[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / virtio / virtio.c

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

/* Unique numbering for virtio devices. */
static unsigned int dev_index;

static ssize_t device_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	return sprintf(buf, "0x%04x\n", dev->id.device);
}
static ssize_t vendor_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	return sprintf(buf, "0x%04x\n", dev->id.vendor);
}
static ssize_t status_show(struct device *_d,
			   struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
}
static ssize_t modalias_show(struct device *_d,
			     struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);

	return sprintf(buf, "virtio:d%08Xv%08X\n",
		       dev->id.device, dev->id.vendor);
}
static ssize_t features_show(struct device *_d,
			     struct device_attribute *attr, char *buf)
{
	struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
	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 < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
		len += sprintf(buf+len, "%c",
			       test_bit(i, dev->features) ? '1' : '0');
	len += sprintf(buf+len, "\n");
	return len;
}
static struct device_attribute virtio_dev_attrs[] = {
	__ATTR_RO(device),
	__ATTR_RO(vendor),
	__ATTR_RO(status),
	__ATTR_RO(modalias),
	__ATTR_RO(features),
	__ATTR_NULL
};

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 = container_of(_dv,struct virtio_device,dev);
	const struct virtio_device_id *ids;

	ids = container_of(_dr, struct virtio_driver, driver)->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 = container_of(_dv,struct virtio_device,dev);

	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 = container_of(vdev->dev.driver,
						 struct virtio_driver, driver);

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

static int virtio_dev_probe(struct device *_d)
{
	int err, i;
	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	struct virtio_driver *drv = container_of(dev->dev.driver,
						 struct virtio_driver, driver);
	u32 device_features;

	/* 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);

	/* Features supported by both device and driver into dev->features. */
	memset(dev->features, 0, sizeof(dev->features));
	for (i = 0; i < drv->feature_table_size; i++) {
		unsigned int f = drv->feature_table[i];
		BUG_ON(f >= 32);
		if (device_features & (1 << f))
			set_bit(f, dev->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 & (1 << i))
			set_bit(i, dev->features);

	dev->config->finalize_features(dev);

	err = drv->probe(dev);
	if (err)
		add_status(dev, VIRTIO_CONFIG_S_FAILED);
	else
		add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);

	return err;
}

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

	drv->remove(dev);

	/* Driver should have reset device. */
	BUG_ON(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_attrs = virtio_dev_attrs,
	.uevent = virtio_uevent,
	.probe = virtio_dev_probe,
	.remove = virtio_dev_remove,
};

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. */
	dev->index = dev_index++;
	dev_set_name(&dev->dev, "virtio%u", dev->index);

	/* 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);
	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)
{
	device_unregister(&dev->dev);
}
EXPORT_SYMBOL_GPL(unregister_virtio_device);

