net/smc: introduce smc_pnet_find_alt_roce()

Introduce a new function in smc_pnet.c that searches for an alternate
IB device, using an existing link group and a primary IB device. The
alternate IB device needs to be active and must have the same PNETID
as the link group.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/smc_pnet.h b/net/smc/smc_pnet.h
index ea207f8..811a659 100644
--- a/net/smc/smc_pnet.h
+++ b/net/smc/smc_pnet.h
@@ -19,6 +19,7 @@
 struct smc_ib_device;
 struct smcd_dev;
 struct smc_init_info;
+struct smc_link_group;
 
 /**
  * struct smc_pnettable - SMC PNET table anchor
@@ -48,5 +49,7 @@ void smc_pnet_find_roce_resource(struct sock *sk, struct smc_init_info *ini);
 void smc_pnet_find_ism_resource(struct sock *sk, struct smc_init_info *ini);
 int smc_pnetid_by_table_ib(struct smc_ib_device *smcibdev, u8 ib_port);
 int smc_pnetid_by_table_smcd(struct smcd_dev *smcd);
-
+void smc_pnet_find_alt_roce(struct smc_link_group *lgr,
+			    struct smc_init_info *ini,
+			    struct smc_ib_device *known_dev);
 #endif