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path: root/drivers/of/base.c
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Diffstat (limited to 'drivers/of/base.c')
-rw-r--r--drivers/of/base.c274
1 files changed, 205 insertions, 69 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 5f81bfea524..4557a142c75 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -24,6 +24,7 @@
#include <linux/of_graph.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
+#include <linux/string.h>
#include <linux/proc_fs.h>
#include "of_private.h"
@@ -36,6 +37,12 @@ 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,
@@ -93,14 +100,14 @@ 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);
}
/**
@@ -110,16 +117,15 @@ 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;
}
@@ -152,11 +158,154 @@ 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;
+
+ 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_aliases_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_aliases_mutex);
+ return rc;
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+static void of_node_remove(struct device_node *np)
+{
+ struct property *pp;
+
+ BUG_ON(!of_node_is_initialized(np));
+
+ /* only remove properties if on sysfs */
+ if (of_node_is_attached(np)) {
+ for_each_property_of_node(np, pp)
+ sysfs_remove_bin_file(&np->kobj, &pp->attr);
+ kobject_del(&np->kobj);
+ }
+
+ /* finally remove the kobj_init ref */
+ of_node_put(np);
+}
+#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);
+
+ /* Symlink in /proc as required by userspace ABI */
+ if (of_allnodes)
+ proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+
+ return 0;
+}
+core_initcall(of_init);
+
static struct property *__of_find_property(const struct device_node *np,
const char *name, int *lenp)
{
@@ -1531,6 +1680,10 @@ static int of_property_notify(int action, struct device_node *np,
{
struct of_prop_reconfig pr;
+ /* only call notifiers if the node is attached */
+ if (!of_node_is_attached(np))
+ return 0;
+
pr.dn = np;
pr.prop = prop;
return of_reconfig_notify(action, &pr);
@@ -1544,11 +1697,31 @@ static int of_property_notify(int action, struct device_node *np,
#endif
/**
+ * __of_add_property - Add a property to a node without lock operations
+ */
+static int __of_add_property(struct device_node *np, struct property *prop)
+{
+ struct property **next;
+
+ prop->next = NULL;
+ next = &np->properties;
+ while (*next) {
+ if (strcmp(prop->name, (*next)->name) == 0)
+ /* duplicate ! don't insert it */
+ return -EEXIST;
+
+ next = &(*next)->next;
+ }
+ *next = prop;
+
+ return 0;
+}
+
+/**
* of_add_property - Add a property to a node
*/
int of_add_property(struct device_node *np, struct property *prop)
{
- struct property **next;
unsigned long flags;
int rc;
@@ -1556,27 +1729,16 @@ int of_add_property(struct device_node *np, struct property *prop)
if (rc)
return rc;
- prop->next = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
- next = &np->properties;
- while (*next) {
- if (strcmp(prop->name, (*next)->name) == 0) {
- /* duplicate ! don't insert it */
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
- return -1;
- }
- next = &(*next)->next;
- }
- *next = prop;
+ rc = __of_add_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
+ if (rc)
+ return rc;
-#ifdef CONFIG_PROC_DEVICETREE
- /* try to add to proc as well if it was initialized */
- if (np->pde)
- proc_device_tree_add_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
+ if (of_node_is_attached(np))
+ __of_add_property_sysfs(np, prop);
- return 0;
+ return rc;
}
/**
@@ -1616,11 +1778,11 @@ int of_remove_property(struct device_node *np, struct property *prop)
if (!found)
return -ENODEV;
-#ifdef CONFIG_PROC_DEVICETREE
- /* try to remove the proc node as well */
- if (np->pde)
- proc_device_tree_remove_prop(np->pde, prop);
-#endif /* CONFIG_PROC_DEVICETREE */
+ /* at early boot, bail hear and defer setup to of_init() */
+ if (!of_kset)
+ return 0;
+
+ sysfs_remove_bin_file(&np->kobj, &prop->attr);
return 0;
}
@@ -1666,16 +1828,17 @@ 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 (np->pde)
- proc_device_tree_update_prop(np->pde, newprop, oldprop);
-#endif /* CONFIG_PROC_DEVICETREE */
-
return 0;
}
@@ -1710,22 +1873,6 @@ int of_reconfig_notify(unsigned long action, void *p)
return notifier_to_errno(rc);
}
-#ifdef CONFIG_PROC_DEVICETREE
-static void of_add_proc_dt_entry(struct device_node *dn)
-{
- struct proc_dir_entry *ent;
-
- ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
- if (ent)
- proc_device_tree_add_node(dn, ent);
-}
-#else
-static void of_add_proc_dt_entry(struct device_node *dn)
-{
- return;
-}
-#endif
-
/**
* of_attach_node - Plug a device node into the tree and global list.
*/
@@ -1743,24 +1890,13 @@ int of_attach_node(struct device_node *np)
np->allnext = of_allnodes;
np->parent->child = np;
of_allnodes = np;
+ of_node_clear_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- of_add_proc_dt_entry(np);
+ of_node_add(np);
return 0;
}
-#ifdef CONFIG_PROC_DEVICETREE
-static void of_remove_proc_dt_entry(struct device_node *dn)
-{
- proc_remove(dn->pde);
-}
-#else
-static void of_remove_proc_dt_entry(struct device_node *dn)
-{
- return;
-}
-#endif
-
/**
* of_detach_node - "Unplug" a node from the device tree.
*
@@ -1816,7 +1952,7 @@ int of_detach_node(struct device_node *np)
of_node_set_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- of_remove_proc_dt_entry(np);
+ of_node_remove(np);
return rc;
}
#endif /* defined(CONFIG_OF_DYNAMIC) */
@@ -1852,9 +1988,9 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
of_chosen = of_find_node_by_path("/chosen@0");
if (of_chosen) {
- const char *name;
-
- name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+ const char *name = of_get_property(of_chosen, "stdout-path", NULL);
+ if (!name)
+ name = of_get_property(of_chosen, "linux,stdout-path", NULL);
if (name)
of_stdout = of_find_node_by_path(name);
}