[SCSI] libfc: add support of large receive offload by ddp in fc_fcp

When LLD supports direct data placement (ddp) for large receive of an scsi
i/o coming into fc_fcp, we call into libfc_function_template's ddp_setup()
to prepare for a ddp of large receive for this read I/O. When I/O is complete,
we call the corresponding ddp_done() to get the length of data ddped as well
as to let LLD do clean up.

fc_fcp_ddp_setup()/fc_fcp_ddp_done() are added to setup and complete a ddped
read I/O described by the given fc_fcp_pkt. They would call into corresponding
ddp_setup/ddp_done implemented by the fcoe layer. Eventually, fcoe layer calls
into LLD's ddp_setup/ddp_done provided through net_device

Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 8a0c5c239e9c..992af05aacf1 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -489,7 +489,7 @@ static u16 fc_em_alloc_xid(struct fc_exch_mgr *mp, const struct fc_frame *fp)
         struct fc_exch *ep = NULL;
 
         if (mp->max_read) {
-                if (fc_frame_is_read(fp)) {
+                if (fc_fcp_is_read(fr_fsp(fp))) {
                         min = mp->min_xid;
                         max = mp->max_read;
                         plast = &mp->last_read;
@@ -1841,6 +1841,8 @@ struct fc_seq *fc_exch_seq_send(struct fc_lport *lp,
         fc_exch_setup_hdr(ep, fp, ep->f_ctl);
         sp->cnt++;
 
+        fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
+
         if (unlikely(lp->tt.frame_send(lp, fp)))
                 goto err;