net: hns3: add match_id to check mailbox response from PF to VF

When VF need response from PF, VF will wait (1us - 1s) to receive
the response, or it will wait timeout and the VF action fails.
If VF do not receive response in 1st action because timeout,
the 2nd action may receive response for the 1st action, and get
incorrect response data.VF must reciveve the right response from
PF,or it will cause unexpected error.

This patch adds match_id to check mailbox response from PF to VF,
to make sure VF get the right response:
1. The message sent from VF was labelled with match_id which was a
unique 16-bit non-zero value.
2. The response sent from PF will label with match_id which got from
the request.
3. The VF uses the match_id to match request and response message.

This scheme depends on PF driver supports match_id, if PF driver doesn't
support then VF will uses the original scheme.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/hisilicon/hns3/hclge_mbx.h

@@ -98,6 +98,7 @@ struct hclgevf_mbx_resp_status {
 	u32 origin_mbx_msg;
 	bool received_resp;
 	int resp_status;
+	u16 match_id;
 	u8 additional_info[HCLGE_MBX_MAX_RESP_DATA_SIZE];
 };
 

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

@@ -13,6 +13,7 @@ static int hclgevf_resp_to_errno(u16 resp_code)
 	return resp_code ? -resp_code : 0;
 }
 
+#define HCLGEVF_MBX_MATCH_ID_START	1
 static void hclgevf_reset_mbx_resp_status(struct hclgevf_dev *hdev)
 {
 	/* this function should be called with mbx_resp.mbx_mutex held
@@ -21,6 +22,10 @@ static void hclgevf_reset_mbx_resp_status(struct hclgevf_dev *hdev)
 	hdev->mbx_resp.received_resp  = false;
 	hdev->mbx_resp.origin_mbx_msg = 0;
 	hdev->mbx_resp.resp_status    = 0;
+	hdev->mbx_resp.match_id++;
+	/* Update match_id and ensure the value of match_id is not zero */
+	if (hdev->mbx_resp.match_id == 0)
+		hdev->mbx_resp.match_id = HCLGEVF_MBX_MATCH_ID_START;
 	memset(hdev->mbx_resp.additional_info, 0, HCLGE_MBX_MAX_RESP_DATA_SIZE);
 }
 
@@ -115,6 +120,7 @@ int hclgevf_send_mbx_msg(struct hclgevf_dev *hdev,
 	if (need_resp) {
 		mutex_lock(&hdev->mbx_resp.mbx_mutex);
 		hclgevf_reset_mbx_resp_status(hdev);
+		req->match_id = hdev->mbx_resp.match_id;
 		status = hclgevf_cmd_send(&hdev->hw, &desc, 1);
 		if (status) {
 			dev_err(&hdev->pdev->dev,
@@ -211,6 +217,19 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 				resp->additional_info[i] = *temp;
 				temp++;
 			}
+
+			/* If match_id is not zero, it means PF support
+			 * match_id. If the match_id is right, VF get the
+			 * right response, otherwise ignore the response.
+			 * Driver will clear hdev->mbx_resp when send
+			 * next message which need response.
+			 */
+			if (req->match_id) {
+				if (req->match_id == resp->match_id)
+					resp->received_resp = true;
+			} else {
+				resp->received_resp = true;
+			}
 			break;
 		case HCLGE_MBX_LINK_STAT_CHANGE:
 		case HCLGE_MBX_ASSERTING_RESET: