[linux-2.6-block.git] / drivers / virtio / virtio.c

#include <linux/virtio.h>
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <uapi/linux/virtio_ids.h>

/* Unique numbering for virtio devices. */
static DEFINE_IDA(virtio_index_ida);

static ssize_t device_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	return sprintf(buf, "0x%04x\n", dev->id.device);
}
static DEVICE_ATTR_RO(device);

static ssize_t vendor_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	return sprintf(buf, "0x%04x\n", dev->id.vendor);
}
static DEVICE_ATTR_RO(vendor);

static ssize_t status_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
}
static DEVICE_ATTR_RO(status);

static ssize_t modalias_show(struct device *_d,
			     struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	return sprintf(buf, "virtio:d%08Xv%08X\n",
		       dev->id.device, dev->id.vendor);
}
static DEVICE_ATTR_RO(modalias);

static ssize_t features_show(struct device *_d,
			     struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	unsigned int i;
	ssize_t len = 0;

	/* We actually represent this as a bitstring, as it could be
	 * arbitrary length in future. */
	for (i = 0; i < sizeof(dev->features)*8; i++)
		len += sprintf(buf+len, "%c",
			       __virtio_test_bit(dev, i) ? '1' : '0');
	len += sprintf(buf+len, "\n");
	return len;
}
static DEVICE_ATTR_RO(features);

static struct attribute *virtio_dev_attrs[] = {
	&dev_attr_device.attr,
	&dev_attr_vendor.attr,
	&dev_attr_status.attr,
	&dev_attr_modalias.attr,
	&dev_attr_features.attr,
	NULL,
};
ATTRIBUTE_GROUPS(virtio_dev);

static inline int virtio_id_match(const struct virtio_device *dev,
				  const struct virtio_device_id *id)
{
	if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
		return 0;

	return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor == dev->id.vendor;
}

/* This looks through all the IDs a driver claims to support.  If any of them
 * match, we return 1 and the kernel will call virtio_dev_probe(). */
static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
{
	unsigned int i;
	struct virtio_device *dev = dev_to_virtio(_dv);
	const struct virtio_device_id *ids;

	ids = drv_to_virtio(_dr)->id_table;
	for (i = 0; ids[i].device; i++)
		if (virtio_id_match(dev, &ids[i]))
			return 1;
	return 0;
}

static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
{
	struct virtio_device *dev = dev_to_virtio(_dv);

	return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
			      dev->id.device, dev->id.vendor);
}

static void add_status(struct virtio_device *dev, unsigned status)
{
	dev->config->set_status(dev, dev->config->get_status(dev) | status);
}

void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
					 unsigned int fbit)
{
	unsigned int i;
	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);

	for (i = 0; i < drv->feature_table_size; i++)
		if (drv->feature_table[i] == fbit)
			return;

	if (drv->feature_table_legacy) {
		for (i = 0; i < drv->feature_table_size_legacy; i++)
			if (drv->feature_table_legacy[i] == fbit)
				return;
	}

	BUG();
}
EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);

static void __virtio_config_changed(struct virtio_device *dev)
{
	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);

	if (!dev->config_enabled)
		dev->config_change_pending = true;
	else if (drv && drv->config_changed)
		drv->config_changed(dev);
}

void virtio_config_changed(struct virtio_device *dev)
{
	unsigned long flags;

	spin_lock_irqsave(&dev->config_lock, flags);
	__virtio_config_changed(dev);
	spin_unlock_irqrestore(&dev->config_lock, flags);
}
EXPORT_SYMBOL_GPL(virtio_config_changed);

static void virtio_config_disable(struct virtio_device *dev)
{
	spin_lock_irq(&dev->config_lock);
	dev->config_enabled = false;
	spin_unlock_irq(&dev->config_lock);
}

static void virtio_config_enable(struct virtio_device *dev)
{
	spin_lock_irq(&dev->config_lock);
	dev->config_enabled = true;
	if (dev->config_change_pending)
		__virtio_config_changed(dev);
	dev->config_change_pending = false;
	spin_unlock_irq(&dev->config_lock);
}

static int virtio_dev_probe(struct device *_d)
{
	int err, i;
	struct virtio_device *dev = dev_to_virtio(_d);
	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
	u64 device_features;
	u64 driver_features;
	u64 driver_features_legacy;
	unsigned status;

