v4.19.13 snapshot.
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
new file mode 100644
index 0000000..708fd3a
--- /dev/null
+++ b/drivers/pci/pcie/err.c
@@ -0,0 +1,389 @@
+// 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)
+ */
+
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/aer.h>
+#include "portdrv.h"
+#include "../pci.h"
+
+struct aer_broadcast_data {
+ enum pci_channel_state state;
+ enum pci_ers_result result;
+};
+
+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, void *data)
+{
+ pci_ers_result_t vote;
+ const struct pci_error_handlers *err_handler;
+ struct aer_broadcast_data *result_data;
+
+ result_data = (struct aer_broadcast_data *) data;
+
+ device_lock(&dev->dev);
+ dev->error_state = result_data->state;
+
+ if (!dev->driver ||
+ !dev->driver->err_handler ||
+ !dev->driver->err_handler->error_detected) {
+ if (result_data->state == pci_channel_io_frozen &&
+ dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
+ /*
+ * In case of fatal recovery, if one of down-
+ * stream device has no driver. We might be
+ * unable to recover because a later insmod
+ * of a driver for this device is unaware of
+ * its hw state.
+ */
+ pci_printk(KERN_DEBUG, dev, "device has %s\n",
+ dev->driver ?
+ "no AER-aware driver" : "no driver");
+ }
+
+ /*
+ * If there's any device in the subtree that does not
+ * have an error_detected callback, returning
+ * PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of
+ * the subsequent mmio_enabled/slot_reset/resume
+ * callbacks of "any" device in the subtree. All the
+ * devices in the subtree are left in the error state
+ * without recovery.
+ */
+
+ if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
+ vote = PCI_ERS_RESULT_NO_AER_DRIVER;
+ else
+ vote = PCI_ERS_RESULT_NONE;
+ } else {
+ err_handler = dev->driver->err_handler;
+ vote = err_handler->error_detected(dev, result_data->state);
+ pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
+ }
+
+ result_data->result = merge_result(result_data->result, vote);
+ device_unlock(&dev->dev);
+ return 0;
+}
+
+static int report_mmio_enabled(struct pci_dev *dev, void *data)
+{
+ pci_ers_result_t vote;
+ const struct pci_error_handlers *err_handler;
+ struct aer_broadcast_data *result_data;
+
+ result_data = (struct aer_broadcast_data *) data;
+
+ 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_data->result = merge_result(result_data->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;
+ const struct pci_error_handlers *err_handler;
+ struct aer_broadcast_data *result_data;
+
+ result_data = (struct aer_broadcast_data *) data;
+
+ 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_data->result = merge_result(result_data->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);
+ dev->error_state = pci_channel_io_normal;
+
+ if (!dev->driver ||
+ !dev->driver->err_handler ||
+ !dev->driver->err_handler->resume)
+ goto out;
+
+ err_handler = dev->driver->err_handler;
+ err_handler->resume(dev);
+ pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
+out:
+ device_unlock(&dev->dev);
+ return 0;
+}
+
+/**
+ * default_reset_link - default reset function
+ * @dev: pointer to pci_dev data structure
+ *
+ * Invoked when performing link reset on a Downstream Port or a
+ * Root Port with no aer driver.
+ */
+static pci_ers_result_t default_reset_link(struct pci_dev *dev)
+{
+ int rc;
+
+ rc = pci_bridge_secondary_bus_reset(dev);
+ pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n");
+ return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
+}
+
+static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
+{
+ struct pci_dev *udev;
+ pci_ers_result_t status;
+ struct pcie_port_service_driver *driver = NULL;
+
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ /* Reset this port for all subordinates */
+ udev = dev;
+ } else {
+ /* Reset the upstream component (likely downstream port) */
+ udev = dev->bus->self;
+ }
+
+ /* Use the aer driver of the component firstly */
+ driver = pcie_port_find_service(udev, service);
+
+ if (driver && driver->reset_link) {
+ status = driver->reset_link(udev);
+ } else if (udev->has_secondary_link) {
+ status = default_reset_link(udev);
+ } else {
+ pci_printk(KERN_DEBUG, dev, "no link-reset support at upstream device %s\n",
+ pci_name(udev));
+ return PCI_ERS_RESULT_DISCONNECT;
+ }
+
+ if (status != PCI_ERS_RESULT_RECOVERED) {
+ pci_printk(KERN_DEBUG, dev, "link reset at upstream device %s failed\n",
+ pci_name(udev));
+ return PCI_ERS_RESULT_DISCONNECT;
+ }
+
+ return status;
+}
+
+/**
+ * broadcast_error_message - handle message broadcast to downstream drivers
+ * @dev: pointer to from where in a hierarchy message is broadcasted down
+ * @state: error state
+ * @error_mesg: message to print
+ * @cb: callback to be broadcasted
+ *
+ * Invoked during error recovery process. Once being invoked, the content
+ * of error severity will be broadcasted to all downstream drivers in a
+ * hierarchy in question.
