powerpc+of: Add of node/property notification chain for adds and removes
This patch moves the notification chain for updates to the device tree
from the powerpc/pseries code to the base OF code. This makes this
functionality available to all architectures.
Additionally the notification chain is updated to allow notifications
for property add/remove/update. To make this work a pointer to a new
struct (of_prop_reconfig) is passed to the routines in the notification chain.
The of_prop_reconfig property contains a pointer to the node containing the
property and a pointer to the property itself. In the case of property
updates, the property pointer refers to the new property.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/of/base.c b/drivers/of/base.c
index bbd073f..87b6385 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1028,6 +1028,24 @@
}
EXPORT_SYMBOL(of_parse_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;
+
+ 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
+
/**
* prom_add_property - Add a property to a node
*/
@@ -1035,6 +1053,11 @@
{
struct property **next;
unsigned long flags;
+ int rc;
+
+ rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
+ if (rc)
+ return rc;
prop->next = NULL;
write_lock_irqsave(&devtree_lock, flags);
@@ -1072,6 +1095,11 @@
struct property **next;
unsigned long flags;
int found = 0;
+ int rc;
+
+ rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
+ if (rc)
+ return rc;
write_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
@@ -1114,7 +1142,11 @@
{
struct property **next, *oldprop;
unsigned long flags;
- int found = 0;
+ int rc, found = 0;
+
+ rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
+ if (rc)
+ return rc;
if (!newprop->name)
return -EINVAL;
@@ -1160,6 +1192,26 @@
* 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);
+}
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+
+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);
+}
+
#ifdef CONFIG_PROC_DEVICETREE
static void of_add_proc_dt_entry(struct device_node *dn)
{
@@ -1179,9 +1231,14 @@
/**
* of_attach_node - Plug a device node into the tree and global list.
*/
-void of_attach_node(struct device_node *np)
+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;
write_lock_irqsave(&devtree_lock, flags);
np->sibling = np->parent->child;
@@ -1191,6 +1248,7 @@
write_unlock_irqrestore(&devtree_lock, flags);
of_add_proc_dt_entry(np);
+ return 0;
}
#ifdef CONFIG_PROC_DEVICETREE
@@ -1220,23 +1278,28 @@
* The caller must hold a reference to the node. The memory associated with
* the node is not freed until its refcount goes to zero.
*/
-void of_detach_node(struct device_node *np)
+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;
write_lock_irqsave(&devtree_lock, flags);
if (of_node_check_flag(np, OF_DETACHED)) {
/* someone already detached it */
write_unlock_irqrestore(&devtree_lock, flags);
- return;
+ return rc;
}
parent = np->parent;
if (!parent) {
write_unlock_irqrestore(&devtree_lock, flags);
- return;
+ return rc;
}
if (allnodes == np)
@@ -1265,6 +1328,7 @@
write_unlock_irqrestore(&devtree_lock, flags);
of_remove_proc_dt_entry(np);
+ return rc;
}
#endif /* defined(CONFIG_OF_DYNAMIC) */