Update pipeline.h: use vlib_get_buffers

It's not clear that fine-graind pipelining will ever produce optimal
performance. That having been written, it's an easier coding model for
folks interesting in decent results without having to manually
implement 2 or 4 way fine-grained parallelism.

Change-Id: Ida877292832eaf759ffbb6d2e16012f8fbd427e5
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vnet/l2tp/decap.c b/src/vnet/l2tp/decap.c
index 304862b..334f1fe 100644
--- a/src/vnet/l2tp/decap.c
+++ b/src/vnet/l2tp/decap.c
@@ -56,18 +56,16 @@
 #define NSTAGES 3
 
 static inline void
-stage0 (vlib_main_t * vm, vlib_node_runtime_t * node, u32 buffer_index)
+stage0 (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
 {
-  vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
   vlib_prefetch_buffer_header (b, STORE);
   /* l2tpv3 header is a long way away, need 2 cache lines */
   CLIB_PREFETCH (b->data, 2 * CLIB_CACHE_LINE_BYTES, STORE);
 }
 
 static inline void
-stage1 (vlib_main_t * vm, vlib_node_runtime_t * node, u32 bi)
+stage1 (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
 {
-  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   l2t_main_t *lm = &l2t_main;
   ip6_header_t *ip6 = vlib_buffer_get_current (b);
   u32 session_index;
@@ -116,9 +114,8 @@
 }
 
 static inline u32
-last_stage (vlib_main_t * vm, vlib_node_runtime_t * node, u32 bi)
+last_stage (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_buffer_t * b)
 {
-  vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   l2t_main_t *lm = &l2t_main;
   ip6_header_t *ip6 = vlib_buffer_get_current (b);
   vlib_node_t *n = vlib_get_node (vm, node->node_index);