[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>
diff --git a/include/scsi/fc_frame.h b/include/scsi/fc_frame.h
index 04d34a7..5951105 100644
--- a/include/scsi/fc_frame.h
+++ b/include/scsi/fc_frame.h
@@ -54,8 +54,7 @@
 #define fr_eof(fp)	(fr_cb(fp)->fr_eof)
 #define fr_flags(fp)	(fr_cb(fp)->fr_flags)
 #define fr_max_payload(fp)	(fr_cb(fp)->fr_max_payload)
-#define fr_cmd(fp)	(fr_cb(fp)->fr_cmd)
-#define fr_dir(fp)	(fr_cmd(fp)->sc_data_direction)
+#define fr_fsp(fp)	(fr_cb(fp)->fr_fsp)
 #define fr_crc(fp)	(fr_cb(fp)->fr_crc)
 
 struct fc_frame {
@@ -66,7 +65,7 @@
 	struct packet_type  *ptype;
 	struct fc_lport	*fr_dev;	/* transport layer private pointer */
 	struct fc_seq	*fr_seq;	/* for use with exchange manager */
-	struct scsi_cmnd *fr_cmd;	/* for use of scsi command */
+	struct fc_fcp_pkt *fr_fsp;	/* for the corresponding fcp I/O */
 	u32		fr_crc;
 	u16		fr_max_payload;	/* max FC payload */
 	enum fc_sof	fr_sof;		/* start of frame delimiter */
@@ -218,20 +217,6 @@
 	return fc_frame_rctl(fp) == FC_RCTL_DD_UNSOL_CMD;
 }
 
-static inline bool fc_frame_is_read(const struct fc_frame *fp)
-{
-	if (fc_frame_is_cmd(fp) && fr_cmd(fp))
-		return fr_dir(fp) == DMA_FROM_DEVICE;
-	return false;
-}
-
-static inline bool fc_frame_is_write(const struct fc_frame *fp)
-{
-	if (fc_frame_is_cmd(fp) && fr_cmd(fp))
-		return fr_dir(fp) == DMA_TO_DEVICE;
-	return false;
-}
-
 /*
  * Check for leaks.
  * Print the frame header of any currently allocated frame, assuming there