[mirror_ubuntu-bionic-kernel.git] / drivers / s390 / cio / ccwgroup.c

/*
 *  drivers/s390/cio/ccwgroup.c
 *  bus driver for ccwgroup
 *
 *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
 *                       IBM Corporation
 *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
 *               Cornelia Huck (cornelia.huck@de.ibm.com)
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/dcache.h>

#include <asm/semaphore.h>
#include <asm/ccwdev.h>
#include <asm/ccwgroup.h>

/* In Linux 2.4, we had a channel device layer called "chandev"
 * that did all sorts of obscure stuff for networking devices.
 * This is another driver that serves as a replacement for just
 * one of its functions, namely the translation of single subchannels
 * to devices that use multiple subchannels.
 */

/* a device matches a driver if all its slave devices match the same
 * entry of the driver */
static int
ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	gdev = container_of(dev, struct ccwgroup_device, dev);
	gdrv = container_of(drv, struct ccwgroup_driver, driver);

	if (gdev->creator_id == gdrv->driver_id)
		return 1;

	return 0;
}
static int
ccwgroup_uevent (struct device *dev, char **envp, int num_envp, char *buffer,
		  int buffer_size)
{
	/* TODO */
	return 0;
}

static struct bus_type ccwgroup_bus_type;

static void
__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
{
	int i;
	char str[8];

	for (i = 0; i < gdev->count; i++) {
		sprintf(str, "cdev%d", i);
		sysfs_remove_link(&gdev->dev.kobj, str);
		sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
	}
	
}

/*
 * Provide an 'ungroup' attribute so the user can remove group devices no
 * longer needed or accidentially created. Saves memory :)
 */
static void ccwgroup_ungroup_callback(struct device *dev)
{
	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);

	__ccwgroup_remove_symlinks(gdev);
	device_unregister(dev);
}

static ssize_t
ccwgroup_ungroup_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct ccwgroup_device *gdev;
	int rc;

	gdev = to_ccwgroupdev(dev);

	if (gdev->state != CCWGROUP_OFFLINE)
		return -EINVAL;

	/* Note that we cannot unregister the device from one of its
	 * attribute methods, so we have to use this roundabout approach.
	 */
	rc = device_schedule_callback(dev, ccwgroup_ungroup_callback);
	if (rc)
		count = rc;
	return count;
}

static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);

static void
ccwgroup_release (struct device *dev)
{
	struct ccwgroup_device *gdev;
	int i;

	gdev = to_ccwgroupdev(dev);

	for (i = 0; i < gdev->count; i++) {
		gdev->cdev[i]->dev.driver_data = NULL;
		put_device(&gdev->cdev[i]->dev);
	}
	kfree(gdev);
}

static int
__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
{
	char str[8];
	int i, rc;

	for (i = 0; i < gdev->count; i++) {
		rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
				       "group_device");
		if (rc) {
			for (--i; i >= 0; i--)
				sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
						  "group_device");
			return rc;
		}
	}
	for (i = 0; i < gdev->count; i++) {
		sprintf(str, "cdev%d", i);
		rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
				       str);
		if (rc) {
			for (--i; i >= 0; i--) {
				sprintf(str, "cdev%d", i);
				sysfs_remove_link(&gdev->dev.kobj, str);
			}
			for (i = 0; i < gdev->count; i++)
				sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
						  "group_device");
			return rc;
		}
	}
	return 0;
}

/*
 * try to add a new ccwgroup device for one driver
 * argc and argv[] are a list of bus_id's of devices
 * belonging to the driver.
 */
int
ccwgroup_create(struct device *root,
		unsigned int creator_id,
		struct ccw_driver *cdrv,
		int argc, char *argv[])
{
	struct ccwgroup_device *gdev;
	int i;
	int rc;

	if (argc > 256) /* disallow dumb users */
		return -EINVAL;

	gdev = kzalloc(sizeof(*gdev) + argc*sizeof(gdev->cdev[0]), GFP_KERNEL);
	if (!gdev)
		return -ENOMEM;

	atomic_set(&gdev->onoff, 0);

	for (i = 0; i < argc; i++) {
		gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);

