 26 Mar 2019 21:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553634092; bh=OyGK1NDb6I+kvmdYDA5ghahPKtxN//wz8HKe7ZLrN+0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=JcClrNqyk5eZ7rxw7wJLEdMQnJxOILg+JOon3W/UEbG1wN+WvErOp0teCMBEVqQVF Et04xqqSrLrVmSD69pPrJHudTNi4mNFdO9Nr6cBpILMD5oyzjloaaEMmemK1Yzdl0b VPtS5gW6qGdgzmfv4jjK8OijNJeHi/+TQqO8btLo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732036AbfCZVBb (ORCPT ); Tue, 26 Mar 2019 17:01:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:37484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731840AbfCZVBb (ORCPT ); Tue, 26 Mar 2019 17:01:31 -0400 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 116AF20700; Tue, 26 Mar 2019 21:01:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553634090; bh=OyGK1NDb6I+kvmdYDA5ghahPKtxN//wz8HKe7ZLrN+0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Xp+J0KVSVV4Ue36xx428+Eu1xX4Itdd0ESx0zA5J9ujq7Wj7Jd0PGC4qZWRzDEjMh w+uLHMyZxfZxOgOAOn5NNJfjhQs6jy5AHSRALgnLr+PTdJBe3jaCF6/m4LCv262W8A 7s1aLP9xoEHERLHNnxCdt+TQzs/+4Mjyv/GJs+3k= Date: Tue, 26 Mar 2019 16:01:28 -0500 From: Bjorn Helgaas To: Sergey Miroshnichenko Cc: linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux@yadro.com Subject: Re: [PATCH RFC v4 17/21] PCI: Calculate boundaries for bridge windows Message-ID: <20190326210128.GW24180@google.com> References: <20190311133122.11417-1-s.miroshnichenko@yadro.com> <20190311133122.11417-18-s.miroshnichenko@yadro.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190311133122.11417-18-s.miroshnichenko@yadro.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Mar 11, 2019 at 04:31:18PM +0300, Sergey Miroshnichenko wrote: > If a bridge window contains fixed areas (there are PCIe devices with > immovable BARs located on this bus), I think what you mean by "immovable BARs" is "drivers that don't support moving BARs". I want to keep the concept of legacy and EA resources separate because those are immovable in principle, but drivers can always be improved. > this window must be allocated > within the bound memory area, limited by windows size and by address > range of fixed resources, calculated as follows: > > | <-- bus's fixed_range_hard --> | > | <-- fixed_range_hard.end - window size --> | > | <-- fixed_range_hard.start + window size --> | > | <-- bus's fixed_range_soft --> | > > Signed-off-by: Sergey Miroshnichenko > --- > drivers/pci/setup-bus.c | 56 +++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 4 ++- > 2 files changed, 59 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index a1fd7f3c5ea8..f4737339d5ec 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1809,6 +1809,61 @@ static enum enable_type pci_realloc_detect(struct pci_bus *bus, > } > #endif > > +static void pci_bus_update_fixed_range_soft(struct pci_bus *bus) > +{ > + struct pci_dev *dev; > + struct pci_bus *parent = bus->parent; > + int idx; > + > + list_for_each_entry(dev, &bus->devices, bus_list) > + if (dev->subordinate) > + pci_bus_update_fixed_range_soft(dev->subordinate); > + > + if (!parent || !bus->self) > + return; > + > + for (idx = 0; idx < ARRAY_SIZE(bus->fixed_range_hard); ++idx) { > + struct resource *r; > + resource_size_t soft_start, soft_end; > + resource_size_t hard_start = bus->fixed_range_hard[idx].start; > + resource_size_t hard_end = bus->fixed_range_hard[idx].end; > + > + if (hard_start > hard_end) > + continue; > + > + r = bus->resource[idx]; > + > + soft_start = hard_end - resource_size(r) + 1; > + soft_end = hard_start + resource_size(r) - 1; > + > + if (soft_start > hard_start) > + soft_start = hard_start; > + > + if (soft_end < hard_end) > + soft_end = hard_end; > + > + list_for_each_entry(dev, &parent->devices, bus_list) { > + struct pci_bus *sibling = dev->subordinate; > + resource_size_t s_start, s_end; > + > + if (!sibling || sibling == bus) > + continue; > + > + s_start = sibling->fixed_range_hard[idx].start; > + s_end = sibling->fixed_range_hard[idx].end; > + > + if (s_start > s_end) > + continue; > + > + if (s_end < hard_start && s_end > soft_start) > + soft_start = s_end; > + } > + > + bus->fixed_range_soft[idx].start = soft_start; > + bus->fixed_range_soft[idx].end = soft_end; > + } > +} > + > /* > * first try will not touch pci bridge res > * second and later try will clear small leaf bridge res > @@ -1847,6 +1902,7 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus) > /* Depth first, calculate sizes and alignments of all > subordinate buses. */ > __pci_bus_size_bridges(bus, add_list); > + pci_bus_update_fixed_range_soft(bus); > > /* Depth last, allocate resources and update the hardware. */ > __pci_bus_assign_resources(bus, add_list, &fail_head); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 7a4d62d84bc1..75a56db73ad4 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -574,9 +574,11 @@ struct pci_bus { > > /* > * If there are fixed resources in the bridge window, the hard range > - * contains the lowest and the highest addresses of them. > + * contains the lowest and the highest addresses of them, and this > + * bridge window must reside within the soft range. > */ > struct resource fixed_range_hard[PCI_BRIDGE_RESOURCE_NUM]; > + struct resource fixed_range_soft[PCI_BRIDGE_RESOURCE_NUM]; > > struct pci_ops *ops; /* Configuration access functions */ > struct msi_controller *msi; /* MSI controller */ > -- > 2.20.1 >