diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/virtio.h | 7 | ||||
| -rw-r--r-- | include/linux/virtio_config.h | 36 |
2 files changed, 36 insertions, 7 deletions
diff --git a/include/linux/virtio.h b/include/linux/virtio.h index e7d10845b3c1..06005fa9e982 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -76,6 +76,7 @@ struct virtqueue_ops { * @dev: underlying device. * @id: the device type identification (used to match it with a driver). * @config: the configuration ops for this device. + * @features: the features supported by both driver and device. * @priv: private pointer for the driver's use. */ struct virtio_device @@ -84,6 +85,8 @@ struct virtio_device struct device dev; struct virtio_device_id id; struct virtio_config_ops *config; + /* Note that this is a Linux set_bit-style bitmap. */ + unsigned long features[1]; void *priv; }; @@ -94,6 +97,8 @@ void unregister_virtio_device(struct virtio_device *dev); * virtio_driver - operations for a virtio I/O driver * @driver: underlying device driver (populate name and owner). * @id_table: the ids serviced by this driver. + * @feature_table: an array of feature numbers supported by this device. + * @feature_table_size: number of entries in the feature table array. * @probe: the function to call when a device is found. Returns a token for * remove, or PTR_ERR(). * @remove: the function when a device is removed. @@ -103,6 +108,8 @@ void unregister_virtio_device(struct virtio_device *dev); struct virtio_driver { struct device_driver driver; const struct virtio_device_id *id_table; + const unsigned int *feature_table; + unsigned int feature_table_size; int (*probe)(struct virtio_device *dev); void (*remove)(struct virtio_device *dev); void (*config_changed)(struct virtio_device *dev); diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 475572e976fe..50db245c81ad 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -20,11 +20,6 @@ /** * virtio_config_ops - operations for configuring a virtio device - * @feature: search for a feature in this config - * vdev: the virtio_device - * bit: the feature bit - * Returns true if the feature is supported. Acknowledges the feature - * so the host can see it. * @get: read the value of a configuration field * vdev: the virtio_device * offset: the offset of the configuration field @@ -50,10 +45,15 @@ * callback: the virqtueue callback * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT). * @del_vq: free a virtqueue found by find_vq(). + * @get_features: get the array of feature bits for this device. + * vdev: the virtio_device + * Returns the first 32 feature bits (all we currently need). + * @set_features: confirm what device features we'll be using. + * vdev: the virtio_device + * feature: the first 32 feature bits */ struct virtio_config_ops { - bool (*feature)(struct virtio_device *vdev, unsigned bit); void (*get)(struct virtio_device *vdev, unsigned offset, void *buf, unsigned len); void (*set)(struct virtio_device *vdev, unsigned offset, @@ -65,8 +65,30 @@ struct virtio_config_ops unsigned index, void (*callback)(struct virtqueue *)); void (*del_vq)(struct virtqueue *vq); + u32 (*get_features)(struct virtio_device *vdev); + void (*set_features)(struct virtio_device *vdev, u32 features); }; +/* If driver didn't advertise the feature, it will never appear. */ +void virtio_check_driver_offered_feature(const struct virtio_device *vdev, + unsigned int fbit); + +/** + * virtio_has_feature - helper to determine if this device has this feature. + * @vdev: the device + * @fbit: the feature bit + */ +static inline bool virtio_has_feature(const struct virtio_device *vdev, + unsigned int fbit) +{ + /* Did you forget to fix assumptions on max features? */ + if (__builtin_constant_p(fbit)) + BUILD_BUG_ON(fbit >= 32); + + virtio_check_driver_offered_feature(vdev, fbit); + return test_bit(fbit, vdev->features); +} + /** * virtio_config_val - look for a feature and get a virtio config entry. * @vdev: the virtio device @@ -84,7 +106,7 @@ static inline int virtio_config_buf(struct virtio_device *vdev, unsigned int offset, void *buf, unsigned len) { - if (!vdev->config->feature(vdev, fbit)) + if (!virtio_has_feature(vdev, fbit)) return -ENOENT; vdev->config->get(vdev, offset, buf, len); |