+ */
+static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
+ enum pci_channel_state state,
+ char *error_mesg,
+ int (*cb)(struct pci_dev *, void *))
+{
+ struct aer_broadcast_data result_data;
+
+ pci_printk(KERN_DEBUG, dev, "broadcast %s message\n", error_mesg);
+ result_data.state = state;
+ if (cb == report_error_detected)
+ result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
+ else
+ result_data.result = PCI_ERS_RESULT_RECOVERED;
+
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ /*
+ * If the error is reported by a bridge, we think this error
+ * is related to the downstream link of the bridge, so we
+ * do error recovery on all subordinates of the bridge instead
+ * of the bridge and clear the error status of the bridge.
+ */
+ if (cb == report_error_detected)
+ dev->error_state = state;
+ pci_walk_bus(dev->subordinate, cb, &result_data);
+ if (cb == report_resume) {
+ pci_aer_clear_device_status(dev);
+ pci_cleanup_aer_uncorrect_error_status(dev);
+ dev->error_state = pci_channel_io_normal;
+ }
+ } else {
+ /*
+ * If the error is reported by an end point, we think this
+ * error is related to the upstream link of the end point.
+ * The error is non fatal so the bus is ok; just invoke
+ * the callback for the function that logged the error.
+ */
+ cb(dev, &result_data);
+ }
+
+ return result_data.result;
+}
+
+/**
+ * pcie_do_fatal_recovery - handle fatal error recovery process
+ * @dev: pointer to a pci_dev data structure of agent detecting an error
+ *
+ * Invoked when an error is fatal. Once being invoked, removes the devices
+ * beneath this AER agent, followed by reset link e.g. secondary bus reset
+ * followed by re-enumeration of devices.
+ */
+void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
+{
+ struct pci_dev *udev;
+ struct pci_bus *parent;
+ struct pci_dev *pdev, *temp;
+ pci_ers_result_t result;
+
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
+ udev = dev;
+ else
+ udev = dev->bus->self;
+
+ parent = udev->subordinate;
+ pci_lock_rescan_remove();
+ pci_dev_get(dev);
+ list_for_each_entry_safe_reverse(pdev, temp, &parent->devices,
+ bus_list) {
+ pci_dev_get(pdev);
+ pci_dev_set_disconnected(pdev, NULL);
+ if (pci_has_subordinate(pdev))
+ pci_walk_bus(pdev->subordinate,
+ pci_dev_set_disconnected, NULL);
+ pci_stop_and_remove_bus_device(pdev);
+ pci_dev_put(pdev);
+ }
+
+ result = reset_link(udev, service);
+
+ if ((service == PCIE_PORT_SERVICE_AER) &&
+ (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
+ /*
+ * If the error is reported by a bridge, we think this error
+ * is related to the downstream link of the bridge, so we
+ * do error recovery on all subordinates of the bridge instead
+ * of the bridge and clear the error status of the bridge.
+ */
+ pci_aer_clear_fatal_status(dev);
+ pci_aer_clear_device_status(dev);
+ }
+
+ if (result == PCI_ERS_RESULT_RECOVERED) {
+ if (pcie_wait_for_link(udev, true))
+ pci_rescan_bus(udev->bus);
+ pci_info(dev, "Device recovery from fatal error successful\n");
+ } else {
+ pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
+ pci_info(dev, "Device recovery from fatal error failed\n");
+ }
+
+ pci_dev_put(dev);
+ pci_unlock_rescan_remove();
+}
+
+/**
+ * pcie_do_nonfatal_recovery - handle nonfatal error recovery process
+ * @dev: pointer to a pci_dev data structure of agent detecting an error
+ *
+ * Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
+ * error detected message to all downstream drivers within a hierarchy in
+ * question and return the returned code.
+ */
+void pcie_do_nonfatal_recovery(struct pci_dev *dev)
+{
+ pci_ers_result_t status;
+ enum pci_channel_state state;
+
+ state = pci_channel_io_normal;
+
+ status = broadcast_error_message(dev,
+ state,
+ "error_detected",
+ report_error_detected);
+
+ if (status == PCI_ERS_RESULT_CAN_RECOVER)
+ status = broadcast_error_message(dev,
+ state,
+ "mmio_enabled",
+ report_mmio_enabled);
+
+ if (status == PCI_ERS_RESULT_NEED_RESET) {
+ /*
+ * TODO: Should call platform-specific
+ * functions to reset slot before calling
+ * drivers' slot_reset callbacks?
+ */
+ status = broadcast_error_message(dev,
+ state,
+ "slot_reset",
+ report_slot_reset);
+ }
+
+ if (status != PCI_ERS_RESULT_RECOVERED)
+ goto failed;
+
+ broadcast_error_message(dev,
+ state,
+ "resume",
+ report_resume);
+
+ pci_info(dev, "AER: Device recovery successful\n");
+ return;
+
+failed:
+ pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
+
+ /* TODO: Should kernel panic here? */
+ pci_info(dev, "AER: Device recovery failed\n");
+}