[SCSI] 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>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/libfc/fc_exch.c

@@ -558,6 +558,22 @@ 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
@@ -2329,6 +2345,9 @@ 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;
 

include/scsi/libfc.h

@@ -554,6 +554,16 @@ struct libfc_function_template {
 	 */
 	struct fc_seq *(*seq_start_next)(struct fc_seq *);
 
+	/*
+	 * 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);
+
 	/*
 	 * Assign a sequence for an incoming request frame.
 	 *