From patchwork Thu Oct 3 23:39:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 1171487 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46kqKf2MbZz9sQp for ; Fri, 4 Oct 2019 09:41:58 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731844AbfJCXli (ORCPT ); Thu, 3 Oct 2019 19:41:38 -0400 Received: from mga11.intel.com ([192.55.52.93]:39187 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731809AbfJCXli (ORCPT ); Thu, 3 Oct 2019 19:41:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Oct 2019 16:41:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,254,1566889200"; d="scan'208";a="343819280" Received: from skuppusw-desk.jf.intel.com ([10.54.74.33]) by orsmga004.jf.intel.com with ESMTP; 03 Oct 2019 16:41:35 -0700 From: sathyanarayanan.kuppuswamy@linux.intel.com To: bhelgaas@google.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, Huong Nguyen , Austin Bolen Subject: [PATCH v9 4/8] PCI/DPC: Add Error Disconnect Recover (EDR) support Date: Thu, 3 Oct 2019 16:39:00 -0700 Message-Id: <87ad0761e82ef58a1228693231cbdbd8d84cd74a.1570145778.git.sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Kuppuswamy Sathyanarayanan As per ACPI specification r6.3, sec 5.6.6, when firmware owns Downstream Port Containment (DPC), its expected to use the "Error Disconnect Recover" (EDR) notification to alert OSPM of a DPC event and if OS supports EDR, its expected to handle the software state invalidation and port recovery in OS, and also let firmware know the recovery status via _OST ACPI call. Related _OST status codes can be found in ACPI specification r6.3, sec 6.3.5.2. Also, as per PCI firmware specification r3.2 Downstream Port Containment Related Enhancements ECN, sec 4.5.1, table 4-6, If DPC is controlled by firmware (firmware first mode), firmware is responsible for configuring the DPC and OS is responsible for error recovery. Also, OS is allowed to modify DPC registers only during the EDR notification window. So with EDR support, OS should provide DPC port services even in firmware first mode. Cc: Keith Busch Signed-off-by: Kuppuswamy Sathyanarayanan Acked-by: Keith Busch Tested-by: Huong Nguyen Tested-by: Austin Bolen --- drivers/pci/pci-acpi.c | 91 ++++++++++++++++++++++++++++ drivers/pci/pcie/Kconfig | 10 ++++ drivers/pci/pcie/dpc.c | 125 ++++++++++++++++++++++++++++++++++++++- include/linux/pci-acpi.h | 11 ++++ 4 files changed, 236 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 0c02d500158f..6d9ddef0caf8 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -103,6 +103,97 @@ int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment, } #endif +#if defined(CONFIG_PCIE_DPC) && defined(CONFIG_ACPI) + +/* + * _DSM wrapper function to enable/disable DPC port. + * @dpc : DPC device structure + * @enable: status of DPC port (0 or 1). + * + * returns 0 on success or errno on failure. + */ +int acpi_enable_dpc_port(struct pci_dev *pdev, acpi_handle handle, bool enable) +{ + union acpi_object *obj; + int status = 0; + union acpi_object argv4; + + argv4.type = ACPI_TYPE_INTEGER; + argv4.integer.value = enable; + + obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5, + EDR_PORT_ENABLE_DSM, &argv4); + if (!obj) + return -EIO; + + if (obj->type != ACPI_TYPE_INTEGER || obj->integer.value != enable) + status = -EIO; + + ACPI_FREE(obj); + + return status; +} + +/* + * _DSM wrapper function to locate DPC port. + * @dpc : DPC device structure + * + * returns pci_dev or NULL. + */ +struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev, acpi_handle handle) +{ + union acpi_object *obj; + u16 port; + + obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5, + EDR_PORT_LOCATE_DSM, NULL); + if (!obj) + return pci_dev_get(pdev); + + if (obj->type != ACPI_TYPE_INTEGER) { + ACPI_FREE(obj); + return NULL; + } + + /* + * Firmware returns DPC port BDF details in following format: + * 15:8 = bus + * 7:3 = device + * 2:0 = function + */ + port = obj->integer.value; + + ACPI_FREE(obj); + + return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus), + PCI_BUS_NUM(port), port & 0xff); +} + +/* + * _OST wrapper function to let firmware know the status of EDR event. + * @dpc : DPC device structure. + * @status: Status of EDR event. + */ +int acpi_send_edr_status(struct pci_dev *pdev, acpi_handle handle, u16 status) +{ + u32 ost_status; + + pci_dbg(pdev, "Sending EDR status :%x\n", status); + + ost_status = PCI_DEVID(pdev->bus->number, pdev->devfn); + ost_status = (ost_status << 16) | status; + + status = acpi_evaluate_ost(handle, + ACPI_NOTIFY_DISCONNECT_RECOVER, + ost_status, NULL); + if (ACPI_FAILURE(status)) + return -EINVAL; + + return 0; +} + +#endif /* CONFIG_PCIE_DPC && CONFIG_ACPI */ + phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle) { acpi_status status = AE_NOT_EXIST; diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig index 362eb8cfa53b..9a05015af7cd 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -150,3 +150,13 @@ config PCIE_BW This enables PCI Express Bandwidth Change Notification. If you know link width or rate changes occur only to correct unreliable links, you may answer Y. + +config PCIE_EDR + bool "PCI Express Error Disconnect Recover support" + default n + depends on PCIE_DPC && ACPI + help + This options adds Error Disconnect