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>
ec3d41c4	5
b769f579 RR	6	/* Unique numbering for virtio devices. */
	7	static unsigned int dev_index;
	8
ec3d41c4 RR	9	static ssize_t device_show(struct device *_d,
	10	struct device_attribute attr, char buf)
	11	{
	12	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
be6528b2	13	return sprintf(buf, "0x%04x\n", dev->id.device);
ec3d41c4 RR	14	}
	15	static ssize_t vendor_show(struct device *_d,
	16	struct device_attribute attr, char buf)
	17	{
	18	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
be6528b2	19	return sprintf(buf, "0x%04x\n", dev->id.vendor);
ec3d41c4 RR	20	}
	21	static ssize_t status_show(struct device *_d,
	22	struct device_attribute attr, char buf)
	23	{
	24	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
be6528b2	25	return sprintf(buf, "0x%08x\n", dev->config->get_status(dev));
ec3d41c4	26	}
b01d9f28 RR	27	static ssize_t modalias_show(struct device *_d,
	28	struct device_attribute attr, char buf)
	29	{
	30	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	31
	32	return sprintf(buf, "virtio:d%08Xv%08X\n",
	33	dev->id.device, dev->id.vendor);
	34	}
a9289282 RR	35	static ssize_t features_show(struct device *_d,
	36	struct device_attribute attr, char buf)
	37	{
	38	struct virtio_device *dev = container_of(_d, struct virtio_device, dev);
	39	unsigned int i;
	40	ssize_t len = 0;
	41
	42	/* We actually represent this as a bitstring, as it could be
	43	* arbitrary length in future. */
	44	for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
	45	len += sprintf(buf+len, "%c",
	46	test_bit(i, dev->features) ? '1' : '0');
	47	len += sprintf(buf+len, "\n");
	48	return len;
	49	}
ec3d41c4 RR	50	static struct device_attribute virtio_dev_attrs[] = {
	51	__ATTR_RO(device),
	52	__ATTR_RO(vendor),
	53	__ATTR_RO(status),
b01d9f28	54	__ATTR_RO(modalias),
a9289282	55	__ATTR_RO(features),
ec3d41c4 RR	56	__ATTR_NULL
	57	};
	58
	59	static inline int virtio_id_match(const struct virtio_device *dev,
	60	const struct virtio_device_id *id)
	61	{
e3353853	62	if (id->device != dev->id.device && id->device != VIRTIO_DEV_ANY_ID)
ec3d41c4 RR	63	return 0;
ec3d41c4 RR	64
c89e8016	65	return id->vendor == VIRTIO_DEV_ANY_ID \|\| id->vendor == dev->id.vendor;
ec3d41c4 RR	66	}
	67
	68	/* This looks through all the IDs a driver claims to support. If any of them
	69	* match, we return 1 and the kernel will call virtio_dev_probe(). */
	70	static int virtio_dev_match(struct device _dv, struct device_driver _dr)
	71	{
	72	unsigned int i;
	73	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
	74	const struct virtio_device_id *ids;
	75
	76	ids = container_of(_dr, struct virtio_driver, driver)->id_table;
	77	for (i = 0; ids[i].device; i++)
	78	if (virtio_id_match(dev, &ids[i]))
	79	return 1;
	80	return 0;
	81	}
	82
b01d9f28 RR	83	static int virtio_uevent(struct device _dv, struct kobj_uevent_env env)
	84	{
	85	struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
	86
	87	return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
	88	dev->id.device, dev->id.vendor);
	89	}
	90
ec3d41c4 RR	91	static void add_status(struct virtio_device *dev, unsigned status)
	92	{
	93	dev->config->set_status(dev, dev->config->get_status(dev) \| status);
	94	}
	95
c45a6816 RR	96	void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
	97	unsigned int fbit)
	98	{
	99	unsigned int i;
	100	struct virtio_driver *drv = container_of(vdev->dev.driver,
	101	struct virtio_driver, driver);
	102
	103	for (i = 0; i < drv->feature_table_size; i++)
	104	if (drv->feature_table[i] == fbit)
	105	return;
	106	BUG();
	107	}
	108	EXPORT_SYMBOL_GPL(virtio_check_driver_offered_feature);
	109
ec3d41c4 RR	110	static int virtio_dev_probe(struct device *_d)
ec3d41c4 RR	111	{
c45a6816	112	int err, i;
ec3d41c4 RR	113	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	114	struct virtio_driver *drv = container_of(dev->dev.driver,
	115	struct virtio_driver, driver);
