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Diffstat (limited to 'include/target/configfs_macros.h')
| -rw-r--r-- | include/target/configfs_macros.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/include/target/configfs_macros.h b/include/target/configfs_macros.h new file mode 100644 index 00000000000..7fe74608b43 --- /dev/null +++ b/include/target/configfs_macros.h @@ -0,0 +1,147 @@ +/* -*- mode: c; c-basic-offset: 8; -*- + * vim: noexpandtab sw=8 ts=8 sts=0: + * + * configfs_macros.h - extends macros for configfs + * + * 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. + * + * Added CONFIGFS_EATTR() macros from original configfs.h macros + * Copright (C) 2008-2009 Nicholas A. Bellinger <nab@linux-iscsi.org> + * + * Please read Documentation/filesystems/configfs.txt before using the + * configfs interface, ESPECIALLY the parts about reference counts and + * item destructors. + */ + +#ifndef _CONFIGFS_MACROS_H_ +#define _CONFIGFS_MACROS_H_ + +#include <linux/configfs.h> + +/* + * 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 _name isends up as + * 'struct _name_attribute, as well as names of to CONFIGFS_ATTR_OPS() below. + * The argument _item is the name of the structure containing the + * struct config_item or struct config_group structure members + */ +#define CONFIGFS_EATTR_STRUCT(_name, _item) \ +struct _name##_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_EATTR(_name, _mode, _show, _store) \ + * struct myitem_attribute childless_attr_##_name = \ + * __CONFIGFS_EATTR(_name, _mode, _show, _store) + */ +#define __CONFIGFS_EATTR(_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_EATTR_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 _name is the name of the attribute defined by + * CONFIGFS_ATTR_STRUCT(). The argument _item is the name of the structure + * containing the struct config_item or struct config_group structure member. + * The argument _item_member is the actual name of the struct config_* struct + * in your _item structure. Meaning my_structure->some_config_group. + * ^^_item^^^^^ ^^_item_member^^^ + * This macro expects the attributes to be named "struct <name>_attribute". + */ +#define CONFIGFS_EATTR_OPS_TO_FUNC(_name, _item, _item_member) \ +static struct _item *to_##_name(struct config_item *ci) \ +{ \ + return (ci) ? container_of(to_config_group(ci), struct _item, \ + _item_member) : NULL; \ +} + +#define CONFIGFS_EATTR_OPS_SHOW(_name, _item) \ +static ssize_t _name##_attr_show(struct config_item *item, \ + struct configfs_attribute *attr, \ + char *page) \ +{ \ + struct _item *_item = to_##_name(item); \ + struct _name##_attribute * _name##_attr = \ + container_of(attr, struct _name##_attribute, attr); \ + ssize_t ret = 0; \ + \ + if (_name##_attr->show) \ + ret = _name##_attr->show(_item, page); \ + return ret; \ +} + +#define CONFIGFS_EATTR_OPS_STORE(_name, _item) \ +static ssize_t _name##_attr_store(struct config_item *item, \ + struct configfs_attribute *attr, \ + const char *page, size_t count) \ +{ \ + struct _item *_item = to_##_name(item); \ + struct _name##_attribute * _name##_attr = \ + container_of(attr, struct _name##_attribute, attr); \ + ssize_t ret = -EINVAL; \ + \ + if (_name##_attr->store) \ + ret = _name##_attr->store(_item, page, count); \ + return ret; \ +} + +#define CONFIGFS_EATTR_OPS(_name, _item, _item_member) \ + CONFIGFS_EATTR_OPS_TO_FUNC(_name, _item, _item_member); \ + CONFIGFS_EATTR_OPS_SHOW(_name, _item); \ + CONFIGFS_EATTR_OPS_STORE(_name, _item); + +#define CONFIGFS_EATTR_OPS_RO(_name, _item, _item_member) \ + CONFIGFS_EATTR_OPS_TO_FUNC(_name, _item, _item_member); \ + CONFIGFS_EATTR_OPS_SHOW(_name, _item); + +#endif /* _CONFIGFS_MACROS_H_ */ |