4 files changed, 69 insertions, 51 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index b403f9d98461..ad4929cbd876 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -37,10 +37,13 @@ struct device_node *of_chosen;
 struct device_node *of_aliases;
 static struct device_node *of_stdout;
 
-static struct kset *of_kset;
+struct kset *of_kset;
 
 /*
- * Used to protect the of_aliases, to hold off addition of nodes to sysfs
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
+ * This mutex must be held whenever modifications are being made to the
+ * device tree. The of_{attach,detach}_node() and
+ * of_{add,remove,update}_property() helpers make sure this happens.
  */
 DEFINE_MUTEX(of_mutex);
 
@@ -127,13 +130,16 @@ static const char *safe_name(struct kobject *kobj, const char *orig_name)
         return name;
 }
 
-static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
 {
         int rc;
 
         /* Important: Don't leak passwords */
         bool secure = strncmp(pp->name, "security-", 9) == 0;
 
+        if (!of_kset || !of_node_is_attached(np))
+                return 0;
+
         sysfs_bin_attr_init(&pp->attr);
         pp->attr.attr.name = safe_name(&np->kobj, pp->name);
         pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
@@ -145,12 +151,15 @@ static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
         return rc;
 }
 
-static int __of_node_add(struct device_node *np)
+int __of_attach_node_sysfs(struct device_node *np)
 {
         const char *name;
         struct property *pp;
         int rc;
 
+        if (!of_kset)
+                return 0;
+
         np->kobj.kset = of_kset;
         if (!np->parent) {
                 /* Nodes without parents are new top level trees */
@@ -172,26 +181,6 @@ static int __of_node_add(struct device_node *np)
         return 0;
 }
 
-int of_node_add(struct device_node *np)
-{
-        int rc = 0;
-
-        BUG_ON(!of_node_is_initialized(np));
-
-        /*
-         * Grab the mutex here so that in a race condition between of_init() and
-         * of_node_add(), node addition will still be consistent.
-         */
-        mutex_lock(&of_mutex);
-        if (of_kset)
-                rc = __of_node_add(np);
-        else
-                /* This scenario may be perfectly valid, but report it anyway */
-                pr_info("of_node_add(%s) before of_init()\n", np->full_name);
-        mutex_unlock(&of_mutex);
-        return rc;
-}
-
 static int __init of_init(void)
 {
         struct device_node *np;
@@ -204,7 +193,7 @@ static int __init of_init(void)
                 return -ENOMEM;
         }
         for_each_of_allnodes(np)
-                __of_node_add(np);
+                __of_attach_node_sysfs(np);
         mutex_unlock(&of_mutex);
 
         /* Symlink in /proc as required by userspace ABI */
@@ -1689,15 +1678,17 @@ int of_add_property(struct device_node *np, struct property *prop)
         if (rc)
                 return rc;
 
+        mutex_lock(&of_mutex);
+
         raw_spin_lock_irqsave(&devtree_lock, flags);
         rc = __of_add_property(np, prop);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
-        if (rc)
-                return rc;
 
-        if (of_node_is_attached(np))
+        if (!rc)
                 __of_add_property_sysfs(np, prop);
 
+        mutex_unlock(&of_mutex);
+
         return rc;
 }
 
@@ -1720,6 +1711,13 @@ int __of_remove_property(struct device_node *np, struct property *prop)
         return 0;
 }
 
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
+{
+        /* at early boot, bail here and defer setup to of_init() */
+        if (of_kset && of_node_is_attached(np))
+                sysfs_remove_bin_file(&np->kobj, &prop->attr);
+}
+
 /**
  * of_remove_property - Remove a property from a node.
  *
@@ -1737,20 +1735,18 @@ int of_remove_property(struct device_node *np, struct property *prop)
         if (rc)
                 return rc;
 
+        mutex_lock(&of_mutex);
+
         raw_spin_lock_irqsave(&devtree_lock, flags);
         rc = __of_remove_property(np, prop);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-        if (rc)
-                return rc;
-
-        /* at early boot, bail hear and defer setup to of_init() */
-        if (!of_kset)
-                return 0;
+        if (!rc)
+                __of_remove_property_sysfs(np, prop);
 
-        sysfs_remove_bin_file(&np->kobj, &prop->attr);
+        mutex_unlock(&of_mutex);
 
