Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
new file mode 100644
index 0000000..a1f3f09
--- /dev/null
+++ b/drivers/base/swnode.c
@@ -0,0 +1,912 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Software nodes for the firmware node framework.
+ *
+ * Copyright (C) 2018, Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+struct swnode {
+ int id;
+ struct kobject kobj;
+ struct fwnode_handle fwnode;
+ const struct software_node *node;
+
+ /* hierarchy */
+ struct ida child_ids;
+ struct list_head entry;
+ struct list_head children;
+ struct swnode *parent;
+
+ unsigned int allocated:1;
+};
+
+static DEFINE_IDA(swnode_root_ids);
+static struct kset *swnode_kset;
+
+#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
+
+static const struct fwnode_operations software_node_ops;
+
+bool is_software_node(const struct fwnode_handle *fwnode)
+{
+ return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
+}
+EXPORT_SYMBOL_GPL(is_software_node);
+
+#define to_swnode(__fwnode) \
+ ({ \
+ typeof(__fwnode) __to_swnode_fwnode = __fwnode; \
+ \
+ is_software_node(__to_swnode_fwnode) ? \
+ container_of(__to_swnode_fwnode, \
+ struct swnode, fwnode) : NULL; \
+ })
+
+static struct swnode *
+software_node_to_swnode(const struct software_node *node)
+{
+ struct swnode *swnode = NULL;
+ struct kobject *k;
+
+ if (!node)
+ return NULL;
+
+ spin_lock(&swnode_kset->list_lock);
+
+ list_for_each_entry(k, &swnode_kset->list, entry) {
+ swnode = kobj_to_swnode(k);
+ if (swnode->node == node)
+ break;
+ swnode = NULL;
+ }
+
+ spin_unlock(&swnode_kset->list_lock);
+
+ return swnode;
+}
+
+const struct software_node *to_software_node(struct fwnode_handle *fwnode)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ return swnode ? swnode->node : NULL;
+}
+EXPORT_SYMBOL_GPL(to_software_node);
+
+struct fwnode_handle *software_node_fwnode(const struct software_node *node)
+{
+ struct swnode *swnode = software_node_to_swnode(node);
+
+ return swnode ? &swnode->fwnode : NULL;
+}
+EXPORT_SYMBOL_GPL(software_node_fwnode);
+
+/* -------------------------------------------------------------------------- */
+/* property_entry processing */
+
+static const struct property_entry *
+property_entry_get(const struct property_entry *prop, const char *name)
+{
+ if (!prop)
+ return NULL;
+
+ for (; prop->name; prop++)
+ if (!strcmp(name, prop->name))
+ return prop;
+
+ return NULL;
+}
+
+static void
+property_set_pointer(struct property_entry *prop, const void *pointer)
+{
+ switch (prop->type) {
+ case DEV_PROP_U8:
+ if (prop->is_array)
+ prop->pointer.u8_data = pointer;
+ else
+ prop->value.u8_data = *((u8 *)pointer);
+ break;
+ case DEV_PROP_U16:
+ if (prop->is_array)
+ prop->pointer.u16_data = pointer;
+ else
+ prop->value.u16_data = *((u16 *)pointer);
+ break;
+ case DEV_PROP_U32:
+ if (prop->is_array)
+ prop->pointer.u32_data = pointer;
+ else
+ prop->value.u32_data = *((u32 *)pointer);
+ break;
+ case DEV_PROP_U64:
+ if (prop->is_array)
+ prop->pointer.u64_data = pointer;
+ else
+ prop->value.u64_data = *((u64 *)pointer);
+ break;
+ case DEV_PROP_STRING:
+ if (prop->is_array)
+ prop->pointer.str = pointer;
+ else
+ prop->value.str = pointer;
+ break;
+ default:
+ break;
+ }
+}
+
+static const void *property_get_pointer(const struct property_entry *prop)
+{
+ switch (prop->type) {
+ case DEV_PROP_U8:
+ if (prop->is_array)
+ return prop->pointer.u8_data;
+ return &prop->value.u8_data;
+ case DEV_PROP_U16:
+ if (prop->is_array)
