Merge citrix branch into master.

[sliver-openvswitch.git] / datapath / datapath.h

diff --git a/datapath/datapath.h b/datapath/datapath.h
index b520084..122706a 100644 (file)
--- 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 *);