		/* all devices have to be of the same type in
		 * order to be grouped */
		if (!gdev->cdev[i]
		    || gdev->cdev[i]->id.driver_info !=
		    gdev->cdev[0]->id.driver_info) {
			rc = -EINVAL;
			goto free_dev;
		}
		/* Don't allow a device to belong to more than one group. */
		if (gdev->cdev[i]->dev.driver_data) {
			rc = -EINVAL;
			goto free_dev;
		}
		gdev->cdev[i]->dev.driver_data = gdev;
	}

	gdev->creator_id = creator_id;
	gdev->count = argc;
	gdev->dev.bus = &ccwgroup_bus_type;
	gdev->dev.parent = root;
	gdev->dev.release = ccwgroup_release;

	snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
			gdev->cdev[0]->dev.bus_id);

	rc = device_register(&gdev->dev);
	
	if (rc)
		goto free_dev;
	get_device(&gdev->dev);
	rc = device_create_file(&gdev->dev, &dev_attr_ungroup);

	if (rc) {
		device_unregister(&gdev->dev);
		goto error;
	}

	rc = __ccwgroup_create_symlinks(gdev);
	if (!rc) {
		put_device(&gdev->dev);
		return 0;
	}
	device_remove_file(&gdev->dev, &dev_attr_ungroup);
	device_unregister(&gdev->dev);
error:
	for (i = 0; i < argc; i++)
		if (gdev->cdev[i]) {
			put_device(&gdev->cdev[i]->dev);
			gdev->cdev[i]->dev.driver_data = NULL;
		}
	put_device(&gdev->dev);
	return rc;
free_dev:
	for (i = 0; i < argc; i++)
		if (gdev->cdev[i]) {
			if (gdev->cdev[i]->dev.driver_data == gdev)
				gdev->cdev[i]->dev.driver_data = NULL;
			put_device(&gdev->cdev[i]->dev);
		}
	kfree(gdev);
	return rc;
}

static int __init
init_ccwgroup (void)
{
	return bus_register (&ccwgroup_bus_type);
}

static void __exit
cleanup_ccwgroup (void)
{
	bus_unregister (&ccwgroup_bus_type);
}

module_init(init_ccwgroup);
module_exit(cleanup_ccwgroup);

/************************** driver stuff ******************************/

static int
ccwgroup_set_online(struct ccwgroup_device *gdev)
{
	struct ccwgroup_driver *gdrv;
	int ret;

	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
		return -EAGAIN;
	if (gdev->state == CCWGROUP_ONLINE) {
		ret = 0;
		goto out;
	}
	if (!gdev->dev.driver) {
		ret = -EINVAL;
		goto out;
	}
	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0))
		goto out;

	gdev->state = CCWGROUP_ONLINE;
 out:
	atomic_set(&gdev->onoff, 0);
	return ret;
}

static int
ccwgroup_set_offline(struct ccwgroup_device *gdev)
{
	struct ccwgroup_driver *gdrv;
	int ret;

	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
		return -EAGAIN;
	if (gdev->state == CCWGROUP_OFFLINE) {
		ret = 0;
		goto out;
	}
	if (!gdev->dev.driver) {
		ret = -EINVAL;
		goto out;
	}
	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0))
		goto out;

	gdev->state = CCWGROUP_OFFLINE;
 out:
	atomic_set(&gdev->onoff, 0);
	return ret;
}

static ssize_t
ccwgroup_online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;
	unsigned int value;
	int ret;

	gdev = to_ccwgroupdev(dev);
	if (!dev->driver)
		return count;

