// SPDX-License-Identifier: GPL-2.0
/*
* 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.
*/
#define pr_fmt(fmt) "OF: " fmt
#include <linux/cleanup.h>
#include <linux/device.h>
#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"
static struct device_node *kobj_to_device_node(struct kobject *kobj)
{
return container_of(kobj, struct device_node, kobj);
}
/**
* of_node_get() - Increment refcount of a node
* @node: Node to inc refcount, NULL is supported to simplify writing of
* callers
*
* Return: The node with refcount incremented.
*/
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 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);
static const char *action_names[] = {
[0] = "INVALID",
[OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
[OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
[OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
[OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
[OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
};
#define _do_print(func, prefix, action, node, prop, ...) ({ \
func("changeset: " prefix "%-15s %pOF%s%s\n", \
##__VA_ARGS__, action_names[action], node, \
prop ? ":" : "", prop ? prop->name : ""); \
})
#define of_changeset_action_err(...) _do_print(pr_err, __VA_ARGS__)
#define of_changeset_action_debug(...) _do_print(pr_debug, __VA_ARGS__)
int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
{
int rc;
struct of_reconfig_data *pr = p;
of_changeset_action_debug("notify: ", action, pr->dn, pr->prop);
rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
return notifier_to_errno(rc);
}
/*
* of_reconfig_get_state_change() - Returns new state of device
* @action - action of the of notifier
* @arg - argument of the of notifier
*
* Returns the new state of a device based on the notifier used.
*
* Return: OF_RECONFIG_CHANGE_REMOVE on device going from enabled to
* disabled, OF_RECONFIG_CHANGE_ADD on device going from disabled to
* enabled and OF_RECONFIG_NO_CHANGE on no change.
*/
int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
{
struct property *prop, *old_prop = NULL;
int is_status, status_state, old_status_state, prev_state, new_state;
/* figure out if a device should be created or destroyed */
switch (action) {
case OF_RECONFIG_ATTACH_NODE:
case OF_RECONFIG_DETACH_NODE:
prop = of_find_property(pr->dn, "status", NULL);
break;
case OF_RECONFIG_ADD_PROPERTY:
case OF_RECONFIG_REMOVE_PROPERTY:
prop = pr->prop;
break;
case OF_RECONFIG_UPDATE_PROPERTY:
prop = pr->prop;
old_prop = pr->old_prop;
break;
default:
return OF_RECONFIG_NO_CHANGE;
}
is_status = 0;
status_state = -1;
old_status_state = -1;
prev_state = -1;
new_state = -1;
if (prop && !strcmp(prop->name, "status")) {
is_status = 1;
status_state = !strcmp(prop->value, "okay") ||
!strcmp(prop->value, "ok");
if (old_prop)
old_status_state = !strcmp(old_prop->value, "okay") ||
!strcmp(old_prop->value, "ok");
}
switch (action) {
case OF_RECONFIG_ATTACH_NODE:
prev_state = 0;
/* -1 & 0 status either missing or okay */
new_state = status_state != 0;
break;
case OF_RECONFIG_DETACH_NODE:
/* -1 & 0 status either missing or okay */
prev_state = status_state != 0;
new_state = 0;
break;
case OF_RECONFIG_ADD_PROPERTY:
if (is_status) {
/* no status property -> enabled (legacy) */
prev_state = 1;
new_state = status_state;
}
break;
case OF_RECONFIG_REMOVE_PROPERTY:
if (is_status) {
prev_state = status_state;
/* no status property -> enabled (legacy) */
new_state = 1;
}
break;
case OF_RECONFIG_UPDATE_PROPERTY:
if (is_status) {
prev_state = old_status_state != 0;
new_state = status_state != 0;
}
break;
}
if (prev_state == new_state)
return OF_RECONFIG_NO_CHANGE;
return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
}
EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
int of_property_notify(int action, struct device_node *np,
struct property *prop, struct property *oldprop)
{
struct of_reconfig_data pr;
/* only call notifiers if the node is attached */
if (!of_node_is_attached(np))
return 0;
pr.dn = np;
pr.prop = prop;
pr.old_prop = oldprop;
return of_reconfig_notify(action, &pr);
}
static void __of_attach_node(struct device_node *np)
{
const __be32 *phandle;
int sz;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
if (!of_node_check_flag(np, OF_OVERLAY)) {
np->name = __of_get_property(np, "name", NULL);
if (!np->name)
np->name = "<NULL>";
phandle = __of_get_property(np, "phandle", &sz);
if (!phandle)
phandle = __of_get_property(np, "linux,phandle", &sz);
if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
phandle = __of_get_property(np, "ibm,phandle", &sz);
if (phandle && (sz >= 4))
np->phandle = be32_to_cpup(phandle);
else
np->phandle = 0;
}
np->child = NULL;
np->sibling = np->parent->child;
np->parent->child = np;
of_node_clear_flag(np, OF_DETACHED);
np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
raw_spin_unlock_irqrestore(&devtree_lock, flags);
__of_attach_node_sysfs(np);
}
/**
* of_attach_node() - Plug a device node into the tree and global list.
