[PATCH 1/3] exporting capability name/code pairs (final)

[Kohei KaiGai <kaigai@ak.jp.nec.com>]

[1/3] Add a private data field within kobj_attribute structure.

This patch add a private data field, declared as void *, within kobj_attribute
structure. The _show() and _store() method in the sysfs attribute entries can
refer this information to identify what entry is accessed.
It makes easier to share a single method implementation with several similar
entries, like ones to export the list of capabilities the running kernel
supported.

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
--
 include/linux/kobject.h |    1 +
 include/linux/sysfs.h   |    7 +++++++
 2 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index caa3f41..57d5bf1 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -130,6 +130,7 @@ struct kobj_attribute {
 			char *buf);
 	ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
 			 const char *buf, size_t count);
+	void *data;	/* a private field */
 };

 extern struct sysfs_ops kobj_sysfs_ops;
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 8027104..6f40ff9 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -50,6 +50,13 @@ struct attribute_group {
 	.store	= _store,					\
 }

+#define __ATTR_DATA(_name,_mode,_show,_store,_data) {		\
+	.attr = {.name = __stringify(_name), .mode = _mode },   \
+	.show	= _show,					\
+	.store	= _store,					\
+	.data	= (void *)(_data),				\
+}
+	
 #define __ATTR_RO(_name) { \
 	.attr	= { .name = __stringify(_name), .mode = 0444 },	\
 	.show	= _name##_show,					\

-- 
OSS Platform Development Division, NEC
KaiGai Kohei <kaigai@ak.jp.nec.com>