From patchwork Tue Jun 21 16:49:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bjorn Helgaas X-Patchwork-Id: 9190969 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BE09F601C0 for ; Tue, 21 Jun 2016 16:50:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC22F27BE5 for ; Tue, 21 Jun 2016 16:50:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9D7EE280F4; Tue, 21 Jun 2016 16:50:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F167927BE5 for ; Tue, 21 Jun 2016 16:50:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752482AbcFUQty (ORCPT ); Tue, 21 Jun 2016 12:49:54 -0400 Received: from mail.kernel.org ([198.145.29.136]:53958 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752288AbcFUQtw (ORCPT ); Tue, 21 Jun 2016 12:49:52 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B5FBB20122; Tue, 21 Jun 2016 16:49:50 +0000 (UTC) Received: from localhost (unknown [69.71.1.1]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 61634200F3; Tue, 21 Jun 2016 16:49:49 +0000 (UTC) Date: Tue, 21 Jun 2016 11:49:47 -0500 From: Bjorn Helgaas To: Valentine Barshak Cc: Geert Uytterhoeven , Bjorn Helgaas , linux-pci@vger.kernel.org, Thomas Petazzoni , Rob Herring , Jason Cooper , Scott Branden , Jon Mason , Jingoo Han , Pratyush Anand , linux-kernel@vger.kernel.org, rfi@lists.rocketboards.org, linux-renesas-soc@vger.kernel.org, Simon Horman , Thierry Reding , Tanmay Inamdar , Ray Jui , linux-tegra@vger.kernel.org, Ley Foon Tan , Michal Simek , =?iso-8859-1?Q?S=F6ren?= Brinkmann , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v1 19/25] PCI: rcar Gen2: Request host bridge window resources Message-ID: <20160621164947.GA7603@localhost> References: <20160606225630.20936.77349.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20160606230706.20936.13086.stgit@bhelgaas-glaptop2.roam.corp.google.com> <20160621142623.GA29966@localhost> <20160621154100.GA4782@cogentembedded.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160621154100.GA4782@cogentembedded.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue, Jun 21, 2016 at 06:41:00PM +0300, Valentine Barshak wrote: > On Tue, Jun 21, 2016 at 09:26:23AM -0500, Bjorn Helgaas wrote: > > [+cc Valentine] > > > > Hi Bjorn, > > > Hi Geert, > > > > Thanks a lot for testing this, and sorry for the breakage. > > > > On Tue, Jun 21, 2016 at 12:41:31PM +0200, Geert Uytterhoeven wrote: > > > On Tue, Jun 7, 2016 at 1:07 AM, Bjorn Helgaas wrote: > > > > Request host bridge window resources so they appear in ioport_resource and > > > > iomem_resource and are reflected in /proc/ioports and /proc/iomem. > > > > > > > > Signed-off-by: Bjorn Helgaas > > > > --- > > > > drivers/pci/host/pci-rcar-gen2.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c > > > > index 9980a4b..617a6b2 100644 > > > > --- a/drivers/pci/host/pci-rcar-gen2.c > > > > +++ b/drivers/pci/host/pci-rcar-gen2.c > > > > @@ -194,6 +194,7 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) > > > > struct rcar_pci_priv *priv = sys->private_data; > > > > void __iomem *reg = priv->reg; > > > > u32 val; > > > > + int ret; > > > > > > > > pm_runtime_enable(priv->dev); > > > > pm_runtime_get_sync(priv->dev); > > > > @@ -275,6 +276,9 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) > > > > /* Add PCI resources */ > > > > pci_add_resource(&sys->resources, &priv->io_res); > > > > pci_add_resource(&sys->resources, &priv->mem_res); > > > > + ret = devm_request_pci_bus_resources(priv->dev, &sys->resources); > > > > + if (ret < 0) > > > > + return ret; > > > > > > > > /* Setup bus number based on platform device id / of bus-range */ > > > > sys->busnr = priv->busnr; > > > > > > This patch (commit 1bd019707b7c9249d34c5d348f1ef75eb4d83e89 in pci/next) > > > broke PCI on r8a7791/koelsch. Dmesg differences are: > > > > > > pci-rcar-gen2 ee090000.pci: PCI: bus0 revision 11 > > > -pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00 > > > -pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff] > > > -pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff] > > > > This is probably a result of this code in drivers/pci/host/pci-rcar-gen2.c: > > > > /* > > * The controller does not support/use port I/O, > > * so setup a dummy port I/O region here. > > */ > > priv->io_res.start = priv->mem_res.start; > > priv->io_res.end = priv->mem_res.end; > > priv->io_res.flags = IORESOURCE_IO; > > > > We try to avoid adding dummy regions like this, but maybe we missed > > this one. I haven't found any email discussion about it yet, so I > > don't know what the reason for this one is. Valentine, do you > > remember? > > I do not, but I think I've found something in my mailbox. > Below is the quote from the original conversation with: > (Re: [PATCH] pci: Add R-Car Gen2 internal PCI support) > > [quote starts] > >>+ priv->mem_res = *mem_res; > >>+ /* > >>+ * The controller does not support/use port I/O, > >>+ * so setup a dummy port I/O region here. > >>+ */ > >>+ priv->io_res.start = priv->mem_res.start; > >>+ priv->io_res.end = priv->mem_res.end; > >>+ priv->io_res.flags = IORESOURCE_IO; > >> > > I don't understand this. There's no requirement (at least as far as the > > PCI core is concerned) to supply an I/O aperture at all, and I think it > > would be better if you didn't. > > > > Oh, I see ... maybe pcibios_init_resources() forces you to have an > > I/O resource to avoid having it give you a default one? And I > > suppose that since you have several host bridges, these dummy I/O > > regions have to be distinct. Ugh. Well, I guess this is something > > you'd have to fix here or in the ARM code, it's up to you what to do. > > Exactly. This is to avoid assigning default I/O resources. > [quote ends] Oh, right, now I remember. Thanks for digging that out. I propose the patches below to remove the requirement for having an I/O space. Any chance one of you could test them? commit 8387e687f72747b994c54e29e31861f0db07eb0c Author: Bjorn Helgaas Date: Tue Jun 21 10:54:29 2016 -0500 ARM: Make PCI I/O space optional For callers of pci_common_init_dev(), we previously always required a PCI I/O port resource. If the caller's ->setup() function had added an I/O resource, we used that; otherwise, we added a default 64K I/O port space for it. There are PCI host bridges that do not support I/O port space, and we should not add fictitious spaces for them. If a caller sets struct hw_pci.io_optional, assume it is responsible for adding any I/O port resource it desires, and do not add any default I/O port space. Signed-off-by: Bjorn Helgaas Tested-by: Geert Uytterhoeven diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h index 0070e85..2d88af5 100644 --- a/arch/arm/include/asm/mach/pci.h +++ b/arch/arm/include/asm/mach/pci.h @@ -22,6 +22,7 @@ struct hw_pci { struct msi_controller *msi_ctrl; struct pci_ops *ops; int nr_controllers; + unsigned int io_optional:1; void **private_data; int (*setup)(int nr, struct pci_sys_data *); struct pci_bus *(*scan)(int nr, struct pci_sys_data *); diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index 05e61a2..65f12ef 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -410,7 +410,8 @@ static int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return irq; } -static int pcibios_init_resources(int busnr, struct pci_sys_data *sys) +static int pcibios_init_resource(int busnr, struct pci_sys_data *sys, + int io_optional) { int ret; struct resource_entry *window; @@ -420,6 +421,14 @@ static int pcibios_init_resources(int busnr, struct pci_sys_data *sys) &iomem_resource, sys->mem_offset); } + /* + * If a platform says I/O port support is optional, we don't add + * the default I/O space. The platform is responsible for adding + * any I/O space it needs. + */ + if (io_optional) + return 0; + resource_list_for_each_entry(window, &sys->resources) if (resource_type(window->res) == IORESOURCE_IO) return 0; @@ -466,7 +475,7 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw, if (ret > 0) { struct pci_host_bridge *host_bridge; - ret = pcibios_init_resources(nr, sys); + ret = pcibios_init_resource(nr, sys, hw->io_optional); if (ret) { kfree(sys); break; commit eeb4d6cdf8960c484c5a6eb9b310145b75a59ec1 Author: Bjorn Helgaas Date: Tue Jun 21 09:19:34 2016 -0500 PCI: rcar: Drop gen2 dummy I/O port region Previously we added a dummy I/O port region even though the R-Car controller doesn't support PCI port I/O. This resulted in bogus root bus resources like this: pci_bus 0000:00: root bus resource [io 0xee080000-0xee0810ff] pci_bus 0000:00: root bus resource [mem 0xee080000-0xee0810ff] Drop the unused dummy I/O port region and set struct hw_pci.io_optional so the ARM PCI code doesn't add a default one for us. Signed-off-by: Bjorn Helgaas diff --git a/drivers/pci/host/pci-rcar-gen2.c b/drivers/pci/host/pci-rcar-gen2.c index 9980a4b..ddf7765 100644 --- a/drivers/pci/host/pci-rcar-gen2.c +++ b/drivers/pci/host/pci-rcar-gen2.c @@ -97,7 +97,6 @@ struct rcar_pci_priv { struct device *dev; void __iomem *reg; - struct resource io_res; struct resource mem_res; struct resource *cfg_res; unsigned busnr; @@ -273,7 +272,6 @@ static int rcar_pci_setup(int nr, struct pci_sys_data *sys) rcar_pci_setup_errirq(priv); /* Add PCI resources */ - pci_add_resource(&sys->resources, &priv->io_res); pci_add_resource(&sys->resources, &priv->mem_res); /* Setup bus number based on platform device id / of bus-range */ @@ -371,14 +369,6 @@ static int rcar_pci_probe(struct platform_device *pdev) return -ENOMEM; priv->mem_res = *mem_res; - /* - * The controller does not support/use port I/O, - * so setup a dummy port I/O region here. - */ - priv->io_res.start = priv->mem_res.start; - priv->io_res.end = priv->mem_res.end; - priv->io_res.flags = IORESOURCE_IO; - priv->cfg_res = cfg_res; priv->irq = platform_get_irq(pdev, 0); @@ -421,6 +411,7 @@ static int rcar_pci_probe(struct platform_device *pdev) hw_private[0] = priv; memset(&hw, 0, sizeof(hw)); hw.nr_controllers = ARRAY_SIZE(hw_private); + hw.io_optional = 1; hw.private_data = hw_private; hw.map_irq = rcar_pci_map_irq; hw.ops = &rcar_pci_ops;