+ return prop->pointer.u16_data;
+ return &prop->value.u16_data;
+ case DEV_PROP_U32:
+ if (prop->is_array)
+ return prop->pointer.u32_data;
+ return &prop->value.u32_data;
+ case DEV_PROP_U64:
+ if (prop->is_array)
+ return prop->pointer.u64_data;
+ return &prop->value.u64_data;
+ case DEV_PROP_STRING:
+ if (prop->is_array)
+ return prop->pointer.str;
+ return &prop->value.str;
+ default:
+ return NULL;
+ }
+}
+
+static const void *property_entry_find(const struct property_entry *props,
+ const char *propname, size_t length)
+{
+ const struct property_entry *prop;
+ const void *pointer;
+
+ prop = property_entry_get(props, propname);
+ if (!prop)
+ return ERR_PTR(-EINVAL);
+ pointer = property_get_pointer(prop);
+ if (!pointer)
+ return ERR_PTR(-ENODATA);
+ if (length > prop->length)
+ return ERR_PTR(-EOVERFLOW);
+ return pointer;
+}
+
+static int property_entry_read_u8_array(const struct property_entry *props,
+ const char *propname,
+ u8 *values, size_t nval)
+{
+ const void *pointer;
+ size_t length = nval * sizeof(*values);
+
+ pointer = property_entry_find(props, propname, length);
+ if (IS_ERR(pointer))
+ return PTR_ERR(pointer);
+
+ memcpy(values, pointer, length);
+ return 0;
+}
+
+static int property_entry_read_u16_array(const struct property_entry *props,
+ const char *propname,
+ u16 *values, size_t nval)
+{
+ const void *pointer;
+ size_t length = nval * sizeof(*values);
+
+ pointer = property_entry_find(props, propname, length);
+ if (IS_ERR(pointer))
+ return PTR_ERR(pointer);
+
+ memcpy(values, pointer, length);
+ return 0;
+}
+
+static int property_entry_read_u32_array(const struct property_entry *props,
+ const char *propname,
+ u32 *values, size_t nval)
+{
+ const void *pointer;
+ size_t length = nval * sizeof(*values);
+
+ pointer = property_entry_find(props, propname, length);
+ if (IS_ERR(pointer))
+ return PTR_ERR(pointer);
+
+ memcpy(values, pointer, length);
+ return 0;
+}
+
+static int property_entry_read_u64_array(const struct property_entry *props,
+ const char *propname,
+ u64 *values, size_t nval)
+{
+ const void *pointer;
+ size_t length = nval * sizeof(*values);
+
+ pointer = property_entry_find(props, propname, length);
+ if (IS_ERR(pointer))
+ return PTR_ERR(pointer);
+
+ memcpy(values, pointer, length);
+ return 0;
+}
+
+static int
+property_entry_count_elems_of_size(const struct property_entry *props,
+ const char *propname, size_t length)
+{
+ const struct property_entry *prop;
+
+ prop = property_entry_get(props, propname);
+ if (!prop)
+ return -EINVAL;
+
+ return prop->length / length;
+}
+
+static int property_entry_read_int_array(const struct property_entry *props,
+ const char *name,
+ unsigned int elem_size, void *val,
+ size_t nval)
+{
+ if (!val)
+ return property_entry_count_elems_of_size(props, name,
+ elem_size);
+ switch (elem_size) {
+ case sizeof(u8):
+ return property_entry_read_u8_array(props, name, val, nval);
+ case sizeof(u16):
+ return property_entry_read_u16_array(props, name, val, nval);
+ case sizeof(u32):
+ return property_entry_read_u32_array(props, name, val, nval);
+ case sizeof(u64):
+ return property_entry_read_u64_array(props, name, val, nval);
+ }
+
+ return -ENXIO;
+}
+
+static int property_entry_read_string_array(const struct property_entry *props,
+ const char *propname,
+ const char **strings, size_t nval)
+{
+ const struct property_entry *prop;
+ const void *pointer;
+ size_t array_len, length;
+
+ /* Find out the array length. */
+ prop = property_entry_get(props, propname);
