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=-14.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6319FC4338F for ; Fri, 6 Aug 2021 22:23:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 28B4761131 for ; Fri, 6 Aug 2021 22:23:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 28B4761131 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=KjqgGbwQk5yWNcncoMjrLltHdjkXic5TamxoYepUT1U=; b=X1pSa+j7fV51dy dzW1Y2kOsr6g9/QxB/nVsNxH/x53uTs23+QWuaaHpsAqBihqVO+9LuDYQnZ7KG9ftNs+NnW6zZuai UoWdmQ251lNez+BWscRzdAkD6RxvZy8AQ3xBUcplUCD0S3F/qsmwN1iK1M6M6RxekEW3xKCwxzhGT 1lMQyiZlnd/vUJo9LW3RymCChK/UGTAIp+Sf9t/rwRCI+4lH4OaWShtpo6+eVV+PrKw4UlNpxfZ0O ukIV31H8GpbiV7kc0Va7p6tXIiCPPwToD9OIBlv10uBjpcRogZzdXohEhsMiM3lA5t/NiwsvXcdse KqXTIJTNhlC6eOJaTDPg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mC8E2-00DkQ5-45; Fri, 06 Aug 2021 22:21:58 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mC8Dy-00DkPS-37; Fri, 06 Aug 2021 22:21:55 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1D27F61050; Fri, 6 Aug 2021 22:21:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628288513; bh=UYsjy2E3yhimUFnBlBJOSfmSWLozHm9GL4oX3tbHK1g=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=NbRryqMgEPgafGh/mL+ZhMbNrOHEuCWrF9ePeSSFqjsuxLkMjWFhzFjmxdYevikQq rAnJV9eke+haJI39SXaqpltJSeWeXH9iMLscoKMLKkJEuUExlqDJmPQ30vmzo1hiXy Ueb5IjBL0EJXJ0iyMmiAW5QS+UZqnaHSZtZwP8DK02A6ZXrIGvXaw9gacpeKmJyme6 7l5fQNGSA6jjEGI3x6o+1lY55u97ViLawLUupRViSsdk5xXCL32K0BeM3PziCFmdSJ 7klPseCMxNxMZ3kLjbgVF5nnsDhaSki7sOK+G4355XbgsnCdfwo5va7slfyEu1SR9O ZkV58UL4JVxew== Date: Fri, 6 Aug 2021 17:21:51 -0500 From: Bjorn Helgaas To: Jeremy Linton Cc: linux-pci@vger.kernel.org, lorenzo.pieralisi@arm.com, nsaenz@kernel.org, bhelgaas@google.com, rjw@rjwysocki.net, lenb@kernel.org, robh@kernel.org, kw@linux.com, f.fainelli@gmail.com, bcm-kernel-feedback-list@broadcom.com, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] PCI: brcmstb: Add ACPI config space quirk Message-ID: <20210806222151.GA1892781@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210805211200.491275-3-jeremy.linton@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210806_152154_216276_F353409D X-CRM114-Status: GOOD ( 34.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 05, 2021 at 04:11:59PM -0500, Jeremy Linton wrote: > The PFTF CM4 is an ACPI platform that is following the PCIe SMCCC > standard because its PCIe config space isn't ECAM compliant and is > split into two parts. One part for the root port registers and a > moveable window which points at a given device's 4K config space. > Thus it doesn't have a MCFG (and really any MCFG provided would be > nonsense anyway). As Linux doesn't support the PCIe SMCCC standard > we key off a Linux specific host bridge _DSD to add custom ECAM > ops and cfgres. The cfg op selects between those two regions, as > well as disallowing problematic accesses, particularly if the link > is down because there isn't an attached device. I'm not sure SMCCC is *really* relevant here. If it is, an expansion of the acronym and a link to a spec would be helpful. But AFAICT the only important thing here is that it doesn't have standard ECAM, and we're going to work around that. I don't see anything about _DSD in this series. > Signed-off-by: Jeremy Linton > --- > drivers/pci/controller/Makefile | 1 + > drivers/pci/controller/pcie-brcmstb-acpi.c | 77 ++++++++++++++++++++++ > include/linux/pci-ecam.h | 1 + > 3 files changed, 79 insertions(+) > create mode 100644 drivers/pci/controller/pcie-brcmstb-acpi.c > > diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile > index aaf30b3dcc14..65aa6fd3ed89 100644 > --- a/drivers/pci/controller/Makefile > +++ b/drivers/pci/controller/Makefile > @@ -57,5 +57,6 @@ ifdef CONFIG_PCI_QUIRKS > obj-$(CONFIG_ARM64) += pci-thunder-ecam.o > obj-$(CONFIG_ARM64) += pci-thunder-pem.o > obj-$(CONFIG_ARM64) += pci-xgene.o > +obj-$(CONFIG_ARM64) += pcie-brcmstb-acpi.o > endif > endif > diff --git a/drivers/pci/controller/pcie-brcmstb-acpi.c b/drivers/pci/controller/pcie-brcmstb-acpi.c > new file mode 100644 > index 000000000000..76944876155f > --- /dev/null > +++ b/drivers/pci/controller/pcie-brcmstb-acpi.c > @@ -0,0 +1,77 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * ACPI quirks for Brcm2711 PCIe host controller > + * As used on the Raspberry Pi Compute Module 4 > + * > + * Copyright (C) 2021 Arm Ltd. > + */ > + > +#include > +#include > +#include Do we use something from pci-acpi.h? > +#include > +#include "../pci.h" > +#include "pcie-brcmstb.h" > + > +static int brcm_acpi_init(struct pci_config_window *cfg) > +{ > + /* > + * This platform doesn't technically have anything that could be called > + * ECAM. Its config region has root port specific registers between > + * standard PCIe defined config registers. Thus the region setup by the > + * generic ECAM code needs to be adjusted. The HW can access bus 0-ff > + * but the footprint isn't a nice power of 2 (40k). For purposes of > + * mapping the config region we are just going to squash the standard > + * and nonstandard registers together rather than mapping them > + * separately. This code simply honors the quirk provided base+size > + * instead. > + */ > + iounmap(cfg->win); > + cfg->win = pci_remap_cfgspace(cfg->res.start, resource_size(&cfg->res)); > + if (!cfg->win) > + goto err_exit; > + > + /* MSI is nonstandard as well */ > + pci_no_msi(); > + > + return 0; > +err_exit: > + dev_err(cfg->parent, "PCI: Failed to remap config\n"); > + return -ENOMEM; > +} > + > +static void __iomem *brcm_pcie_map_conf2(struct pci_bus *bus, unsigned int devfn, > + int where) Rewrap to fit in 80 columns. 81 is just ... weird :) > +{ > + struct pci_config_window *cfg = bus->sysdata; > + void __iomem *base = cfg->win; > + int idx; > + u32 up; > + > + /* Accesses to the RC go right to the RC registers if slot==0 */ > + if (pci_is_root_bus(bus)) > + return PCI_SLOT(devfn) ? NULL : base + where; > + > + /* Assure link up before sending request */ > + up = readl(base + PCIE_MISC_PCIE_STATUS); > + if (!(up & PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK)) > + return NULL; > + > + if (!(up & PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK)) > + return NULL; What happens if the link goes down here? Hopefully that's a recoverable error? > + /* For devices, write to the config space index register */ > + idx = PCIE_ECAM_OFFSET(bus->number, devfn, 0); > + writel(idx, base + PCIE_EXT_CFG_INDEX); > + return base + PCIE_EXT_CFG_DATA + where; > +} > + > +const struct pci_ecam_ops bcm2711_pcie_ops = { > + .init = brcm_acpi_init, > + .bus_shift = 1, > + .pci_ops = { > + .map_bus = brcm_pcie_map_conf2, > + .read = pci_generic_config_read, > + .write = pci_generic_config_write, > + } > +}; > diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h > index adea5a4771cf..a5de0285bb7f 100644 > --- a/include/linux/pci-ecam.h > +++ b/include/linux/pci-ecam.h > @@ -87,6 +87,7 @@ extern const struct pci_ecam_ops xgene_v1_pcie_ecam_ops; /* APM X-Gene PCIe v1 * > extern const struct pci_ecam_ops xgene_v2_pcie_ecam_ops; /* APM X-Gene PCIe v2.x */ > extern const struct pci_ecam_ops al_pcie_ops; /* Amazon Annapurna Labs PCIe */ > extern const struct pci_ecam_ops tegra194_pcie_ops; /* Tegra194 PCIe */ > +extern const struct pci_ecam_ops bcm2711_pcie_ops; /* Bcm2711 PCIe */ > #endif > > #if IS_ENABLED(CONFIG_PCI_HOST_COMMON) > -- > 2.31.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel