[SCSI] transport_srp: add rport roles attribute

This adds a 'roles' attribute to rport like transport_fc. The role can
be initiator or target. That is, the initiator driver creates target
remote ports and the target driver creates initiator remote ports.

Signed-off-by: FUJITA Tomonori <[e-mail]>
Signed-off-by: Mike Christie <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/infiniband/ulp/srp/ib_srp.c

···
 
 	memcpy(ids.port_id, &target->id_ext, 8);
 	memcpy(ids.port_id + 8, &target->ioc_guid, 8);
+	ids.roles = SRP_RPORT_ROLE_TARGET;
 	rport = srp_rport_add(target->scsi_host, &ids);
 	if (IS_ERR(rport)) {
 		scsi_remove_host(target->scsi_host);

drivers/scsi/ibmvscsi/ibmvscsi.c

···
 	/* we don't have a proper target_port_id so let's use the fake one */
 	memcpy(ids.port_id, hostdata->madapter_info.partition_name,
 	       sizeof(ids.port_id));
+	ids.roles = SRP_RPORT_ROLE_TARGET;
 	rport = srp_rport_add(host, &ids);
 	if (IS_ERR(rport))
 		goto add_srp_port_failed;

drivers/scsi/scsi_transport_srp.c

···
 #define to_srp_host_attrs(host)	((struct srp_host_attrs *)(host)->shost_data)
 
 #define SRP_HOST_ATTRS 0
-#define SRP_RPORT_ATTRS 3
+#define SRP_RPORT_ATTRS 2
 
 struct srp_internal {
 	struct scsi_transport_template t;
···
 }
 
 static CLASS_DEVICE_ATTR(port_id, S_IRUGO, show_srp_rport_id, NULL);
+
+static const struct {
+	u32 value;
+	char *name;
+} srp_rport_role_names[] = {
+	{SRP_RPORT_ROLE_INITIATOR, "SRP Initiator"},
+	{SRP_RPORT_ROLE_TARGET, "SRP Target"},
+};
+
+static ssize_t
+show_srp_rport_roles(struct class_device *cdev, char *buf)
+{
+	struct srp_rport *rport = transport_class_to_srp_rport(cdev);
+	int i;
+	char *name = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(srp_rport_role_names); i++)
+		if (srp_rport_role_names[i].value == rport->roles) {
+			name = srp_rport_role_names[i].name;
+			break;
+		}
+	return sprintf(buf, "%s\n", name ? : "unknown");
+}
+
+static CLASS_DEVICE_ATTR(roles, S_IRUGO, show_srp_rport_roles, NULL);
 
 static void srp_rport_release(struct device *dev)
 {
···
 	rport->dev.release = srp_rport_release;
 
 	memcpy(rport->port_id, ids->port_id, sizeof(rport->port_id));
+	rport->roles = ids->roles;
 
 	id = atomic_inc_return(&to_srp_host_attrs(shost)->next_port_id);
 	sprintf(rport->dev.bus_id, "port-%d:%d", shost->host_no, id);
···
 
 	count = 0;
 	SETUP_RPORT_ATTRIBUTE_RD(port_id);
+	SETUP_RPORT_ATTRIBUTE_RD(roles);
 	i->rport_attrs[count] = NULL;
 
 	i->f = ft;

include/scsi/scsi_transport_srp.h

···
 #include <linux/types.h>
 #include <linux/mutex.h>
 
+#define SRP_RPORT_ROLE_INITIATOR 0
+#define SRP_RPORT_ROLE_TARGET 1
+
 struct srp_rport_identifiers {
 	u8 port_id[16];
+	u8 roles;
 };
 
 struct srp_rport {
 	struct device dev;
 
 	u8 port_id[16];
+	u8 roles;
 };
 
 struct srp_function_template {