+ if (!prop)
+ return -EINVAL;
+
+ if (prop->is_array)
+ /* Find the length of an array. */
+ array_len = property_entry_count_elems_of_size(props, propname,
+ sizeof(const char *));
+ else
+ /* The array length for a non-array string property is 1. */
+ array_len = 1;
+
+ /* Return how many there are if strings is NULL. */
+ if (!strings)
+ return array_len;
+
+ array_len = min(nval, array_len);
+ length = array_len * sizeof(*strings);
+
+ pointer = property_entry_find(props, propname, length);
+ if (IS_ERR(pointer))
+ return PTR_ERR(pointer);
+
+ memcpy(strings, pointer, length);
+
+ return array_len;
+}
+
+static void property_entry_free_data(const struct property_entry *p)
+{
+ const void *pointer = property_get_pointer(p);
+ size_t i, nval;
+
+ if (p->is_array) {
+ if (p->type == DEV_PROP_STRING && p->pointer.str) {
+ nval = p->length / sizeof(const char *);
+ for (i = 0; i < nval; i++)
+ kfree(p->pointer.str[i]);
+ }
+ kfree(pointer);
+ } else if (p->type == DEV_PROP_STRING) {
+ kfree(p->value.str);
+ }
+ kfree(p->name);
+}
+
+static int property_copy_string_array(struct property_entry *dst,
+ const struct property_entry *src)
+{
+ const char **d;
+ size_t nval = src->length / sizeof(*d);
+ int i;
+
+ d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return -ENOMEM;
+
+ for (i = 0; i < nval; i++) {
+ d[i] = kstrdup(src->pointer.str[i], GFP_KERNEL);
+ if (!d[i] && src->pointer.str[i]) {
+ while (--i >= 0)
+ kfree(d[i]);
+ kfree(d);
+ return -ENOMEM;
+ }
+ }
+
+ dst->pointer.str = d;
+ return 0;
+}
+
+static int property_entry_copy_data(struct property_entry *dst,
+ const struct property_entry *src)
+{
+ const void *pointer = property_get_pointer(src);
+ const void *new;
+ int error;
+
+ if (src->is_array) {
+ if (!src->length)
+ return -ENODATA;
+
+ if (src->type == DEV_PROP_STRING) {
+ error = property_copy_string_array(dst, src);
+ if (error)
+ return error;
+ new = dst->pointer.str;
+ } else {
+ new = kmemdup(pointer, src->length, GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+ }
+ } else if (src->type == DEV_PROP_STRING) {
+ new = kstrdup(src->value.str, GFP_KERNEL);
+ if (!new && src->value.str)
+ return -ENOMEM;
+ } else {
+ new = pointer;
+ }
+
+ dst->length = src->length;
+ dst->is_array = src->is_array;
+ dst->type = src->type;
+
+ property_set_pointer(dst, new);
+
+ dst->name = kstrdup(src->name, GFP_KERNEL);
+ if (!dst->name)
+ goto out_free_data;
+
+ return 0;
+
+out_free_data:
+ property_entry_free_data(dst);
+ return -ENOMEM;
+}
+
+/**
+ * property_entries_dup - duplicate array of properties
+ * @properties: array of properties to copy
+ *
+ * This function creates a deep copy of the given NULL-terminated array
+ * of property entries.
+ */
+struct property_entry *
+property_entries_dup(const struct property_entry *properties)
+{
+ struct property_entry *p;
+ int i, n = 0;
+ int ret;
+
+ if (!properties)
+ return NULL;
+
+ while (properties[n].name)
+ n++;
+
+ p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < n; i++) {
+ ret = property_entry_copy_data(&p[i], &properties[i]);
+ if (ret) {
+ while (--i >= 0)
+ property_entry_free_data(&p[i]);
+ kfree(p);
+ return ERR_PTR(ret);
+ }
+ }
+
+ return p;
+}
+EXPORT_SYMBOL_GPL(property_entries_dup);
+
+/**
+ * property_entries_free - free previously allocated array of properties
+ * @properties: array of properties to destroy
+ *
+ * This function frees given NULL-terminated array of property entries,
+ * along with their data.
