4 files changed, 75 insertions, 0 deletions

diff --git a/arch/powerpc/boot/flatdevtree.c b/arch/powerpc/boot/flatdevtree.c
index 0af7291fc67c..cf30675c6116 100644
--- a/arch/powerpc/boot/flatdevtree.c
+++ b/arch/powerpc/boot/flatdevtree.c
@@ -975,3 +975,62 @@ void *ft_create_node(struct ft_cxt *cxt, const void *parent, const char *name)
         }
         return NULL;
 }
+
+/* Returns the start of the path within the provided buffer, or NULL on
+ * error.
+ */
+char *ft_get_path(struct ft_cxt *cxt, const void *phandle,
+                  char *buf, int len)
+{
+        const char *path_comp[FT_MAX_DEPTH];
+        struct ft_atom atom;
+        char *p, *next, *pos;
+        int depth = 0, i;
+        void *node;
+
+        node = ft_node_ph2node(cxt, phandle);
+        if (node == NULL)
+                return NULL;
+
+        p = ft_root_node(cxt);
+
+        while ((next = ft_next(cxt, p, &atom)) != NULL) {
+                switch (atom.tag) {
+                case OF_DT_BEGIN_NODE:
+                        path_comp[depth++] = atom.name;
+                        if (p == node)
+                                goto found;
+
+                        break;
+
+                case OF_DT_END_NODE:
+                        if (--depth == 0)
+                                return NULL;
+                }
+
+                p = next;
+        }
+
+found:
+        pos = buf;
+        for (i = 1; i < depth; i++) {
+                int this_len;
+
+                if (len <= 1)
+                        return NULL;
+
+                *pos++ = '/';
+                len--;
+
+                strncpy(pos, path_comp[i], len);
+
+                if (pos[len - 1] != 0)
+                        return NULL;
+
+                this_len = strlen(pos);
+                len -= this_len;
+                pos += this_len;
+        }
+
+        return buf;
+}
diff --git a/arch/powerpc/boot/flatdevtree.h b/arch/powerpc/boot/flatdevtree.h
index 2c1c826c4eca..b0957a2d967f 100644
--- a/arch/powerpc/boot/flatdevtree.h
+++ b/arch/powerpc/boot/flatdevtree.h
@@ -108,5 +108,6 @@ void *ft_find_node_by_prop_value(struct ft_cxt *cxt, const void *prev,
                                  const char *propname, const char *propval,
                                  int proplen);
 void *ft_create_node(struct ft_cxt *cxt, const void *parent, const char *name);
+char *ft_get_path(struct ft_cxt *cxt, const void *phandle, char *buf, int len);
 
 #endif /* FLATDEVTREE_H */
diff --git a/arch/powerpc/boot/flatdevtree_misc.c b/arch/powerpc/boot/flatdevtree_misc.c
index 8d1debe8d941..b3670096fa71 100644
--- a/arch/powerpc/boot/flatdevtree_misc.c
+++ b/arch/powerpc/boot/flatdevtree_misc.c
@@ -58,6 +58,11 @@ static unsigned long fdtm_finalize(void)
         return (unsigned long)cxt.bph;
 }
 
+static char *fdtm_get_path(const void *phandle, char *buf, int len)
+{
+        return ft_get_path(&cxt, phandle, buf, len);
+}
+
 int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device)
 {
         dt_ops.finddevice = fdtm_finddevice;
@@ -67,6 +72,7 @@ int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device)
         dt_ops.create_node = fdtm_create_node;
         dt_ops.find_node_by_prop_value = fdtm_find_node_by_prop_value;
         dt_ops.finalize = fdtm_finalize;
+        dt_ops.get_path = fdtm_get_path;
 
         return ft_open(&cxt, dt_blob, max_size, max_find_device,
                         platform_ops.realloc);
diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 45c2268d5c56..703255bf0089 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -47,6 +47,7 @@ struct dt_ops {
                                          const char *propname,
                                          const char *propval, int proplen);
         unsigned long (*finalize)(void);
+        char *(*get_path)(const void *phandle, char *buf, int len);
 };
 extern struct dt_ops dt_ops;
 
@@ -170,6 +171,14 @@ static inline void *find_node_by_linuxphandle(const u32 linuxphandle)
                         (char *)&linuxphandle, sizeof(u32));
 }
 
+static inline char *get_path(const void *phandle, char *buf, int len)
+{
+        if (dt_ops.get_path)
+                return dt_ops.get_path(phandle, buf, len);
+
+        return NULL;
+}
+
 static inline void *malloc(unsigned long size)
 {
         return (platform_ops.malloc) ? platform_ops.malloc(size) : NULL;