c45a6816	116	u32 device_features;
ec3d41c4	117
c45a6816	118	/* We have a driver! */
ec3d41c4	119	add_status(dev, VIRTIO_CONFIG_S_DRIVER);
c45a6816 RR	120
	121	/* Figure out what features the device supports. */
	122	device_features = dev->config->get_features(dev);
	123
	124	/* Features supported by both device and driver into dev->features. */
	125	memset(dev->features, 0, sizeof(dev->features));
	126	for (i = 0; i < drv->feature_table_size; i++) {
	127	unsigned int f = drv->feature_table[i];
	128	BUG_ON(f >= 32);
	129	if (device_features & (1 << f))
	130	set_bit(f, dev->features);
	131	}
	132
c624896e	133	/* Transport features always preserved to pass to finalize_features. */
dd7c7bc4 RR	134	for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
	135	if (device_features & (1 << i))
	136	set_bit(i, dev->features);
	137
ef688e15 RR	138	dev->config->finalize_features(dev);
ef688e15 RR	139
ec3d41c4 RR	140	err = drv->probe(dev);
	141	if (err)
	142	add_status(dev, VIRTIO_CONFIG_S_FAILED);
ef688e15	143	else
b92dea67	144	add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
ef688e15	145
ec3d41c4 RR	146	return err;
	147	}
	148
74b2553f RR	149	static int virtio_dev_remove(struct device *_d)
	150	{
	151	struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
	152	struct virtio_driver *drv = container_of(dev->dev.driver,
	153	struct virtio_driver, driver);
	154
74b2553f	155	drv->remove(dev);
6e5aa7ef RR	156
	157	/* Driver should have reset device. */
	158	BUG_ON(dev->config->get_status(dev));
	159
	160	/* Acknowledge the device's existence again. */
	161	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
74b2553f RR	162	return 0;
	163	}
	164
e962fa66 MM	165	static struct bus_type virtio_bus = {
	166	.name = "virtio",
	167	.match = virtio_dev_match,
	168	.dev_attrs = virtio_dev_attrs,
	169	.uevent = virtio_uevent,
	170	.probe = virtio_dev_probe,
	171	.remove = virtio_dev_remove,
	172	};
	173
ec3d41c4 RR	174	int register_virtio_driver(struct virtio_driver *driver)
ec3d41c4 RR	175	{
c45a6816 RR	176	/* Catch this early. */
c45a6816 RR	177	BUG_ON(driver->feature_table_size && !driver->feature_table);
ec3d41c4	178	driver->driver.bus = &virtio_bus;
ec3d41c4 RR	179	return driver_register(&driver->driver);
	180	}
	181	EXPORT_SYMBOL_GPL(register_virtio_driver);
	182
	183	void unregister_virtio_driver(struct virtio_driver *driver)
	184	{
	185	driver_unregister(&driver->driver);
	186	}
	187	EXPORT_SYMBOL_GPL(unregister_virtio_driver);
	188
	189	int register_virtio_device(struct virtio_device *dev)
	190	{
	191	int err;
	192
	193	dev->dev.bus = &virtio_bus;
b769f579 RR	194
	195	/* Assign a unique device index and hence name. */
	196	dev->index = dev_index++;
99e0b6c8	197	dev_set_name(&dev->dev, "virtio%u", dev->index);
ec3d41c4	198
6e5aa7ef RR	199	/* We always start by resetting the device, in case a previous
	200	* driver messed it up. This also tests that code path a little. */
	201	dev->config->reset(dev);
	202
ec3d41c4 RR	203	/* Acknowledge that we've seen the device. */
	204	add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
	205
9499f5e7 RR	206	INIT_LIST_HEAD(&dev->vqs);
9499f5e7 RR	207
ec3d41c4 RR	208	/* device_register() causes the bus infrastructure to look for a
	209	* matching driver. */
	210	err = device_register(&dev->dev);
	211	if (err)
	212	add_status(dev, VIRTIO_CONFIG_S_FAILED);
	213	return err;
	214	}
	215	EXPORT_SYMBOL_GPL(register_virtio_device);
	216
	217	void unregister_virtio_device(struct virtio_device *dev)
	218	{
	219	device_unregister(&dev->dev);
	220	}
	221	EXPORT_SYMBOL_GPL(unregister_virtio_device);
	222
ec3d41c4 RR	223	static int virtio_init(void)
	224	{
	225	if (bus_register(&virtio_bus) != 0)
	226	panic("virtio bus registration failed");
	227	return 0;
	228	}
c6fd4701 RR	229
	230	static void __exit virtio_exit(void)
	231	{
	232	bus_unregister(&virtio_bus);
	233	}
ec3d41c4	234	core_initcall(virtio_init);
c6fd4701 RR	235	module_exit(virtio_exit);
	236
	237	MODULE_LICENSE("GPL");