From patchwork Thu Aug 19 21:56:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 12448019 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 5A7FCC4338F for ; Thu, 19 Aug 2021 21:57:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FE7E610A3 for ; Thu, 19 Aug 2021 21:57:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235761AbhHSV55 (ORCPT ); Thu, 19 Aug 2021 17:57:57 -0400 Received: from foss.arm.com ([217.140.110.172]:47528 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235727AbhHSV54 (ORCPT ); Thu, 19 Aug 2021 17:57:56 -0400 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 073E9142F; Thu, 19 Aug 2021 14:57:19 -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 749833F40C; Thu, 19 Aug 2021 14:57:18 -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, sdonthineni@nvidia.com, stefan.wahren@i2se.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 v2 2/4] PCI: brcmstb: Add ACPI config space quirk Date: Thu, 19 Aug 2021 16:56:53 -0500 Message-Id: <20210819215655.84866-3-jeremy.linton@arm.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210819215655.84866-1-jeremy.linton@arm.com> References: <20210819215655.84866-1-jeremy.linton@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The PFTF CM4 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 Linux specific host bridge _DSD selects a custom ECAM ops and cfgres. The cfg op picks between those two regions while disallowing problematic accesses. Signed-off-by: Jeremy Linton Acked-by: Florian Fainelli --- drivers/pci/controller/Makefile | 1 + drivers/pci/controller/pcie-brcmstb-acpi.c | 74 ++++++++++++++++++++++ include/linux/pci-ecam.h | 1 + 3 files changed, 76 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..71f6def3074c --- /dev/null +++ b/drivers/pci/controller/pcie-brcmstb-acpi.c @@ -0,0 +1,74 @@ +// 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 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; + + /* 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)