	/* We have a driver! */
	add_status(dev, VIRTIO_CONFIG_S_DRIVER);

	/* Figure out what features the device supports. */
	device_features = dev->config->get_features(dev);

	/* Figure out what features the driver supports. */
	driver_features = 0;
	for (i = 0; i < drv->feature_table_size; i++) {
		unsigned int f = drv->feature_table[i];
		BUG_ON(f >= 64);
		driver_features |= (1ULL << f);
	}

	/* Some drivers have a separate feature table for virtio v1.0 */
	if (drv->feature_table_legacy) {
		driver_features_legacy = 0;
		for (i = 0; i < drv->feature_table_size_legacy; i++) {
			unsigned int f = drv->feature_table_legacy[i];
			BUG_ON(f >= 64);
			driver_features_legacy |= (1ULL << f);
		}
	} else {
		driver_features_legacy = driver_features;
	}

	if (device_features & (1ULL << VIRTIO_F_VERSION_1))
		dev->features = driver_features & device_features;
	else
		dev->features = driver_features_legacy & device_features;

	/* Transport features always preserved to pass to finalize_features. */
	for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
		if (device_features & (1ULL << i))
			__virtio_set_bit(dev, i);

	err = dev->config->finalize_features(dev);
	if (err)
		goto err;

	if (virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
		add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
		status = dev->config->get_status(dev);
		if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
			dev_err(_d, "virtio: device refuses features: %x\n",
			       status);
			err = -ENODEV;
			goto err;
		}
	}

	err = drv->probe(dev);
	if (err)
		goto err;

	add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
	if (drv->scan)
		drv->scan(dev);

	virtio_config_enable(dev);

	return 0;
err:
	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	return err;

}

static int virtio_dev_remove(struct device *_d)
{
	struct virtio_device *dev = dev_to_virtio(_d);
	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);

	virtio_config_disable(dev);

	drv->remove(dev);

	/* Driver should have reset device. */
	WARN_ON_ONCE(dev->config->get_status(dev));

	/* Acknowledge the device's existence again. */
	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
	return 0;
}

static struct bus_type virtio_bus = {
	.name  = "virtio",
	.match = virtio_dev_match,
	.dev_groups = virtio_dev_groups,
	.uevent = virtio_uevent,
	.probe = virtio_dev_probe,
	.remove = virtio_dev_remove,
};

bool virtio_device_is_legacy_only(struct virtio_device_id id)
{
	return id.device == VIRTIO_ID_BALLOON;
}
EXPORT_SYMBOL_GPL(virtio_device_is_legacy_only);

int register_virtio_driver(struct virtio_driver *driver)
{
	/* Catch this early. */
	BUG_ON(driver->feature_table_size && !driver->feature_table);
	driver->driver.bus = &virtio_bus;
	return driver_register(&driver->driver);
}
EXPORT_SYMBOL_GPL(register_virtio_driver);

void unregister_virtio_driver(struct virtio_driver *driver)
{
	driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(unregister_virtio_driver);

int register_virtio_device(struct virtio_device *dev)
{
	int err;

	dev->dev.bus = &virtio_bus;

	/* Assign a unique device index and hence name. */
	err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
	if (err < 0)
		goto out;

	dev->index = err;
	dev_set_name(&dev->dev, "virtio%u", dev->index);

	spin_lock_init(&dev->config_lock);
	dev->config_enabled = false;
	dev->config_change_pending = false;

