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>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 3823edf..1f61a90 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -32,8 +32,8 @@
LIST_HEAD(aliases_lookup);
-struct device_node *of_allnodes;
-EXPORT_SYMBOL(of_allnodes);
+struct device_node *of_root;
+EXPORT_SYMBOL(of_root);
struct device_node *of_chosen;
struct device_node *of_aliases;
struct device_node *of_stdout;
@@ -48,7 +48,7 @@
*/
DEFINE_MUTEX(of_mutex);
-/* use when traversing tree through the allnext, child, sibling,
+/* use when traversing tree through the child, sibling,
* or parent members of struct device_node.
*/
DEFINE_RAW_SPINLOCK(devtree_lock);
@@ -204,7 +204,7 @@
mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
- if (of_allnodes)
+ if (of_root)
proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
return 0;
@@ -245,6 +245,23 @@
}
EXPORT_SYMBOL(of_find_property);
+struct device_node *__of_find_all_nodes(struct device_node *prev)
+{
+ struct device_node *np;
+ if (!prev) {
+ np = of_root;
+ } else if (prev->child) {
+ np = prev->child;
+ } else {
+ /* Walk back up looking for a sibling, or the end of the structure */
+ np = prev;
+ while (np->parent && !np->sibling)
+ np = np->parent;
+ np = np->sibling; /* Might be null at the end of the tree */
+ }
+ return np;
+}
+
/**
* of_find_all_nodes - Get next node in global list
* @prev: Previous node or NULL to start iteration
@@ -259,10 +276,8 @@
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = prev ? prev->allnext : of_allnodes;
- for (; np != NULL; np = np->allnext)
- if (of_node_get(np))
- break;
+ np = __of_find_all_nodes(prev);
+ of_node_get(np);
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
@@ -736,7 +751,7 @@
unsigned long flags;
if (strcmp(path, "/") == 0)
- return of_node_get(of_allnodes);
+ return of_node_get(of_root);
/* The path could begin with an alias */
if (*path != '/') {
@@ -761,7 +776,7 @@
/* Step down the tree matching path components */
raw_spin_lock_irqsave(&devtree_lock, flags);
if (!np)
- np = of_node_get(of_allnodes);
+ np = of_node_get(of_root);
while (np && *path == '/') {
path++; /* Increment past '/' delimiter */
np = __of_find_node_by_path(np, path);
@@ -790,8 +805,7 @@
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext)
+ for_each_of_allnodes_from(from, np)
if (np->name && (of_node_cmp(np->name, name) == 0)
&& of_node_get(np))
break;
@@ -820,8 +834,7 @@
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext)
+ for_each_of_allnodes_from(from, np)
if (np->type && (of_node_cmp(np->type, type) == 0)
&& of_node_get(np))
break;
@@ -852,12 +865,10 @@
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
+ for_each_of_allnodes_from(from, np)
if (__of_device_is_compatible(np, compatible, type, NULL) &&
of_node_get(np))
break;
- }
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
@@ -884,8 +895,7 @@
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
+ for_each_of_allnodes_from(from, np) {
for (pp = np->properties; pp; pp = pp->next) {
if (of_prop_cmp(pp->name, prop_name) == 0) {
of_node_get(np);
@@ -967,8 +977,7 @@
*match = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np = from ? from->allnext : of_allnodes;
- for (; np; np = np->allnext) {
+ for_each_of_allnodes_from(from, np) {
m = __of_match_node(matches, np);
if (m && of_node_get(np)) {
if (match)
@@ -1025,7 +1034,7 @@
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
- for (np = of_allnodes; np; np = np->allnext)
+ for_each_of_allnodes(np)
if (np->phandle == handle)
break;
of_node_get(np);