+ */
+void property_entries_free(const struct property_entry *properties)
+{
+ const struct property_entry *p;
+
+ if (!properties)
+ return;
+
+ for (p = properties; p->name; p++)
+ property_entry_free_data(p);
+
+ kfree(properties);
+}
+EXPORT_SYMBOL_GPL(property_entries_free);
+
+/* -------------------------------------------------------------------------- */
+/* fwnode operations */
+
+static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ kobject_get(&swnode->kobj);
+
+ return &swnode->fwnode;
+}
+
+static void software_node_put(struct fwnode_handle *fwnode)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ kobject_put(&swnode->kobj);
+}
+
+static bool software_node_property_present(const struct fwnode_handle *fwnode,
+ const char *propname)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ return !!property_entry_get(swnode->node->properties, propname);
+}
+
+static int software_node_read_int_array(const struct fwnode_handle *fwnode,
+ const char *propname,
+ unsigned int elem_size, void *val,
+ size_t nval)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ return property_entry_read_int_array(swnode->node->properties, propname,
+ elem_size, val, nval);
+}
+
+static int software_node_read_string_array(const struct fwnode_handle *fwnode,
+ const char *propname,
+ const char **val, size_t nval)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ return property_entry_read_string_array(swnode->node->properties,
+ propname, val, nval);
+}
+
+static struct fwnode_handle *
+software_node_get_parent(const struct fwnode_handle *fwnode)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ return swnode ? (swnode->parent ? &swnode->parent->fwnode : NULL) : NULL;
+}
+
+static struct fwnode_handle *
+software_node_get_next_child(const struct fwnode_handle *fwnode,
+ struct fwnode_handle *child)
+{
+ struct swnode *p = to_swnode(fwnode);
+ struct swnode *c = to_swnode(child);
+
+ if (!p || list_empty(&p->children) ||
+ (c && list_is_last(&c->entry, &p->children)))
+ return NULL;
+
+ if (c)
+ c = list_next_entry(c, entry);
+ else
+ c = list_first_entry(&p->children, struct swnode, entry);
+ return &c->fwnode;
+}
+
+static struct fwnode_handle *
+software_node_get_named_child_node(const struct fwnode_handle *fwnode,
+ const char *childname)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+ struct swnode *child;
+
+ if (!swnode || list_empty(&swnode->children))
+ return NULL;
+
+ list_for_each_entry(child, &swnode->children, entry) {
+ if (!strcmp(childname, kobject_name(&child->kobj))) {
+ kobject_get(&child->kobj);
+ return &child->fwnode;
+ }
+ }
+ return NULL;
+}
+
+static int
+software_node_get_reference_args(const struct fwnode_handle *fwnode,
+ const char *propname, const char *nargs_prop,
+ unsigned int nargs, unsigned int index,
+ struct fwnode_reference_args *args)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+ const struct software_node_reference *ref;
+ const struct property_entry *prop;
+ struct fwnode_handle *refnode;
+ int i;
+
+ if (!swnode || !swnode->node->references)
+ return -ENOENT;
+
+ for (ref = swnode->node->references; ref->name; ref++)
+ if (!strcmp(ref->name, propname))
+ break;
+
+ if (!ref->name || index > (ref->nrefs - 1))
+ return -ENOENT;
+
+ refnode = software_node_fwnode(ref->refs[index].node);
+ if (!refnode)
+ return -ENOENT;
+
+ if (nargs_prop) {
+ prop = property_entry_get(swnode->node->properties, nargs_prop);
+ if (!prop)
+ return -EINVAL;
+
+ nargs = prop->value.u32_data;
+ }
+
+ if (nargs > NR_FWNODE_REFERENCE_ARGS)
+ return -EINVAL;
+
+ args->fwnode = software_node_get(refnode);
+ args->nargs = nargs;
+
+ for (i = 0; i < nargs; i++)
+ args->args[i] = ref->refs[index].args[i];
+
+ return 0;
+}
+
+static const struct fwnode_operations software_node_ops = {
+ .get = software_node_get,
+ .put = software_node_put,
+ .property_present = software_node_property_present,
+ .property_read_int_array = software_node_read_int_array,
+ .property_read_string_array = software_node_read_string_array,
+ .get_parent = software_node_get_parent,
+ .get_next_child_node = software_node_get_next_child,
+ .get_named_child_node = software_node_get_named_child_node,
+ .get_reference_args = software_node_get_reference_args
+};
+
+/* -------------------------------------------------------------------------- */
+
+/**
+ * software_node_find_by_name - Find software node by name
+ * @parent: Parent of the software node
+ * @name: Name of the software node
+ *
+ * The function will find a node that is child of @parent and that is named
+ * @name. If no node is found, the function returns NULL.
