of: Eliminate of_allnodes list

The device tree structure is composed of two lists; the 'allnodes' list
which is a singly linked list containing every node in the tree, and the
child->parent structure where each parent node has a singly linked list
of children. All of the data in the allnodes list can be easily
reproduced with the parent-child lists, so of_allnodes is actually
unnecessary. Remove it entirely which saves a bit of memory and
simplifies the data structure quite a lot.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Gaurav Minocha <gaurav.minocha.os@gmail.com>
Cc: Pantelis Antoniou <pantelis@pantelis.antoniou@konsulko.com>

1 files changed, 33 insertions, 38 deletions

diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 11b873c54a77..bf7d99317a94 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -148,7 +148,7 @@ static void __init of_selftest_dynamic(void)
 
 static int __init of_selftest_check_node_linkage(struct device_node *np)
 {
-        struct device_node *child, *allnext_index = np;
+        struct device_node *child;
         int count = 0, rc;
 
         for_each_child_of_node(np, child) {
@@ -158,14 +158,6 @@ static int __init of_selftest_check_node_linkage(struct device_node *np)
                         return -EINVAL;
                 }
 
-                while (allnext_index && allnext_index != child)
-                        allnext_index = allnext_index->allnext;
-                if (allnext_index != child) {
-                        pr_err("Node %s is ordered differently in sibling and allnode lists\n",
-                                 child->name);
-                        return -EINVAL;
-                }
-
                 rc = of_selftest_check_node_linkage(child);
                 if (rc < 0)
                         return rc;
@@ -180,12 +172,12 @@ static void __init of_selftest_check_tree_linkage(void)
         struct device_node *np;
         int allnode_count = 0, child_count;
 
-        if (!of_allnodes)
+        if (!of_root)
                 return;
 
         for_each_of_allnodes(np)
                 allnode_count++;
-        child_count = of_selftest_check_node_linkage(of_allnodes);
+        child_count = of_selftest_check_node_linkage(of_root);
 
         selftest(child_count > 0, "Device node data structure is corrupted\n");
         selftest(child_count == allnode_count, "allnodes list size (%i) doesn't match"
@@ -775,33 +767,29 @@ static void update_node_properties(struct device_node *np,
  */
 static int attach_node_and_children(struct device_node *np)
 {
-        struct device_node *next, *root = np, *dup;
+        struct device_node *next, *dup, *child;
 
-        /* skip root node */
-        np = np->child;
-        /* storing a copy in temporary node */
-        dup = np;
+        dup = of_find_node_by_path(np->full_name);
+        if (dup) {
+                update_node_properties(np, dup);
+                return 0;
+        }
 
-        while (dup) {
+        /* Children of the root need to be remembered for removal */
+        if (np->parent == of_root) {
                 if (WARN_ON(last_node_index >= NO_OF_NODES))
                         return -EINVAL;
-                nodes[last_node_index++] = dup;
-                dup = dup->sibling;
+                nodes[last_node_index++] = np;
         }
-        dup = NULL;
 
-        while (np) {
-                next = np->allnext;
-                dup = of_find_node_by_path(np->full_name);
-                if (dup)
-                        update_node_properties(np, dup);
-                else {
-                        np->child = NULL;
-                        if (np->parent == root)
-                                np->parent = of_allnodes;
-                        of_attach_node(np);
-                }
-                np = next;
+        child = np->child;
+        np->child = NULL;
+        np->sibling = NULL;
+        of_attach_node(np);
+        while (child) {
+                next = child->sibling;
+                attach_node_and_children(child);
+                child = next;
         }
 
         return 0;
@@ -846,10 +834,10 @@ static int __init selftest_data_add(void)
                 return -EINVAL;
         }
 
-        if (!of_allnodes) {
+        if (!of_root) {
                 /* enabling flag for removing nodes */
                 selftest_live_tree = true;
-                of_allnodes = selftest_data_node;
+                of_root = selftest_data_node;
 
                 for_each_of_allnodes(np)
                         __of_attach_node_sysfs(np);
@@ -859,7 +847,14 @@ static int __init selftest_data_add(void)
         }
 
         /* attach the sub-tree to live tree */
-        return attach_node_and_children(selftest_data_node);
+        np = selftest_data_node->child;
+        while (np) {
+                struct device_node *next = np->sibling;
+                np->parent = of_root;
+                attach_node_and_children(np);
+                np = next;
+        }
+        return 0;
 }
 
 /**
@@ -889,10 +884,10 @@ static void selftest_data_remove(void)
                 of_node_put(of_chosen);
                 of_aliases = NULL;
                 of_chosen = NULL;
-                for_each_child_of_node(of_allnodes, np)
+                for_each_child_of_node(of_root, np)
                         detach_node_and_children(np);
-                __of_detach_node_sysfs(of_allnodes);
-                of_allnodes = NULL;
+                __of_detach_node_sysfs(of_root);
+                of_root = NULL;
                 return;
         }