Improve L2 Input/Output Feature Infrastructure and Usage

Simplify L2 output feature infra to unify with L2 input feature
infra using the newly improved feature bitmap mechanism.
Updated all L2 features to use the more efficient infra functions.

Change-Id: If8f463826b0af0717129befe92a27ea8cfc40449
Signed-off-by: John Lo <loj@cisco.com>

1 files changed, 69 insertions, 46 deletions

diff --git a/src/vnet/l2/l2_output.c b/src/vnet/l2/l2_output.c
index 51d5e1453fb..b3537a355cf 100644
--- a/src/vnet/l2/l2_output.c
+++ b/src/vnet/l2/l2_output.c
@@ -98,6 +98,57 @@ split_horizon_violation (u8 shg1, u8 shg2)
     }
 }
 
+/** Determine the next L2 node based on the output feature bitmap */
+static_always_inline void
+l2_output_dispatch (vlib_buffer_t * b0, vlib_node_runtime_t * node,
+		    u32 * cached_sw_if_index, u32 * cached_next_index,
+		    u32 sw_if_index, u32 feature_bitmap, u32 * next0)
+{
+  /*
+   * The output feature bitmap always have at least the L2 output bit set
+   * for a normal L2 interface (or 0 if the interface is changed from L2
+   * to L3 mode). So if the feature bitmap is 0 or just have L2 output bits set,
+   * we know there is no more feature and will just output packets on interface.
+   * Otherwise, get the index of the next feature node.
+   */
+  if (PREDICT_FALSE ((feature_bitmap & ~L2OUTPUT_FEAT_OUTPUT) != 0))
+    {
+      /* Save bitmap for the next feature graph nodes */
+      vnet_buffer (b0)->l2.feature_bitmap = feature_bitmap;
+
+      /* Determine the next node */
+      *next0 =
+	feat_bitmap_get_next_node_index (l2output_main.l2_out_feat_next,
+					 feature_bitmap);
+    }
+  else
+    {
+      /*
+       * There are no features. Send packet to TX node for sw_if_index0
+       * This is a little tricky in that the output interface next node indexes
+       * are not precomputed at init time.
+       */
+
+      if (sw_if_index == *cached_sw_if_index)
+	{
+	  /* We hit in the one-entry cache. Use it. */
+	  *next0 = *cached_next_index;
+	}
+      else
+	{
+	  /* Look up the output TX node for the sw_if_index */
+	  *next0 = vec_elt (l2output_main.output_node_index_vec, sw_if_index);
+
+	  if (PREDICT_FALSE (*next0 == L2OUTPUT_NEXT_DROP))
+	    b0->error = node->errors[L2OUTPUT_ERROR_MAPPING_DROP];
+
+	  /* Update the one-entry cache */
+	  *cached_sw_if_index = sw_if_index;
+	  *cached_next_index = *next0;
+	}
+    }
+}
+
 static_always_inline void
 l2output_vtr (vlib_node_runtime_t * node, l2_output_config_t * config,
 	      u32 feature_bitmap, vlib_buffer_t * b, u32 * next)
@@ -239,41 +290,18 @@ l2output_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  feature_bitmap3 = config3->feature_bitmap;
 
 	  /* Determine next node */
-	  l2_output_dispatch (msm->vlib_main,
-			      msm->vnet_main,
-			      node,
-			      l2output_node.index,
-			      &cached_sw_if_index,
-			      &cached_next_index,
-			      &msm->next_nodes,
-			      b0, sw_if_index0, feature_bitmap0, &next0);
-
-	  l2_output_dispatch (msm->vlib_main,
-			      msm->vnet_main,
-			      node,
-			      l2output_node.index,
-			      &cached_sw_if_index,
-			      &cached_next_index,
-			      &msm->next_nodes,
-			      b1, sw_if_index1, feature_bitmap1, &next1);
-
-	  l2_output_dispatch (msm->vlib_main,
-			      msm->vnet_main,
-			      node,
-			      l2output_node.index,
-			      &cached_sw_if_index,
-			      &cached_next_index,
-			      &msm->next_nodes,
-			      b2, sw_if_index2, feature_bitmap2, &next2);
-
-	  l2_output_dispatch (msm->vlib_main,
-			      msm->vnet_main,
-			      node,
-			      l2output_node.index,
-			      &cached_sw_if_index,
-			      &cached_next_index,
-			      &msm->next_nodes,
-			      b3, sw_if_index3, feature_bitmap3, &next3);
+	  l2_output_dispatch (b0, node, &cached_sw_if_index,
+			      &cached_next_index, sw_if_index0,
+			      feature_bitmap0, &next0);
+	  l2_output_dispatch (b1, node, &cached_sw_if_index,
+			      &cached_next_index, sw_if_index1,
+			      feature_bitmap1, &next1);
+	  l2_output_dispatch (b2, node, &cached_sw_if_index,
+			      &cached_next_index, sw_if_index2,
+			      feature_bitmap2, &next2);
+	  l2_output_dispatch (b3, node, &cached_sw_if_index,
+			      &cached_next_index, sw_if_index3,
+			      feature_bitmap3, &next3);
 
 	  l2output_vtr (node, config0, feature_bitmap0, b0, &next0);
 	  l2output_vtr (node, config1, feature_bitmap1, b1, &next1);
@@ -401,14 +429,9 @@ l2output_node_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  feature_bitmap0 = config0->feature_bitmap;
 
 	  /* Determine next node */
-	  l2_output_dispatch (msm->vlib_main,
-			      msm->vnet_main,
-			      node,
-			      l2output_node.index,
-			      &cached_sw_if_index,
-			      &cached_next_index,
-			      &msm->next_nodes,
-			      b0, sw_if_index0, feature_bitmap0, &next0);
+	  l2_output_dispatch (b0, node, &cached_sw_if_index,
+			      &cached_next_index, sw_if_index0,
+			      feature_bitmap0, &next0);
 
 	  l2output_vtr (node, config0, feature_bitmap0, b0, &next0);
 
@@ -598,10 +621,10 @@ VLIB_NODE_FUNCTION_MULTIARCH (l2output_node, l2output_node_fn)
 			       l2output_node.index,
 			       L2OUTPUT_N_FEAT,
 			       l2output_get_feat_names (),
-			       mp->next_nodes.feat_next_node_index);
+			       mp->l2_out_feat_next);
 
   /* Initialize the output node mapping table */
-  vec_validate_init_empty (mp->next_nodes.output_node_index_vec, 100,
+  vec_validate_init_empty (mp->output_node_index_vec, 100,
 			   L2OUTPUT_NEXT_DROP);
 
   return 0;
@@ -621,7 +644,7 @@ l2output_create_output_node_mapping (vlib_main_t * vlib_main,
   /* dynamically create graph node arc  */
   u32 next = vlib_node_add_next (vlib_main, l2output_node.index,
 				 hw0->output_node_index);
-  l2output_main.next_nodes.output_node_index_vec[sw_if_index] = next;
+  l2output_main.output_node_index_vec[sw_if_index] = next;
 }
 
 /* Get a pointer to the config for the given interface */