Recover support as specified + in PCI firmware specification v3.2 Downstream Port Containment + Related Enhancements ECN. Enable this if you want to support hybrid + DPC model which uses both firmware and OS to implement DPC. diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index 4137ec7b48cc..a8b634e05694 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include "portdrv.h" #include "../pci.h" @@ -24,6 +26,11 @@ struct dpc_dev { u8 rp_log_size; /* Set True if DPC is controlled by firmware */ bool firmware_dpc; + pci_ers_result_t error_state; + struct mutex edr_lock; +#ifdef CONFIG_ACPI + struct acpi_device *adev; +#endif }; static const char * const rp_pio_error_string[] = { @@ -152,6 +159,9 @@ static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) if (!pcie_wait_for_link(pdev, true)) return PCI_ERS_RESULT_DISCONNECT; + /* Since the device recovery is done just update the error state */ + dpc->error_state = PCI_ERS_RESULT_RECOVERED; + return PCI_ERS_RESULT_RECOVERED; } @@ -296,13 +306,90 @@ static irqreturn_t dpc_irq(int irq, void *context) return IRQ_HANDLED; } +static void dpc_error_resume(struct pci_dev *dev) +{ + struct dpc_dev *dpc = to_dpc_dev(dev); + + dpc->error_state = PCI_ERS_RESULT_RECOVERED; +} + +#ifdef CONFIG_ACPI + +static void edr_handle_event(acpi_handle handle, u32 event, void *data) +{ + struct dpc_dev *dpc = (struct dpc_dev *) data; + struct pci_dev *pdev = dpc->dev->port; + u16 status; + + pci_info(pdev, "ACPI event %x received\n", event); + + if (event != ACPI_NOTIFY_DISCONNECT_RECOVER) + return; + + /* + * Check if _DSM(0xD) is available, and if present locate the + * port which issued EDR event. + */ + pdev = acpi_locate_dpc_port(pdev, dpc->adev->handle); + if (!pdev) { + pdev = dpc->dev->port; + pci_err(pdev, "No valid port found\n"); + return; + } + + dpc = to_dpc_dev(pdev); + if (!dpc) { + pci_err(pdev, "DPC port is NULL\n"); + goto done; + } + + mutex_lock(&dpc->edr_lock); + + dpc->error_state = PCI_ERS_RESULT_DISCONNECT; + + /* + * Check if the port supports DPC: + * + * If port supports DPC, then fall back to default error + * recovery. + */ + if (dpc->cap_pos) { + /* Check if there is a valid DPC trigger */ + pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, + &status); + if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) { + pci_err(pdev, "Invalid DPC trigger %x\n", status); + goto edr_unlock; + } + dpc_process_error(dpc); + } + + /* + * If recovery is successful, send _OST(0xF, BDF << 16 | 0x80) + * to firmware. If not successful, send _OST(0xF, BDF << 16 | 0x81). + */ + if (dpc->error_state == PCI_ERS_RESULT_RECOVERED) + status = 0x80; + else + status = 0x81; + + acpi_send_edr_status(pdev, dpc->adev->handle, status); + +edr_unlock: + mutex_unlock(&dpc->edr_lock); +done: + pci_dev_put(pdev); +} + +#endif + #define FLAG(x, y) (((x) & (y)) ? '+' : '-') static int dpc_probe(struct pcie_device *dev) { struct dpc_dev *dpc; struct pci_dev *pdev = dev->port; struct device *device = &dev->device; - int status; + int status = 0; u16 ctl, cap; dpc = devm_kzalloc(device, sizeof(*dpc), GFP_KERNEL); @@ -312,6 +399,8 @@ static int dpc_probe(struct pcie_device *dev) dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC); dpc->dev = dev; set_service_data(dev, dpc); + dpc->error_state = PCI_ERS_RESULT_NONE; + mutex_init(&dpc->edr_lock); if (pcie_aer_get_firmware_first(pdev)) dpc->firmware_dpc = 1; @@ -334,6 +423,39 @@ static int dpc_probe(struct pcie_device *dev) } } +#ifdef CONFIG_ACPI + if (dpc->firmware_dpc) { + struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); + acpi_status astatus; + + if (!adev) { + pci_err(pdev, "No valid ACPI device found\n"); + return -ENODEV; + } + + dpc->adev = adev; + + astatus = acpi_install_notify_handler(adev->handle, + ACPI_SYSTEM_NOTIFY, + edr_handle_event, + dpc); + + if (ACPI_FAILURE(astatus)) { + pci_err(pdev, + "Install ACPI_SYSTEM_NOTIFY handler failed\n"); + return -EBUSY; + } + + status = acpi_enable_dpc_port(pdev, adev->handle, true); + if (status) { + pci_err(pdev, "Enable DPC port failed\n"); + acpi_remove_notify_handler(adev->handle, + ACPI_SYSTEM_NOTIFY, + edr_handle_event); + return status; + } + } +#endif pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap); pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl); @@ -384,6 +506,7 @@ static struct pcie_port_service_driver dpcdriver = { .probe = dpc_probe, .remove = dpc_remove, .reset_link = dpc_reset_link, + .error_resume = dpc_error_resume, }; int __init pcie_dpc_init(void) diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index 62b7fdcc661c..36ffe1e16e69 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -117,6 +117,17 @@ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } static inline void acpi_pci_remove_bus(struct pci_bus *bus) { } #endif /* CONFIG_ACPI */ +#if defined(CONFIG_PCIE_DPC) && defined(CONFIG_ACPI) +#define EDR_PORT_ENABLE_DSM 0x0C +#define EDR_PORT_LOCATE_DSM 0x0D +int acpi_enable_dpc_port(struct pci_dev *pdev, acpi_handle handle, + bool enable); +struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev, + acpi_handle handle); +int acpi_send_edr_status(struct pci_dev *pdev, + acpi_handle handle, u16 status); +#endif + #ifdef CONFIG_ACPI_APEI extern bool aer_acpi_firmware_first(void); #else