	/* We always start by resetting the device, in case a previous
	 * driver messed it up.  This also tests that code path a little. */
	dev->config->reset(dev);

	/* Acknowledge that we've seen the device. */
	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);

	INIT_LIST_HEAD(&dev->vqs);

	/* device_register() causes the bus infrastructure to look for a
	 * matching driver. */
	err = device_register(&dev->dev);
out:
	if (err)
		add_status(dev, VIRTIO_CONFIG_S_FAILED);
	return err;
}
EXPORT_SYMBOL_GPL(register_virtio_device);

void unregister_virtio_device(struct virtio_device *dev)
{
	int index = dev->index; /* save for after device release */

	device_unregister(&dev->dev);
	ida_simple_remove(&virtio_index_ida, index);
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);

#ifdef CONFIG_PM_SLEEP
int virtio_device_freeze(struct virtio_device *dev)
{
	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);

	virtio_config_disable(dev);

	dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;

	if (drv && drv->freeze)
		return drv->freeze(dev);

	return 0;
}
EXPORT_SYMBOL_GPL(virtio_device_freeze);

int virtio_device_restore(struct virtio_device *dev)
{
	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
	int ret;

	/* We always start by resetting the device, in case a previous
	 * driver messed it up. */
	dev->config->reset(dev);

	/* Acknowledge that we've seen the device. */
	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);

	/* Maybe driver failed before freeze.
	 * Restore the failed status, for debugging. */
	if (dev->failed)
		add_status(dev, VIRTIO_CONFIG_S_FAILED);

	if (!drv)
		return 0;

	/* We have a driver! */
	add_status(dev, VIRTIO_CONFIG_S_DRIVER);

	ret = dev->config->finalize_features(dev);
	if (ret)
		goto err;

	if (drv->restore) {
		ret = drv->restore(dev);
		if (ret)
			goto err;
	}

	/* Finally, tell the device we're all set */
	add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);

	virtio_config_enable(dev);

	return 0;

err:
	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	return ret;
}
EXPORT_SYMBOL_GPL(virtio_device_restore);
#endif

static int virtio_init(void)
{
	if (bus_register(&virtio_bus) != 0)
		panic("virtio bus registration failed");
	return 0;
}

