net/smc: introduce CHID callback for ISM devices

With SMCD version 2 the CHIDs of ISM devices are needed for the
CLC handshake.
This patch provides the new callback to retrieve the CHID of an
ISM device.

Signed-off-by: Ursula Braun <[e-mail]>
Signed-off-by: Karsten Graul <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/s390/net/ism_drv.c

···
 	*eid = &SYSTEM_EID.seid_string[0];
 }
 
+static u16 ism_get_chid(struct smcd_dev *smcd)
+{
+	struct ism_dev *ismdev;
+
+	ismdev = (struct ism_dev *)smcd->priv;
+	if (!ismdev || !ismdev->pdev)
+		return 0;
+
+	return to_zpci(ismdev->pdev)->pchid;
+}
+
 static void ism_handle_event(struct ism_dev *ism)
 {
 	struct smcd_event *entry;
···
 	.signal_event = ism_signal_ieq,
 	.move_data = ism_move,
 	.get_system_eid = ism_get_system_eid,
+	.get_chid = ism_get_chid,
 };
 
 static int ism_dev_init(struct ism_dev *ism)

include/net/smc.h

···
 			 bool sf, unsigned int offset, void *data,
 			 unsigned int size);
 	void (*get_system_eid)(struct smcd_dev *dev, u8 **eid);
+	u16 (*get_chid)(struct smcd_dev *dev);
 };
 
 struct smcd_dev {

net/smc/af_smc.c

···
 	smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
 	if (!ini->ism_dev[0])
 		return SMC_CLC_DECL_NOSMCDDEV;
+	else
+		ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
 	return 0;
 }
 

net/smc/smc_core.h

···
 	/* SMC-D */
 	u64			ism_peer_gid[SMC_MAX_ISM_DEVS + 1];
 	struct smcd_dev		*ism_dev[SMC_MAX_ISM_DEVS + 1];
+	u16			ism_chid[SMC_MAX_ISM_DEVS + 1];
 };
 
 /* Find the connection associated with the given alert token in the link group.

net/smc/smc_ism.c

···
 	smcd->ops->get_system_eid(smcd, eid);
 }
 
+u16 smc_ism_get_chid(struct smcd_dev *smcd)
+{
+	return smcd->ops->get_chid(smcd);
+}
+
 /* Set a connection using this DMBE. */
 void smc_ism_set_conn(struct smc_connection *conn)
 {

net/smc/smc_ism.h

···
 		  void *data, size_t len);
 int smc_ism_signal_shutdown(struct smc_link_group *lgr);
 void smc_ism_get_system_eid(struct smcd_dev *dev, u8 **eid);
+u16 smc_ism_get_chid(struct smcd_dev *dev);
 void smc_ism_init(void);
 #endif