	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	if (!try_module_get(gdrv->owner))
		return -EINVAL;

	value = simple_strtoul(buf, NULL, 0);
	ret = count;
	if (value == 1)
		ccwgroup_set_online(gdev);
	else if (value == 0)
		ccwgroup_set_offline(gdev);
	else
		ret = -EINVAL;
	module_put(gdrv->owner);
	return ret;
}

static ssize_t
ccwgroup_online_show (struct device *dev, struct device_attribute *attr, char *buf)
{
	int online;

	online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);

	return sprintf(buf, online ? "1\n" : "0\n");
}

static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);

static int
ccwgroup_probe (struct device *dev)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	int ret;

	gdev = to_ccwgroupdev(dev);
	gdrv = to_ccwgroupdrv(dev->driver);

	if ((ret = device_create_file(dev, &dev_attr_online)))
		return ret;

	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
	if (ret)
		device_remove_file(dev, &dev_attr_online);

	return ret;
}

static int
ccwgroup_remove (struct device *dev)
{
	struct ccwgroup_device *gdev;
	struct ccwgroup_driver *gdrv;

	gdev = to_ccwgroupdev(dev);
	gdrv = to_ccwgroupdrv(dev->driver);

	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);

	device_remove_file(dev, &dev_attr_online);

	if (gdrv && gdrv->remove)
		gdrv->remove(gdev);
	return 0;
}

static struct bus_type ccwgroup_bus_type = {
	.name   = "ccwgroup",
	.match  = ccwgroup_bus_match,
	.uevent = ccwgroup_uevent,
	.probe  = ccwgroup_probe,
	.remove = ccwgroup_remove,
};

int
ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
{
	/* register our new driver with the core */
	cdriver->driver.bus = &ccwgroup_bus_type;
	cdriver->driver.name = cdriver->name;

	return driver_register(&cdriver->driver);
}

static int
__ccwgroup_match_all(struct device *dev, void *data)
{
	return 1;
}

void
ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
{
	struct device *dev;

	/* We don't want ccwgroup devices to live longer than their driver. */
	get_driver(&cdriver->driver);
	while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,
					 __ccwgroup_match_all))) {
		__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
		device_unregister(dev);
		put_device(dev);
	}
	put_driver(&cdriver->driver);
	driver_unregister(&cdriver->driver);
}

int
ccwgroup_probe_ccwdev(struct ccw_device *cdev)
{
	return 0;
}

static struct ccwgroup_device *
__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
{
	struct ccwgroup_device *gdev;

	if (cdev->dev.driver_data) {
		gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
		if (get_device(&gdev->dev)) {
			if (device_is_registered(&gdev->dev))
				return gdev;
			put_device(&gdev->dev);
		}
		return NULL;
	}
	return NULL;
}

void
ccwgroup_remove_ccwdev(struct ccw_device *cdev)
{
	struct ccwgroup_device *gdev;

	/* Ignore offlining errors, device is gone anyway. */
	ccw_device_set_offline(cdev);
	/* If one of its devices is gone, the whole group is done for. */
	gdev = __ccwgroup_get_gdev_by_cdev(cdev);
	if (gdev) {
		__ccwgroup_remove_symlinks(gdev);
		device_unregister(&gdev->dev);
		put_device(&gdev->dev);
	}
}

MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccwgroup_driver_register);
EXPORT_SYMBOL(ccwgroup_driver_unregister);
EXPORT_SYMBOL(ccwgroup_create);
EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/cio/ccwgroup.c
	3	* bus driver for ccwgroup
1da177e4 LT	4	*
	5	* Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
	6	* IBM Corporation
	7	* Author(s): Arnd Bergmann (arndb@de.ibm.com)
4ce3b30c	8	* Cornelia Huck (cornelia.huck@de.ibm.com)
1da177e4 LT	9	*/
	10	#include <linux/module.h>
	11	#include <linux/errno.h>
	12	#include <linux/slab.h>
	13	#include <linux/list.h>
	14	#include <linux/device.h>
	15	#include <linux/init.h>
	16	#include <linux/ctype.h>
	17	#include <linux/dcache.h>
	18
	19	#include <asm/semaphore.h>
	20	#include <asm/ccwdev.h>
	21	#include <asm/ccwgroup.h>
	22
	23	/* In Linux 2.4, we had a channel device layer called "chandev"
	24	* that did all sorts of obscure stuff for networking devices.
	25	* This is another driver that serves as a replacement for just
	26	* one of its functions, namely the translation of single subchannels
	27	* to devices that use multiple subchannels.
	28	*/
	29
	30	/* a device matches a driver if all its slave devices match the same
	31	* entry of the driver */
	32	static int
	33	ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
	34	{
	35	struct ccwgroup_device *gdev;
	36	struct ccwgroup_driver *gdrv;
	37
	38	gdev = container_of(dev, struct ccwgroup_device, dev);
	39	gdrv = container_of(drv, struct ccwgroup_driver, driver);
	40
	41	if (gdev->creator_id == gdrv->driver_id)
	42	return 1;
	43
	44	return 0;
	45	}
	46	static int
6d20b035	47	ccwgroup_uevent (struct device dev, char envp, int num_envp, char buffer,
1da177e4 LT	48	int buffer_size)
	49	{
	50	/* TODO */
	51	return 0;
	52	}
	53
f9ccf456	54	static struct bus_type ccwgroup_bus_type;
1da177e4	55
4d284cac	56	static void
1da177e4 LT	57	__ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
	58	{
	59	int i;
	60	char str[8];
	61
	62	for (i = 0; i < gdev->count; i++) {
	63	sprintf(str, "cdev%d", i);
	64	sysfs_remove_link(&gdev->dev.kobj, str);
	65	sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
	66	}
	67
	68	}
	69
	70	/*
	71	* Provide an 'ungroup' attribute so the user can remove group devices no
	72	* longer needed or accidentially created. Saves memory :)
	73	*/
d9a9cdfb AS	74	static void ccwgroup_ungroup_callback(struct device *dev)
	75	{
	76	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
	77
	78	__ccwgroup_remove_symlinks(gdev);
	79	device_unregister(dev);
	80	}
	81
1da177e4	82	static ssize_t
3fd3c0a5	83	ccwgroup_ungroup_store(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	84	{
1da177e4 LT	85	struct ccwgroup_device *gdev;
d9a9cdfb	86	int rc;
1da177e4 LT	87
	88	gdev = to_ccwgroupdev(dev);
	89
	90	if (gdev->state != CCWGROUP_OFFLINE)
	91	return -EINVAL;
	92
d9a9cdfb AS	93	/* Note that we cannot unregister the device from one of its
	94	* attribute methods, so we have to use this roundabout approach.
	95	*/
	96	rc = device_schedule_callback(dev, ccwgroup_ungroup_callback);
	97	if (rc)
	98	count = rc;
1da177e4 LT	99	return count;
	100	}
	101
	102	static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
	103
	104	static void
	105	ccwgroup_release (struct device *dev)
	106	{
