dpif-netdev: Split out generic lookup function

This commit splits the generic hash-lookup-verify function to its own file, for cleaner seperation between optimized versions. Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com> Tested-by: Malvika Gupta <malvika.gupta@arm.com> Acked-by: Ilya Maximets <i.maximets@samsung.com> Signed-off-by: Ian Stokes <ian.stokes@intel.com>
2025-08-31 14:25:26 +00:00 · 2019-07-18 14:03:04 +01:00
parent f5ace7cd8a
commit 92c7c870d6
3 changed files with 100 additions and 68 deletions
--- a/lib/dpif-netdev-lookup-generic.c
+++ b/lib/dpif-netdev-lookup-generic.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014, 2016, 2017 Nicira, Inc.
+ * Copyright (c) 2019 Intel Corporation.
+ *
+ * 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.
+ */
+
+#include <config.h>
+#include "dpif-netdev.h"
+#include "dpif-netdev-private.h"
+
+#include "bitmap.h"
+#include "cmap.h"
+
+#include "dp-packet.h"
+#include "dpif.h"
+#include "dpif-netdev-perf.h"
+#include "dpif-provider.h"
+#include "flow.h"
+#include "packets.h"
+#include "pvector.h"
+
+/* Returns a hash value for the bits of 'key' where there are 1-bits in
+ * 'mask'. */
+static inline uint32_t
+netdev_flow_key_hash_in_mask(const struct netdev_flow_key *key,
+                             const struct netdev_flow_key *mask)
+{
+    const uint64_t *p = miniflow_get_values(&mask->mf);
+    uint32_t hash = 0;
+    uint64_t value;
+
+    NETDEV_FLOW_KEY_FOR_EACH_IN_FLOWMAP (value, key, mask->mf.map) {
+        hash = hash_add64(hash, value & *p);
+        p++;
+    }
+
+    return hash_finish(hash, (p - miniflow_get_values(&mask->mf)) * 8);
+}
+
+uint32_t
+dpcls_subtable_lookup_generic(struct dpcls_subtable *subtable,
+                              uint32_t keys_map,
+                              const struct netdev_flow_key *keys[],
+                              struct dpcls_rule **rules)
+{
+    int i;
+    uint32_t found_map;
+
+    /* Compute hashes for the remaining keys.  Each search-key is
+     * masked with the subtable's mask to avoid hashing the wildcarded
+     * bits. */
+    uint32_t hashes[NETDEV_MAX_BURST];
+    ULLONG_FOR_EACH_1 (i, keys_map) {
+        hashes[i] = netdev_flow_key_hash_in_mask(keys[i], &subtable->mask);
+    }
+
+    /* Lookup. */
+    const struct cmap_node *nodes[NETDEV_MAX_BURST];
+    found_map = cmap_find_batch(&subtable->rules, keys_map, hashes, nodes);
+
+    /* Check results.  When the i-th bit of found_map is set, it means
+     * that a set of nodes with a matching hash value was found for the
+     * i-th search-key.  Due to possible hash collisions we need to check
+     * which of the found rules, if any, really matches our masked
+     * search-key. */
+    ULLONG_FOR_EACH_1 (i, found_map) {
+        struct dpcls_rule *rule;
+
+        CMAP_NODE_FOR_EACH (rule, cmap_node, nodes[i]) {
+            if (OVS_LIKELY(dpcls_rule_matches_key(rule, keys[i]))) {
+                rules[i] = rule;
+                /* Even at 20 Mpps the 32-bit hit_cnt cannot wrap
+                 * within one second optimization interval. */
+                subtable->hit_cnt++;
+                goto next;
+            }
+        }
+
+        /* None of the found rules was a match.  Reset the i-th bit to
+         * keep searching this key in the next subtable. */
+        ULLONG_SET0(found_map, i);  /* Did not match. */
+    next:
+        ; /* Keep Sparse happy. */
+    }
+
+    return found_map;
+}