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authorBen Pfaff <blp@nicira.com>2009-09-02 10:14:53 -0700
committerBen Pfaff <blp@nicira.com>2009-09-02 10:14:53 -0700
commitf1acd62b54376a425a975f9af501c4c8c5689b39 (patch)
treea579f967870b61d3a226acdc62cc079c8ce996d1 /datapath/datapath.h
parent2c7807ac4f578bfdd7a46b79028935c9aa34cde3 (diff)
parent0ad9b732910b8f1aa7fc47ea57ff79e7618a4e6d (diff)
Merge citrix branch into master.
Diffstat (limited to 'datapath/datapath.h')
-rw-r--r--datapath/datapath.h42
1 files changed, 38 insertions, 4 deletions
diff --git a/datapath/datapath.h b/datapath/datapath.h
index b5200848..122706a8 100644
--- a/datapath/datapath.h
+++ b/datapath/datapath.h
@@ -29,20 +29,54 @@
#define DP_MAX_PORTS 256
#define DP_MAX_GROUPS 16
-#define DP_L2_BITS (PAGE_SHIFT - ilog2(sizeof(struct sw_flow*)))
+#define DP_L2_BITS (PAGE_SHIFT - ilog2(sizeof(struct dp_bucket*)))
#define DP_L2_SIZE (1 << DP_L2_BITS)
#define DP_L2_SHIFT 0
-#define DP_L1_BITS (PAGE_SHIFT - ilog2(sizeof(struct sw_flow**)))
+#define DP_L1_BITS (PAGE_SHIFT - ilog2(sizeof(struct dp_bucket**)))
#define DP_L1_SIZE (1 << DP_L1_BITS)
#define DP_L1_SHIFT DP_L2_BITS
+/* For 4 kB pages, this is 1,048,576 on 32-bit or 262,144 on 64-bit. */
#define DP_MAX_BUCKETS (DP_L1_SIZE * DP_L2_SIZE)
+/**
+ * struct dp_table - flow table
+ * @n_buckets: number of buckets (a power of 2 between %DP_L1_SIZE and
+ * %DP_MAX_BUCKETS)
+ * @buckets: pointer to @n_buckets/%DP_L1_SIZE pointers to %DP_L1_SIZE pointers
+ * to buckets
+ * @hash_seed: random number used for flow hashing, to make the hash
+ * distribution harder to predict
+ * @rcu: RCU callback structure
+ *
+ * The @buckets array is logically an array of pointers to buckets. It is
+ * broken into two levels to avoid the need to kmalloc() any object larger than
+ * a single page or to use vmalloc(). @buckets is always nonnull, as is each
+ * @buckets[i], but each @buckets[i][j] is nonnull only if the specified hash
+ * bucket is nonempty (for 0 <= i < @n_buckets/%DP_L1_SIZE, 0 <= j <
+ * %DP_L1_SIZE).
+ */
struct dp_table {
unsigned int n_buckets;
- struct sw_flow ***flows[2];
+ struct dp_bucket ***buckets;
+ unsigned int hash_seed;
+ struct rcu_head rcu;
+};
+
+/**
+ * struct dp_bucket - single bucket within datapath flow table
+ * @rcu: RCU callback structure
+ * @n_flows: number of flows in @flows[] array
+ * @flows: array of @n_flows pointers to flows
+ *
+ * The expected number of flows per bucket is 1, but this allows for an
+ * arbitrary number of collisions.
+ */
+struct dp_bucket {
struct rcu_head rcu;
+ unsigned int n_flows;
+ struct sw_flow *flows[];
};
#define DP_N_QUEUES 2
@@ -105,7 +139,7 @@ extern int (*dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
struct dp_table *dp_table_create(unsigned int n_buckets);
void dp_table_destroy(struct dp_table *, int free_flows);
struct sw_flow *dp_table_lookup(struct dp_table *, const struct odp_flow_key *);
-struct sw_flow **dp_table_lookup_for_insert(struct dp_table *, const struct odp_flow_key *);
+int dp_table_insert(struct dp_table *, struct sw_flow *);
int dp_table_delete(struct dp_table *, struct sw_flow *);
int dp_table_expand(struct datapath *);
int dp_table_flush(struct datapath *);