libfc: add method for setting handler for incoming exchange

Add a method for setting handler for incoming exchange.
For multi-sequence exchanges, this allows the target driver
to add a response handler for handling subsequent sequences,
and exchange manager resets.

The new function is called fc_seq_set_resp().

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>

---
 drivers/scsi/libfc/fc_exch.c |   19 +++++++++++++++++++
 include/scsi/libfc.h         |   11 ++++++++++-
 2 files changed, 29 insertions(+), 1 deletions(-)


---
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index ec2a1ae..0000ddf 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -544,6 +544,22 @@ static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
 	return sp;
 }
 
+/*
+ * Set the response handler for the exchange associated with a sequence.
+ */
+static void fc_seq_set_resp(struct fc_seq *sp,
+			    void (*resp)(struct fc_seq *, struct fc_frame *,
+					 void *),
+			    void *arg)
+{
+	struct fc_exch *ep = fc_seq_exch(sp);
+
+	spin_lock_bh(&ep->ex_lock);
+	ep->resp = resp;
+	ep->arg = arg;
+	spin_unlock_bh(&ep->ex_lock);
+}
+
 /**
  * fc_seq_exch_abort() - Abort an exchange and sequence
  * @req_sp:	The sequence to be aborted
@@ -2297,6 +2313,9 @@ int fc_exch_init(struct fc_lport *lport)
 	if (!lport->tt.seq_start_next)
 		lport->tt.seq_start_next = fc_seq_start_next;
 
+	if (!lport->tt.seq_set_resp)
+		lport->tt.seq_set_resp = fc_seq_set_resp;
+
 	if (!lport->tt.exch_seq_send)
 		lport->tt.exch_seq_send = fc_exch_seq_send;
 
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index 8b907e1..06cabab 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -564,6 +564,16 @@ struct libfc_function_template {
 	struct fc_seq *(*seq_assign)(struct fc_lport *, struct fc_frame *);
 
 	/*
+	 * Set a response handler for the exchange of the sequence.
+	 *
+	 * STATUS: OPTIONAL
+	 */
+	void (*seq_set_resp)(struct fc_seq *sp,
+			     void (*resp)(struct fc_seq *, struct fc_frame *,
+					  void *),
+			     void *arg);
+
+	/*
 	 * Reset an exchange manager, completing all sequences and exchanges.
 	 * If s_id is non-zero, reset only exchanges originating from that FID.
 	 * If d_id is non-zero, reset only exchanges sending to that FID.
@@ -1059,7 +1069,6 @@ void fc_fill_reply_hdr(struct fc_frame *, const struct fc_frame *,
 void fc_fill_hdr(struct fc_frame *, const struct fc_frame *,
 		 enum fc_rctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset);
 
-
 /*
  * EXCHANGE MANAGER LAYER
  *****************************/