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#include <linux/virtio.h>
#include <linux/spinlock.h>
#include <linux/virtio_config.h>
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, "%hu", 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, "%hu", 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", dev->config->get_status(dev));
}
static struct device_attribute virtio_dev_attrs[] = {
__ATTR_RO(device),
__ATTR_RO(vendor),
__ATTR_RO(status),
__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)
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 struct bus_type virtio_bus = {
.name = "virtio",
.match = virtio_dev_match,
.dev_attrs = virtio_dev_attrs,
};
static void add_status(struct virtio_device *dev, unsigned status)
{
dev->config->set_status(dev, dev->config->get_status(dev) | status);
}
static int virtio_dev_probe(struct device *_d)
{
int err;
struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
struct virtio_driver *drv = container_of(dev->dev.driver,
struct virtio_driver, driver);
add_status(dev, VIRTIO_CONFIG_S_DRIVER);
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
else
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
return err;
}
int register_virtio_driver(struct virtio_driver *driver)
{
driver->driver.bus = &virtio_bus;
driver->driver.probe = virtio_dev_probe;
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;
sprintf(dev->dev.bus_id, "%u", dev->index);
/* Acknowledge that we've seen the device. */
add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
/* 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);
int __virtio_config_val(struct virtio_device *vdev,
u8 type, void *val, size_t size)
{
void *token;
unsigned int len;
token = vdev->config->find(vdev, type, &len);
if (!token)
return -ENOENT;
if (len != size)
return -EIO;
vdev->config->get(vdev, token, val, size);
return 0;
}
EXPORT_SYMBOL_GPL(__virtio_config_val);
int virtio_use_bit(struct virtio_device *vdev,
void *token, unsigned int len, unsigned int bitnum)
{
unsigned long bits[16];
/* This makes it convenient to pass-through find() results. */
if (!token)
return 0;
/* bit not in range of this bitfield? */
if (bitnum * 8 >= len / 2)
return 0;
/* Giant feature bitfields are silly. */
BUG_ON(len > sizeof(bits));
vdev->config->get(vdev, token, bits, len);
if (!test_bit(bitnum, bits))
return 0;
/* Set acknowledge bit, and write it back. */
set_bit(bitnum + len * 8 / 2, bits);
vdev->config->set(vdev, token, bits, len);
return 1;
}
EXPORT_SYMBOL_GPL(virtio_use_bit);
static int virtio_init(void)
{
if (bus_register(&virtio_bus) != 0)
panic("virtio bus registration failed");
return 0;
}
core_initcall(virtio_init);
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