* @np: Pointer to the caller's Device Node
*/
int of_attach_node(struct device_node *np)
{
struct of_reconfig_data rd;
memset(&rd, 0, sizeof(rd));
rd.dn = np;
mutex_lock(&of_mutex);
__of_attach_node(np);
mutex_unlock(&of_mutex);
of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
return 0;
}
void __of_detach_node(struct device_node *np)
{
struct device_node *parent;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
parent = np->parent;
if (WARN_ON(of_node_check_flag(np, OF_DETACHED) || !parent)) {
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return;
}
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);
/* race with of_find_node_by_phandle() prevented by devtree_lock */
__of_phandle_cache_inv_entry(np->phandle);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
__of_detach_node_sysfs(np);
}
/**
* of_detach_node() - "Unplug" a node from the device tree.
* @np: Pointer to the caller's Device Node
*/
int of_detach_node(struct device_node *np)
{
struct of_reconfig_data rd;
memset(&rd, 0, sizeof(rd));
rd.dn = np;
mutex_lock(&of_mutex);
__of_detach_node(np);
mutex_unlock(&of_mutex);
of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
return 0;
}
EXPORT_SYMBOL_GPL(of_detach_node);
void __of_prop_free(struct property *prop)
{
kfree(prop->name);
kfree(prop->value);
kfree(prop);
}
static void property_list_free(struct property *prop_list)
{
struct property *prop, *next;
for (prop = prop_list; prop != NULL; prop = next) {
next = prop->next;
__of_prop_free(prop);
}
}
/**
* of_node_release() - release a dynamically allocated node
* @kobj: kernel object 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);
/*
* can not use '"%pOF", node' in pr_err() calls from this function
* because an of_node_get(node) when refcount is already zero
* will result in an error and a stack dump
*/
/* We should never be releasing nodes that haven't been detached. */
if (!of_node_check_flag(node, OF_DETACHED)) {
pr_err("ERROR: %s() detected bad of_node_put() on %pOF/%s\n",
__func__, node->parent, node->full_name);
/*
* of unittests will test this path. Do not print the stack
* trace when the error is caused by unittest so that we do
* not display what a normal developer might reasonably
* consider a real bug.
*/
if (!IS_ENABLED(CONFIG_OF_UNITTEST) ||
strcmp(node->parent->full_name, "testcase-data")) {
dump_stack();
pr_err("ERROR: next of_node_put() on this node will result in a kobject warning 'refcount_t: underflow; use-after-free.'\n");
}
return;
}
if (!of_node_check_flag(node, OF_DYNAMIC))
return;
if (of_node_check_flag(node, OF_OVERLAY)) {
if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) {
/* premature refcount of zero, do not free memory */
pr_err("ERROR: memory leak before free overlay changeset, %pOF\n",
node);
return;
}
/*
* If node->properties non-empty then properties were added
* to this node either by different overlay that has not
* yet been removed, or by a non-overlay mechanism.
*/
if (node->properties)
pr_err("ERROR: %s(), unexpected properties in %pOF\n",
__func__, node);
}
if (node->child)
pr_err("ERROR: %s() unexpected children for %pOF/%s\n",
__func__, node->parent, node->full_name);
property_list_free(node->properties);
property_list_free(node->deadprops);
fwnode_links_purge(of_fwnode_handle(node));
kfree(node->full_name);
kfree(node->data);
kfree(node);
}
/**
* __of_prop_dup - Copy a property dynamically.
* @prop: Property to copy
* @allocflags: Allocation flags (typically pass GFP_KERNEL)
*
* Copy a property by dynamically allocating the memory of both the
* property structure and the property name & contents. The property's
* flags have the OF_DYNAMIC bit set so that we can differentiate between
* dynamically allocated properties and not.
