[IPV4] fib_trie: cleanup

Try this out:
     * replace macro's with inlines
     * get rid of places doing multiple evaluations of NODE_PARENT

[akpm@linux-foundation.org: rcu_dereference wants an lval]

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 36 insertions, 32 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 9ca786a6fd3c..f28f9f5f240c 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -93,15 +93,8 @@ typedef unsigned int t_key;
 #define T_TNODE 0
 #define T_LEAF  1
 #define NODE_TYPE_MASK  0x1UL
-#define NODE_PARENT(node) \
-        ((struct tnode *)rcu_dereference(((node)->parent & ~NODE_TYPE_MASK)))
-
 #define NODE_TYPE(node) ((node)->parent & NODE_TYPE_MASK)
 
-#define NODE_SET_PARENT(node, ptr)              \
-        rcu_assign_pointer((node)->parent,      \
-                           ((unsigned long)(ptr)) | NODE_TYPE(node))
-
 #define IS_TNODE(n) (!(n->parent & T_LEAF))
 #define IS_LEAF(n) (n->parent & T_LEAF)
 
@@ -174,6 +167,19 @@ static void tnode_free(struct tnode *tn);
 static struct kmem_cache *fn_alias_kmem __read_mostly;
 static struct trie *trie_local = NULL, *trie_main = NULL;
 
+static inline struct tnode *node_parent(struct node *node)
+{
+        struct tnode *ret;
+
+        ret = (struct tnode *)(node->parent & ~NODE_TYPE_MASK);
+        return rcu_dereference(ret);
+}
+
+static inline void node_set_parent(struct node *node, struct tnode *ptr)
+{
+        rcu_assign_pointer(node->parent,
+                           (unsigned long)ptr | NODE_TYPE(node));
+}
 
 /* rcu_read_lock needs to be hold by caller from readside */
 
@@ -446,7 +452,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w
                 tn->full_children++;
 
         if (n)
-                NODE_SET_PARENT(n, tn);
+                node_set_parent(n, tn);
 
         rcu_assign_pointer(tn->child[i], n);
 }
@@ -481,7 +487,7 @@ static struct node *resize(struct trie *t, struct tnode *tn)
                                 continue;
 
                         /* compress one level */
-                        NODE_SET_PARENT(n, NULL);
+                        node_set_parent(n, NULL);
                         tnode_free(tn);
                         return n;
                 }
@@ -636,7 +642,7 @@ static struct node *resize(struct trie *t, struct tnode *tn)
 
                         /* compress one level */
 
-                        NODE_SET_PARENT(n, NULL);
+                        node_set_parent(n, NULL);
                         tnode_free(tn);
                         return n;
                 }
@@ -961,24 +967,21 @@ fib_find_node(struct trie *t, u32 key)
 static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
 {
         int wasfull;
-        t_key cindex, key;
-        struct tnode *tp = NULL;
-
-        key = tn->key;
+        t_key cindex, key = tn->key;
+        struct tnode *tp;
 
-        while (tn != NULL && NODE_PARENT(tn) != NULL) {
-
-                tp = NODE_PARENT(tn);
+        while (tn != NULL && (tp = node_parent((struct node *)tn)) != NULL) {
                 cindex = tkey_extract_bits(key, tp->pos, tp->bits);
                 wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
                 tn = (struct tnode *) resize (t, (struct tnode *)tn);
                 tnode_put_child_reorg((struct tnode *)tp, cindex,(struct node*)tn, wasfull);
 
-                if (!NODE_PARENT(tn))
+                tp = node_parent((struct node *) tn);
+                if (!tp)
                         break;
-
-                tn = NODE_PARENT(tn);
+                tn = tp;
         }
+
         /* Handle last (top) tnode */
         if (IS_TNODE(tn))
                 tn = (struct tnode*) resize(t, (struct tnode *)tn);
@@ -1031,7 +1034,7 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
                         pos = tn->pos + tn->bits;
                         n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));
 
-                        BUG_ON(n && NODE_PARENT(n) != tn);
+                        BUG_ON(n && node_parent(n) != tn);
                 } else
                         break;
         }
@@ -1083,7 +1086,7 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
         if (t->trie && n == NULL) {
                 /* Case 2: n is NULL, and will just insert a new leaf */
 
-                NODE_SET_PARENT(l, tp);
+                node_set_parent((struct node *)l, tp);
 
                 cindex = tkey_extract_bits(key, tp->pos, tp->bits);
                 put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
@@ -1114,7 +1117,7 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
                         goto err;
                 }
 
-                NODE_SET_PARENT(tn, tp);
+                node_set_parent((struct node *)tn, tp);
 
                 missbit = tkey_extract_bits(key, newpos, 1);
                 put_child(t, tn, missbit, (struct node *)l);
@@ -1495,12 +1498,13 @@ backtrace:
                 if (chopped_off <= pn->bits) {
                         cindex &= ~(1 << (chopped_off-1));
                 } else {
-                        if (NODE_PARENT(pn) == NULL)
+                        struct tnode *parent = node_parent((struct node *) pn);
+                        if (!parent)
                                 goto failed;
 
                         /* Get Child's index */
-                        cindex = tkey_extract_bits(pn->key, NODE_PARENT(pn)->pos, NODE_PARENT(pn)->bits);
-                        pn = NODE_PARENT(pn);
+                        cindex = tkey_extract_bits(pn->key, parent->pos, parent->bits);
+                        pn = parent;
                         chopped_off = 0;
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
@@ -1536,7 +1540,7 @@ static int trie_leaf_remove(struct trie *t, t_key key)
                 check_tnode(tn);
                 n = tnode_get_child(tn ,tkey_extract_bits(key, tn->pos, tn->bits));
 
-                BUG_ON(n && NODE_PARENT(n) != tn);
+                BUG_ON(n && node_parent(n) != tn);
         }
         l = (struct leaf *) n;
 
@@ -1551,7 +1555,7 @@ static int trie_leaf_remove(struct trie *t, t_key key)
         t->revision++;
         t->size--;
 
-        tp = NODE_PARENT(n);
+        tp = node_parent(n);
         tnode_free((struct tnode *) n);
 
         if (tp) {
@@ -1703,7 +1707,7 @@ static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
 
                 p = (struct tnode*) trie;  /* Start */
         } else
-                p = (struct tnode *) NODE_PARENT(c);
+                p = node_parent(c);
 
         while (p) {
                 int pos, last;
@@ -1740,7 +1744,7 @@ static struct leaf *nextleaf(struct trie *t, struct leaf *thisleaf)
 up:
                 /* No more children go up one step  */
                 c = (struct node *) p;
-                p = (struct tnode *) NODE_PARENT(p);
+                p = node_parent(c);
         }
         return NULL; /* Ready. Root of trie */
 }
@@ -2043,7 +2047,7 @@ rescan:
         }
 
         /* Current node exhausted, pop back up */
-        p = NODE_PARENT(tn);
+        p = node_parent((struct node *)tn);
         if (p) {
                 cindex = tkey_extract_bits(tn->key, p->pos, p->bits)+1;
                 tn = p;
@@ -2317,7 +2321,7 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
         if (v == SEQ_START_TOKEN)
                 return 0;
 
-        if (!NODE_PARENT(n)) {
+        if (!node_parent(n)) {
                 if (iter->trie == trie_local)
                         seq_puts(seq, "<local>:\n");
                 else