net: hns3: add barrier in vf mailbox reply process

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7OQCS
CVE: NA

----------------------------

In hclgevf_mbx_handler() and hclgevf_get_mbx_resp() functions,
there is a typical store-store and load-load scenario between
received_resp and additional_info. This patch adds barrier
to fix the problem.
Signed-off-by: NYonglong Liu <liuyonglong@huawei.com>

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_mbx.c

@@ -82,6 +82,9 @@ static int hclgevf_get_mbx_resp(struct hclgevf_dev *hdev, u16 code0, u16 code1,
 		i++;
 	}
 
+	/* ensure additional_info will be seen after received_resp */
+	smp_rmb();
+
 	if (i >= HCLGEVF_MAX_TRY_TIMES) {
 		dev_err(&hdev->pdev->dev,
 			"VF could not get mbx(%u,%u) resp(=%d) from PF in %d tries\n",
@@ -240,6 +243,11 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 				temp++;
 			}
 
+			/* ensure additional_info will be seen before setting
+			 * received_resp
+			 */
+			smp_wmb();
+
 			if (req->match_id) {
 				/* If match_id is not zero, it means PF support
 				 * match_id. If the match_id is right, VF get