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=-22.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 B6270C432BE for ; Thu, 26 Aug 2021 07:18:42 +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 7D36F61053 for ; Thu, 26 Aug 2021 07:18:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 7D36F61053 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com 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:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=z21awN4H6tWMfbUwDkaAdqJUCX3VcJAoxMZH9YK/k70=; b=MjLsrrgWQ6farS iBfImKlbxJvQw7DwYjmxWGo1HcL7RvjlnmGKAdbI7bZj1TvrCXmvEi2G43s62vmF2NAOVSIwg8h7u pQ23ZV9t4aCC4ZDjScwl798jC7EsGKKQ6jzO6iS/0X7Dquazd08SymNSEz6TyeCirWlIOoyySWC6p DYjJvX/e+DRCDEnBwUcA+Wc76PnA2rEMT7xKtTVsXKTz/xPzHPEV1qAa995HM08XGA2pWKIa+QujK wqOZnz1TR42bFkVlDA+/D6/8wAu7RsQQjhLXcUZH/DP8yjuFgHr/vKFmFmjPQ4a/fvHGxr6zVsnJG DNG5v7SXiEp7B2UbM66A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mJ9cY-009Nn6-2C; Thu, 26 Aug 2021 07:16:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mJ9cJ-009Nhd-AF; Thu, 26 Aug 2021 07:16:05 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8674E1042; Thu, 26 Aug 2021 00:16:01 -0700 (PDT) Received: from u200856.usa.arm.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 084753F5A1; Thu, 26 Aug 2021 00:16:00 -0700 (PDT) From: Jeremy Linton To: linux-pci@vger.kernel.org Cc: 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, Jeremy Linton Subject: [PATCH v3 2/4] PCI: brcmstb: Add ACPI config space quirk Date: Thu, 26 Aug 2021 02:15:55 -0500 Message-Id: <20210826071557.29239-3-jeremy.linton@arm.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210826071557.29239-1-jeremy.linton@arm.com> References: <20210826071557.29239-1-jeremy.linton@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210826_001603_511903_7B01018E X-CRM114-Status: GOOD ( 22.69 ) 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 The Pi Firmware Task Force (PFTF: https://github.com/pftf) Compute Module 4 (CM4: an embedded form factor RPi4) is an ACPI platform that isn't ECAM compliant. Its config space is in two parts. One part is for the root port registers and a second moveable window pointing at a device's 4K config space. Thus it doesn't have an MCFG, and any MCFG provided would be nonsense anyway. Instead, a custom pci_ecam_ops quirk is created. The custom ops override the .init and .map_bus functions. The former to assure that cfg->win points at a single mapping that contains the root port registers and the device config window, as well as disabling MSIs due to lack of a GICv2M. map_bus() then provides the address of either the standard portion of the root port registers or to the device config window after it has been moved. Additionally, some basic bus/device filtering exist to avoid sending config transactions to invalid devices on the RP's primary or secondary bus. A basic link check is also made to assure that something is operational on the secondary side before probing the remainder of the config space. If either of these constraints are violated and a config operation is lost in the ether because an EP doesn't respond an unrecoverable SERROR is raised. Signed-off-by: Jeremy Linton Acked-by: Florian Fainelli Acked-by: Bjorn Helgaas --- drivers/pci/controller/Makefile | 1 + drivers/pci/controller/pcie-brcmstb-acpi.c | 79 ++++++++++++++++++++++ include/linux/pci-ecam.h | 1 + 3 files changed, 81 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..528b2b3ffbd2 --- /dev/null +++ b/drivers/pci/controller/pcie-brcmstb-acpi.c @@ -0,0 +1,79 @@ +// 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 +#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. + */ + 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) +{ + 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 the link is up before sending requests downstream. This is done + * to avoid sending transactions to EPs that don't exist. Link flap + * conditions/etc make this race more probable. The resulting unrecoverable + * SERRORs will result in the machine crashing. + */ + 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; + + /* 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