}
EXPORT_SYMBOL_GPL(device_remove_bin_file);
+/**
+ * device_schedule_callback_owner - helper to schedule a callback for a device
+ * @dev: device.
+ * @func: callback function to invoke later.
+ * @owner: module owning the callback routine
+ *
+ * Attribute methods must not unregister themselves or their parent device
+ * (which would amount to the same thing). Attempts to do so will deadlock,
+ * since unregistration is mutually exclusive with driver callbacks.
+ *
+ * Instead methods can call this routine, which will attempt to allocate
+ * and schedule a workqueue request to call back @func with @dev as its
+ * argument in the workqueue's process context. @dev will be pinned until
+ * @func returns.
+ *
+ * This routine is usually called via the inline device_schedule_callback(),
+ * which automatically sets @owner to THIS_MODULE.
+ *
+ * Returns 0 if the request was submitted, -ENOMEM if storage could not
+ * be allocated, -ENODEV if a reference to @owner isn't available.
+ *
+ * NOTE: This routine won't work if CONFIG_SYSFS isn't set! It uses an
+ * underlying sysfs routine (since it is intended for use by attribute
+ * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
+ */
+int device_schedule_callback_owner(struct device *dev,
+ void (*func)(struct device *), struct module *owner)
+{
+ return sysfs_schedule_callback(&dev->kobj,
+ (void (*)(void *)) func, dev, owner);
+}
+EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
+
static void klist_children_get(struct klist_node *n)
{
struct device_private *p = to_device_private_parent(n);
kernfs_remove_by_name(kobj->sd, attr->attr.name);
}
EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
+
+struct sysfs_schedule_callback_struct {
+ struct list_head workq_list;
+ struct kobject *kobj;
+ void (*func)(void *);
+ void *data;
+ struct module *owner;
+ struct work_struct work;
+};
+
+static struct workqueue_struct *sysfs_workqueue;
+static DEFINE_MUTEX(sysfs_workq_mutex);
+static LIST_HEAD(sysfs_workq);
+static void sysfs_schedule_callback_work(struct work_struct *work)
+{
+ struct sysfs_schedule_callback_struct *ss = container_of(work,
+ struct sysfs_schedule_callback_struct, work);
+
+ (ss->func)(ss->data);
+ kobject_put(ss->kobj);
+ module_put(ss->owner);
+ mutex_lock(&sysfs_workq_mutex);
+ list_del(&ss->workq_list);
+ mutex_unlock(&sysfs_workq_mutex);
+ kfree(ss);
+}
+
+/**
+ * sysfs_schedule_callback - helper to schedule a callback for a kobject
+ * @kobj: object we're acting for.
+ * @func: callback function to invoke later.
+ * @data: argument to pass to @func.
+ * @owner: module owning the callback code
+ *
+ * sysfs attribute methods must not unregister themselves or their parent
+ * kobject (which would amount to the same thing). Attempts to do so will
+ * deadlock, since unregistration is mutually exclusive with driver
+ * callbacks.
+ *
+ * Instead methods can call this routine, which will attempt to allocate
+ * and schedule a workqueue request to call back @func with @data as its
+ * argument in the workqueue's process context. @kobj will be pinned
+ * until @func returns.
+ *
+ * Returns 0 if the request was submitted, -ENOMEM if storage could not
+ * be allocated, -ENODEV if a reference to @owner isn't available,
+ * -EAGAIN if a callback has already been scheduled for @kobj.
+ */
+int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
+ void *data, struct module *owner)
+{
+ struct sysfs_schedule_callback_struct *ss, *tmp;
+
+ if (!try_module_get(owner))
+ return -ENODEV;
+
+ mutex_lock(&sysfs_workq_mutex);
+ list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list)
+ if (ss->kobj == kobj) {
+ module_put(owner);
+ mutex_unlock(&sysfs_workq_mutex);
+ return -EAGAIN;
+ }
+ mutex_unlock(&sysfs_workq_mutex);
+
+ if (sysfs_workqueue == NULL) {
+ sysfs_workqueue = create_singlethread_workqueue("sysfsd");
+ if (sysfs_workqueue == NULL) {
+ module_put(owner);
+ return -ENOMEM;
+ }
+ }
+
+ ss = kmalloc(sizeof(*ss), GFP_KERNEL);
+ if (!ss) {
+ module_put(owner);
+ return -ENOMEM;
+ }
+ kobject_get(kobj);
+ ss->kobj = kobj;
+ ss->func = func;
+ ss->data = data;
+ ss->owner = owner;
+ INIT_WORK(&ss->work, sysfs_schedule_callback_work);
+ INIT_LIST_HEAD(&ss->workq_list);
+ mutex_lock(&sysfs_workq_mutex);
+ list_add_tail(&ss->workq_list, &sysfs_workq);
+ mutex_unlock(&sysfs_workq_mutex);
+ queue_work(sysfs_workqueue, &ss->work);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(sysfs_schedule_callback);
const struct bin_attribute *attr);
extern void device_remove_bin_file(struct device *dev,
const struct bin_attribute *attr);
+extern int device_schedule_callback_owner(struct device *dev,
+ void (*func)(struct device *dev), struct module *owner);
+
+/* This is a macro to avoid include problems with THIS_MODULE */
+#define device_schedule_callback(dev, func) \
+ device_schedule_callback_owner(dev, func, THIS_MODULE)
/* device resource management */
typedef void (*dr_release_t)(struct device *dev, void *res);
extern struct device *__root_device_register(const char *name,
struct module *owner);
-/* This is a macro to avoid include problems with THIS_MODULE */
+/*
+ * This is a macro to avoid include problems with THIS_MODULE,
+ * just as per what is done for device_schedule_callback() above.
+ */
#define root_device_register(name) \
__root_device_register(name, THIS_MODULE)
#ifdef CONFIG_SYSFS
+int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
+ void *data, struct module *owner);
+
int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
void sysfs_remove_dir(struct kobject *kobj);
int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
#else /* CONFIG_SYSFS */
+static inline int sysfs_schedule_callback(struct kobject *kobj,
+ void (*func)(void *), void *data, struct module *owner)
+{
+ return -ENOSYS;
+}
+
static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
{
return 0;
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