*
* Return: The newly allocated property or NULL on out of memory error.
*/
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
{
struct property *new;
new = kzalloc(sizeof(*new), allocflags);
if (!new)
return NULL;
/*
* NOTE: There is no check for zero length value.
* In case of a boolean property, this will allocate a value
* of zero bytes. We do this to work around the use
* of of_get_property() calls on boolean values.
*/
new->name = kstrdup(prop->name, allocflags);
new->value = kmemdup(prop->value, prop->length, allocflags);
new->length = prop->length;
if (!new->name || !new->value)
goto err_free;
/* mark the property as dynamic */
of_property_set_flag(new, OF_DYNAMIC);
return new;
err_free:
__of_prop_free(new);
return NULL;
}
/**
* __of_node_dup() - Duplicate or create an empty device node dynamically.
* @np: if not NULL, contains properties to be duplicated in new node
* @full_name: string value to be duplicated into new node's full_name field
*
* Create a device tree node, optionally duplicating the properties of
* another node. The node data are dynamically allocated and all the node
* flags have the OF_DYNAMIC & OF_DETACHED bits set.
*
* Return: The newly allocated node or NULL on out of memory error. Use
* of_node_put() on it when done to free the memory allocated for it.
*/
struct device_node *__of_node_dup(const struct device_node *np,
const char *full_name)
{
struct device_node *node;
node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!node)
return NULL;
node->full_name = kstrdup(full_name, GFP_KERNEL);
if (!node->full_name) {
kfree(node);
return NULL;
}
of_node_set_flag(node, OF_DYNAMIC);
of_node_set_flag(node, OF_DETACHED);
of_node_init(node);
/* Iterate over and duplicate all properties */
if (np) {
struct property *pp, *new_pp;
for_each_property_of_node(np, pp) {
new_pp = __of_prop_dup(pp, GFP_KERNEL);
if (!new_pp)
goto err_prop;
if (__of_add_property(node, new_pp)) {
__of_prop_free(new_pp);
goto err_prop;
}
}
}
return node;
err_prop:
of_node_put(node); /* Frees the node and properties */
return NULL;
}
/**
* of_changeset_create_node - Dynamically create a device node and attach to
* a given changeset.
*
* @ocs: Pointer to changeset
* @parent: Pointer to parent device node
* @full_name: Node full name
*
* Return: Pointer to the created device node or NULL in case of an error.
*/
struct device_node *of_changeset_create_node(struct of_changeset *ocs,
struct device_node *parent,
const char *full_name)
{
struct device_node *np;
int ret;
np = __of_node_dup(NULL, full_name);
if (!np)
return NULL;
np->parent = parent;
ret = of_changeset_attach_node(ocs, np);
if (ret) {
of_node_put(np);
return NULL;
}
return np;
}
EXPORT_SYMBOL(of_changeset_create_node);
static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
{
if (ce->action == OF_RECONFIG_ATTACH_NODE &&
of_node_check_flag(ce->np, OF_OVERLAY)) {
if (kref_read(&ce->np->kobj.kref) > 1) {
pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n",
kref_read(&ce->np->kobj.kref), ce->np);
} else {
of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET);
}
}
of_node_put(ce->np);
list_del(&ce->node);
kfree(ce);
}
static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
struct of_changeset_entry *rce)
{
memcpy(rce, ce, sizeof(*rce));
switch (ce->action) {
case OF_RECONFIG_ATTACH_NODE:
rce->action = OF_RECONFIG_DETACH_NODE;
break;
case OF_RECONFIG_DETACH_NODE:
rce->action = OF_RECONFIG_ATTACH_NODE;
break;
case OF_RECONFIG_ADD_PROPERTY:
rce->action = OF_RECONFIG_REMOVE_PROPERTY;
break;
case OF_RECONFIG_REMOVE_PROPERTY:
rce->action = OF_RECONFIG_ADD_PROPERTY;
break;
case OF_RECONFIG_UPDATE_PROPERTY:
rce->old_prop = ce->prop;
rce->prop = ce->old_prop;
/* update was used but original property did not exist */
if (!rce->prop) {
rce->action = OF_RECONFIG_REMOVE_PROPERTY;
rce->prop = ce->prop;
}
break;
}
}
