[linux.git] / kernel / ksysfs.c

/*
 * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
 * 		     are not related to any other subsystem
 *
 * Copyright (C) 2004 Kay Sievers <[email protected]>
 * 
 * This file is release under the GPLv2
 *
 */

#include <linux/config.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/init.h>

u64 uevent_seqnum;
char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";

#define KERNEL_ATTR_RO(_name) \
static struct subsys_attribute _name##_attr = __ATTR_RO(_name)

#define KERNEL_ATTR_RW(_name) \
static struct subsys_attribute _name##_attr = \
	__ATTR(_name, 0644, _name##_show, _name##_store)

#ifdef CONFIG_HOTPLUG
/* current uevent sequence number */
static ssize_t uevent_seqnum_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
}
KERNEL_ATTR_RO(uevent_seqnum);

/* uevent helper program, used during early boo */
static ssize_t uevent_helper_show(struct subsystem *subsys, char *page)
{
	return sprintf(page, "%s\n", uevent_helper);
}
static ssize_t uevent_helper_store(struct subsystem *subsys, const char *page, size_t count)
{
	if (count+1 > UEVENT_HELPER_PATH_LEN)
		return -ENOENT;
	memcpy(uevent_helper, page, count);
	uevent_helper[count] = '\0';
	if (count && uevent_helper[count-1] == '\n')
		uevent_helper[count-1] = '\0';
	return count;
}
KERNEL_ATTR_RW(uevent_helper);
#endif

decl_subsys(kernel, NULL, NULL);
EXPORT_SYMBOL_GPL(kernel_subsys);

static struct attribute * kernel_attrs[] = {
#ifdef CONFIG_HOTPLUG
	&uevent_seqnum_attr.attr,
	&uevent_helper_attr.attr,
#endif
	NULL
};

static struct attribute_group kernel_attr_group = {
	.attrs = kernel_attrs,
};

static int __init ksysfs_init(void)
{
	int error = subsystem_register(&kernel_subsys);
	if (!error)
		error = sysfs_create_group(&kernel_subsys.kset.kobj,
					   &kernel_attr_group);

	return error;
}

core_initcall(ksysfs_init);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
	3	* are not related to any other subsystem
	4	*
	5	* Copyright (C) 2004 Kay Sievers <[email protected]>
	6	*
	7	* This file is release under the GPLv2
	8	*
	9	*/
	10
	11	#include <linux/config.h>
	12	#include <linux/kobject.h>
	13	#include <linux/string.h>
	14	#include <linux/sysfs.h>
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17
f743ca5e	18	u64 uevent_seqnum;
	19	char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
	20
1da177e4 LT	21	#define KERNEL_ATTR_RO(_name) \
	22	static struct subsys_attribute _name##_attr = __ATTR_RO(_name)
	23
	24	#define KERNEL_ATTR_RW(_name) \
	25	static struct subsys_attribute _name##_attr = \
	26	__ATTR(_name, 0644, _name##_show, _name##_store)
	27
	28	#ifdef CONFIG_HOTPLUG
0f76e5ac KS	29	/* current uevent sequence number */
0f76e5ac KS	30	static ssize_t uevent_seqnum_show(struct subsystem subsys, char page)
1da177e4	31	{
312c004d	32	return sprintf(page, "%llu\n", (unsigned long long)uevent_seqnum);
1da177e4	33	}
0f76e5ac KS	34	KERNEL_ATTR_RO(uevent_seqnum);
	35
	36	/* uevent helper program, used during early boo */
	37	static ssize_t uevent_helper_show(struct subsystem subsys, char page)
	38	{
312c004d	39	return sprintf(page, "%s\n", uevent_helper);
0f76e5ac KS	40	}
	41	static ssize_t uevent_helper_store(struct subsystem subsys, const char page, size_t count)
	42	{
312c004d	43	if (count+1 > UEVENT_HELPER_PATH_LEN)
0f76e5ac	44	return -ENOENT;
312c004d KS	45	memcpy(uevent_helper, page, count);
	46	uevent_helper[count] = '\0';
	47	if (count && uevent_helper[count-1] == '\n')
	48	uevent_helper[count-1] = '\0';
0f76e5ac KS	49	return count;
	50	}
	51	KERNEL_ATTR_RW(uevent_helper);
1da177e4 LT	52	#endif
	53
	54	decl_subsys(kernel, NULL, NULL);
	55	EXPORT_SYMBOL_GPL(kernel_subsys);
	56
	57	static struct attribute * kernel_attrs[] = {
	58	#ifdef CONFIG_HOTPLUG
0f76e5ac KS	59	&uevent_seqnum_attr.attr,
0f76e5ac KS	60	&uevent_helper_attr.attr,
1da177e4 LT	61	#endif
	62	NULL
	63	};
	64
	65	static struct attribute_group kernel_attr_group = {
	66	.attrs = kernel_attrs,
	67	};
	68
	69	static int __init ksysfs_init(void)
	70	{
	71	int error = subsystem_register(&kernel_subsys);
	72	if (!error)
	73	error = sysfs_create_group(&kernel_subsys.kset.kobj,
	74	&kernel_attr_group);
	75
	76	return error;
	77	}
	78
	79	core_initcall(ksysfs_init);