111 lines
3.6 KiB
C
111 lines
3.6 KiB
C
#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>
|
|
|
|
/**
|
|
* virtqueue - a queue to register buffers for sending or receiving.
|
|
* @callback: the function to call when buffers are consumed (can be NULL).
|
|
* If this returns false, callbacks are suppressed until vq_ops->restart
|
|
* is called.
|
|
* @vdev: the virtio device this queue was created for.
|
|
* @vq_ops: the operations for this virtqueue (see below).
|
|
* @priv: a pointer for the virtqueue implementation to use.
|
|
*/
|
|
struct virtqueue
|
|
{
|
|
bool (*callback)(struct virtqueue *vq);
|
|
struct virtio_device *vdev;
|
|
struct virtqueue_ops *vq_ops;
|
|
void *priv;
|
|
};
|
|
|
|
/**
|
|
* virtqueue_ops - operations for virtqueue abstraction layer
|
|
* @add_buf: expose buffer to other end
|
|
* vq: the struct virtqueue we're talking about.
|
|
* sg: the description of the buffer(s).
|
|
* out_num: the number of sg readable by other side
|
|
* in_num: the number of sg which are writable (after readable ones)
|
|
* data: the token identifying the buffer.
|
|
* Returns 0 or an error.
|
|
* @kick: update after add_buf
|
|
* vq: the struct virtqueue
|
|
* After one or more add_buf calls, invoke this to kick the other side.
|
|
* @get_buf: get the next used buffer
|
|
* vq: the struct virtqueue we're talking about.
|
|
* len: the length written into the buffer
|
|
* Returns NULL or the "data" token handed to add_buf.
|
|
* @restart: restart callbacks after callback returned false.
|
|
* vq: the struct virtqueue we're talking about.
|
|
* This returns "false" (and doesn't re-enable) if there are pending
|
|
* buffers in the queue, to avoid a race.
|
|
* @shutdown: "unadd" all buffers.
|
|
* vq: the struct virtqueue we're talking about.
|
|
* Remove everything from the queue.
|
|
*
|
|
* Locking rules are straightforward: the driver is responsible for
|
|
* locking. No two operations may be invoked simultaneously.
|
|
*
|
|
* All operations can be called in any context.
|
|
*/
|
|
struct virtqueue_ops {
|
|
int (*add_buf)(struct virtqueue *vq,
|
|
struct scatterlist sg[],
|
|
unsigned int out_num,
|
|
unsigned int in_num,
|
|
void *data);
|
|
|
|
void (*kick)(struct virtqueue *vq);
|
|
|
|
void *(*get_buf)(struct virtqueue *vq, unsigned int *len);
|
|
|
|
bool (*restart)(struct virtqueue *vq);
|
|
|
|
void (*shutdown)(struct virtqueue *vq);
|
|
};
|
|
|
|
/**
|
|
* virtio_device - representation of a device using virtio
|
|
* @index: unique position on the virtio bus
|
|
* @dev: underlying device.
|
|
* @id: the device type identification (used to match it with a driver).
|
|
* @config: the configuration ops for this device.
|
|
* @priv: private pointer for the driver's use.
|
|
*/
|
|
struct virtio_device
|
|
{
|
|
int index;
|
|
struct device dev;
|
|
struct virtio_device_id id;
|
|
struct virtio_config_ops *config;
|
|
void *priv;
|
|
};
|
|
|
|
int register_virtio_device(struct virtio_device *dev);
|
|
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.
|
|
* @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.
|
|
*/
|
|
struct virtio_driver {
|
|
struct device_driver driver;
|
|
const struct virtio_device_id *id_table;
|
|
int (*probe)(struct virtio_device *dev);
|
|
void (*remove)(struct virtio_device *dev);
|
|
};
|
|
|
|
int register_virtio_driver(struct virtio_driver *drv);
|
|
void unregister_virtio_driver(struct virtio_driver *drv);
|
|
#endif /* _LINUX_VIRTIO_H */
|