9 files changed, 209 insertions, 18 deletions

diff --git a/Documentation/ABI/testing/sysfs-firmware-ofw b/Documentation/ABI/testing/sysfs-firmware-ofw
new file mode 100644
index 000000000000..f562b188e71d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-ofw
@@ -0,0 +1,28 @@
+What:           /sys/firmware/devicetree/*
+Date:           November 2013
+Contact:        Grant Likely <grant.likely@linaro.org>
+Description:
+                When using OpenFirmware or a Flattened Device Tree to enumerate
+                hardware, the device tree structure will be exposed in this
+                directory.
+
+                It is possible for multiple device-tree directories to exist.
+                Some device drivers use a separate detached device tree which
+                have no attachment to the system tree and will appear in a
+                different subdirectory under /sys/firmware/devicetree.
+
+                Userspace must not use the /sys/firmware/devicetree/base
+                path directly, but instead should follow /proc/device-tree
+                symlink. It is possible that the absolute path will change
+                in the future, but the symlink is the stable ABI.
+
+                The /proc/device-tree symlink replaces the devicetree /proc
+                filesystem support, and has largely the same semantics and
+                should be compatible with existing userspace.
+
+                The contents of /sys/firmware/devicetree/ is a
+                hierarchy of directories, one per device tree node. The
+                directory name is the resolved path component name (node
+                name plus address). Properties are represented as files
+                in the directory. The contents of each file is the exact
+                binary data from the device tree.
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index a8fe5aa3d34f..022b38e6a80b 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -11,7 +11,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/kref.h>
 #include <linux/notifier.h>
 #include <linux/spinlock.h>
 #include <linux/cpu.h>
@@ -87,7 +86,6 @@ static struct device_node *dlpar_parse_cc_node(struct cc_workarea *ccwa,
         }
 
         of_node_set_flag(dn, OF_DYNAMIC);
-        kref_init(&dn->kref);
 
         return dn;
 }
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index f93cdf55628c..0435bb65d0aa 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -12,7 +12,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/kref.h>
 #include <linux/notifier.h>
 #include <linux/proc_fs.h>
 #include <linux/slab.h>
@@ -70,7 +69,6 @@ static int pSeries_reconfig_add_node(const char *path, struct property *proplist
 
         np->properties = proplist;
         of_node_set_flag(np, OF_DYNAMIC);
-        kref_init(&np->kref);
 
         np->parent = derive_parent(path);
         if (IS_ERR(np->parent)) {
diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c
index 0968b66b4cf9..8ba60424be95 100644
--- a/arch/powerpc/sysdev/msi_bitmap.c
+++ b/arch/powerpc/sysdev/msi_bitmap.c
@@ -202,7 +202,7 @@ void __init test_of_node(void)
 
         /* There should really be a struct device_node allocator */
         memset(&of_node, 0, sizeof(of_node));
-        kref_init(&of_node.kref);
+        kref_init(&of_node.kobj.kref);
         of_node.full_name = node_name;
 
         check(0 == msi_bitmap_alloc(&bmp, size, &of_node));
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) */
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 758b4f8b30b7..96ad1ab7f9d6 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -232,7 +232,6 @@ static void * unflatten_dt_node(struct boot_param_header *blob,
                                 dad->next->sibling = np;
                         dad->next = np;
                 }
-                kref_init(&np->kref);
         }
         /* process properties */
         while (1) {
@@ -327,6 +326,8 @@ static void * unflatten_dt_node(struct boot_param_header *blob,
                         np->name = "<NULL>";
                 if (!np->type)
                         np->type = "<NULL>";
+
+                of_node_add(np);
         }
         while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
                 if (tag == OF_DT_NOP)
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 7b666736c168..e64fa3d3da5f 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -179,8 +179,6 @@ static struct device_node * __init of_pdt_create_node(phandle node,
         of_pdt_incr_unique_id(dp);
         dp->parent = parent;
 
-        kref_init(&dp->kref);
-
         dp->name = of_pdt_get_one_property(node, "name");
         dp->type = of_pdt_get_one_property(node, "device_type");
         dp->phandle = node;
@@ -215,6 +213,7 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
                 *nextp = &dp->allnext;
 
                 dp->full_name = of_pdt_build_full_name(dp);
+                of_node_add(dp);
 
                 dp->child = of_pdt_build_tree(dp,
                                 of_pdt_prom_ops->getchild(node), nextp);
@@ -245,6 +244,7 @@ void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
         of_allnodes->path_component_name = "";
 #endif
         of_allnodes->full_name = "/";
+        of_node_add(of_allnodes);
 
         nextp = &of_allnodes->allnext;
         of_allnodes->child = of_pdt_build_tree(of_allnodes,
diff --git a/drivers/of/testcase-data/tests-phandle.dtsi b/drivers/of/testcase-data/tests-phandle.dtsi
index 0007d3cd7dc2..788a4c24b8f5 100644
--- a/drivers/of/testcase-data/tests-phandle.dtsi
+++ b/drivers/of/testcase-data/tests-phandle.dtsi
@@ -1,6 +1,9 @@
 
 / {
         testcase-data {
+                security-password = "password";
+                duplicate-name = "duplicate";
+                duplicate-name { };
                 phandle-tests {
                         provider0: provider0 {
                                 #phandle-cells = <0>;
diff --git a/include/linux/of.h b/include/linux/of.h
index b3d0f6d86e3b..bd45be5bd565 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -18,7 +18,7 @@
 #include <linux/types.h>
 #include <linux/bitops.h>
 #include <linux/errno.h>
-#include <linux/kref.h>
+#include <linux/kobject.h>
 #include <linux/mod_devicetable.h>
 #include <linux/spinlock.h>
 #include <linux/topology.h>
@@ -37,6 +37,7 @@ struct property {
         struct property *next;
         unsigned long _flags;
         unsigned int unique_id;
+        struct bin_attribute attr;
 };
 
 #if defined(CONFIG_SPARC)
@@ -57,7 +58,7 @@ struct device_node {
         struct  device_node *next;      /* next device of same type */
         struct  device_node *allnext;   /* next in list of all nodes */
         struct  proc_dir_entry *pde;    /* this node's proc directory */
-        struct  kref kref;
+        struct  kobject kobj;
         unsigned long _flags;
         void    *data;
 #if defined(CONFIG_SPARC)
@@ -74,6 +75,8 @@ struct of_phandle_args {
         uint32_t args[MAX_PHANDLE_ARGS];
 };
 
+extern int of_node_add(struct device_node *node);
+
 #ifdef CONFIG_OF_DYNAMIC
 extern struct device_node *of_node_get(struct device_node *node);
 extern void of_node_put(struct device_node *node);
@@ -187,6 +190,8 @@ static inline const char *of_node_full_name(const struct device_node *np)
         return np ? np->full_name : "<no-node>";
 }
 
+#define for_each_of_allnodes(dn) \
+        for (dn = of_allnodes; dn; dn = dn->allnext)
 extern struct device_node *of_find_node_by_name(struct device_node *from,
         const char *name);
 extern struct device_node *of_find_node_by_type(struct device_node *from,