From patchwork Sun Jan 12 22:43:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuppuswamy Sathyanarayanan X-Patchwork-Id: 11329373 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 60F3B14B7 for ; Sun, 12 Jan 2020 22:46:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FE8D2467C for ; Sun, 12 Jan 2020 22:46:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387422AbgALWq1 (ORCPT ); Sun, 12 Jan 2020 17:46:27 -0500 Received: from mga18.intel.com ([134.134.136.126]:34751 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387503AbgALWqJ (ORCPT ); Sun, 12 Jan 2020 17:46:09 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Jan 2020 14:46:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,426,1571727600"; d="scan'208";a="396989492" Received: from skuppusw-desk.jf.intel.com ([10.54.74.33]) by orsmga005.jf.intel.com with ESMTP; 12 Jan 2020 14:46:05 -0800 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, sathyanarayanan.kuppuswamy@linux.intel.com, Keith Busch , Huong Nguyen , Austin Bolen Subject: [PATCH v12 4/8] PCI/DPC: Add Error Disconnect Recover (EDR) support Date: Sun, 12 Jan 2020 14:43:58 -0800 Message-Id: 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 | 98 ++++++++++++++++++++++++++++++ drivers/pci/pcie/Kconfig | 10 ++++ drivers/pci/pcie/dpc.c | 125 ++++++++++++++++++++++++++++++++++++++- include/linux/pci-acpi.h | 11 ++++ 4 files changed, 243 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c index 0c02d500158f..13086518de27 100644 --- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -103,6 +103,104 @@ 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, argv4, req; + int status = 0; + + req.type = ACPI_TYPE_INTEGER; + req.integer.value = enable; + + argv4.type = ACPI_TYPE_PACKAGE; + argv4.package.count = 1; + argv4.package.elements = &req; + + /* As per PCI firmware specification r3.2 Downstream Port Containment + * Related Enhancements ECN, sec 4.6.12, EDR_PORT_ENABLE_DSM is + * optional and hence if its not implemented return success. + */ + obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5, + EDR_PORT_ENABLE_DSM, &argv4); + if (!obj) + return status; + + 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 6e3c04b46fb1..2db8a3109cb5 100644 --- a/drivers/pci/pcie/Kconfig +++ b/drivers/pci/pcie/Kconfig @@ -140,3 +140,13 @@ 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 d29f5d25f3f9..63366344acff 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" @@ -23,6 +25,11 @@ struct dpc_dev { bool rp_extensions; u8 rp_log_size; bool edr_enabled; /* EDR mode is supported */ + 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[] = { @@ -161,6 +168,9 @@ 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; } @@ -305,13 +315,93 @@ 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; + + /* Use ACPI handle of DPC event device for sending EDR status */ + dpc = (struct dpc_dev *) data; + + 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); @@ -324,6 +414,9 @@ static int dpc_probe(struct pcie_device *dev) dpc->edr_enabled = 1; set_service_data(dev, dpc); + dpc->error_state = PCI_ERS_RESULT_NONE; + mutex_init(&dpc->edr_lock); + /* * As per PCIe spec r5.0, implementation note titled "Determination * of DPC Control", to avoid conflicts over whether platform @@ -352,6 +445,35 @@ static int dpc_probe(struct pcie_device *dev) } } +#ifdef CONFIG_ACPI + struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); + + if (pcie_aer_get_firmware_first(pdev) && adev) { + acpi_status astatus; + + 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_warn(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); @@ -403,6 +525,7 @@ 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