3 files changed, 78 insertions, 49 deletions

diff --git a/drivers/target/tcm_fc/tcm_fc.h b/drivers/target/tcm_fc/tcm_fc.h
index f7fff7ed63c3..bd4fe21a23b8 100644
--- a/drivers/target/tcm_fc/tcm_fc.h
+++ b/drivers/target/tcm_fc/tcm_fc.h
@@ -187,4 +187,9 @@ void ft_dump_cmd(struct ft_cmd *, const char *caller);
 
 ssize_t ft_format_wwn(char *, size_t, u64);
 
+/*
+ * Underlying HW specific helper function
+ */
+void ft_invl_hw_context(struct ft_cmd *);
+
 #endif /* __TCM_FC_H__ */
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index a9e9a31da11d..03977e8996d8 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -320,6 +320,7 @@ static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
 	default:
 		pr_debug("%s: unhandled frame r_ctl %x\n",
 		       __func__, fh->fh_r_ctl);
+		ft_invl_hw_context(cmd);
 		fc_frame_free(fp);
 		transport_generic_free_cmd(&cmd->se_cmd, 0, 0);
 		break;
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c
index 11e6483fc127..06943eeb3c84 100644
--- a/drivers/target/tcm_fc/tfc_io.c
+++ b/drivers/target/tcm_fc/tfc_io.c
@@ -214,62 +214,49 @@ void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 	if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 		goto drop;
 
+	f_ctl = ntoh24(fh->fh_f_ctl);
+	ep = fc_seq_exch(seq);
+	lport = ep->lp;
+	if (cmd->was_ddp_setup) {
+		BUG_ON(!ep);
+		BUG_ON(!lport);
+	}
+
 	/*
-	 * Doesn't expect even single byte of payload. Payload
+	 * Doesn't expect payload if DDP is setup. Payload
 	 * is expected to be copied directly to user buffers
-	 * due to DDP (Large Rx offload) feature, hence
-	 * BUG_ON if BUF is non-NULL
+	 * due to DDP (Large Rx offload),
 	 */
 	buf = fc_frame_payload_get(fp, 1);
-	if (cmd->was_ddp_setup && buf) {
-		pr_debug("%s: When DDP was setup, not expected to"
-				 "receive frame with payload, Payload shall be"
-				 "copied directly to buffer instead of coming "
-				 "via. legacy receive queues\n", __func__);
-		BUG_ON(buf);
-	}
+	if (buf)
+		pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
+				"cmd->sg_cnt 0x%x. DDP was setup"
+				" hence not expected to receive frame with "
+				"payload, Frame will be dropped if "
+				"'Sequence Initiative' bit in f_ctl is "
+				"not set\n", __func__, ep->xid, f_ctl,
+				cmd->sg, cmd->sg_cnt);
+	/*
+ 	 * Invalidate HW DDP context if it was setup for respective
+ 	 * command. Invalidation of HW DDP context is requited in both
+ 	 * situation (success and error). 
+ 	 */
+	ft_invl_hw_context(cmd);
 
 	/*
-	 * If ft_cmd indicated 'ddp_setup', in that case only the last frame
-	 * should come with 'TSI bit being set'. If 'TSI bit is not set and if
-	 * data frame appears here, means error condition. In both the cases
-	 * release the DDP context (ddp_put) and in error case, as well
-	 * initiate error recovery mechanism.
+	 * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
+	 * write data frame is received successfully where payload is
+	 * posted directly to user buffer and only the last frame's
+	 * header is posted in receive queue.
+	 *
+	 * If "Sequence Initiative (TSI)" bit is not set, means error
+	 * condition w.r.t. DDP, hence drop the packet and let explict
+	 * ABORTS from other end of exchange timer trigger the recovery.
 	 */
-	ep = fc_seq_exch(seq);
-	if (cmd->was_ddp_setup) {
-		BUG_ON(!ep);
-		lport = ep->lp;
-		BUG_ON(!lport);
-	}
-	if (cmd->was_ddp_setup && ep->xid != FC_XID_UNKNOWN) {
-		f_ctl = ntoh24(fh->fh_f_ctl);
-		/*
-		 * If TSI bit set in f_ctl, means last write data frame is
-		 * received successfully where payload is posted directly
-		 * to user buffer and only the last frame's header is posted
-		 * in legacy receive queue
-		 */
-		if (f_ctl & FC_FC_SEQ_INIT) { /* TSI bit set in FC frame */
-			cmd->write_data_len = lport->tt.ddp_done(lport,
-								ep->xid);
-			goto last_frame;
-		} else {
-			/*
-			 * Updating the write_data_len may be meaningless at
-			 * this point, but just in case if required in future
-			 * for debugging or any other purpose
-			 */
-			pr_err("%s: Received frame with TSI bit not"
-					" being SET, dropping the frame, "
-					"cmd->sg <%p>, cmd->sg_cnt <0x%x>\n",
-					__func__, cmd->sg, cmd->sg_cnt);
-			cmd->write_data_len = lport->tt.ddp_done(lport,
-							      ep->xid);
-			lport->tt.seq_exch_abort(cmd->seq, 0);
-			goto drop;
-		}
-	}
+	if (f_ctl & FC_FC_SEQ_INIT)
+		goto last_frame;
+	else
+		goto drop;
 
 	rel_off = ntohl(fh->fh_parm_offset);
 	frame_len = fr_len(fp);
@@ -332,3 +319,39 @@ last_frame:
 drop:
 	fc_frame_free(fp);
 }
+
+/*
+ * Handle and cleanup any HW specific resources if
+ * received ABORTS, errors, timeouts.
+ */
+void ft_invl_hw_context(struct ft_cmd *cmd)
+{
+	struct fc_seq *seq = cmd->seq;
+	struct fc_exch *ep = NULL;
+	struct fc_lport *lport = NULL;
+
+	BUG_ON(!cmd);
+
+	/* Cleanup the DDP context in HW if DDP was setup */
+	if (cmd->was_ddp_setup && seq) {
+		ep = fc_seq_exch(seq);
+		if (ep) {
+			lport = ep->lp;
+			if (lport && (ep->xid <= lport->lro_xid))
+				/*
+				 * "ddp_done" trigger invalidation of HW
+				 * specific DDP context
+				 */
+				cmd->write_data_len = lport->tt.ddp_done(lport,
+								      ep->xid);
+
+				/*
+				 * Resetting same variable to indicate HW's
+				 * DDP context has been invalidated to avoid
+				 * re_invalidation of same context (context is
+				 * identified using ep->xid)
+				 */
+				cmd->was_ddp_setup = 0;
+		}
+	}
+}