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1// SPDX-License-Identifier: GPL-2.02/*3 * PCI Error Disconnect Recover support4 * Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>5 *6 * Copyright (C) 2020 Intel Corp.7 */8 9#define dev_fmt(fmt) "EDR: " fmt10 11#include <linux/pci.h>12#include <linux/pci-acpi.h>13 14#include "portdrv.h"15#include "../pci.h"16 17#define EDR_PORT_DPC_ENABLE_DSM 0x0C18#define EDR_PORT_LOCATE_DSM 0x0D19#define EDR_OST_SUCCESS 0x8020#define EDR_OST_FAILED 0x8121 22/*23 * _DSM wrapper function to enable/disable DPC24 * @pdev : PCI device structure25 *26 * returns 0 on success or errno on failure.27 */28static int acpi_enable_dpc(struct pci_dev *pdev)29{30 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);31 union acpi_object *obj, argv4, req;32 int status = 0;33 34 /*35 * Per PCI Firmware r3.3, sec 4.6.12, EDR_PORT_DPC_ENABLE_DSM is36 * optional. Return success if it's not implemented.37 */38 if (!acpi_check_dsm(adev->handle, &pci_acpi_dsm_guid, 6,39 1ULL << EDR_PORT_DPC_ENABLE_DSM))40 return 0;41 42 req.type = ACPI_TYPE_INTEGER;43 req.integer.value = 1;44 45 argv4.type = ACPI_TYPE_PACKAGE;46 argv4.package.count = 1;47 argv4.package.elements = &req;48 49 obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 6,50 EDR_PORT_DPC_ENABLE_DSM, &argv4);51 if (!obj)52 return 0;53 54 if (obj->type != ACPI_TYPE_INTEGER) {55 pci_err(pdev, FW_BUG "Enable DPC _DSM returned non integer\n");56 status = -EIO;57 }58 59 if (obj->integer.value != 1) {60 pci_err(pdev, "Enable DPC _DSM failed to enable DPC\n");61 status = -EIO;62 }63 64 ACPI_FREE(obj);65 66 return status;67}68 69/*70 * _DSM wrapper function to locate DPC port71 * @pdev : Device which received EDR event72 *73 * Returns pci_dev or NULL. Caller is responsible for dropping a reference74 * on the returned pci_dev with pci_dev_put().75 */76static struct pci_dev *acpi_dpc_port_get(struct pci_dev *pdev)77{78 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);79 union acpi_object *obj;80 u16 port;81 82 /*83 * If EDR_PORT_LOCATE_DSM is not implemented under the target of84 * EDR, the target is the port that experienced the containment85 * event (PCI Firmware r3.3, sec 4.6.13).86 */87 if (!acpi_check_dsm(adev->handle, &pci_acpi_dsm_guid, 5,88 1ULL << EDR_PORT_LOCATE_DSM))89 return pci_dev_get(pdev);90 91 obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 5,92 EDR_PORT_LOCATE_DSM, NULL);93 if (!obj)94 return pci_dev_get(pdev);95 96 if (obj->type != ACPI_TYPE_INTEGER) {97 ACPI_FREE(obj);98 pci_err(pdev, FW_BUG "Locate Port _DSM returned non integer\n");99 return NULL;100 }101 102 /*103 * Bit 31 represents the success/failure of the operation. If bit104 * 31 is set, the operation failed.105 */106 if (obj->integer.value & BIT(31)) {107 ACPI_FREE(obj);108 pci_err(pdev, "Locate Port _DSM failed\n");109 return NULL;110 }111 112 /*113 * Firmware returns DPC port BDF details in following format:114 * 15:8 = bus115 * 7:3 = device116 * 2:0 = function117 */118 port = obj->integer.value;119 120 ACPI_FREE(obj);121 122 return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),123 PCI_BUS_NUM(port), port & 0xff);124}125 126/*127 * _OST wrapper function to let firmware know the status of EDR event128 * @pdev : Device used to send _OST129 * @edev : Device which experienced EDR event130 * @status : Status of EDR event131 */132static int acpi_send_edr_status(struct pci_dev *pdev, struct pci_dev *edev,133 u16 status)134{135 