+ *
+ * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
+ */
+const struct software_node *
+software_node_find_by_name(const struct software_node *parent, const char *name)
+{
+ struct swnode *swnode = NULL;
+ struct kobject *k;
+
+ if (!name)
+ return NULL;
+
+ spin_lock(&swnode_kset->list_lock);
+
+ list_for_each_entry(k, &swnode_kset->list, entry) {
+ swnode = kobj_to_swnode(k);
+ if (parent == swnode->node->parent && swnode->node->name &&
+ !strcmp(name, swnode->node->name)) {
+ kobject_get(&swnode->kobj);
+ break;
+ }
+ swnode = NULL;
+ }
+
+ spin_unlock(&swnode_kset->list_lock);
+
+ return swnode ? swnode->node : NULL;
+}
+EXPORT_SYMBOL_GPL(software_node_find_by_name);
+
+static int
+software_node_register_properties(struct software_node *node,
+ const struct property_entry *properties)
+{
+ struct property_entry *props;
+
+ props = property_entries_dup(properties);
+ if (IS_ERR(props))
+ return PTR_ERR(props);
+
+ node->properties = props;
+
+ return 0;
+}
+
+static void software_node_release(struct kobject *kobj)
+{
+ struct swnode *swnode = kobj_to_swnode(kobj);
+
+ if (swnode->allocated) {
+ property_entries_free(swnode->node->properties);
+ kfree(swnode->node);
+ }
+ ida_destroy(&swnode->child_ids);
+ kfree(swnode);
+}
+
+static struct kobj_type software_node_type = {
+ .release = software_node_release,
+ .sysfs_ops = &kobj_sysfs_ops,
+};
+
+static struct fwnode_handle *
+swnode_register(const struct software_node *node, struct swnode *parent,
+ unsigned int allocated)
+{
+ struct swnode *swnode;
+ int ret;
+
+ swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
+ if (!swnode) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
+ 0, 0, GFP_KERNEL);
+ if (ret < 0) {
+ kfree(swnode);
+ goto out_err;
+ }
+
+ swnode->id = ret;
+ swnode->node = node;
+ swnode->parent = parent;
+ swnode->allocated = allocated;
+ swnode->kobj.kset = swnode_kset;
+ swnode->fwnode.ops = &software_node_ops;
+
+ ida_init(&swnode->child_ids);
+ INIT_LIST_HEAD(&swnode->entry);
+ INIT_LIST_HEAD(&swnode->children);
+
+ if (node->name)
+ ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
+ parent ? &parent->kobj : NULL,
+ "%s", node->name);
+ else
+ ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
+ parent ? &parent->kobj : NULL,
+ "node%d", swnode->id);
+ if (ret) {
+ kobject_put(&swnode->kobj);
+ return ERR_PTR(ret);
+ }
+
+ if (parent)
+ list_add_tail(&swnode->entry, &parent->children);
+
+ kobject_uevent(&swnode->kobj, KOBJ_ADD);
+ return &swnode->fwnode;
+
+out_err:
+ if (allocated)
+ property_entries_free(node->properties);
+ return ERR_PTR(ret);
+}
+
+/**
+ * software_node_register_nodes - Register an array of software nodes
+ * @nodes: Zero terminated array of software nodes to be registered
+ *
+ * Register multiple software nodes at once.
