2 files changed, 68 insertions, 0 deletions

diff --git a/arch/powerpc/boot/flatdevtree.c b/arch/powerpc/boot/flatdevtree.c
index 88b178a77e87..f6e37c2ee4dd 100644
--- a/arch/powerpc/boot/flatdevtree.c
+++ b/arch/powerpc/boot/flatdevtree.c
@@ -820,6 +820,71 @@ int ft_get_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
         return -1;
 }
 
+void *__ft_find_node_by_prop_value(struct ft_cxt *cxt, void *prev,
+                                   const char *propname, const char *propval,
+                                   unsigned int proplen)
+{
+        struct ft_atom atom;
+        char *p = ft_root_node(cxt);
+        char *next;
+        int past_prev = prev ? 0 : 1;
+        int depth = -1;
+
+        while ((next = ft_next(cxt, p, &atom)) != NULL) {
+                const void *data;
+                unsigned int size;
+
+                switch (atom.tag) {
+                case OF_DT_BEGIN_NODE:
+                        depth++;
+
+                        if (prev == p) {
+                                past_prev = 1;
+                                break;
+                        }
+
+                        if (!past_prev || depth < 1)
+                                break;
+
+                        data = __ft_get_prop(cxt, p, propname, &size);
+                        if (!data || size != proplen)
+                                break;
+                        if (memcmp(data, propval, size))
+                                break;
+
+                        return p;
+
+                case OF_DT_END_NODE:
+                        if (depth-- == 0)
+                                return NULL;
+
+                        break;
+                }
+
+                p = next;
+        }
+
+        return NULL;
+}
+
+void *ft_find_node_by_prop_value(struct ft_cxt *cxt, const void *prev,
+                                 const char *propname, const char *propval,
+                                 int proplen)
+{
+        void *node = NULL;
+
+        if (prev) {
+                node = ft_node_ph2node(cxt, prev);
+
+                if (!node)
+                        return NULL;
+        }
+
+        node = __ft_find_node_by_prop_value(cxt, node, propname,
+                                            propval, proplen);
+        return ft_get_phandle(cxt, node);
+}
+
 int ft_set_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
                 const void *buf, const unsigned int buflen)
 {
diff --git a/arch/powerpc/boot/flatdevtree.h b/arch/powerpc/boot/flatdevtree.h
index 950042493fb7..e3e3e79937ff 100644
--- a/arch/powerpc/boot/flatdevtree.h
+++ b/arch/powerpc/boot/flatdevtree.h
@@ -105,5 +105,8 @@ int ft_get_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
 int ft_set_prop(struct ft_cxt *cxt, const void *phandle, const char *propname,
                 const void *buf, const unsigned int buflen);
 void *ft_get_parent(struct ft_cxt *cxt, const void *phandle);
+void *ft_find_node_by_prop_value(struct ft_cxt *cxt, const void *prev,
+                                 const char *propname, const char *propval,
+                                 int proplen);
 
 #endif /* FLATDEVTREE_H */