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author | Sachin Saxena <sachin.saxena@freescale.com> | 2018-02-28 20:28:52 +0530 |
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committer | Sachin Saxena <sachin.saxena@nxp.com> | 2018-02-28 20:34:56 +0530 |
commit | 0689fce93ba269c48f83a2f70f971b3976d04c90 (patch) | |
tree | 4cc2908df3598507cc1828ac19d8c43b22450ffa /src/vnet/l2/feat_bitmap.h | |
parent | 746b57564deede624261ab8a96c94f562f24d22c (diff) | |
parent | d594711a5d79859a7d0bde83a516f7ab52051d9b (diff) |
Merge branch 'stable/1710' of https://gerrit.fd.io/r/vpp into 17101710
Diffstat (limited to 'src/vnet/l2/feat_bitmap.h')
-rw-r--r-- | src/vnet/l2/feat_bitmap.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/src/vnet/l2/feat_bitmap.h b/src/vnet/l2/feat_bitmap.h new file mode 100644 index 00000000..5940ff7e --- /dev/null +++ b/src/vnet/l2/feat_bitmap.h @@ -0,0 +1,110 @@ +/* + * feat_bitmap.h: bitmap for managing feature invocation + * + * Copyright (c) 2013 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef included_vnet_l2_feat_bitmap_h +#define included_vnet_l2_feat_bitmap_h + +#include <vlib/vlib.h> +#include <vnet/vnet.h> + +/* + * The feature bitmap is a way of organizing input and output feature graph nodes. + * The set of features to be executed are arranged in a bitmap with one bit per + * feature and each bit positioned in the same order that the features should be + * executed. Features can be dynamically removed from the set by masking off their + * corresponding bits. The bitmap is stored in packet context. Each feature clears + * its bit and then calls feat_bitmap_get_next_node_index() to go to the next + * graph node. + */ + + +/* 32 features in a u32 bitmap */ +#define FEAT_MAX 32 + +/** + Initialize the feature next-node indexes of a graph node. + Should be called by the init function of each feature graph node. +*/ +always_inline void +feat_bitmap_init_next_nodes (vlib_main_t * vm, u32 node_index, /* the current graph node index */ + u32 num_features, /* number of entries in feat_names */ + char **feat_names, /* array of feature graph node names */ + u32 * next_nodes) /* array of 32 next indexes to init */ +{ + u32 idx; + + ASSERT (num_features <= FEAT_MAX); + + for (idx = 0; idx < num_features; idx++) + { + if (vlib_get_node_by_name (vm, (u8 *) feat_names[idx])) + { + next_nodes[idx] = + vlib_node_add_named_next (vm, node_index, feat_names[idx]); + } + else + { // Node may be in plugin which is not installed, use drop node + next_nodes[idx] = + vlib_node_add_named_next (vm, node_index, "feature-bitmap-drop"); + } + } + + /* All unassigned bits go to the drop node */ + for (; idx < FEAT_MAX; idx++) + { + next_nodes[idx] = vlib_node_add_named_next (vm, node_index, + "feature-bitmap-drop"); + } +} + +/** + Return the graph node index for the feature corresponding to the + first set bit in the bitmap. +*/ +always_inline u32 +feat_bitmap_get_next_node_index (u32 * next_nodes, u32 bitmap) +{ + u32 first_bit; + + count_leading_zeros (first_bit, bitmap); + first_bit = uword_bits - 1 - first_bit; + return next_nodes[first_bit]; +} + +/** + Return the graph node index for the feature corresponding to the next + set bit after clearing the current feature bit in the feature_bitmap + of the current packet. +*/ +always_inline u32 +vnet_l2_feature_next (vlib_buffer_t * b, u32 * next_nodes, u32 feat_bit) +{ + vnet_buffer (b)->l2.feature_bitmap &= ~feat_bit; + u32 fb = vnet_buffer (b)->l2.feature_bitmap; + ASSERT (fb != 0); + return feat_bitmap_get_next_node_index (next_nodes, fb); +} + +#endif /* included_vnet_l2_feat_bitmap_h */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |