[SPARC64]: Handle LDC resets properly in domain-services driver.

Reset the handshake and per-capability state so that when the
link comes back up we'll renegotiate the DS version and then
reregister all of the services.

Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc64/kernel/ds.c

@@ -1013,6 +1013,19 @@ static void ds_up(struct ds_info *dp)
 		dp->hs_state = DS_HS_START;
 }
 
+static void ds_reset(struct ds_info *dp)
+{
+	int i;
+
+	dp->hs_state = 0;
+
+	for (i = 0; i < ARRAY_SIZE(ds_states); i++) {
+		struct ds_cap_state *cp = &ds_states[i];
+
+		cp->state = CAP_STATE_UNKNOWN;
+	}
+}
+
 static void ds_event(void *arg, int event)
 {
 	struct ds_info *dp = arg;
@@ -1028,6 +1041,12 @@ static void ds_event(void *arg, int event)
 		return;
 	}
 
+	if (event == LDC_EVENT_RESET) {
+		ds_reset(dp);
+		spin_unlock_irqrestore(&ds_lock, flags);
+		return;
+	}
+
 	if (event != LDC_EVENT_DATA_READY) {
 		printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
 		spin_unlock_irqrestore(&ds_lock, flags);