From: Ben Pfaff <blp@nicira.com>
Date: Tue, 30 Nov 2010 23:58:55 +0000 (-0800)
Subject: datapath: Change vals[] in struct port_lookup_key into discrete members.
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4029c21acb33723ecc3f621c1c75819651889b58;p=openvswitch

datapath: Change vals[] in struct port_lookup_key into discrete members.

The 'vals' array is only convenient for use by port_hash().  It's a
liability otherwise, since it makes the code wider and harder to read and
seems to me less amenable to compiler optimization.

In an upcoming patch the key needed in struct port_lookup_key will
increase in size to 64 bits, so that using an array of u32 becomes even
more problematic.  Therefore, this commit gets rid of the array in favor
of discrete named members that carry the same information.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
---

diff --git a/datapath/tunnel.c b/datapath/tunnel.c
index e666a917..d3625d35 100644
--- a/datapath/tunnel.c
+++ b/datapath/tunnel.c
@@ -164,15 +164,11 @@ static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
 	}
 }
 
-enum lookup_key {
-	LOOKUP_TUNNEL_TYPE	= 0,
-	LOOKUP_SADDR		= 1,
-	LOOKUP_DADDR		= 2,
-	LOOKUP_KEY		= 3,
-};
-
 struct port_lookup_key {
-	u32 vals[4];			/* Contains enum lookup_key keys. */
+	u32 tunnel_type;
+	__be32 saddr;
+	__be32 daddr;
+	__be32 key;
 	const struct tnl_mutable_config *mutable;
 };
 
@@ -187,25 +183,25 @@ static int port_cmp(const struct tbl_node *node, void *target)
 
 	lookup->mutable = rcu_dereference(tnl_vport->mutable);
 
-	return (lookup->mutable->tunnel_type == lookup->vals[LOOKUP_TUNNEL_TYPE]) &&
-	       lookup->mutable->port_config.daddr == lookup->vals[LOOKUP_DADDR] &&
-	       lookup->mutable->port_config.in_key == lookup->vals[LOOKUP_KEY] &&
-	       lookup->mutable->port_config.saddr == lookup->vals[LOOKUP_SADDR];
+	return (lookup->mutable->tunnel_type == lookup->tunnel_type &&
+		lookup->mutable->port_config.daddr == lookup->daddr &&
+		lookup->mutable->port_config.in_key == lookup->key &&
+		lookup->mutable->port_config.saddr == lookup->saddr);
 }
 
-static u32 port_hash(struct port_lookup_key *lookup)
+static u32 port_hash(struct port_lookup_key *k)
 {
-	return jhash2(lookup->vals, ARRAY_SIZE(lookup->vals), 0);
+	return jhash_3words(k->key, k->saddr, k->daddr, k->tunnel_type);
 }
 
 static u32 mutable_hash(const struct tnl_mutable_config *mutable)
 {
 	struct port_lookup_key lookup;
 
-	lookup.vals[LOOKUP_SADDR] = mutable->port_config.saddr;
-	lookup.vals[LOOKUP_DADDR] = mutable->port_config.daddr;
-	lookup.vals[LOOKUP_KEY] = mutable->port_config.in_key;
-	lookup.vals[LOOKUP_TUNNEL_TYPE] = mutable->tunnel_type;
+	lookup.saddr = mutable->port_config.saddr;
+	lookup.daddr = mutable->port_config.daddr;
+	lookup.key = mutable->port_config.in_key;
+	lookup.tunnel_type = mutable->tunnel_type;
 
 	return port_hash(&lookup);
 }
@@ -316,12 +312,12 @@ struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key,
 	if (unlikely(!table))
 		return NULL;
 
-	lookup.vals[LOOKUP_SADDR] = saddr;
-	lookup.vals[LOOKUP_DADDR] = daddr;
+	lookup.saddr = saddr;
+	lookup.daddr = daddr;
 
 	if (tunnel_type & TNL_T_KEY_EXACT) {
-		lookup.vals[LOOKUP_KEY] = key;
-		lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_MATCH;
+		lookup.key = key;
+		lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_MATCH;
 
 		if (key_local_remote_ports) {
 			tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
@@ -330,19 +326,19 @@ struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key,
 		}
 
 		if (key_remote_ports) {
-			lookup.vals[LOOKUP_SADDR] = 0;
+			lookup.saddr = 0;
 
 			tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
 			if (tbl_node)
 				goto found;
 
-			lookup.vals[LOOKUP_SADDR] = saddr;
+			lookup.saddr = saddr;
 		}
 	}
 
 	if (tunnel_type & TNL_T_KEY_MATCH) {
-		lookup.vals[LOOKUP_KEY] = 0;
-		lookup.vals[LOOKUP_TUNNEL_TYPE] = tunnel_type & ~TNL_T_KEY_EXACT;
+		lookup.key = 0;
+		lookup.tunnel_type = tunnel_type & ~TNL_T_KEY_EXACT;
 
 		if (local_remote_ports) {
 			tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
@@ -351,7 +347,7 @@ struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key,
 		}
 
 		if (remote_ports) {
-			lookup.vals[LOOKUP_SADDR] = 0;
+			lookup.saddr = 0;
 
 			tbl_node = tbl_lookup(table, &lookup, port_hash(&lookup), port_cmp);
 			if (tbl_node)