net/smc: decouple ism_client from SMC-D DMB registration

The struct 'ism_client' is specialized for s390 platform firmware ISM.
So replace it with 'void' to make SMCD DMB registration helper generic
for both Emulated-ISM and existing ISM.

Signed-off-by: Wen Gu <[e-mail]>
Reviewed-by: Wenjia Zhang <[e-mail]>
Reviewed-and-tested-by: Jan Karcher <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

drivers/s390/net/ism_drv.c

···
 }
 
 static int smcd_register_dmb(struct smcd_dev *smcd, struct smcd_dmb *dmb,
-			     struct ism_client *client)
+			     void *client)
 {
 	return ism_register_dmb(smcd->priv, (struct ism_dmb *)dmb, client);
 }

include/net/smc.h

···
 #define ISM_ERROR	0xFFFF
 
 struct smcd_dev;
-struct ism_client;
 
 struct smcd_gid {
 	u64	gid;
···
 	int (*query_remote_gid)(struct smcd_dev *dev, struct smcd_gid *rgid,
 				u32 vid_valid, u32 vid);
 	int (*register_dmb)(struct smcd_dev *dev, struct smcd_dmb *dmb,
-			    struct ism_client *client);
+			    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);
···
 struct smcd_dev {
 	const struct smcd_ops *ops;
 	void *priv;
+	void *client;
 	struct list_head list;
 	spinlock_t lock;
 	struct smc_connection **conn;

net/smc/smc_ism.c

···
 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 			 struct smc_buf_desc *dmb_desc)
 {
-#if IS_ENABLED(CONFIG_ISM)
 	struct smcd_dmb dmb;
 	int rc;
 
···
 	dmb.sba_idx = dmb_desc->sba_idx;
 	dmb.vlan_id = lgr->vlan_id;
 	dmb.rgid = lgr->peer_gid.gid;
-	rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, &smc_ism_client);
+	rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb, lgr->smcd->client);
 	if (!rc) {
 		dmb_desc->sba_idx = dmb.sba_idx;
 		dmb_desc->token = dmb.dmb_tok;
···
 		dmb_desc->len = dmb.dmb_len;
 	}
 	return rc;
-#else
-	return 0;
-#endif
 }
 
 static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd,
···
 	if (!smcd)
 		return;
 	smcd->priv = ism;
+	smcd->client = &smc_ism_client;
 	ism_set_priv(ism, &smc_ism_client, smcd);
 	if (smc_pnetid_by_dev_port(&ism->pdev->dev, 0, smcd->pnetid))
 		smc_pnetid_by_table_smcd(smcd);