diff options
Diffstat (limited to 'kernel/include/linux/virtio.h')
| -rw-r--r-- | kernel/include/linux/virtio.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/kernel/include/linux/virtio.h b/kernel/include/linux/virtio.h new file mode 100644 index 000000000..8f4d4bfa6 --- /dev/null +++ b/kernel/include/linux/virtio.h @@ -0,0 +1,173 @@ +#ifndef _LINUX_VIRTIO_H +#define _LINUX_VIRTIO_H +/* Everything a virtio driver needs to work with any particular virtio + * implementation. */ +#include <linux/types.h> +#include <linux/scatterlist.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/mod_devicetable.h> +#include <linux/gfp.h> +#include <linux/vringh.h> + +/** + * virtqueue - a queue to register buffers for sending or receiving. + * @list: the chain of virtqueues for this device + * @callback: the function to call when buffers are consumed (can be NULL). + * @name: the name of this virtqueue (mainly for debugging) + * @vdev: the virtio device this queue was created for. + * @priv: a pointer for the virtqueue implementation to use. + * @index: the zero-based ordinal number for this queue. + * @num_free: number of elements we expect to be able to fit. + * + * A note on @num_free: with indirect buffers, each buffer needs one + * element in the queue, otherwise a buffer will need one element per + * sg element. + */ +struct virtqueue { + struct list_head list; + void (*callback)(struct virtqueue *vq); + const char *name; + struct virtio_device *vdev; + unsigned int index; + unsigned int num_free; + void *priv; +}; + +int virtqueue_add_outbuf(struct virtqueue *vq, + struct scatterlist sg[], unsigned int num, + void *data, + gfp_t gfp); + +int virtqueue_add_inbuf(struct virtqueue *vq, + struct scatterlist sg[], unsigned int num, + void *data, + gfp_t gfp); + +int virtqueue_add_sgs(struct virtqueue *vq, + struct scatterlist *sgs[], + unsigned int out_sgs, + unsigned int in_sgs, + void *data, + gfp_t gfp); + +bool virtqueue_kick(struct virtqueue *vq); + +bool virtqueue_kick_prepare(struct virtqueue *vq); + +bool virtqueue_notify(struct virtqueue *vq); + +void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); + +void virtqueue_disable_cb(struct virtqueue *vq); + +bool virtqueue_enable_cb(struct virtqueue *vq); + +unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); + +bool virtqueue_poll(struct virtqueue *vq, unsigned); + +bool virtqueue_enable_cb_delayed(struct virtqueue *vq); + +void *virtqueue_detach_unused_buf(struct virtqueue *vq); + +unsigned int virtqueue_get_vring_size(struct virtqueue *vq); + +bool virtqueue_is_broken(struct virtqueue *vq); + +void *virtqueue_get_avail(struct virtqueue *vq); +void *virtqueue_get_used(struct virtqueue *vq); + +/** + * virtio_device - representation of a device using virtio + * @index: unique position on the virtio bus + * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) + * @config_enabled: configuration change reporting enabled + * @config_change_pending: configuration change reported while disabled + * @config_lock: protects configuration change reporting + * @dev: underlying device. + * @id: the device type identification (used to match it with a driver). + * @config: the configuration ops for this device. + * @vringh_config: configuration ops for host vrings. + * @vqs: the list of virtqueues for this device. + * @features: the features supported by both driver and device. + * @priv: private pointer for the driver's use. + */ +struct virtio_device { + int index; + bool failed; + bool config_enabled; + bool config_change_pending; + spinlock_t config_lock; + struct device dev; + struct virtio_device_id id; + const struct virtio_config_ops *config; + const struct vringh_config_ops *vringh_config; + struct list_head vqs; + u64 features; + void *priv; +}; + +static inline struct virtio_device *dev_to_virtio(struct device *_dev) +{ + return container_of(_dev, struct virtio_device, dev); +} + +int register_virtio_device(struct virtio_device *dev); +void unregister_virtio_device(struct virtio_device *dev); + +void virtio_break_device(struct virtio_device *dev); + +void virtio_config_changed(struct virtio_device *dev); +#ifdef CONFIG_PM_SLEEP +int virtio_device_freeze(struct virtio_device *dev); +int virtio_device_restore(struct virtio_device *dev); +#endif + +/** + * 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 driver. + * @feature_table_size: number of entries in the feature table array. + * @feature_table_legacy: same as feature_table but when working in legacy mode. + * @feature_table_size_legacy: number of entries in feature table legacy array. + * @probe: the function to call when a device is found. Returns 0 or -errno. + * @remove: the function to call when a device is removed. + * @config_changed: optional function to call when the device configuration + * changes; may be called in interrupt context. + */ +struct virtio_driver { + struct device_driver driver; + const struct virtio_device_id *id_table; + const unsigned int *feature_table; + unsigned int feature_table_size; + const unsigned int *feature_table_legacy; + unsigned int feature_table_size_legacy; + int (*probe)(struct virtio_device *dev); + void (*scan)(struct virtio_device *dev); + void (*remove)(struct virtio_device *dev); + void (*config_changed)(struct virtio_device *dev); +#ifdef CONFIG_PM + int (*freeze)(struct virtio_device *dev); + int (*restore)(struct virtio_device *dev); +#endif +}; + +static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) +{ + return container_of(drv, struct virtio_driver, driver); +} + +int register_virtio_driver(struct virtio_driver *drv); +void unregister_virtio_driver(struct virtio_driver *drv); + +/* module_virtio_driver() - Helper macro for drivers that don't do + * anything special in module init/exit. This eliminates a lot of + * boilerplate. Each module may only use this macro once, and + * calling it replaces module_init() and module_exit() + */ +#define module_virtio_driver(__virtio_driver) \ + module_driver(__virtio_driver, register_virtio_driver, \ + unregister_virtio_driver) +#endif /* _LINUX_VIRTIO_H */ |