static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
bool revert)
{
struct of_reconfig_data rd;
struct of_changeset_entry ce_inverted;
int ret = 0;
if (revert) {
__of_changeset_entry_invert(ce, &ce_inverted);
ce = &ce_inverted;
}
switch (ce->action) {
case OF_RECONFIG_ATTACH_NODE:
case OF_RECONFIG_DETACH_NODE:
memset(&rd, 0, sizeof(rd));
rd.dn = ce->np;
ret = of_reconfig_notify(ce->action, &rd);
break;
case OF_RECONFIG_ADD_PROPERTY:
case OF_RECONFIG_REMOVE_PROPERTY:
case OF_RECONFIG_UPDATE_PROPERTY:
ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
break;
default:
pr_err("invalid devicetree changeset action: %i\n",
(int)ce->action);
ret = -EINVAL;
}
if (ret)
pr_err("changeset notifier error @%pOF\n", ce->np);
return ret;
}
static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
{
int ret = 0;
of_changeset_action_debug("apply: ", ce->action, ce->np, ce->prop);
switch (ce->action) {
case OF_RECONFIG_ATTACH_NODE:
__of_attach_node(ce->np);
break;
case OF_RECONFIG_DETACH_NODE:
__of_detach_node(ce->np);
break;
case OF_RECONFIG_ADD_PROPERTY:
ret = __of_add_property(ce->np, ce->prop);
break;
case OF_RECONFIG_REMOVE_PROPERTY:
ret = __of_remove_property(ce->np, ce->prop);
break;
case OF_RECONFIG_UPDATE_PROPERTY:
ret = __of_update_property(ce->np, ce->prop, &ce->old_prop);
break;
default:
ret = -EINVAL;
}
if (ret) {
of_changeset_action_err("apply failed: ", ce->action, ce->np, ce->prop);
return ret;
}
return 0;
}
static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
{
struct of_changeset_entry ce_inverted;
__of_changeset_entry_invert(ce, &ce_inverted);
return __of_changeset_entry_apply(&ce_inverted);
}
/**
* of_changeset_init - Initialize a changeset for use
*
* @ocs: changeset pointer
*
* Initialize a changeset structure
*/
void of_changeset_init(struct of_changeset *ocs)
{
memset(ocs, 0, sizeof(*ocs));
INIT_LIST_HEAD(&ocs->entries);
}
EXPORT_SYMBOL_GPL(of_changeset_init);
/**
* of_changeset_destroy - Destroy a changeset
*
* @ocs: changeset pointer
*
* Destroys a changeset. Note that if a changeset is applied,
* its changes to the tree cannot be reverted.
*/
void of_changeset_destroy(struct of_changeset *ocs)
{
struct of_changeset_entry *ce, *cen;
/*
* When a device is deleted, the device links to/from it are also queued
* for deletion. Until these device links are freed, the devices
* themselves aren't freed. If the device being deleted is due to an
* overlay change, this device might be holding a reference to a device
* node that will be freed. So, wait until all already pending device
* links are deleted before freeing a device node. This ensures we don't
* free any device node that has a non-zero reference count.
*/
device_link_wait_removal();
list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
__of_changeset_entry_destroy(ce);
}
EXPORT_SYMBOL_GPL(of_changeset_destroy);
/*
* Apply the changeset entries in @ocs.
* If apply fails, an attempt is made to revert the entries that were
* successfully applied.
*
* If multiple revert errors occur then only the final revert error is reported.
*
* Returns 0 on success, a negative error value in case of an error.
* If a revert error occurs, it is returned in *ret_revert.
*/
int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert)
{
struct of_changeset_entry *ce;
int ret, ret_tmp;
pr_debug("changeset: applying...\n");
list_for_each_entry(ce, &ocs->entries, node) {
ret = __of_changeset_entry_apply(ce);
if (ret) {
pr_err("Error applying changeset (%d)\n", ret);
list_for_each_entry_continue_reverse(ce, &ocs->entries,
node) {
ret_tmp = __of_changeset_entry_revert(ce);
if (ret_tmp)
*ret_revert = ret_tmp;
}
return ret;
}
}
return 0;
}
/*
* Returns 0 on success, a negative error value in case of an error.
*
* If multiple changeset entry notification errors occur then only the
* final notification error is reported.
