Initial import

1 files changed, 260 insertions, 0 deletions

diff --git a/include/linux/configfs.h b/include/linux/configfs.h
new file mode 100644
index 000000000..34025df61
--- /dev/null
+++ b/include/linux/configfs.h
@@ -0,0 +1,260 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * configfs.h - definitions for the device driver filesystem
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Based on sysfs:
+ * 	sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
+ *
+ * Based on kobject.h:
+ *      Copyright (c) 2002-2003	Patrick Mochel
+ *      Copyright (c) 2002-2003	Open Source Development Labs
+ *
+ * configfs Copyright (C) 2005 Oracle.  All rights reserved.
+ *
+ * Please read Documentation/filesystems/configfs/configfs.txt before using
+ * the configfs interface, ESPECIALLY the parts about reference counts and
+ * item destructors.
+ */
+
+#ifndef _CONFIGFS_H_
+#define _CONFIGFS_H_
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/kref.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+
+#include <linux/atomic.h>
+
+#define CONFIGFS_ITEM_NAME_LEN	20
+
+struct module;
+
+struct configfs_item_operations;
+struct configfs_group_operations;
+struct configfs_attribute;
+struct configfs_subsystem;
+
+struct config_item {
+	char			*ci_name;
+	char			ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
+	struct kref		ci_kref;
+	struct list_head	ci_entry;
+	struct config_item	*ci_parent;
+	struct config_group	*ci_group;
+	struct config_item_type	*ci_type;
+	struct dentry		*ci_dentry;
+};
+
+extern int config_item_set_name(struct config_item *, const char *, ...);
+
+static inline char *config_item_name(struct config_item * item)
+{
+	return item->ci_name;
+}
+
+extern void config_item_init(struct config_item *);
+extern void config_item_init_type_name(struct config_item *item,
+				       const char *name,
+				       struct config_item_type *type);
+
+extern struct config_item * config_item_get(struct config_item *);
+extern void config_item_put(struct config_item *);
+
+struct config_item_type {
+	struct module				*ct_owner;
+	struct configfs_item_operations		*ct_item_ops;
+	struct configfs_group_operations	*ct_group_ops;
+	struct configfs_attribute		**ct_attrs;
+};
+
+/**
+ *	group - a group of config_items of a specific type, belonging
+ *	to a specific subsystem.
+ */
+struct config_group {
+	struct config_item		cg_item;
+	struct list_head		cg_children;
+	struct configfs_subsystem 	*cg_subsys;
+	struct config_group		**default_groups;
+};
+
+extern void config_group_init(struct config_group *group);
+extern void config_group_init_type_name(struct config_group *group,
+					const char *name,
+					struct config_item_type *type);
+
+static inline struct config_group *to_config_group(struct config_item *item)
+{
+	return item ? container_of(item,struct config_group,cg_item) : NULL;
+}
+
+static inline struct config_group *config_group_get(struct config_group *group)
+{
+	return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
+}
+
+static inline void config_group_put(struct config_group *group)
+{
+	config_item_put(&group->cg_item);
+}
+
+extern struct config_item *config_group_find_item(struct config_group *,
+						  const char *);
+
+
+struct configfs_attribute {
+	const char		*ca_name;
+	struct module 		*ca_owner;
+	umode_t			ca_mode;
+};
+
+/*
+ * Users often need to create attribute structures for their configurable
+ * attributes, containing a configfs_attribute member and function pointers
+ * for the show() and store() operations on that attribute. If they don't
+ * need anything else on the extended attribute structure, they can use
+ * this macro to define it  The argument _item is the name of the
+ * config_item structure.
+ */
+#define CONFIGFS_ATTR_STRUCT(_item)					\
+struct _item##_attribute {						\
+	struct configfs_attribute attr;					\
+	ssize_t (*show)(struct _item *, char *);			\
+	ssize_t (*store)(struct _item *, const char *, size_t);		\
+}
+
+/*
+ * With the extended attribute structure, users can use this macro
+ * (similar to sysfs' __ATTR) to make defining attributes easier.
