1 files changed, 332 insertions, 0 deletions
diff --git a/drivers/net/ethernet/wangxun/libwx/wx_err.c b/drivers/net/ethernet/wangxun/libwx/wx_err.c
new file mode 100644
index 000000000000..b56fbdc959de
--- /dev/null
+++ b/drivers/net/ethernet/wangxun/libwx/wx_err.c
@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2015 - 2026 Beijing WangXun Technology Co., Ltd. */
+/* Copyright (c) 1999 - 2026 Intel Corporation. */
+
+#include <linux/netdevice.h>
+#include <linux/pci.h>
+#include <linux/aer.h>
+
+#include "wx_type.h"
+#include "wx_lib.h"
+#include "wx_err.h"
+
+/**
+ * wx_io_error_detected - called when PCI error is detected
+ * @pdev: Pointer to PCI device
+ * @state: The current pci connection state
+ *
+ * Return: pci_ers_result_t.
+ *
+ * This function is called after a PCI bus error affecting
+ * this device has been detected.
+ */
+static pci_ers_result_t wx_io_error_detected(struct pci_dev *pdev,
+					     pci_channel_state_t state)
+{
+	struct wx *wx = pci_get_drvdata(pdev);
+	struct net_device *netdev;
+
+	if (!wx)
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	netdev = wx->netdev;
+	if (!netif_device_present(netdev))
+		return PCI_ERS_RESULT_DISCONNECT;
+
+	rtnl_lock();
+	netif_device_detach(netdev);
+	set_bit(WX_FLAG_NEED_PCIE_RECOVERY, wx->flags);
+	wx_soft_quiesce(wx);
+
+	if (state == pci_channel_io_perm_failure) {
+		rtnl_unlock();
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+
+	if (!test_and_set_bit(WX_STATE_DISABLED, wx->state))
+		pci_disable_device(pdev);
+	rtnl_unlock();
+
+	/* Request a slot reset. */
+	return PCI_ERS_RESULT_NEED_RESET;
+}
+
+/**
+ * wx_io_slot_reset - called after the pci bus has been reset.
+ * @pdev: Pointer to PCI device
+ *
+ * Return: pci_ers_result_t.
+ *
+ * Restart the card from scratch, as if from a cold-boot.
+ */
+static pci_ers_result_t wx_io_slot_reset(struct pci_dev *pdev)
+{
+	struct wx *wx = pci_get_drvdata(pdev);
+
+	if (pci_enable_device_mem(pdev)) {
+		wx_err(wx, "Cannot re-enable PCI device after reset.\n");
+		return PCI_ERS_RESULT_DISCONNECT;
+	}
+
+	/* make all memory operations done before clearing the flag */
+	smp_mb__before_atomic();
+	clear_bit(WX_STATE_DISABLED, wx->state);
+	clear_bit(WX_FLAG_NEED_PCIE_RECOVERY, wx->flags);
+	pci_set_master(pdev);
+	pci_restore_state(pdev);
+	pci_wake_from_d3(pdev, false);
+
+	rtnl_lock();
+	if (netif_running(wx->netdev) && wx->down_suspend)
+		wx->down_suspend(wx);
+	if (wx->do_reset)
+		wx->do_reset(wx->netdev, false);
+	rtnl_unlock();
+
+	return PCI_ERS_RESULT_RECOVERED;
+}
+
+/**
+ * wx_io_resume - called when traffic can start flowing again.
+ * @pdev: Pointer to PCI device
+ *
+ * This callback is called when the error recovery driver tells us that
+ * its OK to resume normal operation.
