#ifndef _LINUX_VIRTIO_H
#define _LINUX_VIRTIO_H
#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>

struct virtqueue {
	struct list_head list;
	void (*callback)(struct virtqueue *vq);
	const char *name;
	struct virtio_device *vdev;
	void *priv;
};

int virtqueue_add_buf(struct virtqueue *vq,
		      struct scatterlist sg[],
		      unsigned int out_num,
		      unsigned int in_num,
		      void *data,
		      gfp_t gfp);

void virtqueue_kick(struct virtqueue *vq);

bool virtqueue_kick_prepare(struct virtqueue *vq);

void 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);

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);

struct virtio_device {
	int index;
	struct device dev;
	struct virtio_device_id id;
	struct virtio_config_ops *config;
	struct list_head vqs;
	
	unsigned long features[1];
	void *priv;
};

#define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
int register_virtio_device(struct virtio_device *dev);
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);
#ifdef CONFIG_PM
	int (*freeze)(struct virtio_device *dev);
	int (*restore)(struct virtio_device *dev);
#endif
};

int register_virtio_driver(struct virtio_driver *drv);
void unregister_virtio_driver(struct virtio_driver *drv);
#endif