mlxsw: spectrum_router: Prepare work context for possible bulking

For XMDR register it is possible to carry multiple FIB entry
operations in a single write. However the FW does not restrict mixing
the types of operations, make the code easier and indicate the bulking
is ok only in case the bulk contains FIB operations of the same family
and event.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -6191,14 +6191,25 @@ static void mlxsw_sp_router_fib_event_work(struct work_struct *work)
 	struct mlxsw_sp_router *router = container_of(work, struct mlxsw_sp_router, fib_event_work);
 	struct mlxsw_sp_fib_entry_op_ctx op_ctx = {};
 	struct mlxsw_sp *mlxsw_sp = router->mlxsw_sp;
-	struct mlxsw_sp_fib_event *fib_event, *tmp;
+	struct mlxsw_sp_fib_event *next_fib_event;
+	struct mlxsw_sp_fib_event *fib_event;
 	LIST_HEAD(fib_event_queue);
 
 	spin_lock_bh(&router->fib_event_queue_lock);
 	list_splice_init(&router->fib_event_queue, &fib_event_queue);
 	spin_unlock_bh(&router->fib_event_queue_lock);
 
-	list_for_each_entry_safe(fib_event, tmp, &fib_event_queue, list) {
+	list_for_each_entry_safe(fib_event, next_fib_event,
+				 &fib_event_queue, list) {
+		/* Check if the next entry in the queue exists and it is
+		 * of the same type (family and event) as the currect one.
+		 * In that case it is permitted to do the bulking
+		 * of multiple FIB entries to a single register write.
+		 */
+		op_ctx.bulk_ok = !list_is_last(&fib_event->list, &fib_event_queue) &&
+				 fib_event->family == next_fib_event->family &&
+				 fib_event->event == next_fib_event->event;
+
 		switch (fib_event->family) {
 		case AF_INET:
 			mlxsw_sp_router_fib4_event_process(mlxsw_sp, &op_ctx,

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h

@@ -61,6 +61,7 @@ enum mlxsw_sp_fib_entry_op {
 };
 
 struct mlxsw_sp_fib_entry_op_ctx {
+	u8 bulk_ok:1;
 	char ralue_pl[MLXSW_REG_RALUE_LEN];
 };