+ * An example:
+ * #define MYITEM_ATTR(_name, _mode, _show, _store)	\
+ * struct myitem_attribute childless_attr_##_name =	\
+ *         __CONFIGFS_ATTR(_name, _mode, _show, _store)
+ */
+#define __CONFIGFS_ATTR(_name, _mode, _show, _store)			\
+{									\
+	.attr	= {							\
+			.ca_name = __stringify(_name),			\
+			.ca_mode = _mode,				\
+			.ca_owner = THIS_MODULE,			\
+	},								\
+	.show	= _show,						\
+	.store	= _store,						\
+}
+/* Here is a readonly version, only requiring a show() operation */
+#define __CONFIGFS_ATTR_RO(_name, _show)				\
+{									\
+	.attr	= {							\
+			.ca_name = __stringify(_name),			\
+			.ca_mode = 0444,				\
+			.ca_owner = THIS_MODULE,			\
+	},								\
+	.show	= _show,						\
+}
+
+/*
+ * With these extended attributes, the simple show_attribute() and
+ * store_attribute() operations need to call the show() and store() of the
+ * attributes.  This is a common pattern, so we provide a macro to define
+ * them.  The argument _item is the name of the config_item structure.
+ * This macro expects the attributes to be named "struct <name>_attribute"
+ * and the function to_<name>() to exist;
+ */
+#define CONFIGFS_ATTR_OPS(_item)					\
+static ssize_t _item##_attr_show(struct config_item *item,		\
+				 struct configfs_attribute *attr,	\
+				 char *page)				\
+{									\
+	struct _item *_item = to_##_item(item);				\
+	struct _item##_attribute *_item##_attr =			\
+		container_of(attr, struct _item##_attribute, attr);	\
+	ssize_t ret = 0;						\
+									\
+	if (_item##_attr->show)						\
+		ret = _item##_attr->show(_item, page);			\
+	return ret;							\
+}									\
+static ssize_t _item##_attr_store(struct config_item *item,		\
+				  struct configfs_attribute *attr,	\
+				  const char *page, size_t count)	\
+{									\
+	struct _item *_item = to_##_item(item);				\
+	struct _item##_attribute *_item##_attr =			\
+		container_of(attr, struct _item##_attribute, attr);	\
+	ssize_t ret = -EINVAL;						\
+									\
+	if (_item##_attr->store)					\
+		ret = _item##_attr->store(_item, page, count);		\
+	return ret;							\
+}
+
+/*
+ * If allow_link() exists, the item can symlink(2) out to other
+ * items.  If the item is a group, it may support mkdir(2).
+ * Groups supply one of make_group() and make_item().  If the
+ * group supports make_group(), one can create group children.  If it
+ * supports make_item(), one can create config_item children.  make_group()
+ * and make_item() return ERR_PTR() on errors.  If it has
+ * default_groups on group->default_groups, it has automatically created
+ * group children.  default_groups may coexist alongsize make_group() or
+ * make_item(), but if the group wishes to have only default_groups
+ * children (disallowing mkdir(2)), it need not provide either function.
+ * If the group has commit(), it supports pending and committed (active)
+ * items.
+ */
+struct configfs_item_operations {
+	void (*release)(struct config_item *);
+	ssize_t	(*show_attribute)(struct config_item *, struct configfs_attribute *,char *);
+	ssize_t	(*store_attribute)(struct config_item *,struct configfs_attribute *,const char *, size_t);
+	int (*allow_link)(struct config_item *src, struct config_item *target);
+	int (*drop_link)(struct config_item *src, struct config_item *target);
+};
+
+struct configfs_group_operations {
+	struct config_item *(*make_item)(struct config_group *group, const char *name);
+	struct config_group *(*make_group)(struct config_group *group, const char *name);
+	int (*commit_item)(struct config_item *item);
+	void (*disconnect_notify)(struct config_group *group, struct config_item *item);
+	void (*drop_item)(struct config_group *group, struct config_item *item);
+};
+
+struct configfs_subsystem {
+	struct config_group	su_group;
+	struct mutex		su_mutex;
+};
+
+static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
+{
+	return group ?
+		container_of(group, struct configfs_subsystem, su_group) :
+		NULL;
+}
+
+int configfs_register_subsystem(struct configfs_subsystem *subsys);
+void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
+
+/* These functions can sleep and can alloc with GFP_KERNEL */
+/* WARNING: These cannot be called underneath configfs callbacks!! */
+int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target);
+void configfs_undepend_item(struct configfs_subsystem *subsys, struct config_item *target);
+
+#endif /* _CONFIGFS_H_ */