[SCSI] libfc, tcm_fc: add ddp_targ() to libfc function template to supprot FCoE DDP in target mode

The fcoe driver can implement ddp_targ() similarly to ddp_setup() when fcoe
stack works with existing target frame, e.g., tcm, where the ddp_targ() would
eventually point to the underlying hardware driver's implementation of
ndo_fcoe_ddp_targ() through net_device_ops. This new API sets up DDP context
for target appropriately by setting required bits for DDP context.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

2 files changed, 11 insertions, 2 deletions

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index b2a106729d49..b9cea59d43b4 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -266,8 +266,9 @@ int ft_write_pending(struct se_cmd *se_cmd)
                                 cmd->sg_cnt =
                                         T_TASK(se_cmd)->t_tasks_sg_chained_no;
                         }
-                        if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
-                                                    cmd->sg, cmd->sg_cnt))
+                        if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
+                                                            cmd->sg,
+                                                            cmd->sg_cnt))
                                 cmd->was_ddp_setup = 1;
                 }
         }
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index a3cbda4ddb5c..7d96829b0c00 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -511,6 +511,14 @@ struct libfc_function_template {
          */
         int (*ddp_done)(struct fc_lport *, u16);
         /*
+         * Sets up the DDP context for a given exchange id on the given
+         * scatterlist if LLD supports DDP for FCoE target.
+         *
+         * STATUS: OPTIONAL
+         */
+        int (*ddp_target)(struct fc_lport *, u16, struct scatterlist *,
+                          unsigned int);
+        /*
          * Allow LLD to fill its own Link Error Status Block
          *
          * STATUS: OPTIONAL