[ofa-general] [PATCH] Add LMC support to DOR routing

[Dale Purdy]

DOR routing equilizes traffic across redundant links representing
dimensions.  This change makes DOR compatible with LMC and tries to
equilize traffic across redundant links between LMC aliased LIDs.

Signed-off-by: Dale Purdy <purdy at sgi.com>
---
 opensm/include/opensm/osm_switch.h |    4 +++
 opensm/opensm/osm_switch.c         |   42 +++++++++++++++++++++++------------
 opensm/opensm/osm_ucast_mgr.c      |    8 +++++-
 3 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/opensm/include/opensm/osm_switch.h b/opensm/include/opensm/osm_switch.h
index 0b15e63..7ce28c5 100644
--- a/opensm/include/opensm/osm_switch.h
+++ b/opensm/include/opensm/osm_switch.h
@@ -167,6 +167,7 @@ struct osm_remote_guids_count {
 	struct osm_remote_node {
 		osm_node_t *node;
 		unsigned forwarded_to;
+		uint8_t port;
 	} guids[0];
 };
 /*
@@ -179,6 +180,9 @@ struct osm_remote_guids_count {
 *
 *	forwarded_to
 *		A count of lids forwarded to this node.
+*
+*	port
+*		Port number on the node.
 *********/
 
 /****f* OpenSM: Switch/osm_switch_delete
diff --git a/opensm/opensm/osm_switch.c b/opensm/opensm/osm_switch.c
index 6dde47c..d236329 100644
--- a/opensm/opensm/osm_switch.c
+++ b/opensm/opensm/osm_switch.c
@@ -303,6 +303,7 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
 	osm_node_t *p_rem_node;
 	osm_node_t *p_rem_node_first = NULL;
 	struct osm_remote_node *p_remote_guid = NULL;
+	struct osm_remote_node null_remote_node = {NULL, 0, 0};
 
 	CL_ASSERT(lid_ho > 0);
 
@@ -413,12 +414,37 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
 		check_count =
 		    osm_port_prof_path_count_get(&p_sw->p_prof[port_num]);
 
+		if (dor) {
+			/* Get the Remote Node */
+			p_rem_physp = osm_physp_get_remote(p_physp);
+			p_rem_node = osm_physp_get_node_ptr(p_rem_physp);
+			/* use the first dimension, but spread traffic
+			 * out among the group of ports representing
+			 * that dimension */
+			if (!p_rem_node_first)
+				p_rem_node_first = p_rem_node;
+			else if (p_rem_node != p_rem_node_first)
+				continue;
+			if (routing_for_lmc) {
+				struct osm_remote_guids_count *r = p_port->priv;
+				uint8_t rem_port = osm_physp_get_port_num(p_rem_physp);
+				int j;
+
+				for (j = 0; j < r->count; j++) {
+					p_remote_guid = &r->guids[j];
+					if ((p_remote_guid->node == p_rem_node)
+					    && (p_remote_guid->port == rem_port))
+						break;
+				}
+				if (j == r->count)
+					p_remote_guid = &null_remote_node;
+			}
 		/*
 		   Advanced LMC routing requires tracking of the
 		   best port by the node connected to the other side of
 		   it.
 		 */
-		if (routing_for_lmc) {
+		} else if (routing_for_lmc) {
 			/* Is the sys guid already used ? */
 			p_remote_guid = osm_switch_find_sys_guid_count(p_sw,
 								       p_port->priv,
@@ -454,20 +480,6 @@ osm_switch_recommend_path(IN const osm_switch_t * const p_sw,
 		   the count is min but also lower then the max subscribed
 		 */
 		if (check_count < least_paths) {
-			if (dor) {
-				/* Get the Remote Node */
-				p_rem_physp = osm_physp_get_remote(p_physp);
-				p_rem_node =
-				    osm_physp_get_node_ptr(p_rem_physp);
-				/* use the first dimension, but spread
-				 * traffic out among the group of ports
-				 * representing that dimension */
-				if (port_found) {
-					if (p_rem_node != p_rem_node_first)
-						continue;
-				} else
-					p_rem_node_first = p_rem_node;
-			}
 			port_found = TRUE;
 			best_port = port_num;
 			least_paths = check_count;
diff --git a/opensm/opensm/osm_ucast_mgr.c b/opensm/opensm/osm_ucast_mgr.c
index fe0a446..90d9732 100644
--- a/opensm/opensm/osm_ucast_mgr.c
+++ b/opensm/opensm/osm_ucast_mgr.c
@@ -186,19 +186,22 @@ __osm_ucast_mgr_process_neighbor(IN osm_ucast_mgr_t * const p_mgr,
 /**********************************************************************
  **********************************************************************/
 static struct osm_remote_node *
-find_and_add_remote_sys(osm_switch_t *sw, uint8_t port,
+find_and_add_remote_sys(osm_switch_t *sw, uint8_t port, const boolean_t dor,
 			struct osm_remote_guids_count *r)
 {
 	unsigned i;
 	osm_physp_t *p = osm_node_get_physp_ptr(sw->p_node, port);
 	osm_node_t *node = p->p_remote_physp->p_node;
+	uint8_t rem_port = osm_physp_get_port_num(p->p_remote_physp);
 
 	for (i = 0; i < r->count; i++)
 		if (r->guids[i].node == node)
+		  if (!dor || (r->guids[i].port == rem_port))
 			return &r->guids[i];
 
 	r->guids[i].node = node;
 	r->guids[i].forwarded_to = 0;
+	r->guids[i].port = rem_port;
 	r->count++;
 	return &r->guids[i];
 }
@@ -236,7 +239,7 @@ __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
 	if (lid_ho > max_lid_ho)
 		goto Exit;
 
-	if (lid_offset)
+	if (lid_offset && !p_mgr->is_dor)
 		/* ignore potential overflow - it is handled in osm_switch.c */
 		start_from = osm_switch_get_port_by_lid(p_sw, lid_ho - 1) + 1;
 
@@ -302,6 +305,7 @@ __osm_ucast_mgr_process_port(IN osm_ucast_mgr_t * const p_mgr,
 		osm_switch_count_path(p_sw, port);
 		if (port > 0 && p_port->priv &&
 		    (rem_node_used = find_and_add_remote_sys(p_sw, port,
+							     p_mgr->is_dor,
 							     p_port->priv)))
 			rem_node_used->forwarded_to++;
 	}
-- 
1.6.2