	107	struct ccwgroup_device *gdev;
	108	int i;
	109
	110	gdev = to_ccwgroupdev(dev);
	111
	112	for (i = 0; i < gdev->count; i++) {
	113	gdev->cdev[i]->dev.driver_data = NULL;
	114	put_device(&gdev->cdev[i]->dev);
	115	}
	116	kfree(gdev);
	117	}
	118
4d284cac	119	static int
1da177e4 LT	120	__ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
	121	{
	122	char str[8];
	123	int i, rc;
	124
	125	for (i = 0; i < gdev->count; i++) {
	126	rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj, &gdev->dev.kobj,
	127	"group_device");
	128	if (rc) {
	129	for (--i; i >= 0; i--)
	130	sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
	131	"group_device");
	132	return rc;
	133	}
	134	}
	135	for (i = 0; i < gdev->count; i++) {
	136	sprintf(str, "cdev%d", i);
	137	rc = sysfs_create_link(&gdev->dev.kobj, &gdev->cdev[i]->dev.kobj,
	138	str);
	139	if (rc) {
	140	for (--i; i >= 0; i--) {
	141	sprintf(str, "cdev%d", i);
	142	sysfs_remove_link(&gdev->dev.kobj, str);
	143	}
	144	for (i = 0; i < gdev->count; i++)
	145	sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
	146	"group_device");
	147	return rc;
	148	}
	149	}
	150	return 0;
	151	}
	152
	153	/*
	154	* try to add a new ccwgroup device for one driver
	155	* argc and argv[] are a list of bus_id's of devices
	156	* belonging to the driver.
	157	*/
	158	int
	159	ccwgroup_create(struct device *root,
	160	unsigned int creator_id,
	161	struct ccw_driver *cdrv,
	162	int argc, char *argv[])
	163	{
	164	struct ccwgroup_device *gdev;
	165	int i;
	166	int rc;
1da177e4 LT	167
	168	if (argc > 256) /* disallow dumb users */
	169	return -EINVAL;
	170
88abaab4	171	gdev = kzalloc(sizeof(gdev) + argcsizeof(gdev->cdev[0]), GFP_KERNEL);
1da177e4 LT	172	if (!gdev)
	173	return -ENOMEM;
	174
1da177e4 LT	175	atomic_set(&gdev->onoff, 0);
1da177e4 LT	176
1da177e4 LT	177	for (i = 0; i < argc; i++) {
	178	gdev->cdev[i] = get_ccwdev_by_busid(cdrv, argv[i]);
	179
	180	/* all devices have to be of the same type in
	181	* order to be grouped */
	182	if (!gdev->cdev[i]
	183	\|\| gdev->cdev[i]->id.driver_info !=
	184	gdev->cdev[0]->id.driver_info) {
	185	rc = -EINVAL;
	186	goto free_dev;
	187	}
	188	/* Don't allow a device to belong to more than one group. */
	189	if (gdev->cdev[i]->dev.driver_data) {
	190	rc = -EINVAL;
	191	goto free_dev;
	192	}
1da177e4	193	gdev->cdev[i]->dev.driver_data = gdev;
17088229	194	}
1da177e4 LT	195
	196	gdev->creator_id = creator_id;
	197	gdev->count = argc;
292888c8 HC	198	gdev->dev.bus = &ccwgroup_bus_type;
	199	gdev->dev.parent = root;
	200	gdev->dev.release = ccwgroup_release;
1da177e4 LT	201
	202	snprintf (gdev->dev.bus_id, BUS_ID_SIZE, "%s",
	203	gdev->cdev[0]->dev.bus_id);
	204
	205	rc = device_register(&gdev->dev);
	206
	207	if (rc)
	208	goto free_dev;
	209	get_device(&gdev->dev);
	210	rc = device_create_file(&gdev->dev, &dev_attr_ungroup);
	211
	212	if (rc) {
	213	device_unregister(&gdev->dev);
	214	goto error;
	215	}
	216
	217	rc = __ccwgroup_create_symlinks(gdev);
	218	if (!rc) {
	219	put_device(&gdev->dev);
	220	return 0;
	221	}
	222	device_remove_file(&gdev->dev, &dev_attr_ungroup);
	223	device_unregister(&gdev->dev);
	224	error:
	225	for (i = 0; i < argc; i++)
	226	if (gdev->cdev[i]) {
	227	put_device(&gdev->cdev[i]->dev);
	228	gdev->cdev[i]->dev.driver_data = NULL;