+ */
+static void wx_io_resume(struct pci_dev *pdev)
+{
+	struct wx *wx = pci_get_drvdata(pdev);
+	struct net_device *netdev;
+	int err;
+
+	netdev = wx->netdev;
+	rtnl_lock();
+	if (netif_running(netdev)) {
+		err = netdev->netdev_ops->ndo_open(netdev);
+		if (err) {
+			wx_err(wx, "Failed to open netdev after reset\n");
+			goto out;
+		}
+	}
+	netif_device_attach(netdev);
+out:
+	rtnl_unlock();
+}
+
+const struct pci_error_handlers wx_err_handler = {
+	.error_detected = wx_io_error_detected,
+	.slot_reset = wx_io_slot_reset,
+	.resume = wx_io_resume,
+};
+EXPORT_SYMBOL(wx_err_handler);
+
+static bool wx_check_pcie_error(struct wx *wx)
+{
+	u16 vid, pci_cmd;
+
+	pci_read_config_word(wx->pdev, PCI_VENDOR_ID, &vid);
+	pci_read_config_word(wx->pdev, PCI_COMMAND, &pci_cmd);
+
+	/* PCIe link loss or memory space can't access */
+	if (vid == U16_MAX || !(pci_cmd & PCI_COMMAND_MEMORY))
+		return true;
+
+	return false;
+}
+
+static void wx_pf_reset_subtask(struct wx *wx)
+{
+	if (!test_and_clear_bit(WX_FLAG_NEED_DO_RESET, wx->flags))
+		return;
+
+	wx_warn(wx, "Reset adapter.\n");
+	if (wx->do_reset)
+		wx->do_reset(wx->netdev, true);
+}
+
+static void wx_reset_task(struct work_struct *work)
+{
+	struct wx *wx = container_of(work, struct wx, reset_task);
+
+	rtnl_lock();
+
+	/* If the device has been detached (e.g., due to AER error handling),
+	 * abort the reset task to prevent operating on a dead or unmanaged
+	 * hardware.
+	 */
+	if (!netif_device_present(wx->netdev))
+		goto out;
+
+	if (test_bit(WX_FLAG_NEED_PCIE_RECOVERY, wx->flags)) {
+		/* Double check: Verify if the PCIe error is still present. */
+		if (wx_check_pcie_error(wx))
+			wx_soft_quiesce(wx);
+		else
+			clear_bit(WX_FLAG_NEED_PCIE_RECOVERY, wx->flags);
+		goto out;
+	}
+
+	if (test_bit(WX_STATE_DOWN, wx->state) ||
+	    test_bit(WX_STATE_RESETTING, wx->state))
+		goto out;
+
+	wx_pf_reset_subtask(wx);
+
+out:
+	rtnl_unlock();
+}
+
+void wx_check_err_subtask(struct wx *wx)
+{
+	if (test_bit(WX_FLAG_NEED_DO_RESET, wx->flags))
+		queue_work(wx->reset_wq, &wx->reset_task);
+}
+EXPORT_SYMBOL(wx_check_err_subtask);
+
+int wx_init_err_task(struct wx *wx)
+{
+	wx->reset_wq = alloc_workqueue("%s_reset_wq_%x", WQ_UNBOUND | WQ_HIGHPRI,
+				       1, wx->driver_name, pci_dev_id(wx->pdev));
+	if (!wx->reset_wq) {
+		wx_err(wx, "Failed to create wx_reset_wq workqueue\n");
+		return -ENOMEM;
+	}
+
+	INIT_WORK(&wx->reset_task, wx_reset_task);
+	return 0;
+}
+EXPORT_SYMBOL(wx_init_err_task);
+
+static bool wx_ring_tx_pending(struct wx *wx)
+{
+	int i;
+
+	for (i = 0; i < wx->num_tx_queues; i++) {
+		struct wx_ring *tx_ring = wx->tx_ring[i];
+
+		if (tx_ring->next_to_use != tx_ring->next_to_clean)
+			return true;
+	}
+
+	return false;
+}
+
+static bool wx_vf_tx_pending(struct wx *wx)
+{
+	struct wx_ring_feature *vmdq = &wx->ring_feature[RING_F_VMDQ];
+	u32 q_per_pool = __ALIGN_MASK(1, ~vmdq->mask);
+	u32 i, j;
+
+	if (!wx->num_vfs)
+		return false;
+
+	for (i = 0; i < wx->num_vfs; i++) {
+		for (j = 0; j < q_per_pool; j++) {
+			u32 h, t;
+
+			h = rd32(wx, WX_PX_TR_RP_PV(q_per_pool, i, j));
+			t = rd32(wx, WX_PX_TR_WP_PV(q_per_pool, i, j));
+
+			if (h != t)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+static void wx_watchdog_flush_tx(struct wx *wx)
+{
+	if (!netif_running(wx->netdev))
+		return;
+	if (netif_carrier_ok(wx->netdev))
+		return;
+
+	if (wx_ring_tx_pending(wx) || wx_vf_tx_pending(wx)) {
+		/* We've lost link, so the controller stops DMA,
+		 * but we've got queued Tx work that's never going
+		 * to get done, so reset controller to flush Tx.