*/
int __of_changeset_apply_notify(struct of_changeset *ocs)
{
struct of_changeset_entry *ce;
int ret = 0, ret_tmp;
pr_debug("changeset: emitting notifiers.\n");
/* drop the global lock while emitting notifiers */
mutex_unlock(&of_mutex);
list_for_each_entry(ce, &ocs->entries, node) {
ret_tmp = __of_changeset_entry_notify(ce, 0);
if (ret_tmp)
ret = ret_tmp;
}
mutex_lock(&of_mutex);
pr_debug("changeset: notifiers sent.\n");
return ret;
}
/*
* Returns 0 on success, a negative error value in case of an error.
*
* If a changeset entry apply fails, an attempt is made to revert any
* previous entries in the changeset. If any of the reverts fails,
* that failure is not reported. Thus the state of the device tree
* is unknown if an apply error occurs.
*/
static int __of_changeset_apply(struct of_changeset *ocs)
{
int ret, ret_revert = 0;
ret = __of_changeset_apply_entries(ocs, &ret_revert);
if (!ret)
ret = __of_changeset_apply_notify(ocs);
return ret;
}
/**
* of_changeset_apply - Applies a changeset
*
* @ocs: changeset pointer
*
* Applies a changeset to the live tree.
* Any side-effects of live tree state changes are applied here on
* success, like creation/destruction of devices and side-effects
* like creation of sysfs properties and directories.
*
* Return: 0 on success, a negative error value in case of an error.
* On error the partially applied effects are reverted.
*/
int of_changeset_apply(struct of_changeset *ocs)
{
int ret;
mutex_lock(&of_mutex);
ret = __of_changeset_apply(ocs);
mutex_unlock(&of_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(of_changeset_apply);
/*
* Revert the changeset entries in @ocs.
* If revert fails, an attempt is made to re-apply the entries that were
* successfully removed.
*
* If multiple re-apply errors occur then only the final apply error is
* reported.
*
* Returns 0 on success, a negative error value in case of an error.
* If an apply error occurs, it is returned in *ret_apply.
*/
int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply)
{
struct of_changeset_entry *ce;
int ret, ret_tmp;
pr_debug("changeset: reverting...\n");
list_for_each_entry_reverse(ce, &ocs->entries, node) {
ret = __of_changeset_entry_revert(ce);
if (ret) {
pr_err("Error reverting changeset (%d)\n", ret);
list_for_each_entry_continue(ce, &ocs->entries, node) {
ret_tmp = __of_changeset_entry_apply(ce);
if (ret_tmp)
*ret_apply = ret_tmp;
}
return ret;
}
}
return 0;
}
/*
* If multiple changeset entry notification errors occur then only the
* final notification error is reported.
*/
int __of_changeset_revert_notify(struct of_changeset *ocs)
{
struct of_changeset_entry *ce;
int ret = 0, ret_tmp;
pr_debug("changeset: emitting notifiers.\n");
/* drop the global lock while emitting notifiers */
mutex_unlock(&of_mutex);
list_for_each_entry_reverse(ce, &ocs->entries, node) {
ret_tmp = __of_changeset_entry_notify(ce, 1);
if (ret_tmp)
ret = ret_tmp;
}
mutex_lock(&of_mutex);
pr_debug("changeset: notifiers sent.\n");
return ret;
}
static int __of_changeset_revert(struct of_changeset *ocs)
{
int ret, ret_reply;
ret_reply = 0;
ret = __of_changeset_revert_entries(ocs, &ret_reply);
if (!ret)
ret = __of_changeset_revert_notify(ocs);
return ret;
}
/**
* of_changeset_revert - Reverts an applied changeset
*
* @ocs: changeset pointer
*
* Reverts a changeset returning the state of the tree to what it
* was before the application.
* Any side-effects like creation/destruction of devices and
* removal of sysfs properties and directories are applied.
