datapath: Change listing flows to use an iterator concept.

[sliver-openvswitch.git] / datapath / table.c

diff --git a/datapath/table.c b/datapath/table.c
index d2432e8..35a532e 100644 (file)
--- a/datapath/table.c
+++ b/datapath/table.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009, 2010 Nicira Networks.
+ * Copyright (c) 2009, 2010, 2011 Nicira Networks.
  * Distributed under the terms of the GNU GPL version 2.
  *
  * Significant portions of this file may be copied from parts of the Linux
@@ -40,17 +40,18 @@ static struct tbl_bucket *bucket_alloc(int n_objs)
        return kmalloc(bucket_size(n_objs), GFP_KERNEL);
 }
 
-static void free_buckets(struct tbl_bucket ***l1, unsigned int n_buckets,
+static void free_buckets(struct tbl_bucket __rcu ***l1,
+                        unsigned int n_buckets,
                         void (*free_obj)(struct tbl_node *))
 {
        unsigned int i;
 
        for (i = 0; i < n_buckets >> TBL_L1_SHIFT; i++) {
-               struct tbl_bucket **l2 = l1[i];
+               struct tbl_bucket __rcu **l2 = l1[i];
                unsigned int j;
 
                for (j = 0; j < TBL_L2_SIZE; j++) {
-                       struct tbl_bucket *bucket = l2[j];
+                       struct tbl_bucket *bucket = (struct tbl_bucket __force *)l2[j];
                        if (!bucket)
                                continue;
 
@@ -66,9 +67,9 @@ static void free_buckets(struct tbl_bucket ***l1, unsigned int n_buckets,
        kfree(l1);
 }
 
-static struct tbl_bucket ***alloc_buckets(unsigned int n_buckets)
+static struct tbl_bucket __rcu ***alloc_buckets(unsigned int n_buckets)
 {
-       struct tbl_bucket ***l1;
+       struct tbl_bucket __rcu ***l1;
        unsigned int i;
 
        l1 = kmalloc((n_buckets >> TBL_L1_SHIFT) * sizeof(struct tbl_bucket **),
@@ -76,7 +77,7 @@ static struct tbl_bucket ***alloc_buckets(unsigned int n_buckets)
        if (!l1)
                return NULL;
        for (i = 0; i < n_buckets >> TBL_L1_SHIFT; i++) {
-               l1[i] = (struct tbl_bucket **)get_zeroed_page(GFP_KERNEL);
+               l1[i] = (struct tbl_bucket __rcu **)get_zeroed_page(GFP_KERNEL);
                if (!l1[i]) {
                        free_buckets(l1, i << TBL_L1_SHIFT, NULL);
                        return NULL;
@@ -97,7 +98,7 @@ struct tbl *tbl_create(unsigned int n_buckets)
 {
        struct tbl *table;
 
-       table = kzalloc(sizeof *table, GFP_KERNEL);
+       table = kzalloc(sizeof(*table), GFP_KERNEL);
        if (!table)
                goto err;
 
@@ -250,6 +251,53 @@ int tbl_foreach(struct tbl *table,
        return 0;
 }
 
+/**
+ * tbl_next - find next node in hash table
+ * @table: table to iterate
+ * @bucketp: On entry, hash value of bucket to start from.  On exit, updated
+ * to bucket to start from on next call.
+ * @objp: On entry, index to start from within first bucket.  On exit, updated
+ * to index to start from on next call.
+ *
+ * Returns the next node in @table in hash order, or %NULL when no nodes remain
+ * in the hash table.
+ *
+ * On entry, uses the values that @bucketp and @objp reference to determine
+ * where to begin iteration.  Use 0 for both values to begin a new iteration.
+ * On exit, stores the values to pass on the next iteration into @bucketp and
+ * @objp's referents.
+ */
+struct tbl_node *tbl_next(struct tbl *table, u32 *bucketp, u32 *objp)
+{
+       unsigned int n_l1 = table->n_buckets >> TBL_L1_SHIFT;
+       u32 s_l1_idx = *bucketp >> TBL_L1_SHIFT;
+       u32 s_l2_idx = *bucketp & (TBL_L2_SIZE - 1);
+       u32 s_obj = *objp;
+       unsigned int l1_idx;
+
+       for (l1_idx = s_l1_idx; l1_idx < n_l1; l1_idx++) {
+               struct tbl_bucket __rcu **l2 = table->buckets[l1_idx];
+               unsigned int l2_idx;
+
+               for (l2_idx = s_l2_idx; l2_idx < TBL_L2_SIZE; l2_idx++) {
+                       struct tbl_bucket *bucket;
+
+                       bucket = rcu_dereference(l2[l2_idx]);
+                       if (bucket && s_obj < bucket->n_objs) {
+                               *bucketp = (l1_idx << TBL_L1_SHIFT) + l2_idx;
+                               *objp = s_obj + 1;
+                               return bucket->objs[s_obj];
+                       }
+
+                       s_obj = 0;
+               }
+               s_l2_idx = 0;
+       }
+       *bucketp = 0;
+       *objp = 0;
+       return NULL;
+}
+
 static int insert_table_flow(struct tbl_node *node, void *new_table_)
 {
        struct tbl *new_table = new_table_;