[PATCH net-next v4 03/18] net/smc: extract v2 check helper from SMC-D device registration

[Wen Gu <guwen@linux.alibaba.com>]

This patch extracts v2-capable logic from the process of registering the
ISM device as an SMC-D device, so that the registration process of other
underlying devices can reuse it.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 net/smc/smc_ism.c | 29 ++++++++++++++++++-----------
 net/smc/smc_ism.h |  1 +
 2 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index 455ae0a..8f1ba74 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -69,6 +69,22 @@ bool smc_ism_is_v2_capable(void)
 	return smc_ism_v2_capable;
 }
 
+/* must be called under smcd_dev_list.mutex lock */
+void smc_ism_check_v2_capable(struct smcd_dev *smcd)
+{
+	u8 *system_eid = NULL;
+
+	if (smc_ism_v2_capable)
+		return;
+
+	system_eid = smcd->ops->get_system_eid();
+	if (smcd->ops->supports_v2()) {
+		smc_ism_v2_capable = true;
+		memcpy(smc_ism_v2_system_eid, system_eid,
+		       SMC_MAX_EID_LEN);
+	}
+}
+
 /* Set a connection using this DMBE. */
 void smc_ism_set_conn(struct smc_connection *conn)
 {
@@ -423,16 +439,7 @@ static void smcd_register_dev(struct ism_dev *ism)
 		smc_pnetid_by_table_smcd(smcd);
 
 	mutex_lock(&smcd_dev_list.mutex);
-	if (list_empty(&smcd_dev_list.list)) {
-		u8 *system_eid = NULL;
-
-		system_eid = smcd->ops->get_system_eid();
-		if (smcd->ops->supports_v2()) {
-			smc_ism_v2_capable = true;
-			memcpy(smc_ism_v2_system_eid, system_eid,
-			       SMC_MAX_EID_LEN);
-		}
-	}
+	smc_ism_check_v2_capable(smcd);
 	/* sort list: devices without pnetid before devices with pnetid */
 	if (smcd->pnetid[0])
 		list_add_tail(&smcd->list, &smcd_dev_list.list);
@@ -535,10 +542,10 @@ int smc_ism_init(void)
 {
 	int rc = 0;
 
-#if IS_ENABLED(CONFIG_ISM)
 	smc_ism_v2_capable = false;
 	memset(smc_ism_v2_system_eid, 0, SMC_MAX_EID_LEN);
 
+#if IS_ENABLED(CONFIG_ISM)
 	rc = ism_register_client(&smc_ism_client);
 #endif
 	return rc;
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index 832b2f4..14d2e77 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -42,6 +42,7 @@ int smc_ism_register_dmb(struct smc_link_group *lgr, int buf_size,
 void smc_ism_get_system_eid(u8 **eid);
 u16 smc_ism_get_chid(struct smcd_dev *dev);
 bool smc_ism_is_v2_capable(void);
+void smc_ism_check_v2_capable(struct smcd_dev *dev);
 int smc_ism_init(void);
 void smc_ism_exit(void);
 int smcd_nl_get_device(struct sk_buff *skb, struct netlink_callback *cb);
-- 
1.8.3.1