igc: Add pcie error handler support

Add pcie error detection, slot reset and resume capability
Signed-off-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igc/igc_main.c

@@ -5076,6 +5076,108 @@ static void igc_shutdown(struct pci_dev *pdev)
 	}
 }
 
+/**
+ *  igc_io_error_detected - called when PCI error is detected
+ *  @pdev: Pointer to PCI device
+ *  @state: The current PCI connection state
+ *
+ *  This function is called after a PCI bus error affecting
+ *  this device has been detected.
+ **/
+static pci_ers_result_t igc_io_error_detected(struct pci_dev *pdev,
+					      pci_channel_state_t state)
+{
+	struct net_device *netdev = pci_get_drvdata(pdev);
+	struct igc_adapter *adapter = netdev_priv(netdev);
+
+	netif_device_detach(netdev);
+
+	if (state == pci_channel_io_perm_failure)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	if (netif_running(netdev))
+		igc_down(adapter);
+	pci_disable_device(pdev);
+
+	/* Request a slot reset. */
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+/**
+ *  igc_io_slot_reset - called after the PCI bus has been reset.
+ *  @pdev: Pointer to PCI device
+ *
+ *  Restart the card from scratch, as if from a cold-boot. Implementation
+ *  resembles the first-half of the igc_resume routine.
+ **/
+static pci_ers_result_t igc_io_slot_reset(struct pci_dev *pdev)
+{
+	struct net_device *netdev = pci_get_drvdata(pdev);
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct igc_hw *hw = &adapter->hw;
+	pci_ers_result_t result;
+
+	if (pci_enable_device_mem(pdev)) {
+		dev_err(&pdev->dev,
+			"Could not re-enable PCI device after reset.\n");
+		result = PCI_ERS_RESULT_DISCONNECT;
+	} else {
+		pci_set_master(pdev);
+		pci_restore_state(pdev);
+		pci_save_state(pdev);
+
+		pci_enable_wake(pdev, PCI_D3hot, 0);
+		pci_enable_wake(pdev, PCI_D3cold, 0);
+
+		/* In case of PCI error, adapter loses its HW address
+		 * so we should re-assign it here.
+		 */
+		hw->hw_addr = adapter->io_addr;
+
+		igc_reset(adapter);
+		wr32(IGC_WUS, ~0);
+		result = PCI_ERS_RESULT_RECOVERED;
+	}
+
+	return result;
+}
+
+/**
+ *  igc_io_resume - called when traffic can start to flow again.
+ *  @pdev: Pointer to PCI device
+ *
+ *  This callback is called when the error recovery driver tells us that
+ *  its OK to resume normal operation. Implementation resembles the
+ *  second-half of the igc_resume routine.
+ */
+static void igc_io_resume(struct pci_dev *pdev)
+{
+	struct net_device *netdev = pci_get_drvdata(pdev);
+	struct igc_adapter *adapter = netdev_priv(netdev);
+
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		if (igc_open(netdev)) {
+			dev_err(&pdev->dev, "igc_open failed after reset\n");
+			return;
+		}
+	}
+
+	netif_device_attach(netdev);
+
+	/* let the f/w know that the h/w is now under the control of the
+	 * driver.
+	 */
+	igc_get_hw_control(adapter);
+	rtnl_unlock();
+}
+
+static const struct pci_error_handlers igc_err_handler = {
+	.error_detected = igc_io_error_detected,
+	.slot_reset = igc_io_slot_reset,
+	.resume = igc_io_resume,
+};
+
 #ifdef CONFIG_PM
 static const struct dev_pm_ops igc_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(igc_suspend, igc_resume)
@@ -5093,6 +5195,7 @@ static struct pci_driver igc_driver = {
 	.driver.pm = &igc_pm_ops,
 #endif
 	.shutdown = igc_shutdown,
+	.err_handler = &igc_err_handler,
 };
 
 /**