+		 * (Do the reset outside of interrupt context).
+		 */
+		wx_warn(wx, "initiating reset due to lost link with pending Tx work\n");
+		set_bit(WX_FLAG_NEED_DO_RESET, wx->flags);
+	}
+}
+
+static void wx_detect_tx_hang(struct wx *wx)
+{
+	int i;
+
+	/* If we're down or resetting, just bail */
+	if (!netif_running(wx->netdev) ||
+	    test_bit(WX_STATE_RESETTING, wx->state))
+		return;
+
+	/* Force detection of hung controller */
+	if (netif_carrier_ok(wx->netdev)) {
+		for (i = 0; i < wx->num_tx_queues; i++)
+			set_bit(WX_TX_DETECT_HANG, wx->tx_ring[i]->state);
+	}
+}
+
+void wx_check_hang_subtask(struct wx *wx)
+{
+	if (test_bit(WX_STATE_DOWN, wx->state) ||
+	    test_bit(WX_STATE_RESETTING, wx->state))
+		return;
+
+	wx_watchdog_flush_tx(wx);
+	wx_detect_tx_hang(wx);
+}
+EXPORT_SYMBOL(wx_check_hang_subtask);
+
+static void wx_tx_timeout_recovery(struct wx *wx)
+{
+	/*
+	 * When a PCIe hardware error occurs, the driver should initiate a PCIe
+	 * recovery mechanism. However, this recovery flow relies on the AER
+	 * driver for current kernel policy. Therefore, a self-contained
+	 * recovery mechanism is not implemented yet.
+	 */
+	set_bit(WX_FLAG_NEED_PCIE_RECOVERY, wx->flags);
+	wx_err(wx, "PCIe error detected during tx timeout\n");
+	queue_work(wx->reset_wq, &wx->reset_task);
+}
+
+static void wx_tx_timeout_reset(struct wx *wx)
+{
+	if (test_bit(WX_STATE_DOWN, wx->state))
+		return;
+
+	set_bit(WX_FLAG_NEED_DO_RESET, wx->flags);
+	wx_warn(wx, "initiating reset due to tx timeout\n");
+	wx_service_event_schedule(wx);
+}
+
+void wx_tx_timeout(struct net_device *netdev, unsigned int __always_unused txqueue)
+{
+	struct wx *wx = netdev_priv(netdev);
+
+	if (wx_check_pcie_error(wx))
+		wx_tx_timeout_recovery(wx);
+	else
+		wx_tx_timeout_reset(wx);
+}
+EXPORT_SYMBOL(wx_tx_timeout);
+
+void wx_handle_tx_hang(struct wx_ring *tx_ring, unsigned int next)
+{
+	struct wx *wx = netdev_priv(tx_ring->netdev);
+
+	wx_warn(wx,
+		"Detected Tx Unit Hang: Queue %d, TDH %x, TDT %x, ntu %x, ntc %x, ntc.time_stamp %lx, jiffies %lx\n",
+		tx_ring->queue_index,
+		rd32(wx, WX_PX_TR_RP(tx_ring->reg_idx)),
+		rd32(wx, WX_PX_TR_WP(tx_ring->reg_idx)),
+		tx_ring->next_to_use, next,
+		tx_ring->tx_buffer_info[next].time_stamp, jiffies);
+
+	netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
+
+	wx_tx_timeout_reset(wx);
+}