#include <linux/spinlock.h>
#include <linux/virtio_config.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)
{
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;
+ 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);
+ }
+
err = drv->probe(dev);
if (err)
add_status(dev, VIRTIO_CONFIG_S_FAILED);
- else
+ else {
add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+ /* They should never have set feature bits beyond 32 */
+ dev->config->set_features(dev, dev->features[0]);
+ }
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;
+}
+
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;
driver->driver.probe = virtio_dev_probe;
+ driver->driver.remove = virtio_dev_remove;
return driver_register(&driver->driver);
}
EXPORT_SYMBOL_GPL(register_virtio_driver);
int err;
dev->dev.bus = &virtio_bus;
- sprintf(dev->dev.bus_id, "%u", dev->index);
+
+ /* Assign a unique device index and hence name. */
+ dev->index = dev_index++;
+ sprintf(dev->dev.bus_id, "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);
}
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;
}
+
+static void __exit virtio_exit(void)
+{
+ bus_unregister(&virtio_bus);
+}
core_initcall(virtio_init);
+module_exit(virtio_exit);
+
+MODULE_LICENSE("GPL");