static void __exit virtio_exit(void)
{
	bus_unregister(&virtio_bus);
}
core_initcall(virtio_init);
module_exit(virtio_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
ec3d41c4 RR	1	#include <linux/virtio.h>
	2	#include <linux/spinlock.h>
	3	#include <linux/virtio_config.h>
b5a2c4f1	4	#include <linux/module.h>
90e03207	5	#include <linux/idr.h>
b6098c30	6	#include <uapi/linux/virtio_ids.h>
ec3d41c4	7
b769f579	8	/* Unique numbering for virtio devices. */
90e03207	9	static DEFINE_IDA(virtio_index_ida);
b769f579	10
ec3d41c4 RR	11	static ssize_t device_show(struct device *_d,
	12	struct device_attribute attr, char buf)
	13	{
9bffdca8	14	struct virtio_device *dev = dev_to_virtio(_d);
be6528b2	15	return sprintf(buf, "0x%04x\n", dev->id.device);
ec3d41c4	16	}
3736dab6 GKH	17	static DEVICE_ATTR_RO(device);
3736dab6 GKH	18
ec3d41c4 RR	19	static ssize_t vendor_show(struct device *_d,
	20	struct device_attribute attr, char buf)
	21	{
9bffdca8	22	struct virtio_device *dev = dev_to_virtio(_d);
be6528b2	23	return sprintf(buf, "0x%04x\n", dev->id.vendor);
ec3d41c4	24	}
3736dab6 GKH	25	static DEVICE_ATTR_RO(vendor);
3736dab6 GKH	26
ec3d41c4 RR	27	static ssize_t status_show(struct device *_d,
	28	struct device_attribute attr, char buf)
	29	{
9bffdca8	30	struct virtio_device *dev = dev_to_virtio(_d);
be6528b2	31	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
ec3d41c4	32	}
3736dab6 GKH	33	static DEVICE_ATTR_RO(status);
3736dab6 GKH	34
b01d9f28 RR	35	static ssize_t modalias_show(struct device *_d,
	36	struct device_attribute attr, char buf)
	37	{
9bffdca8	38	struct virtio_device *dev = dev_to_virtio(_d);
b01d9f28 RR	39	return sprintf(buf, "virtio:d%08Xv%08X\n",
	40	dev->id.device, dev->id.vendor);
	41	}
3736dab6 GKH	42	static DEVICE_ATTR_RO(modalias);
3736dab6 GKH	43
a9289282 RR	44	static ssize_t features_show(struct device *_d,
	45	struct device_attribute attr, char buf)
	46	{
9bffdca8	47	struct virtio_device *dev = dev_to_virtio(_d);
a9289282 RR	48	unsigned int i;
	49	ssize_t len = 0;
	50
	51	/* We actually represent this as a bitstring, as it could be
	52	* arbitrary length in future. */
e16e12be	53	for (i = 0; i < sizeof(dev->features)*8; i++)
a9289282	54	len += sprintf(buf+len, "%c",
e16e12be	55	__virtio_test_bit(dev, i) ? '1' : '0');
a9289282 RR	56	len += sprintf(buf+len, "\n");
	57	return len;
	58	}
3736dab6 GKH	59	static DEVICE_ATTR_RO(features);
	60
	61	static struct attribute *virtio_dev_attrs[] = {
	62	&dev_attr_device.attr,
	63	&dev_attr_vendor.attr,
	64	&dev_attr_status.attr,
	65	&dev_attr_modalias.attr,
	66	&dev_attr_features.attr,
	67	NULL,
ec3d41c4	68	};
3736dab6	69	ATTRIBUTE_GROUPS(virtio_dev);
ec3d41c4 RR	70
	71	static inline int virtio_id_match(const struct virtio_device *dev,
	72	const struct virtio_device_id *id)
	73	{
e3353853	74	if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
ec3d41c4 RR	75	return 0;
ec3d41c4 RR	76
c89e8016	77	return id->vendor == VIRTIO_DEV_ANY_ID \|\| id->vendor == dev->id.vendor;
ec3d41c4 RR	78	}
	79
	80	/* This looks through all the IDs a driver claims to support. If any of them
	81	* match, we return 1 and the kernel will call virtio_dev_probe(). */
	82	static int virtio_dev_match(struct device _dv, struct device_driver _dr)
	83	{
	84	unsigned int i;
9bffdca8	85	struct virtio_device *dev = dev_to_virtio(_dv);
ec3d41c4 RR	86	const struct virtio_device_id *ids;
ec3d41c4 RR	87
9a2bdcc8	88	ids = drv_to_virtio(_dr)->id_table;
