[SCSI] scsi_transport_sas: add expander backlink

This patch adds the ability to add a backlink to a particular port.  The
idea is to represent properly ports on expanders that are used
specifically for linking to the parent device in the topology.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index f5772ff61d0d..6cc2314098cf 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -130,6 +130,8 @@ struct sas_port {
 
         int                     port_identifier;
         int                     num_phys;
+        /* port flags */
+        unsigned int            is_backlink:1;
 
         /* the other end of the link */
         struct sas_rphy         *rphy;
@@ -175,6 +177,7 @@ void sas_port_free(struct sas_port *);
 void sas_port_delete(struct sas_port *);
 void sas_port_add_phy(struct sas_port *, struct sas_phy *);
 void sas_port_delete_phy(struct sas_port *, struct sas_phy *);
+void sas_port_mark_backlink(struct sas_port *);
 int scsi_is_sas_port(const struct device *);
 
 extern struct scsi_transport_template *