From 239e81048b7dcd27448db40c845f88ac7c68424e Mon Sep 17 00:00:00 2001
From: Joe Eykholt <jeykholt@cisco.com>
Date: Tue, 20 Jul 2010 15:21:07 -0700
Subject: [PATCH] [SCSI] libfc: add interface to allocate a sequence for
 incoming requests

For incoming ELS and FCP requests, we often don't require an
exchange and sequence, however, sometimes we do.  For those cases,
(primarily FCP requests for targets) add a function to set up
the exchange and sequence.

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 | 25 +++++++++++++++++++++++++
 include/scsi/libfc.h         |  7 +++++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index 61eabd3ce436..027042a6de3b 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -1230,6 +1230,28 @@ free:
 	fc_frame_free(rx_fp);
 }
 
+/**
+ * fc_seq_assign() - Assign exchange and sequence for incoming request
+ * @lport: The local port that received the request
+ * @fp:    The request frame
+ *
+ * On success, the sequence pointer will be returned and also in fr_seq(@fp).
+ */
+static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
+{
+	struct fc_exch_mgr_anchor *ema;
+
+	WARN_ON(lport != fr_dev(fp));
+	WARN_ON(fr_seq(fp));
+	fr_seq(fp) = NULL;
+
+	list_for_each_entry(ema, &lport->ema_list, ema_list)
+		if ((!ema->match || ema->match(fp)) &&
+		    fc_seq_lookup_recip(lport, ema->mp, fp) != FC_RJT_NONE)
+			break;
+	return fr_seq(fp);
+}
+
 /**
  * fc_exch_recv_req() - Handler for an incoming request where is other
  *			end is originating the sequence
@@ -2283,6 +2305,9 @@ int fc_exch_init(struct fc_lport *lport)
 	if (!lport->tt.seq_exch_abort)
 		lport->tt.seq_exch_abort = fc_seq_exch_abort;
 
+	if (!lport->tt.seq_assign)
+		lport->tt.seq_assign = fc_seq_assign;
+
 	return 0;
 }
 EXPORT_SYMBOL(fc_exch_init);
diff --git a/include/scsi/libfc.h b/include/scsi/libfc.h
index a6414ec63809..605f1d7861a7 100644
--- a/include/scsi/libfc.h
+++ b/include/scsi/libfc.h
@@ -555,6 +555,13 @@ struct libfc_function_template {
 	 */
 	struct fc_seq *(*seq_start_next)(struct fc_seq *);
 
+	/*
+	 * Assign a sequence for an incoming request frame.
+	 *
+	 * STATUS: OPTIONAL
+	 */
+	struct fc_seq *(*seq_assign)(struct fc_lport *, struct fc_frame *);
+
 	/*
 	 * Reset an exchange manager, completing all sequences and exchanges.
 	 * If s_id is non-zero, reset only exchanges originating from that FID.