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);136 u32 ost_status;137 138 pci_dbg(pdev, "Status for %s: %#x\n", pci_name(edev), status);139 140 ost_status = PCI_DEVID(edev->bus->number, edev->devfn) << 16;141 ost_status |= status;142 143 status = acpi_evaluate_ost(adev->handle, ACPI_NOTIFY_DISCONNECT_RECOVER,144 ost_status, NULL);145 if (ACPI_FAILURE(status))146 return -EINVAL;147 148 return 0;149}150 151static void edr_handle_event(acpi_handle handle, u32 event, void *data)152{153 struct pci_dev *pdev = data, *edev;154 pci_ers_result_t estate = PCI_ERS_RESULT_DISCONNECT;155 u16 status;156 157 if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)158 return;159 160 /*161 * pdev is a Root Port or Downstream Port that is still present and162 * has triggered a containment event, e.g., DPC, so its child163 * devices have been disconnected (ACPI r6.5, sec 5.6.6).164 */165 pci_info(pdev, "EDR event received\n");166 167 /*168 * Locate the port that experienced the containment event. pdev169 * may be that port or a parent of it (PCI Firmware r3.3, sec170 * 4.6.13).171 */172 edev = acpi_dpc_port_get(pdev);173 if (!edev) {174 pci_err(pdev, "Firmware failed to locate DPC port\n");175 return;176 }177 178 pci_dbg(pdev, "Reported EDR dev: %s\n", pci_name(edev));179 180 /* If port does not support DPC, just send the OST */181 if (!edev->dpc_cap) {182 pci_err(edev, FW_BUG "This device doesn't support DPC\n");183 goto send_ost;184 }185 186 /* Check if there is a valid DPC trigger */187 pci_read_config_word(edev, edev->dpc_cap + PCI_EXP_DPC_STATUS, &status);188 if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {189 pci_err(edev, "Invalid DPC trigger %#010x\n", status);190 goto send_ost;191 }192 193 dpc_process_error(edev);194 pci_aer_raw_clear_status(edev);195 196 /*197 * Irrespective of whether the DPC event is triggered by ERR_FATAL198 * or ERR_NONFATAL, since the link is already down, use the FATAL199 * error recovery path for both cases.200 */201 estate = pcie_do_recovery(edev, pci_channel_io_frozen, dpc_reset_link);202 203send_ost:204 205 /*206 * If recovery is successful, send _OST(0xF, BDF << 16 | 0x80)207 * to firmware. If not successful, send _OST(0xF, BDF << 16 | 0x81).208 */209 if (estate == PCI_ERS_RESULT_RECOVERED) {210 pci_dbg(edev, "DPC port successfully recovered\n");211 pcie_clear_device_status(edev);212 acpi_send_edr_status(pdev, edev, EDR_OST_SUCCESS);213 } else {214 pci_dbg(edev, "DPC port recovery failed\n");215 acpi_send_edr_status(pdev, edev, EDR_OST_FAILED);216 }217 218 pci_dev_put(edev);219}220 221void pci_acpi_add_edr_notifier(struct pci_dev *pdev)222{223 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);224 acpi_status status;225 226 if (!adev) {227 pci_dbg(pdev, "No valid ACPI node, skipping EDR init\n");228 return;229 }230 231 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,232 edr_handle_event, pdev);233 if (ACPI_FAILURE(status)) {234 pci_err(pdev, "Failed to install notify handler\n");235 return;236 }237 238 if (acpi_enable_dpc(pdev))239 acpi_remove_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,240 edr_handle_event);241 else242 pci_dbg(pdev, "Notify handler installed\n");243}244 245void pci_acpi_remove_edr_notifier(struct pci_dev *pdev)246{247 struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);248 249 if (!adev)250 return;251 252 acpi_remove_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,253 edr_handle_event);254 pci_dbg(pdev, "Notify handler removed\n");255}256