regmap: rbtree: Factor out node allocation

In preparation for being slightly smarter about how we allocate memory
factor out the node allocation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index aa0875f..3a00014 100644 (file)
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -304,6 +304,27 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,
        return 0;
 }
 
+static struct regcache_rbtree_node *
+regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
+{
+       struct regcache_rbtree_node *rbnode;
+
+       rbnode = kzalloc(sizeof(*rbnode), GFP_KERNEL);
+       if (!rbnode)
+               return NULL;
+
+       rbnode->blklen = sizeof(*rbnode);
+       rbnode->base_reg = reg;
+       rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
+                               GFP_KERNEL);
+       if (!rbnode->block) {
+               kfree(rbnode);
+               return NULL;
+       }
+
+       return rbnode;
+}
+
 static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
                                 unsigned int value)
 {
@@ -354,23 +375,15 @@ static int regcache_rbtree_write(struct regmap *map, unsigned int reg,
                                return 0;
                        }
                }
-               /* we did not manage to find a place to insert it in an existing
-                * block so create a new rbnode with a single register in its block.
-                * This block will get populated further if any other adjacent
-                * registers get modified in the future.
+
+               /* We did not manage to find a place to insert it in
+                * an existing block so create a new rbnode.
                 */
-               rbnode = kzalloc(sizeof *rbnode, GFP_KERNEL);
+               rbnode = regcache_rbtree_node_alloc(map, reg);
                if (!rbnode)
                        return -ENOMEM;
-               rbnode->blklen = sizeof(*rbnode);
-               rbnode->base_reg = reg;
-               rbnode->block = kmalloc(rbnode->blklen * map->cache_word_size,
-                                       GFP_KERNEL);
-               if (!rbnode->block) {
-                       kfree(rbnode);
-                       return -ENOMEM;
-               }
-               regcache_rbtree_set_register(map, rbnode, 0, value);
+               regcache_rbtree_set_register(map, rbnode,
+                                            reg - rbnode->base_reg, value);
                regcache_rbtree_insert(map, &rbtree_ctx->root, rbnode);
                rbtree_ctx->cached_rbnode = rbnode;
        }