1 files changed, 166 insertions, 8 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 48594f334151..3b70a468c8ab 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -23,6 +23,7 @@
 #include <linux/of.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
+#include <linux/string.h>
 #include <linux/proc_fs.h>
 
 #include "of_private.h"
@@ -35,6 +36,12 @@ struct device_node *of_chosen;
 struct device_node *of_aliases;
 static struct device_node *of_stdout;
 
+static struct kset *of_kset;
+
+/*
+ * Used to protect the of_aliases; but also overloaded to hold off addition of
+ * nodes to sysfs
+ */
 DEFINE_MUTEX(of_aliases_mutex);
 
 /* use when traversing tree through the allnext, child, sibling,
@@ -92,14 +99,14 @@ int __weak of_node_to_nid(struct device_node *np)
 struct device_node *of_node_get(struct device_node *node)
 {
         if (node)
-                kref_get(&node->kref);
+                kobject_get(&node->kobj);
         return node;
 }
 EXPORT_SYMBOL(of_node_get);
 
-static inline struct device_node *kref_to_device_node(struct kref *kref)
+static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
 {
-        return container_of(kref, struct device_node, kref);
+        return container_of(kobj, struct device_node, kobj);
 }
 
 /**
@@ -109,16 +116,15 @@ static inline struct device_node *kref_to_device_node(struct kref *kref)
  *      In of_node_put() this function is passed to kref_put()
  *      as the destructor.
  */
-static void of_node_release(struct kref *kref)
+static void of_node_release(struct kobject *kobj)
 {
-        struct device_node *node = kref_to_device_node(kref);
+        struct device_node *node = kobj_to_device_node(kobj);
         struct property *prop = node->properties;
 
         /* We should never be releasing nodes that haven't been detached. */
         if (!of_node_check_flag(node, OF_DETACHED)) {
                 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
                 dump_stack();
-                kref_init(&node->kref);
                 return;
         }
 
@@ -151,11 +157,140 @@ static void of_node_release(struct kref *kref)
 void of_node_put(struct device_node *node)
 {
         if (node)
-                kref_put(&node->kref, of_node_release);
+                kobject_put(&node->kobj);
 }
 EXPORT_SYMBOL(of_node_put);
+#else
+static void of_node_release(struct kobject *kobj)
+{
+        /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
+}
 #endif /* CONFIG_OF_DYNAMIC */
 
+struct kobj_type of_node_ktype = {
+        .release = of_node_release,
+};
+
+static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
+                                struct bin_attribute *bin_attr, char *buf,
+                                loff_t offset, size_t count)
+{
+        struct property *pp = container_of(bin_attr, struct property, attr);
+        return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
+}
+
+static const char *safe_name(struct kobject *kobj, const char *orig_name)
+{
+        const char *name = orig_name;
+        struct kernfs_node *kn;
+        int i = 0;
+
+        /* don't be a hero. After 16 tries give up */
+        while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
+                sysfs_put(kn);
+                if (name != orig_name)
+                        kfree(name);
+                name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
+        }
+
+        if (name != orig_name)
+                pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
+                        kobject_name(kobj), name);
+        return name;
+}
+
+static 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;
+
+        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;
+        pp->attr.size = secure ? 0 : pp->length;
+        pp->attr.read = of_node_property_read;
+
+        rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
+        WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
+        return rc;
+}
+
+static int __of_node_add(struct device_node *np)
+{
+        const char *name;
+        struct property *pp;
+        int rc;
+
+        np->kobj.kset = of_kset;
+        if (!np->parent) {
+                /* Nodes without parents are new top level trees */
+                rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base"));
+        } else {
+                name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+                if (!name || !name[0])
+                        return -EINVAL;
+
+                rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+        }
+        if (rc)
+                return rc;
+
+        for_each_property_of_node(np, pp)
+                __of_add_property_sysfs(np, pp);
+
+        return 0;
+}
+
+int of_node_add(struct device_node *np)
+{
+        int rc = 0;
+        kobject_init(&np->kobj, &of_node_ktype);
+        mutex_lock(&of_aliases_mutex);
+        if (of_kset)
+                rc = __of_node_add(np);
+        mutex_unlock(&of_aliases_mutex);
+        return rc;
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+static void of_node_remove(struct device_node *np)
+{
+        struct property *pp;
+
+        for_each_property_of_node(np, pp)
+                sysfs_remove_bin_file(&np->kobj, &pp->attr);
+
+        kobject_del(&np->kobj);
+}
+#endif
+
+static int __init of_init(void)
+{
+        struct device_node *np;
+
+        /* Create the kset, and register existing nodes */
+        mutex_lock(&of_aliases_mutex);
+        of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
+        if (!of_kset) {
+                mutex_unlock(&of_aliases_mutex);
+                return -ENOMEM;
+        }
+        for_each_of_allnodes(np)
+                __of_node_add(np);
+        mutex_unlock(&of_aliases_mutex);
+
+#if !defined(CONFIG_PROC_DEVICETREE)
+        /* Symlink to the new tree when PROC_DEVICETREE is disabled */
+        if (of_allnodes)
+                proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+#endif /* CONFIG_PROC_DEVICETREE */
+
+        return 0;
+}
+core_initcall(of_init);
+
 static struct property *__of_find_property(const struct device_node *np,
                                            const char *name, int *lenp)
 {
@@ -1546,6 +1681,14 @@ int of_add_property(struct device_node *np, struct property *prop)
         raw_spin_lock_irqsave(&devtree_lock, flags);
         rc = __of_add_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;
+
+        __of_add_property_sysfs(np, prop);
 
 #ifdef CONFIG_PROC_DEVICETREE
         /* try to add to proc as well if it was initialized */
@@ -1593,6 +1736,12 @@ int of_remove_property(struct device_node *np, struct property *prop)
         if (!found)
                 return -ENODEV;
 
+        /* at early boot, bail hear and defer setup to of_init() */
+        if (!of_kset)
+                return 0;
+
+        sysfs_remove_bin_file(&np->kobj, &prop->attr);
+
 #ifdef CONFIG_PROC_DEVICETREE
         /* try to remove the proc node as well */
         if (np->pde)
@@ -1643,13 +1792,20 @@ int of_update_property(struct device_node *np, struct property *newprop)
                 next = &(*next)->next;
         }
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
+        if (rc)
+                return rc;
+
+        /* Update the sysfs attribute */
+        if (oldprop)
+                sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+        __of_add_property_sysfs(np, newprop);
 
         if (!found)
                 return -ENODEV;
 
 #ifdef CONFIG_PROC_DEVICETREE
         /* try to add to proc as well if it was initialized */
-        if (!rc && np->pde)
+        if (np->pde)
                 proc_device_tree_update_prop(np->pde, newprop, oldprop);
 #endif /* CONFIG_PROC_DEVICETREE */
 
@@ -1723,6 +1879,7 @@ int of_attach_node(struct device_node *np)
         of_node_clear_flag(np, OF_DETACHED);
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
+        of_node_add(np);
         of_add_proc_dt_entry(np);
         return 0;
 }
@@ -1795,6 +1952,7 @@ int of_detach_node(struct device_node *np)
         raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
         of_remove_proc_dt_entry(np);
+        of_node_remove(np);
         return rc;
 }
 #endif /* defined(CONFIG_OF_DYNAMIC) */