	229	}
	230	put_device(&gdev->dev);
	231	return rc;
	232	free_dev:
	233	for (i = 0; i < argc; i++)
	234	if (gdev->cdev[i]) {
17088229	235	if (gdev->cdev[i]->dev.driver_data == gdev)
1da177e4	236	gdev->cdev[i]->dev.driver_data = NULL;
17088229	237	put_device(&gdev->cdev[i]->dev);
1da177e4 LT	238	}
	239	kfree(gdev);
	240	return rc;
	241	}
	242
	243	static int __init
	244	init_ccwgroup (void)
	245	{
	246	return bus_register (&ccwgroup_bus_type);
	247	}
	248
	249	static void __exit
	250	cleanup_ccwgroup (void)
	251	{
	252	bus_unregister (&ccwgroup_bus_type);
	253	}
	254
	255	module_init(init_ccwgroup);
	256	module_exit(cleanup_ccwgroup);
	257
	258	/************************ driver stuff ****************************/
	259
	260	static int
	261	ccwgroup_set_online(struct ccwgroup_device *gdev)
	262	{
	263	struct ccwgroup_driver *gdrv;
	264	int ret;
	265
973bd993	266	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
1da177e4 LT	267	return -EAGAIN;
	268	if (gdev->state == CCWGROUP_ONLINE) {
	269	ret = 0;
	270	goto out;
	271	}
	272	if (!gdev->dev.driver) {
	273	ret = -EINVAL;
	274	goto out;
	275	}
	276	gdrv = to_ccwgroupdrv (gdev->dev.driver);
a0016408	277	if ((ret = gdrv->set_online ? gdrv->set_online(gdev) : 0))
1da177e4 LT	278	goto out;
	279
	280	gdev->state = CCWGROUP_ONLINE;
	281	out:
	282	atomic_set(&gdev->onoff, 0);
	283	return ret;
	284	}
	285
	286	static int
	287	ccwgroup_set_offline(struct ccwgroup_device *gdev)
	288	{
	289	struct ccwgroup_driver *gdrv;
	290	int ret;
	291
973bd993	292	if (atomic_cmpxchg(&gdev->onoff, 0, 1) != 0)
1da177e4 LT	293	return -EAGAIN;
	294	if (gdev->state == CCWGROUP_OFFLINE) {
	295	ret = 0;
	296	goto out;
	297	}
	298	if (!gdev->dev.driver) {
	299	ret = -EINVAL;
	300	goto out;
	301	}
	302	gdrv = to_ccwgroupdrv (gdev->dev.driver);
a0016408	303	if ((ret = gdrv->set_offline ? gdrv->set_offline(gdev) : 0))
1da177e4 LT	304	goto out;
	305
	306	gdev->state = CCWGROUP_OFFLINE;
	307	out:
	308	atomic_set(&gdev->onoff, 0);
	309	return ret;
	310	}
	311
	312	static ssize_t
3fd3c0a5	313	ccwgroup_online_store (struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	314	{
	315	struct ccwgroup_device *gdev;
	316	struct ccwgroup_driver *gdrv;
	317	unsigned int value;
	318	int ret;
	319
	320	gdev = to_ccwgroupdev(dev);
	321	if (!dev->driver)
	322	return count;
	323
	324	gdrv = to_ccwgroupdrv (gdev->dev.driver);
	325	if (!try_module_get(gdrv->owner))
	326	return -EINVAL;
	327
d2c993d8	328	value = simple_strtoul(buf, NULL, 0);
1da177e4 LT	329	ret = count;
	330	if (value == 1)
	331	ccwgroup_set_online(gdev);
	332	else if (value == 0)
	333	ccwgroup_set_offline(gdev);
	334	else
	335	ret = -EINVAL;
	336	module_put(gdrv->owner);
	337	return ret;
	338	}
	339
	340	static ssize_t
3fd3c0a5	341	ccwgroup_online_show (struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	342	{
	343	int online;
	344
	345	online = (to_ccwgroupdev(dev)->state == CCWGROUP_ONLINE);
	346
	347	return sprintf(buf, online ? "1\n" : "0\n");
	348	}
	349
	350	static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);
	351
	352	static int
	353	ccwgroup_probe (struct device *dev)
	354	{
	355	struct ccwgroup_device *gdev;
	356	struct ccwgroup_driver *gdrv;
	357
	358	int ret;
	359
	360	gdev = to_ccwgroupdev(dev);
	361	gdrv = to_ccwgroupdrv(dev->driver);
