net/ncsi: Introduce ncsi_stop_dev()

This introduces ncsi_stop_dev(), as counterpart to ncsi_start_dev(),
to stop the NCSI device so that it can be reenabled in future. This
API should be called when the network device driver is going to
shutdown the device. There are 3 things done in the function: Stop
the channel monitoring; Reset channels to inactive state; Report
NCSI link down.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ncsi.h

@@ -31,6 +31,7 @@ struct ncsi_dev {
 struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
 				   void (*notifier)(struct ncsi_dev *nd));
 int ncsi_start_dev(struct ncsi_dev *nd);
+void ncsi_stop_dev(struct ncsi_dev *nd);
 void ncsi_unregister_dev(struct ncsi_dev *nd);
 #else /* !CONFIG_NET_NCSI */
 static inline struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
@@ -44,6 +45,10 @@ static inline int ncsi_start_dev(struct ncsi_dev *nd)
 	return -ENOTTY;
 }
 
+static void ncsi_stop_dev(struct ncsi_dev *nd)
+{
+}
+
 static inline void ncsi_unregister_dev(struct ncsi_dev *nd)
 {
 }

net/ncsi/ncsi-manage.c

@@ -1187,11 +1187,7 @@ EXPORT_SYMBOL_GPL(ncsi_register_dev);
 int ncsi_start_dev(struct ncsi_dev *nd)
 {
 	struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
-	struct ncsi_package *np;
-	struct ncsi_channel *nc;
-	unsigned long flags;
-	bool chained;
-	int old_state, ret;
+	int ret;
 
 	if (nd->state != ncsi_dev_state_registered &&
 	    nd->state != ncsi_dev_state_functional)
@@ -1203,9 +1199,29 @@ int ncsi_start_dev(struct ncsi_dev *nd)
 		return 0;
 	}
 
-	/* Reset channel's state and start over */
+	if (ndp->flags & NCSI_DEV_HWA)
+		ret = ncsi_enable_hwa(ndp);
+	else
+		ret = ncsi_choose_active_channel(ndp);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ncsi_start_dev);
+
+void ncsi_stop_dev(struct ncsi_dev *nd)
+{
+	struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
+	struct ncsi_package *np;
+	struct ncsi_channel *nc;
+	bool chained;
+	int old_state;
+	unsigned long flags;
+
+	/* Stop the channel monitor and reset channel's state */
 	NCSI_FOR_EACH_PACKAGE(ndp, np) {
 		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			ncsi_stop_channel_monitor(nc);
+
 			spin_lock_irqsave(&nc->lock, flags);
 			chained = !list_empty(&nc->link);
 			old_state = nc->state;
@@ -1217,14 +1233,9 @@ int ncsi_start_dev(struct ncsi_dev *nd)
 		}
 	}
 
-	if (ndp->flags & NCSI_DEV_HWA)
-		ret = ncsi_enable_hwa(ndp);
-	else
-		ret = ncsi_choose_active_channel(ndp);
-
-	return ret;
+	ncsi_report_link(ndp, true);
 }
-EXPORT_SYMBOL_GPL(ncsi_start_dev);
+EXPORT_SYMBOL_GPL(ncsi_stop_dev);
 
 void ncsi_unregister_dev(struct ncsi_dev *nd)
 {