ec3d41c4 RR	89	for (i = 0; ids[i].device; i++)
	90	if (virtio_id_match(dev, &ids[i]))
	91	return 1;
	92	return 0;
	93	}
	94
b01d9f28 RR	95	static int virtio_uevent(struct device _dv, struct kobj_uevent_env env)
b01d9f28 RR	96	{
9bffdca8	97	struct virtio_device *dev = dev_to_virtio(_dv);
b01d9f28 RR	98
	99	return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
	100	dev->id.device, dev->id.vendor);
	101	}
	102
ec3d41c4 RR	103	static void add_status(struct virtio_device *dev, unsigned status)
	104	{
	105	dev->config->set_status(dev, dev->config->get_status(dev) \| status);
	106	}
	107
c45a6816 RR	108	void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
	109	unsigned int fbit)
	110	{
	111	unsigned int i;
9a2bdcc8	112	struct virtio_driver *drv = drv_to_virtio(vdev->dev.driver);
c45a6816 RR	113
	114	for (i = 0; i < drv->feature_table_size; i++)
	115	if (drv->feature_table[i] == fbit)
	116	return;
b3bb62d1 MT	117
	118	if (drv->feature_table_legacy) {
	119	for (i = 0; i < drv->feature_table_size_legacy; i++)
	120	if (drv->feature_table_legacy[i] == fbit)
	121	return;
	122	}
	123
c45a6816 RR	124	BUG();
	125	}
	126	EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
	127
22b7050a MT	128	static void __virtio_config_changed(struct virtio_device *dev)
	129	{
	130	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
	131
	132	if (!dev->config_enabled)
	133	dev->config_change_pending = true;
	134	else if (drv && drv->config_changed)
	135	drv->config_changed(dev);
	136	}
	137
	138	void virtio_config_changed(struct virtio_device *dev)
	139	{
	140	unsigned long flags;
	141
	142	spin_lock_irqsave(&dev->config_lock, flags);
	143	__virtio_config_changed(dev);
	144	spin_unlock_irqrestore(&dev->config_lock, flags);
	145	}
	146	EXPORT_SYMBOL_GPL(virtio_config_changed);
	147
	148	static void virtio_config_disable(struct virtio_device *dev)
	149	{
	150	spin_lock_irq(&dev->config_lock);
	151	dev->config_enabled = false;
	152	spin_unlock_irq(&dev->config_lock);
	153	}
	154
	155	static void virtio_config_enable(struct virtio_device *dev)
	156	{
	157	spin_lock_irq(&dev->config_lock);
	158	dev->config_enabled = true;
	159	if (dev->config_change_pending)
	160	__virtio_config_changed(dev);
	161	dev->config_change_pending = false;
	162	spin_unlock_irq(&dev->config_lock);
	163	}
	164
ec3d41c4 RR	165	static int virtio_dev_probe(struct device *_d)
ec3d41c4 RR	166	{
c45a6816	167	int err, i;
9bffdca8	168	struct virtio_device *dev = dev_to_virtio(_d);
9a2bdcc8	169	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
d0254773	170	u64 device_features;
c102659d	171	u64 driver_features;
b3bb62d1	172	u64 driver_features_legacy;
cb3f6d9d	173	unsigned status;
ec3d41c4	174
c45a6816	175	/* We have a driver! */
ec3d41c4	176	add_status(dev, VIRTIO_CONFIG_S_DRIVER);
c45a6816 RR	177
	178	/* Figure out what features the device supports. */
	179	device_features = dev->config->get_features(dev);
	180
c102659d MT	181	/* Figure out what features the driver supports. */
c102659d MT	182	driver_features = 0;
c45a6816 RR	183	for (i = 0; i < drv->feature_table_size; i++) {
c45a6816 RR	184	unsigned int f = drv->feature_table[i];
d0254773	185	BUG_ON(f >= 64);
c102659d	186	driver_features \|= (1ULL << f);
c45a6816 RR	187	}
c45a6816 RR	188
b3bb62d1 MT	189	/* Some drivers have a separate feature table for virtio v1.0 */
	190	if (drv->feature_table_legacy) {
	191	driver_features_legacy = 0;
	192	for (i = 0; i < drv->feature_table_size_legacy; i++) {
	193	unsigned int f = drv->feature_table_legacy[i];
	194	BUG_ON(f >= 64);
	195	driver_features_legacy \|= (1ULL << f);
	196	}
	197	} else {
	198	driver_features_legacy = driver_features;
	199	}
	200
747ae34a	201	if (device_features & (1ULL << VIRTIO_F_VERSION_1))
b3bb62d1 MT	202	dev->features = driver_features & device_features;
	203	else
	204	dev->features = driver_features_legacy & device_features;
c102659d	205
c624896e	206	/* Transport features always preserved to pass to finalize_features. */
dd7c7bc4	207	for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
d0254773	208	if (device_features & (1ULL << i))
e16e12be	209	__virtio_set_bit(dev, i);
dd7c7bc4	210
5c609a5e MT	211	err = dev->config->finalize_features(dev);
	212	if (err)
	213	goto err;
ef688e15	214
cb3f6d9d MT	215	if (virtio_has_feature(dev, VIRTIO_F_VERSION_1)) {
	216	add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
	217	status = dev->config->get_status(dev);
	218	if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
	219	dev_err(_d, "virtio: device refuses features: %x\n",
	220	status);
	221	err = -ENODEV;
	222	goto err;
	223	}
	224	}
	225
ec3d41c4 RR	226	err = drv->probe(dev);
ec3d41c4 RR	227	if (err)
cb3f6d9d	228	goto err;
22b7050a	229
cb3f6d9d MT	230	add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
	231	if (drv->scan)
	232	drv->scan(dev);
ef688e15	233
cb3f6d9d MT	234	virtio_config_enable(dev);
	235
	236	return 0;
	237	err:
	238	add_status(dev, VIRTIO_CONFIG_S_FAILED);
ec3d41c4	239	return err;
cb3f6d9d	240
ec3d41c4 RR	241	}
ec3d41c4 RR	242
74b2553f RR	243	static int virtio_dev_remove(struct device *_d)
74b2553f RR	244	{
9bffdca8	245	struct virtio_device *dev = dev_to_virtio(_d);
9a2bdcc8	246	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
74b2553f	247
22b7050a MT	248	virtio_config_disable(dev);
22b7050a MT	249
74b2553f	250	drv->remove(dev);
6e5aa7ef RR	251
6e5aa7ef RR	252	/* Driver should have reset device. */
5543a6ac	253	WARN_ON_ONCE(dev->config->get_status(dev));
6e5aa7ef RR	254
	255	/* Acknowledge the device's existence again. */
	256	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
74b2553f RR	257	return 0;
	258	}
	259
e962fa66 MM	260	static struct bus_type virtio_bus = {
	261	.name = "virtio",
	262	.match = virtio_dev_match,
3736dab6	263	.dev_groups = virtio_dev_groups,
e962fa66 MM	264	.uevent = virtio_uevent,
	265	.probe = virtio_dev_probe,
	266	.remove = virtio_dev_remove,
	267	};
	268
b6098c30 MT	269	bool virtio_device_is_legacy_only(struct virtio_device_id id)
	270	{
	271	return id.device == VIRTIO_ID_BALLOON;
	272	}
	273	EXPORT_SYMBOL_GPL(virtio_device_is_legacy_only);
	274
ec3d41c4 RR	275	int register_virtio_driver(struct virtio_driver *driver)
ec3d41c4 RR	276	{
c45a6816 RR	277	/* Catch this early. */
c45a6816 RR	278	BUG_ON(driver->feature_table_size && !driver->feature_table);
ec3d41c4	279	driver->driver.bus = &virtio_bus;
ec3d41c4 RR	280	return driver_register(&driver->driver);
	281	}
	282	EXPORT_SYMBOL_GPL(register_virtio_driver);
	283
	284	void unregister_virtio_driver(struct virtio_driver *driver)
	285	{
	286	driver_unregister(&driver->driver);
	287	}
	288	EXPORT_SYMBOL_GPL(unregister_virtio_driver);
	289
	290	int register_virtio_device(struct virtio_device *dev)
	291	{
	292	int err;
	293
	294	dev->dev.bus = &virtio_bus;
b769f579 RR	295
b769f579 RR	296	/* Assign a unique device index and hence name. */
90e03207 AH	297	err = ida_simple_get(&virtio_index_ida, 0, 0, GFP_KERNEL);
