of: Move CONFIG_OF_DYNAMIC code into a separate file

Split the dynamic device tree code into a separate file to make it
really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without
CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not
get sent. Enabling it turns on reference counting, notifiers and the
ability to add and remove nodes.

v2: Moved of_node_release() into dynamic.c

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: Rob Herring <robh+dt@kernel.org>

drivers/of/Makefile

@@ -1,4 +1,5 @@
 obj-y = base.o device.o platform.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
 obj-$(CONFIG_OF_FLATTREE) += fdt.o
 obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
 obj-$(CONFIG_OF_PROMTREE) += pdt.o

drivers/of/base.c

@@ -88,79 +88,7 @@ int __weak of_node_to_nid(struct device_node *np)
 }
 #endif
 
-#if defined(CONFIG_OF_DYNAMIC)
-/**
- *	of_node_get - Increment refcount of a node
- *	@node:	Node to inc refcount, NULL is supported to
- *		simplify writing of callers
- *
- *	Returns node.
- */
-struct device_node *of_node_get(struct device_node *node)
-{
-	if (node)
-		kobject_get(&node->kobj);
-	return node;
-}
-EXPORT_SYMBOL(of_node_get);
-
-static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
-{
-	return container_of(kobj, struct device_node, kobj);
-}
-
-/**
- *	of_node_release - release a dynamically allocated node
- *	@kref:  kref element of the node to be released
- *
- *	In of_node_put() this function is passed to kref_put()
- *	as the destructor.
- */
-static void of_node_release(struct kobject *kobj)
-{
-	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();
-		return;
-	}
-
-	if (!of_node_check_flag(node, OF_DYNAMIC))
-		return;
-
-	while (prop) {
-		struct property *next = prop->next;
-		kfree(prop->name);
-		kfree(prop->value);
-		kfree(prop);
-		prop = next;
-
-		if (!prop) {
-			prop = node->deadprops;
-			node->deadprops = NULL;
-		}
-	}
-	kfree(node->full_name);
-	kfree(node->data);
-	kfree(node);
-}
-
-/**
- *	of_node_put - Decrement refcount of a node
- *	@node:	Node to dec refcount, NULL is supported to
- *		simplify writing of callers
- *
- */
-void of_node_put(struct device_node *node)
-{
-	if (node)
-		kobject_put(&node->kobj);
-}
-EXPORT_SYMBOL(of_node_put);
-#else
+#ifndef CONFIG_OF_DYNAMIC
 static void of_node_release(struct kobject *kobj)
 {
 	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
@@ -264,25 +192,6 @@ int of_node_add(struct device_node *np)
 	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;
@@ -1747,28 +1656,6 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
 }
 EXPORT_SYMBOL(of_count_phandle_with_args);
 
-#if defined(CONFIG_OF_DYNAMIC)
-static int of_property_notify(int action, struct device_node *np,
-			      struct property *prop)
-{
-	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);
-}
-#else
-static int of_property_notify(int action, struct device_node *np,
-			      struct property *prop)
-{
-	return 0;
-}
-#endif
-
 /**
  * __of_add_property - Add a property to a node without lock operations
  */
@@ -1915,121 +1802,6 @@ int of_update_property(struct device_node *np, struct property *newprop)
 	return 0;
 }
 
-#if defined(CONFIG_OF_DYNAMIC)
-/*
- * Support for dynamic device trees.
- *
- * On some platforms, the device tree can be manipulated at runtime.
- * The routines in this section support adding, removing and changing
- * device tree nodes.
- */
-
-static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
-
-int of_reconfig_notifier_register(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
-}
-EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
-
-int of_reconfig_notifier_unregister(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
-}
-EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
-
-int of_reconfig_notify(unsigned long action, void *p)
-{
-	int rc;
-
-	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
-	return notifier_to_errno(rc);
-}
-
-/**
- * of_attach_node - Plug a device node into the tree and global list.
- */
-int of_attach_node(struct device_node *np)
-{
-	unsigned long flags;
-	int rc;
-
-	rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
-	if (rc)
-		return rc;
-
-	raw_spin_lock_irqsave(&devtree_lock, flags);
-	np->sibling = np->parent->child;
-	np->allnext = np->parent->allnext;
-	np->parent->allnext = np;
-	np->parent->child = np;
-	of_node_clear_flag(np, OF_DETACHED);
-	raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
-	of_node_add(np);
-	return 0;
-}
-
-/**
- * of_detach_node - "Unplug" a node from the device tree.
- *
- * The caller must hold a reference to the node.  The memory associated with
- * the node is not freed until its refcount goes to zero.
- */
-int of_detach_node(struct device_node *np)
-{
-	struct device_node *parent;
-	unsigned long flags;
-	int rc = 0;
-
-	rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
-	if (rc)
-		return rc;
-
-	raw_spin_lock_irqsave(&devtree_lock, flags);
-
-	if (of_node_check_flag(np, OF_DETACHED)) {
-		/* someone already detached it */
-		raw_spin_unlock_irqrestore(&devtree_lock, flags);
-		return rc;
-	}
-
-	parent = np->parent;
-	if (!parent) {
-		raw_spin_unlock_irqrestore(&devtree_lock, flags);
-		return rc;
-	}
-
-	if (of_allnodes == np)
-		of_allnodes = np->allnext;
-	else {
-		struct device_node *prev;
-		for (prev = of_allnodes;
-		     prev->allnext != np;
-		     prev = prev->allnext)
-			;
-		prev->allnext = np->allnext;
-	}
-
-	if (parent->child == np)
-		parent->child = np->sibling;
-	else {
-		struct device_node *prevsib;
-		for (prevsib = np->parent->child;
-		     prevsib->sibling != np;
-		     prevsib = prevsib->sibling)
-			;
-		prevsib->sibling = np->sibling;
-	}
-
-	of_node_set_flag(np, OF_DETACHED);
-	raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
-	of_node_remove(np);
-	return rc;
-}
-#endif /* defined(CONFIG_OF_DYNAMIC) */
-
 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
 			 int id, const char *stem, int stem_len)
 {

