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- // SPDX-License-Identifier: GPL-2.0
- /*
- * This file implements the error recovery as a core part of PCIe error
- * reporting. When a PCIe error is delivered, an error message will be
- * collected and printed to console, then, an error recovery procedure
- * will be executed by following the PCI error recovery rules.
- *
- * Copyright (C) 2006 Intel Corp.
- * Tom Long Nguyen (tom.l.nguyen@intel.com)
- * Zhang Yanmin (yanmin.zhang@intel.com)
- */
- #define dev_fmt(fmt) "AER: " fmt
- #include <linux/pci.h>
- #include <linux/module.h>
- #include <linux/kernel.h>
- #include <linux/errno.h>
- #include <linux/aer.h>
- #include "portdrv.h"
- #include "../pci.h"
- static pci_ers_result_t merge_result(enum pci_ers_result orig,
- enum pci_ers_result new)
- {
- if (new == PCI_ERS_RESULT_NO_AER_DRIVER)
- return PCI_ERS_RESULT_NO_AER_DRIVER;
- if (new == PCI_ERS_RESULT_NONE)
- return orig;
- switch (orig) {
- case PCI_ERS_RESULT_CAN_RECOVER:
- case PCI_ERS_RESULT_RECOVERED:
- orig = new;
- break;
- case PCI_ERS_RESULT_DISCONNECT:
- if (new == PCI_ERS_RESULT_NEED_RESET)
- orig = PCI_ERS_RESULT_NEED_RESET;
- break;
- default:
- break;
- }
- return orig;
- }
- static int report_error_detected(struct pci_dev *dev,
- pci_channel_state_t state,
- enum pci_ers_result *result)
- {
- pci_ers_result_t vote;
- const struct pci_error_handlers *err_handler;
- device_lock(&dev->dev);
- if (!pci_dev_set_io_state(dev, state) ||
- !dev->driver ||
- !dev->driver->err_handler ||
- !dev->driver->err_handler->error_detected) {
- /*
- * If any device in the subtree does not have an error_detected
- * callback, PCI_ERS_RESULT_NO_AER_DRIVER prevents subsequent
- * error callbacks of "any" device in the subtree, and will
- * exit in the disconnected error state.
- */
- if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
- vote = PCI_ERS_RESULT_NO_AER_DRIVER;
- pci_info(dev, "can't recover (no error_detected callback)\n");
- } else {
- vote = PCI_ERS_RESULT_NONE;
- }
- } else {
- err_handler = dev->driver->err_handler;
- vote = err_handler->error_detected(dev, state);
- }
- pci_uevent_ers(dev, vote);
- *result = merge_result(*result, vote);
- device_unlock(&dev->dev);
- return 0;
- }
- static int report_frozen_detected(struct pci_dev *dev, void *data)
- {
- return report_error_detected(dev, pci_channel_io_frozen, data);
- }
- static int report_normal_detected(struct pci_dev *dev, void *data)
- {
- return report_error_detected(dev, pci_channel_io_normal, data);
- }
- static int report_mmio_enabled(struct pci_dev *dev, void *data)
- {
- pci_ers_result_t vote, *result = data;
- const struct pci_error_handlers *err_handler;
- device_lock(&dev->dev);
- if (!dev->driver ||
- !dev->driver->err_handler ||
- !dev->driver->err_handler->mmio_enabled)
- goto out;
- err_handler = dev->driver->err_handler;
- vote = err_handler->mmio_enabled(dev);
- *result = merge_result(*result, vote);
- out:
- device_unlock(&dev->dev);
- return 0;
- }
- static int report_slot_reset(struct pci_dev *dev, void *data)
- {
- pci_ers_result_t vote, *result = data;
- const struct pci_error_handlers *err_handler;
- device_lock(&dev->dev);
- if (!dev->driver ||
- !dev->driver->err_handler ||
- !dev->driver->err_handler->slot_reset)
- goto out;
- err_handler = dev->driver->err_handler;
- vote = err_handler->slot_reset(dev);
- *result = merge_result(*result, vote);
- out:
- device_unlock(&dev->dev);
- return 0;
- }
- static int report_resume(struct pci_dev *dev, void *data)
- {
- const struct pci_error_handlers *err_handler;
- device_lock(&dev->dev);
- if (!pci_dev_set_io_state(dev, pci_channel_io_normal) ||
- !dev->driver ||
- !dev->driver->err_handler ||
- !dev->driver->err_handler->resume)
- goto out;
- err_handler = dev->driver->err_handler;
- err_handler->resume(dev);
- out:
- pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
- device_unlock(&dev->dev);
- return 0;
- }
- pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
- pci_channel_state_t state,
- pci_ers_result_t (*reset_link)(struct pci_dev *pdev))
- {
- pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
- struct pci_bus *bus;
- /*
- * Error recovery runs on all subordinates of the first downstream port.
- * If the downstream port detected the error, it is cleared at the end.
- */
- if (!(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
- pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM))
- dev = dev->bus->self;
- bus = dev->subordinate;
- pci_dbg(dev, "broadcast error_detected message\n");
- if (state == pci_channel_io_frozen) {
- pci_walk_bus(bus, report_frozen_detected, &status);
- status = reset_link(dev);
- if (status != PCI_ERS_RESULT_RECOVERED) {
- pci_warn(dev, "link reset failed\n");
- goto failed;
- }
- } else {
- pci_walk_bus(bus, report_normal_detected, &status);
- }
- if (status == PCI_ERS_RESULT_CAN_RECOVER) {
- status = PCI_ERS_RESULT_RECOVERED;
- pci_dbg(dev, "broadcast mmio_enabled message\n");
- pci_walk_bus(bus, report_mmio_enabled, &status);
- }
- if (status == PCI_ERS_RESULT_NEED_RESET) {
- /*
- * TODO: Should call platform-specific
- * functions to reset slot before calling
- * drivers' slot_reset callbacks?
- */
- status = PCI_ERS_RESULT_RECOVERED;
- pci_dbg(dev, "broadcast slot_reset message\n");
- pci_walk_bus(bus, report_slot_reset, &status);
- }
- if (status != PCI_ERS_RESULT_RECOVERED)
- goto failed;
- pci_dbg(dev, "broadcast resume message\n");
- pci_walk_bus(bus, report_resume, &status);
- if (pcie_aer_is_native(dev))
- pcie_clear_device_status(dev);
- pci_aer_clear_nonfatal_status(dev);
- pci_info(dev, "device recovery successful\n");
- return status;
- failed:
- pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
- /* TODO: Should kernel panic here? */
- pci_info(dev, "device recovery failed\n");
- return status;
- }
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