net: hns3: adjust the process of PF reset

When doing PF reset, the driver needs to do some preparatory work
before asserting PF reset. Since when hardware is resetting, it
is necessary to stop tx/rx queue, clear hardware table, etc,
otherwise hardware may run into unrecoverable state if there is
still IO running when the hardware is resetting.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -2396,7 +2396,6 @@ static void hclge_do_reset(struct hclge_dev *hdev)
 		break;
 	case HNAE3_FUNC_RESET:
 		dev_info(&pdev->dev, "PF Reset requested\n");
-		hclge_func_reset_cmd(hdev, 0);
 		/* schedule again to check later */
 		set_bit(HNAE3_FUNC_RESET, &hdev->reset_pending);
 		hclge_reset_task_schedule(hdev);
@@ -2462,6 +2461,35 @@ static void hclge_clear_reset_cause(struct hclge_dev *hdev)
 	hclge_enable_vector(&hdev->misc_vector, true);
 }
 
+static int hclge_reset_prepare_wait(struct hclge_dev *hdev)
+{
+	int ret = 0;
+
+	switch (hdev->reset_type) {
+	case HNAE3_FUNC_RESET:
+		ret = hclge_func_reset_cmd(hdev, 0);
+		if (ret) {
+			dev_err(&hdev->pdev->dev,
+				"assertting function reset fail %d!\n", ret);
+			return ret;
+		}
+
+		/* After performaning pf reset, it is not necessary to do the
+		 * mailbox handling or send any command to firmware, because
+		 * any mailbox handling or command to firmware is only valid
+		 * after hclge_cmd_init is called.
+		 */
+		set_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);
+		break;
+	default:
+		break;
+	}
+
+	dev_info(&hdev->pdev->dev, "prepare wait ok\n");
+
+	return ret;
+}
+
 static void hclge_reset(struct hclge_dev *hdev)
 {
 	struct hnae3_ae_dev *ae_dev = pci_get_drvdata(hdev->pdev);
@@ -2477,6 +2505,8 @@ static void hclge_reset(struct hclge_dev *hdev)
 	hclge_notify_client(hdev, HNAE3_DOWN_CLIENT);
 	rtnl_unlock();
 
+	hclge_reset_prepare_wait(hdev);
+
 	if (!hclge_reset_wait(hdev)) {
 		rtnl_lock();
 		hclge_notify_client(hdev, HNAE3_UNINIT_CLIENT);
@@ -4873,7 +4903,11 @@ static void hclge_ae_stop(struct hnae3_handle *handle)
 	cancel_work_sync(&hdev->service_task);
 	clear_bit(HCLGE_STATE_SERVICE_SCHED, &hdev->state);
 
-	if (test_bit(HCLGE_STATE_RST_HANDLING, &hdev->state)) {
+	/* If it is not PF reset, the firmware will disable the MAC,
+	 * so it only need to stop phy here.
+	 */
+	if (test_bit(HCLGE_STATE_RST_HANDLING, &hdev->state) &&
+	    hdev->reset_type != HNAE3_FUNC_RESET) {
 		hclge_mac_stop_phy(hdev);
 		return;
 	}