ntb_hw_switchtec: Fix unable to set mw translation bug

When one host receives the link force down message from peer host,
ntb_hw_switchtec driver and NTB client(e.g. ntb_transport) may
simultaneously call function switchtec_ntb_part_op() to set up MWs.
This will lead to the failure to set up the transport MW.

To solve this, we put all the link status checking stuff in the
same work queue.

Signed-off-by: Joey Zhang <[email protected]>

Author: Joey Zhang

ntb_hw_switchtec.c

@@ -123,7 +123,8 @@ struct switchtec_ntb {
 	bool link_is_up;
 	enum ntb_speed link_speed;
 	enum ntb_width link_width;
-	struct work_struct link_reinit_work;
+	struct work_struct check_link_status_work;
+	bool link_force_down;
 };
 
 static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
@@ -500,32 +501,11 @@ enum switchtec_msg {
 
 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);
 
-static void link_reinit_work(struct work_struct *work)
-{
-	struct switchtec_ntb *sndev;
-
-	sndev = container_of(work, struct switchtec_ntb, link_reinit_work);
-	switchtec_ntb_reinit_peer(sndev);
-}
-
-static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
-				     enum switchtec_msg msg)
+static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev)
 {
 	int link_sta;
 	int old = sndev->link_is_up;
 
-	if (msg == MSG_LINK_FORCE_DOWN) {
-		schedule_work(&sndev->link_reinit_work);
-
-		if (sndev->link_is_up) {
-			sndev->link_is_up = 0;
-			ntb_link_event(&sndev->ntb);
-			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
-		}
-
-		return;
-	}
-
 	link_sta = sndev->self_shared->link_sta;
 	if (link_sta) {
 		u64 peer = ioread64(&sndev->peer_shared->magic);
@@ -550,6 +530,38 @@ static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
 	}
 }
 
+static void check_link_status_work(struct work_struct *work)
+{
+	struct switchtec_ntb *sndev;
+
+	sndev = container_of(work, struct switchtec_ntb,
+			     check_link_status_work);
+
+	if (sndev->link_force_down) {
+		sndev->link_force_down = false;
+		switchtec_ntb_reinit_peer(sndev);
+
+		if (sndev->link_is_up) {
+			sndev->link_is_up = 0;
+			ntb_link_event(&sndev->ntb);
+			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
+		}
+
+		return;
+	}
+
+	switchtec_ntb_link_status_update(sndev);
+}
+
+static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
+				     enum switchtec_msg msg)
+{
+	if (msg == MSG_LINK_FORCE_DOWN)
+		sndev->link_force_down = true;
+
+	schedule_work(&sndev->check_link_status_work);
+}
+
 static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
 {
 	struct switchtec_ntb *sndev = stdev->sndev;
@@ -582,7 +594,7 @@ static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
 	sndev->self_shared->link_sta = 1;
 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);
 
-	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
+	switchtec_ntb_link_status_update(sndev);
 
 	return 0;
 }
@@ -596,7 +608,7 @@ static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
 	sndev->self_shared->link_sta = 0;
 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);
 
-	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
+	switchtec_ntb_link_status_update(sndev);
 
 	return 0;
 }
@@ -829,7 +841,8 @@ static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
 	sndev->ntb.topo = NTB_TOPO_NONE;
 	sndev->ntb.ops = &switchtec_ntb_ops;
 
-	INIT_WORK(&sndev->link_reinit_work, link_reinit_work);
+	INIT_WORK(&sndev->check_link_status_work, check_link_status_work);
+	sndev->link_force_down = false;
 
 	sndev->self_partition = sndev->stdev->partition;