@@ -143,7 +143,6 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,
strcpy(new->value, target_path);
strcpy(new->value + target_path_len, label_path);
- /* mark the property as dynamic */
of_property_set_flag(new, OF_DYNAMIC);
return new;
@@ -157,23 +156,24 @@ static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov,
}
+/*
+ * Some special properties are not updated (no error returned).
+ * Update of property in symbols node is not allowed.
+ */
static int of_overlay_apply_single_property(struct of_overlay *ov,
struct device_node *target, struct property *prop,
bool is_symbols_node)
{
struct property *propn = NULL, *tprop;
- /* NOTE: Multiple changes of single properties not supported */
tprop = of_find_property(target, prop->name, NULL);
- /* special properties are not meant to be updated (silent NOP) */
if (of_prop_cmp(prop->name, "name") == 0 ||
of_prop_cmp(prop->name, "phandle") == 0 ||
of_prop_cmp(prop->name, "linux,phandle") == 0)
return 0;
if (is_symbols_node) {
- /* changing a property in __symbols__ node not allowed */
if (tprop)
return -EINVAL;
propn = dup_and_fixup_symbol_prop(ov, prop);
@@ -184,14 +184,19 @@ static int of_overlay_apply_single_property(struct of_overlay *ov,
if (propn == NULL)
return -ENOMEM;
- /* not found? add */
if (tprop == NULL)
return of_changeset_add_property(&ov->cset, target, propn);
- /* found? update */
return of_changeset_update_property(&ov->cset, target, propn);
}
+/*
+ * NOTE: Multiple mods of created nodes not supported.
+ *
+ * Return
+ * -ENOMEM if memory allocation fails
+ * -EINVAL if existing node has a phandle and overlay node has a phandle
+ */
static int of_overlay_apply_single_device_node(struct of_overlay *ov,
struct device_node *target, struct device_node *child)
{
@@ -203,13 +208,11 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
if (cname == NULL)
return -ENOMEM;
- /* NOTE: Multiple mods of created nodes not supported */
for_each_child_of_node(target, tchild)
if (!of_node_cmp(cname, kbasename(tchild->full_name)))
break;
if (tchild != NULL) {
- /* new overlay phandle value conflicts with existing value */
if (child->phandle)
return -EINVAL;
@@ -217,12 +220,10 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
ret = of_overlay_apply_one(ov, tchild, child, 0);
of_node_put(tchild);
} else {
- /* create empty tree as a target */
tchild = __of_node_dup(child, "%pOF/%s", target, cname);
if (!tchild)
return -ENOMEM;
- /* point to parent */
tchild->parent = target;
ret = of_changeset_attach_node(&ov->cset, tchild);
@@ -243,6 +244,8 @@ static int of_overlay_apply_single_device_node(struct of_overlay *ov,
* Note that the in case of an error the target node is left
* in a inconsistent state. Error recovery should be performed
* by using the changeset.
+ *
+ * Do not allow symbols node to have any children.
*/
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node *overlay,
@@ -262,7 +265,6 @@ static int of_overlay_apply_one(struct of_overlay *ov,
}
}
- /* do not allow symbols node to have any children */
if (is_symbols_node)
return 0;
@@ -292,7 +294,6 @@ static int of_overlay_apply(struct of_overlay *ov)
{
int i, err;
- /* first we apply the overlays atomically */
for (i = 0; i < ov->count; i++) {
struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i];
@@ -309,10 +310,10 @@ static int of_overlay_apply(struct of_overlay *ov)
/*
* Find the target node using a number of different strategies
- * in order of preference
+ * in order of preference:
*
- * "target" property containing the phandle of the target
- * "target-path" property containing the path of the target
+ * 1) "target" property containing the phandle of the target
+ * 2) "target-path" property containing the path of the target
*/
static struct device_node *find_target_node(struct device_node *info_node)
{
@@ -320,12 +321,10 @@ static struct device_node *find_target_node(struct device_node *info_node)
u32 val;
int ret;
- /* first try to go by using the target as a phandle */
ret = of_property_read_u32(info_node, "target", &val);
if (ret == 0)
return of_find_node_by_phandle(val);
- /* now try to locate by path */
ret = of_property_read_string(info_node, "target-path", &path);
if (ret == 0)
return of_find_node_by_path(path);
@@ -390,7 +389,6 @@ static int of_build_overlay_info(struct of_overlay *ov,
struct of_overlay_info *ovinfo;
int cnt, err;
- /* worst case; every child is a node */
cnt = 0;
for_each_child_of_node(tree, node)
cnt++;
@@ -423,7 +421,6 @@ static int of_build_overlay_info(struct of_overlay *ov,
cnt++;
}
- /* if nothing filled, return error */
if (cnt == 0) {
kfree(ovinfo);
return -ENODEV;
@@ -479,7 +476,6 @@ int of_overlay_create(struct device_node *tree)
struct of_overlay *ov;
int err, id;
- /* allocate the overlay structure */
ov = kzalloc(sizeof(*ov), GFP_KERNEL);
if (ov == NULL)
return -ENOMEM;
@@ -498,7 +494,6 @@ int of_overlay_create(struct device_node *tree)
}
ov->id = id;
- /* build the overlay info structures */
err = of_build_overlay_info(ov, tree);
if (err) {
pr_err("of_build_overlay_info() failed for tree@%pOF\n",
@@ -513,18 +508,15 @@ int of_overlay_create(struct device_node *tree)
goto err_free_idr;
}
- /* apply the overlay */
err = of_overlay_apply(ov);
if (err)
goto err_abort_trans;
- /* apply the changeset */
err = __of_changeset_apply(&ov->cset);
if (err)
goto err_revert_overlay;
- /* add to the tail of the overlay list */
list_add_tail(&ov->node, &ov_list);
of_overlay_notify(ov, OF_OVERLAY_POST_APPLY);
@@ -547,13 +539,15 @@ int of_overlay_create(struct device_node *tree)
}
EXPORT_SYMBOL_GPL(of_overlay_create);
-/* check whether the given node, lies under the given tree */
+/*
+ * check whether the given node, lies under the given tree
+ * return 1 if under tree, else 0
+ */
static int overlay_subtree_check(struct device_node *tree,
struct device_node *dn)
{
struct device_node *child;
- /* match? */
if (tree == dn)
return 1;
@@ -567,7 +561,10 @@ static int overlay_subtree_check(struct device_node *tree,
return 0;
}
-/* check whether this overlay is the topmost */
+/*
+ * check whether this overlay is the topmost
+ * return 1 if topmost, else 0
+ */
static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn)
{
struct of_overlay *ovt;
@@ -588,7 +585,6 @@ static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn)
}
}
- /* overlay is topmost */
return 1;
}
@@ -638,7 +634,6 @@ int of_overlay_destroy(int id)
goto out;
}
- /* check whether the overlay is safe to remove */
if (!overlay_removal_is_ok(ov)) {
err = -EBUSY;
goto out;