drivers/of/dynamic.c

@@ -0,0 +1,216 @@
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+#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"
+
+/**
+ * of_node_get() - Increment refcount of a node
+ * @node:	Node to inc refcount, NULL is supported to simplify writing of
+ *		callers
+ *
+ * Returns node.
+ */
+struct device_node *of_node_get(struct device_node *node)
+{
+	if (node)
+		kobject_get(&node->kobj);
+	return node;
+}
+EXPORT_SYMBOL(of_node_get);
+
+/**
+ * of_node_put() - Decrement refcount of a node
+ * @node:	Node to dec refcount, NULL is supported to simplify writing of
+ *		callers
+ */
+void of_node_put(struct device_node *node)
+{
+	if (node)
+		kobject_put(&node->kobj);
+}
+EXPORT_SYMBOL(of_node_put);
+
+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);
+}
+
+static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
+
+int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
+
+int of_reconfig_notify(unsigned long action, void *p)
+{
+	int rc;
+
+	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
+	return notifier_to_errno(rc);
+}
+
+int of_property_notify(int action, struct device_node *np,
+		       struct property *prop)
+{
+	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);
+}
+
+/**
+ * of_attach_node() - Plug a device node into the tree and global list.
+ */
+int of_attach_node(struct device_node *np)
+{
+	unsigned long flags;
+	int rc;
+
+	rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+	if (rc)
+		return rc;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np->sibling = np->parent->child;
+	np->allnext = np->parent->allnext;
+	np->parent->allnext = np;
+	np->parent->child = np;
+	of_node_clear_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	of_node_add(np);
+	return 0;
+}
+
+/**
+ * of_detach_node() - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node.  The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+int of_detach_node(struct device_node *np)
+{
+	struct device_node *parent;
+	unsigned long flags;
+	int rc = 0;
+
+	rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+	if (rc)
+		return rc;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (of_node_check_flag(np, OF_DETACHED)) {
+		/* someone already detached it */
+		raw_spin_unlock_irqrestore(&devtree_lock, flags);
+		return rc;
+	}
+
+	parent = np->parent;
+	if (!parent) {
+		raw_spin_unlock_irqrestore(&devtree_lock, flags);
+		return rc;
+	}
+
+	if (of_allnodes == np)
+		of_allnodes = np->allnext;
+	else {
+		struct device_node *prev;
+		for (prev = of_allnodes;
+		     prev->allnext != np;
+		     prev = prev->allnext)
+			;
+		prev->allnext = np->allnext;
+	}
+
+	if (parent->child == np)
+		parent->child = np->sibling;
+	else {
+		struct device_node *prevsib;
+		for (prevsib = np->parent->child;
+		     prevsib->sibling != np;
+		     prevsib = prevsib->sibling)
+			;
+		prevsib->sibling = np->sibling;
+	}
+
+	of_node_set_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	of_node_remove(np);
+	return rc;
+}
+
+/**
+ * of_node_release() - release a dynamically allocated node
+ * @kref: kref element of the node to be released
+ *
+ * In of_node_put() this function is passed to kref_put() as the destructor.
+ */
+void of_node_release(struct kobject *kobj)
+{
+	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();
+		return;
+	}
+
+	if (!of_node_check_flag(node, OF_DYNAMIC))
+		return;
+
+	while (prop) {
+		struct property *next = prop->next;
+		kfree(prop->name);
+		kfree(prop->value);
+		kfree(prop);
+		prop = next;
+
+		if (!prop) {
+			prop = node->deadprops;
+			node->deadprops = NULL;
+		}
+	}
+	kfree(node->full_name);
+	kfree(node->data);
+	kfree(node);
+}

drivers/of/of_private.h

@@ -33,4 +33,22 @@ struct alias_prop {
 
 extern struct mutex of_mutex;
 extern struct list_head aliases_lookup;
+
+static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
+{
+	return container_of(kobj, struct device_node, kobj);
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+extern int of_property_notify(int action, struct device_node *np,
+			      struct property *prop);
+extern void of_node_release(struct kobject *kobj);
+#else /* CONFIG_OF_DYNAMIC */
+static inline int of_property_notify(int action, struct device_node *np,
+				     struct property *prop)
+{
+	return 0;
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
 #endif /* _LINUX_OF_PRIVATE_H */