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- #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).
- * @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
- {
- void (*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.
- * @disable_cb: disable callbacks
- * vq: the struct virtqueue we're talking about.
- * @enable_cb: restart callbacks after disable_cb.
- * 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);
- void (*disable_cb)(struct virtqueue *vq);
- bool (*enable_cb)(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.
- * @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;
- int (*probe)(struct virtio_device *dev);
- void (*remove)(struct virtio_device *dev);
- void (*config_changed)(struct virtio_device *dev);
- };
- int register_virtio_driver(struct virtio_driver *drv);
- void unregister_virtio_driver(struct virtio_driver *drv);
- #endif /* _LINUX_VIRTIO_H */
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