[PATCH net-next 07/18] net/smc: disable SEID on non-s390 architecture

[Wen Gu]

On s390 architecture SMC-Dv2 SEID is generated by ISMv2 device with
partial cpuid. It is predefined and unique to represents the physical
machine (CPC), the maximum communication space of SMC-D.

On non-s390 archs like x86/64 or ARM, there is no similar information
to identify physical machine, especially in virtualization scenarios
like KVM, etc. In such cases, SEID is forcibly disabled and the user-
defined UEID will be used to represent the communicable space.

Signed-off-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx>
---
 net/smc/smc_clc.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index c08e138..be56a7d 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -155,10 +155,12 @@ static int smc_clc_ueid_remove(char *ueid)
 			rc = 0;
 		}
 	}
+#if IS_ENABLED(CONFIG_S390)
 	if (!rc && !smc_clc_eid_table.ueid_cnt) {
 		smc_clc_eid_table.seid_enabled = 1;
 		rc = -EAGAIN;	/* indicate success and enabling of seid */
 	}
+#endif
 	write_unlock(&smc_clc_eid_table.lock);
 	return rc;
 }
@@ -273,22 +275,30 @@ int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)
 
 int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
 {
+#if IS_ENABLED(CONFIG_S390)
 	write_lock(&smc_clc_eid_table.lock);
 	smc_clc_eid_table.seid_enabled = 1;
 	write_unlock(&smc_clc_eid_table.lock);
 	return 0;
+#else
+	return -EOPNOTSUPP;
+#endif
 }
 
 int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
 {
 	int rc = 0;
 
+#if IS_ENABLED(CONFIG_S390)
 	write_lock(&smc_clc_eid_table.lock);
 	if (!smc_clc_eid_table.ueid_cnt)
 		rc = -ENOENT;
 	else
 		smc_clc_eid_table.seid_enabled = 0;
 	write_unlock(&smc_clc_eid_table.lock);
+#else
+	rc = -EOPNOTSUPP;
+#endif
 	return rc;
 }
 
@@ -1290,7 +1300,11 @@ void __init smc_clc_init(void)
 	INIT_LIST_HEAD(&smc_clc_eid_table.list);
 	rwlock_init(&smc_clc_eid_table.lock);
 	smc_clc_eid_table.ueid_cnt = 0;
+#if IS_ENABLED(CONFIG_S390)
 	smc_clc_eid_table.seid_enabled = 1;
+#else
+	smc_clc_eid_table.seid_enabled = 0;
+#endif
 }
 
 void smc_clc_exit(void)
-- 
1.8.3.1