+ */
+int software_node_register_nodes(const struct software_node *nodes)
+{
+ int ret;
+ int i;
+
+ for (i = 0; nodes[i].name; i++) {
+ ret = software_node_register(&nodes[i]);
+ if (ret) {
+ software_node_unregister_nodes(nodes);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(software_node_register_nodes);
+
+/**
+ * software_node_unregister_nodes - Unregister an array of software nodes
+ * @nodes: Zero terminated array of software nodes to be unregistered
+ *
+ * Unregister multiple software nodes at once.
+ */
+void software_node_unregister_nodes(const struct software_node *nodes)
+{
+ struct swnode *swnode;
+ int i;
+
+ for (i = 0; nodes[i].name; i++) {
+ swnode = software_node_to_swnode(&nodes[i]);
+ if (swnode)
+ fwnode_remove_software_node(&swnode->fwnode);
+ }
+}
+EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
+
+/**
+ * software_node_register - Register static software node
+ * @node: The software node to be registered
+ */
+int software_node_register(const struct software_node *node)
+{
+ struct swnode *parent = software_node_to_swnode(node->parent);
+
+ if (software_node_to_swnode(node))
+ return -EEXIST;
+
+ return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
+}
+EXPORT_SYMBOL_GPL(software_node_register);
+
+struct fwnode_handle *
+fwnode_create_software_node(const struct property_entry *properties,
+ const struct fwnode_handle *parent)
+{
+ struct software_node *node;
+ struct swnode *p = NULL;
+ int ret;
+
+ if (parent) {
+ if (IS_ERR(parent))
+ return ERR_CAST(parent);
+ if (!is_software_node(parent))
+ return ERR_PTR(-EINVAL);
+ p = to_swnode(parent);
+ }
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ ret = software_node_register_properties(node, properties);
+ if (ret) {
+ kfree(node);
+ return ERR_PTR(ret);
+ }
+
+ node->parent = p ? p->node : NULL;
+
+ return swnode_register(node, p, 1);
+}
+EXPORT_SYMBOL_GPL(fwnode_create_software_node);
+
+void fwnode_remove_software_node(struct fwnode_handle *fwnode)
+{
+ struct swnode *swnode = to_swnode(fwnode);
+
+ if (!swnode)
+ return;
+
+ if (swnode->parent) {
+ ida_simple_remove(&swnode->parent->child_ids, swnode->id);
+ list_del(&swnode->entry);
+ } else {
+ ida_simple_remove(&swnode_root_ids, swnode->id);
+ }
+
+ kobject_put(&swnode->kobj);
+}
+EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
+
+int software_node_notify(struct device *dev, unsigned long action)
+{
+ struct fwnode_handle *fwnode = dev_fwnode(dev);
+ struct swnode *swnode;
+ int ret;
+
+ if (!fwnode)
+ return 0;
+
+ if (!is_software_node(fwnode))
+ fwnode = fwnode->secondary;
+ if (!is_software_node(fwnode))
+ return 0;
+
+ swnode = to_swnode(fwnode);
+
+ switch (action) {
+ case KOBJ_ADD:
+ ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
+ "software_node");
+ if (ret)
+ break;
+
+ ret = sysfs_create_link(&swnode->kobj, &dev->kobj,
+ dev_name(dev));
+ if (ret) {
+ sysfs_remove_link(&dev->kobj, "software_node");
+ break;
+ }
+ kobject_get(&swnode->kobj);
+ break;
+ case KOBJ_REMOVE:
+ sysfs_remove_link(&swnode->kobj, dev_name(dev));
+ sysfs_remove_link(&dev->kobj, "software_node");
+ kobject_put(&swnode->kobj);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int __init software_node_init(void)
+{
+ swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
+ if (!swnode_kset)
+ return -ENOMEM;
+ return 0;
+}
+postcore_initcall(software_node_init);
+
+static void __exit software_node_exit(void)
+{
+ ida_destroy(&swnode_root_ids);
+ kset_unregister(swnode_kset);
+}
+__exitcall(software_node_exit);