net/smc: mark optional smcd_ops and check for support when called

Some operations are not supported by new introduced Emulated-ISM, so
mark them as optional and check if the device supports them when called.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-and-tested-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Wen Gu

include/net/smc.h

@@ -59,19 +59,21 @@ struct smcd_ops {
 	int (*register_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb,
 			    void *client);
 	int (*unregister_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb);
-	int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
-	int (*del_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
-	int (*set_vlan_required)(struct smcd_dev *dev);
-	int (*reset_vlan_required)(struct smcd_dev *dev);
-	int (*signal_event)(struct smcd_dev *dev, struct smcd_gid *rgid,
-			    u32 trigger_irq, u32 event_code, u64 info);
 	int (*move_data)(struct smcd_dev *dev, u64 dmb_tok, unsigned int idx,
 			 bool sf, unsigned int offset, void *data,
 			 unsigned int size);
 	int (*supports_v2)(void);
 	void (*get_local_gid)(struct smcd_dev *dev, struct smcd_gid *gid);
 	u16 (*get_chid)(struct smcd_dev *dev);
 	struct device* (*get_dev)(struct smcd_dev *dev);
+
+	/* optional operations */
+	int (*add_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
+	int (*del_vlan_id)(struct smcd_dev *dev, u64 vlan_id);
+	int (*set_vlan_required)(struct smcd_dev *dev);
+	int (*reset_vlan_required)(struct smcd_dev *dev);
+	int (*signal_event)(struct smcd_dev *dev, struct smcd_gid *rgid,
+			    u32 trigger_irq, u32 event_code, u64 info);
 };
 
 struct smcd_dev {

net/smc/smc_ism.c

@@ -126,6 +126,8 @@ int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 
 	if (!vlanid)			/* No valid vlan id */
 		return -EINVAL;
+	if (!smcd->ops->add_vlan_id)
+		return -EOPNOTSUPP;
 
 	/* create new vlan entry, in case we need it */
 	new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
@@ -171,6 +173,8 @@ int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
 
 	if (!vlanid)			/* No valid vlan id */
 		return -EINVAL;
+	if (!smcd->ops->del_vlan_id)
+		return -EOPNOTSUPP;
 
 	spin_lock_irqsave(&smcd->lock, flags);
 	list_for_each_entry(vlan, &smcd->vlan, list) {
@@ -368,7 +372,8 @@ static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
 		smc_smcd_terminate(wrk->smcd, &peer_gid, ev_info.vlan_id);
 		break;
 	case ISM_EVENT_CODE_TESTLINK:	/* Activity timer */
-		if (ev_info.code == ISM_EVENT_REQUEST) {
+		if (ev_info.code == ISM_EVENT_REQUEST &&
+		    wrk->smcd->ops->signal_event) {
 			ev_info.code = ISM_EVENT_RESPONSE;
 			wrk->smcd->ops->signal_event(wrk->smcd,
 						     &peer_gid,
@@ -538,6 +543,8 @@ int smc_ism_signal_shutdown(struct smc_link_group *lgr)
 
 	if (lgr->peer_shutdown)
 		return 0;
+	if (!lgr->smcd->ops->signal_event)
+		return 0;
 
 	memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
 	ev_info.vlan_id = lgr->vlan_id;