	298	if (err < 0)
	299	goto out;
	300
	301	dev->index = err;
99e0b6c8	302	dev_set_name(&dev->dev, "virtio%u", dev->index);
ec3d41c4	303
22b7050a MT	304	spin_lock_init(&dev->config_lock);
	305	dev->config_enabled = false;
	306	dev->config_change_pending = false;
	307
6e5aa7ef RR	308	/* We always start by resetting the device, in case a previous
	309	* driver messed it up. This also tests that code path a little. */
	310	dev->config->reset(dev);
	311
ec3d41c4 RR	312	/* Acknowledge that we've seen the device. */
	313	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
	314
9499f5e7 RR	315	INIT_LIST_HEAD(&dev->vqs);
9499f5e7 RR	316
ec3d41c4 RR	317	/* device_register() causes the bus infrastructure to look for a
	318	* matching driver. */
	319	err = device_register(&dev->dev);
90e03207	320	out:
ec3d41c4 RR	321	if (err)
	322	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	323	return err;
	324	}
	325	EXPORT_SYMBOL_GPL(register_virtio_device);
	326
	327	void unregister_virtio_device(struct virtio_device *dev)
	328	{
237242bd CH	329	int index = dev->index; /* save for after device release */
237242bd CH	330
ec3d41c4	331	device_unregister(&dev->dev);
237242bd	332	ida_simple_remove(&virtio_index_ida, index);
ec3d41c4 RR	333	}
	334	EXPORT_SYMBOL_GPL(unregister_virtio_device);
	335
c6716bae MT	336	#ifdef CONFIG_PM_SLEEP
	337	int virtio_device_freeze(struct virtio_device *dev)
	338	{
	339	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
	340
22b7050a MT	341	virtio_config_disable(dev);
22b7050a MT	342
c6716bae MT	343	dev->failed = dev->config->get_status(dev) & VIRTIO_CONFIG_S_FAILED;
	344
	345	if (drv && drv->freeze)
	346	return drv->freeze(dev);
	347
	348	return 0;
	349	}
	350	EXPORT_SYMBOL_GPL(virtio_device_freeze);
	351
	352	int virtio_device_restore(struct virtio_device *dev)
	353	{
	354	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
5c609a5e	355	int ret;
c6716bae MT	356
	357	/* We always start by resetting the device, in case a previous
	358	* driver messed it up. */
	359	dev->config->reset(dev);
	360
	361	/* Acknowledge that we've seen the device. */
	362	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
	363
	364	/* Maybe driver failed before freeze.
	365	* Restore the failed status, for debugging. */
	366	if (dev->failed)
	367	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	368
	369	if (!drv)
	370	return 0;
	371
	372	/* We have a driver! */
	373	add_status(dev, VIRTIO_CONFIG_S_DRIVER);
	374
5c609a5e MT	375	ret = dev->config->finalize_features(dev);
	376	if (ret)
	377	goto err;
c6716bae MT	378
c6716bae MT	379	if (drv->restore) {
5c609a5e MT	380	ret = drv->restore(dev);
	381	if (ret)
	382	goto err;
c6716bae MT	383	}
	384
	385	/* Finally, tell the device we're all set */
	386	add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
	387
22b7050a MT	388	virtio_config_enable(dev);
22b7050a MT	389
c6716bae	390	return 0;
5c609a5e MT	391
	392	err:
	393	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	394	return ret;
c6716bae MT	395	}
	396	EXPORT_SYMBOL_GPL(virtio_device_restore);
	397	#endif
	398
ec3d41c4 RR	399	static int virtio_init(void)
	400	{
	401	if (bus_register(&virtio_bus) != 0)
	402	panic("virtio bus registration failed");
	403	return 0;
	404	}
c6fd4701 RR	405
	406	static void __exit virtio_exit(void)
	407	{
	408	bus_unregister(&virtio_bus);
	409	}
ec3d41c4	410	core_initcall(virtio_init);
c6fd4701 RR	411	module_exit(virtio_exit);
	412
	413	MODULE_LICENSE("GPL");