The device tree data structure uses a custom linked list implemenation
which is baroque and prone to bugs. Replace the child node lists with a
list_head and the common list_head accessor functions.
Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxx>
---
drivers/of/base.c | 43 +++++++++++++++++++------------------------
drivers/of/fdt.c | 12 +++---------
include/linux/of.h | 8 +++++---
3 files changed, 27 insertions(+), 36 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 6c0bd86b802f..69f5648babd8 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -47,6 +47,12 @@ static struct kset *of_kset;
#define for_each_of_allnodes_continue(dn) \
list_for_each_entry_continue(dn, &of_allnodes, allnext)
+#define of_children_prepare(parent, child) \
+ list_prepare_entry(child, &parent->children, childnext)
+#define for_each_of_children(parent, child) \
+ list_for_each_entry(child, &parent->children, childnext)
+#define for_each_of_children_continue(parent, child) \
+ list_for_each_entry_continue(child, &parent->children, childnext)
/*
* Used to protect the of_aliases; but also overloaded to hold off addition of
* nodes to sysfs
@@ -711,11 +717,11 @@ static struct device_node *__of_get_next_child(const struct device_node *node,
if (!node)
return NULL;
- next = prev ? prev->sibling : node->child;
- for (; next; next = next->sibling)
- if (of_node_get(next))
- break;
of_node_put(prev);
+ next = list_next_entry(of_children_prepare(node, prev), childnext);
+ if (&next->childnext == &node->children)
+ next = NULL;
+ of_node_get(next);
return next;
}
#define __for_each_child_of_node(parent, child) \
@@ -754,21 +760,21 @@ EXPORT_SYMBOL(of_get_next_child);
struct device_node *of_get_next_available_child(const struct device_node *node,
struct device_node *prev)
{
- struct device_node *next;
+ struct device_node *next = NULL;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
- next = prev ? prev->sibling : node->child;
- for (; next; next = next->sibling) {
- if (!__of_device_is_available(next))
- continue;
- if (of_node_get(next))
+ of_node_put(prev);
+ prev = of_children_prepare(node, prev);
+ for_each_of_children_continue(node, prev) {
+ if (__of_device_is_available(prev)) {
+ next = of_node_get(prev);
break;
+ }
}
- of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
@@ -1976,8 +1982,7 @@ int of_attach_node(struct device_node *np)
raw_spin_lock_irqsave(&devtree_lock, flags);
list_add_tail(&np->allnext, &of_allnodes);
- np->sibling = np->parent->child;
- np->parent->child = np;
+ list_add_tail(&np->childnext, &np->parent->children);
of_node_clear_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
@@ -2016,17 +2021,7 @@ int of_detach_node(struct device_node *np)
}
list_del(&np->allnext);
-
- if (parent->child == np)
- parent->child = np->sibling;
- else {
- struct device_node *prevsib;
- for (prevsib = np->parent->child;
- prevsib->sibling != np;
- prevsib = prevsib->sibling)
- ;
- prevsib->sibling = np->sibling;
- }
+ list_del(&np->childnext);
of_node_set_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 6876ac3d4b30..2ff96cac1496 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -155,6 +155,7 @@ static void * unflatten_dt_node(void *blob,
char *fn;
of_node_init(np);
np->full_name = fn = ((char *)np) + sizeof(*np);
+ np->parent = dad;
if (new_format) {
/* rebuild full path for new format */
if (dad && dad->parent) {
@@ -174,15 +175,8 @@ static void * unflatten_dt_node(void *blob,
prev_pp = &np->properties;
list_add_tail(&np->allnext, allnext);
- if (dad != NULL) {
- np->parent = dad;
- /* we temporarily use the next field as `last_child'*/
- if (dad->next == NULL)
- dad->child = np;
- else
- dad->next->sibling = np;
- dad->next = np;
- }
+ if (np->parent)
+ list_add_tail(&np->childnext, &np->parent->children);
}
/* process properties */
for (offset = fdt_first_property_offset(blob, *poffset);
diff --git a/include/linux/of.h b/include/linux/of.h
index e082db3c284f..11bef100bc43 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -52,10 +52,11 @@ struct device_node {
struct property *properties;
struct property *deadprops; /* removed properties */
+
+ struct list_head children; /* next device of same type */
struct device_node *parent;
- struct device_node *child;
- struct device_node *sibling;
- struct device_node *next; /* next device of same type */
+
+ struct list_head childnext;
struct list_head allnext;
struct kobject kobj;
unsigned long _flags;
@@ -80,6 +81,7 @@ extern int of_node_add(struct device_node *node);
extern struct kobj_type of_node_ktype;
static inline void of_node_init(struct device_node *node)
{
+ INIT_LIST_HEAD(&node->children);
kobject_init(&node->kobj, &of_node_ktype);
}
--
1.9.1
--
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