	362
	363	if ((ret = device_create_file(dev, &dev_attr_online)))
	364	return ret;
	365
	366	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	367	ret = gdrv->probe ? gdrv->probe(gdev) : -ENODEV;
	368	if (ret)
	369	device_remove_file(dev, &dev_attr_online);
	370
	371	return ret;
	372	}
	373
	374	static int
	375	ccwgroup_remove (struct device *dev)
	376	{
	377	struct ccwgroup_device *gdev;
	378	struct ccwgroup_driver *gdrv;
	379
	380	gdev = to_ccwgroupdev(dev);
	381	gdrv = to_ccwgroupdrv(dev->driver);
	382
	383	pr_debug("%s: device %s\n", __func__, gdev->dev.bus_id);
	384
	385	device_remove_file(dev, &dev_attr_online);
	386
	387	if (gdrv && gdrv->remove)
	388	gdrv->remove(gdev);
	389	return 0;
	390	}
	391
f9ccf456 RK	392	static struct bus_type ccwgroup_bus_type = {
	393	.name = "ccwgroup",
	394	.match = ccwgroup_bus_match,
	395	.uevent = ccwgroup_uevent,
	396	.probe = ccwgroup_probe,
	397	.remove = ccwgroup_remove,
	398	};
	399
1da177e4 LT	400	int
	401	ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
	402	{
	403	/* register our new driver with the core */
292888c8 HC	404	cdriver->driver.bus = &ccwgroup_bus_type;
292888c8 HC	405	cdriver->driver.name = cdriver->name;
1da177e4 LT	406
	407	return driver_register(&cdriver->driver);
	408	}
	409
b0744bd2	410	static int
887ab599	411	__ccwgroup_match_all(struct device dev, void data)
1da177e4	412	{
887ab599	413	return 1;
1da177e4 LT	414	}
	415
	416	void
	417	ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
	418	{
887ab599 CH	419	struct device *dev;
887ab599 CH	420
1da177e4 LT	421	/* We don't want ccwgroup devices to live longer than their driver. */
1da177e4 LT	422	get_driver(&cdriver->driver);
887ab599 CH	423	while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,
	424	__ccwgroup_match_all))) {
	425	__ccwgroup_remove_symlinks(to_ccwgroupdev(dev));
	426	device_unregister(dev);
	427	put_device(dev);
	428	}
1da177e4 LT	429	put_driver(&cdriver->driver);
	430	driver_unregister(&cdriver->driver);
	431	}
	432
	433	int
	434	ccwgroup_probe_ccwdev(struct ccw_device *cdev)
	435	{
	436	return 0;
	437	}
	438
4d284cac	439	static struct ccwgroup_device *
1da177e4 LT	440	__ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
	441	{
	442	struct ccwgroup_device *gdev;
	443
	444	if (cdev->dev.driver_data) {
	445	gdev = (struct ccwgroup_device *)cdev->dev.driver_data;
	446	if (get_device(&gdev->dev)) {
d305ef5d	447	if (device_is_registered(&gdev->dev))
1da177e4 LT	448	return gdev;
	449	put_device(&gdev->dev);
	450	}
	451	return NULL;
	452	}
	453	return NULL;
	454	}
	455
	456	void
	457	ccwgroup_remove_ccwdev(struct ccw_device *cdev)
	458	{
	459	struct ccwgroup_device *gdev;
	460
	461	/* Ignore offlining errors, device is gone anyway. */
	462	ccw_device_set_offline(cdev);
	463	/* If one of its devices is gone, the whole group is done for. */
	464	gdev = __ccwgroup_get_gdev_by_cdev(cdev);
	465	if (gdev) {
	466	__ccwgroup_remove_symlinks(gdev);
	467	device_unregister(&gdev->dev);
	468	put_device(&gdev->dev);
	469	}
	470	}
	471
	472	MODULE_LICENSE("GPL");
	473	EXPORT_SYMBOL(ccwgroup_driver_register);
	474	EXPORT_SYMBOL(ccwgroup_driver_unregister);
	475	EXPORT_SYMBOL(ccwgroup_create);
	476	EXPORT_SYMBOL(ccwgroup_probe_ccwdev);
	477	EXPORT_SYMBOL(ccwgroup_remove_ccwdev);