-        return 0;
+        return rc;
 }
 
 int __of_update_property(struct device_node *np, struct property *newprop,
@@ -1779,6 +1775,18 @@ int __of_update_property(struct device_node *np, struct property *newprop,
         return 0;
 }
 
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+                struct property *oldprop)
+{
+        /* At early boot, bail out and defer setup to of_init() */
+        if (!of_kset)
+                return;
+
+        if (oldprop)
+                sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+        __of_add_property_sysfs(np, newprop);
+}
+
 /*
  * of_update_property - Update a property in a node, if the property does
  * not exist, add it.
@@ -1801,22 +1809,18 @@ int of_update_property(struct device_node *np, struct property *newprop)
         if (rc)
                 return rc;
 
+        mutex_lock(&of_mutex);
+
         raw_spin_lock_irqsave(&devtree_lock, flags);
         rc = __of_update_property(np, newprop, &oldprop);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
-        if (rc)
-                return rc;
 
-        /* At early boot, bail out and defer setup to of_init() */
-        if (!of_kset)
-                return 0;
+        if (!rc)
+                __of_update_property_sysfs(np, newprop, oldprop);
 
-        /* Update the sysfs attribute */
-        if (oldprop)
-                sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
-        __of_add_property_sysfs(np, newprop);
+        mutex_unlock(&of_mutex);
 
-        return 0;
+        return rc;
 }
 
 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 75fcc66fcefd..c875787fa394 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -41,11 +41,13 @@ void of_node_put(struct device_node *node)
 }
 EXPORT_SYMBOL(of_node_put);
 
-static void of_node_remove(struct device_node *np)
+void __of_detach_node_sysfs(struct device_node *np)
 {
         struct property *pp;
 
         BUG_ON(!of_node_is_initialized(np));
+        if (!of_kset)
+                return;
 
         /* only remove properties if on sysfs */
         if (of_node_is_attached(np)) {
@@ -115,11 +117,13 @@ int of_attach_node(struct device_node *np)
         if (rc)
                 return rc;
 
+        mutex_lock(&of_mutex);
         raw_spin_lock_irqsave(&devtree_lock, flags);
         __of_attach_node(np);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-        of_node_add(np);
+        __of_attach_node_sysfs(np);
+        mutex_unlock(&of_mutex);
         return 0;
 }
 
@@ -174,11 +178,13 @@ int of_detach_node(struct device_node *np)
         if (rc)
                 return rc;
 
+        mutex_lock(&of_mutex);
         raw_spin_lock_irqsave(&devtree_lock, flags);
         __of_detach_node(np);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
-        of_node_remove(np);
+        __of_detach_node_sysfs(np);
+        mutex_unlock(&of_mutex);
         return rc;
 }
 
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 0f6089722af9..0d99ba8caeed 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -33,6 +33,8 @@ struct alias_prop {
 
 extern struct mutex of_mutex;
 extern struct list_head aliases_lookup;
+extern struct kset *of_kset;
+
 
 static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
 {
@@ -62,11 +64,19 @@ struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
 struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
 
 extern int __of_add_property(struct device_node *np, struct property *prop);
+extern int __of_add_property_sysfs(struct device_node *np,
+                struct property *prop);
 extern int __of_remove_property(struct device_node *np, struct property *prop);
+extern void __of_remove_property_sysfs(struct device_node *np,
+                struct property *prop);
 extern int __of_update_property(struct device_node *np,
                 struct property *newprop, struct property **oldprop);
+extern void __of_update_property_sysfs(struct device_node *np,
+                struct property *newprop, struct property *oldprop);
 
 extern void __of_attach_node(struct device_node *np);
+extern int __of_attach_node_sysfs(struct device_node *np);
 extern void __of_detach_node(struct device_node *np);
+extern void __of_detach_node_sysfs(struct device_node *np);
 
 #endif /* _LINUX_OF_PRIVATE_H */
diff --git a/include/linux/of.h b/include/linux/of.h
index abf829a1f150..705fa12fca7f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -74,8 +74,6 @@ struct of_phandle_args {
         uint32_t args[MAX_PHANDLE_ARGS];
 };
 
-extern int of_node_add(struct device_node *node);
-
 /* initialize a node */
 extern struct kobj_type of_node_ktype;
 static inline void of_node_init(struct device_node *node)