net/smc: Refactor smc ism v2 capability handling

Encapsulate the smc ism v2 capability boolean value
in a function for better information hiding.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/smc/af_smc.c

@@ -668,7 +668,7 @@ static int smc_find_proposal_devices(struct smc_sock *smc,
 				ini->smc_type_v1 = SMC_TYPE_N;
 		} /* else RDMA is supported for this connection */
 	}
-	if (smc_ism_v2_capable && smc_find_ism_v2_device_clnt(smc, ini))
+	if (smc_ism_is_v2_capable() && smc_find_ism_v2_device_clnt(smc, ini))
 		ini->smc_type_v2 = SMC_TYPE_N;
 
 	/* if neither ISM nor RDMA are supported, fallback */
@@ -920,7 +920,7 @@ static int smc_connect_check_aclc(struct smc_init_info *ini,
 /* perform steps before actually connecting */
 static int __smc_connect(struct smc_sock *smc)
 {
-	u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
+	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
 	struct smc_clc_msg_accept_confirm_v2 *aclc2;
 	struct smc_clc_msg_accept_confirm *aclc;
 	struct smc_init_info *ini = NULL;
@@ -945,9 +945,9 @@ static int __smc_connect(struct smc_sock *smc)
 						    version);
 
 	ini->smcd_version = SMC_V1;
-	ini->smcd_version |= smc_ism_v2_capable ? SMC_V2 : 0;
+	ini->smcd_version |= smc_ism_is_v2_capable() ? SMC_V2 : 0;
 	ini->smc_type_v1 = SMC_TYPE_B;
-	ini->smc_type_v2 = smc_ism_v2_capable ? SMC_TYPE_D : SMC_TYPE_N;
+	ini->smc_type_v2 = smc_ism_is_v2_capable() ? SMC_TYPE_D : SMC_TYPE_N;
 
 	/* get vlan id from IP device */
 	if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
@@ -1355,7 +1355,7 @@ static int smc_listen_v2_check(struct smc_sock *new_smc,
 		rc = SMC_CLC_DECL_PEERNOSMC;
 		goto out;
 	}
-	if (!smc_ism_v2_capable) {
+	if (!smc_ism_is_v2_capable()) {
 		ini->smcd_version &= ~SMC_V2;
 		rc = SMC_CLC_DECL_NOISM2SUPP;
 		goto out;
@@ -1681,7 +1681,7 @@ static void smc_listen_work(struct work_struct *work)
 {
 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
 						smc_listen_work);
-	u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
+	u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
 	struct socket *newclcsock = new_smc->clcsock;
 	struct smc_clc_msg_accept_confirm *cclc;
 	struct smc_clc_msg_proposal_area *buf;

net/smc/smc_ism.c

@@ -21,7 +21,7 @@ struct smcd_dev_list smcd_dev_list = {
 	.mutex = __MUTEX_INITIALIZER(smcd_dev_list.mutex)
 };
 
-bool smc_ism_v2_capable;
+static bool smc_ism_v2_capable;
 
 /* Test if an ISM communication is possible - same CPC */
 int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
@@ -51,6 +51,12 @@ u16 smc_ism_get_chid(struct smcd_dev *smcd)
 	return smcd->ops->get_chid(smcd);
 }
 
+/* HW supports ISM V2 and thus System EID is defined */
+bool smc_ism_is_v2_capable(void)
+{
+	return smc_ism_v2_capable;
+}
+
 /* Set a connection using this DMBE. */
 void smc_ism_set_conn(struct smc_connection *conn)
 {

net/smc/smc_ism.h

@@ -10,6 +10,7 @@
 #define SMCD_ISM_H
 
 #include <linux/uio.h>
+#include <linux/types.h>
 #include <linux/mutex.h>
 
 #include "smc.h"
@@ -20,9 +21,6 @@ struct smcd_dev_list {	/* List of SMCD devices */
 };
 
 extern struct smcd_dev_list	smcd_dev_list;	/* list of smcd devices */
-extern bool	smc_ism_v2_capable;	/* HW supports ISM V2 and thus
-					 * System EID is defined
-					 */
 
 struct smc_ism_vlanid {			/* VLAN id set on ISM device */
 	struct list_head list;
@@ -52,5 +50,6 @@ int smc_ism_write(struct smcd_dev *dev, const struct smc_ism_position *pos,
 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);
+bool smc_ism_is_v2_capable(void);
 void smc_ism_init(void);
 #endif