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_revert(struct of_changeset *ocs)
{
int ret;
mutex_lock(&of_mutex);
ret = __of_changeset_revert(ocs);
mutex_unlock(&of_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(of_changeset_revert);
/**
* of_changeset_action - Add an action to the tail of the changeset list
*
* @ocs: changeset pointer
* @action: action to perform
* @np: Pointer to device node
* @prop: Pointer to property
*
* On action being one of:
* + OF_RECONFIG_ATTACH_NODE
* + OF_RECONFIG_DETACH_NODE,
* + OF_RECONFIG_ADD_PROPERTY
* + OF_RECONFIG_REMOVE_PROPERTY,
* + OF_RECONFIG_UPDATE_PROPERTY
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_action(struct of_changeset *ocs, unsigned long action,
struct device_node *np, struct property *prop)
{
struct of_changeset_entry *ce;
if (WARN_ON(action >= ARRAY_SIZE(action_names)))
return -EINVAL;
ce = kzalloc(sizeof(*ce), GFP_KERNEL);
if (!ce)
return -ENOMEM;
/* get a reference to the node */
ce->action = action;
ce->np = of_node_get(np);
ce->prop = prop;
/* add it to the list */
list_add_tail(&ce->node, &ocs->entries);
return 0;
}
EXPORT_SYMBOL_GPL(of_changeset_action);
static int of_changeset_add_prop_helper(struct of_changeset *ocs,
struct device_node *np,
const struct property *pp)
{
struct property *new_pp;
int ret;
new_pp = __of_prop_dup(pp, GFP_KERNEL);
if (!new_pp)
return -ENOMEM;
ret = of_changeset_add_property(ocs, np, new_pp);
if (ret)
__of_prop_free(new_pp);
return ret;
}
/**
* of_changeset_add_prop_string - Add a string property to a changeset
*
* @ocs: changeset pointer
* @np: device node pointer
* @prop_name: name of the property to be added
* @str: pointer to null terminated string
*
* Create a string property and add it to a changeset.
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_add_prop_string(struct of_changeset *ocs,
struct device_node *np,
const char *prop_name, const char *str)
{
struct property prop;
prop.name = (char *)prop_name;
prop.length = strlen(str) + 1;
prop.value = (void *)str;
return of_changeset_add_prop_helper(ocs, np, &prop);
}
EXPORT_SYMBOL_GPL(of_changeset_add_prop_string);
/**
* of_changeset_add_prop_string_array - Add a string list property to
* a changeset
*
* @ocs: changeset pointer
* @np: device node pointer
* @prop_name: name of the property to be added
* @str_array: pointer to an array of null terminated strings
* @sz: number of string array elements
*
* Create a string list property and add it to a changeset.
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_add_prop_string_array(struct of_changeset *ocs,
struct device_node *np,
const char *prop_name,
const char * const *str_array, size_t sz)
{
struct property prop;
int i, ret;
char *vp;
prop.name = (char *)prop_name;
prop.length = 0;
for (i = 0; i < sz; i++)
prop.length += strlen(str_array[i]) + 1;
prop.value = kmalloc(prop.length, GFP_KERNEL);
if (!prop.value)
return -ENOMEM;
vp = prop.value;
for (i = 0; i < sz; i++) {
vp += snprintf(vp, (char *)prop.value + prop.length - vp, "%s",
str_array[i]) + 1;
}
ret = of_changeset_add_prop_helper(ocs, np, &prop);
kfree(prop.value);
return ret;
}
EXPORT_SYMBOL_GPL(of_changeset_add_prop_string_array);
/**
* of_changeset_add_prop_u32_array - Add a property of 32 bit integers
* property to a changeset
*
* @ocs: changeset pointer
* @np: device node pointer
* @prop_name: name of the property to be added
* @array: pointer to an array of 32 bit integers
* @sz: number of array elements
*
* Create a property of 32 bit integers and add it to a changeset.
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
struct device_node *np,
const char *prop_name,
const u32 *array, size_t sz)
{
struct property prop;
__be32 *val __free(kfree) = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
int i;
if (!val)
return -ENOMEM;
for (i = 0; i < sz; i++)
val[i] = cpu_to_be32(array[i]);
prop.name = (char *)prop_name;
prop.length = sizeof(u32) * sz;
prop.value = (void *)val;
return of_changeset_add_prop_helper(ocs, np, &prop);
}
EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
/**
* of_changeset_add_prop_bool - Add a boolean property (i.e. a property without
* any values) to a changeset.
*
* @ocs: changeset pointer
* @np: device node pointer
* @prop_name: name of the property to be added
*
* Create a boolean property and add it to a changeset.
*
* Return: 0 on success, a negative error value in case of an error.
*/
int of_changeset_add_prop_bool(struct of_changeset *ocs, struct device_node *np,
const char *prop_name)
{
struct property prop;
prop.name = (char *)prop_name;
prop.length = 0;
prop.value = NULL;
return of_changeset_add_prop_helper(ocs, np, &prop);
}
EXPORT_SYMBOL_GPL(of_changeset_add_prop_bool);
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