[deliverable/linux.git] / include / linux / virtio.h

#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 re-enables callbacks; it returns "false" if there are pending
 *	buffers in the queue, to detect a possible race between the driver
 *	checking for more work, and enabling callbacks.
 *
 * 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);
};

/**
 * 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 */
Commit	Line	Data
ec3d41c4 RR	1	#ifndef _LINUX_VIRTIO_H
	2	#define _LINUX_VIRTIO_H
	3	/* Everything a virtio driver needs to work with any particular virtio
	4	* implementation. */
	5	#include <linux/types.h>
	6	#include <linux/scatterlist.h>
	7	#include <linux/spinlock.h>
	8	#include <linux/device.h>
	9	#include <linux/mod_devicetable.h>
	10
	11	/**
	12	* virtqueue - a queue to register buffers for sending or receiving.
	13	* @callback: the function to call when buffers are consumed (can be NULL).
ec3d41c4 RR	14	* @vdev: the virtio device this queue was created for.
	15	* @vq_ops: the operations for this virtqueue (see below).
	16	* @priv: a pointer for the virtqueue implementation to use.
	17	*/
	18	struct virtqueue
	19	{
18445c4d	20	void (callback)(struct virtqueue vq);
ec3d41c4 RR	21	struct virtio_device *vdev;
	22	struct virtqueue_ops *vq_ops;
	23	void *priv;
	24	};
	25
	26	/**
	27	* virtqueue_ops - operations for virtqueue abstraction layer
	28	* @add_buf: expose buffer to other end
	29	* vq: the struct virtqueue we're talking about.
	30	* sg: the description of the buffer(s).
	31	* out_num: the number of sg readable by other side
	32	* in_num: the number of sg which are writable (after readable ones)
	33	* data: the token identifying the buffer.
	34	* Returns 0 or an error.
	35	* @kick: update after add_buf
	36	* vq: the struct virtqueue
	37	* After one or more add_buf calls, invoke this to kick the other side.
	38	* @get_buf: get the next used buffer
	39	* vq: the struct virtqueue we're talking about.
	40	* len: the length written into the buffer
	41	* Returns NULL or the "data" token handed to add_buf.
18445c4d RR	42	* @disable_cb: disable callbacks
	43	* vq: the struct virtqueue we're talking about.
	44	* @enable_cb: restart callbacks after disable_cb.
ec3d41c4	45	* vq: the struct virtqueue we're talking about.
4265f161 CB	46	* This re-enables callbacks; it returns "false" if there are pending
	47	* buffers in the queue, to detect a possible race between the driver
	48	* checking for more work, and enabling callbacks.
ec3d41c4 RR	49	*
	50	* Locking rules are straightforward: the driver is responsible for
	51	* locking. No two operations may be invoked simultaneously.
	52	*
	53	* All operations can be called in any context.
	54	*/
	55	struct virtqueue_ops {
	56	int (add_buf)(struct virtqueue vq,
	57	struct scatterlist sg[],
	58	unsigned int out_num,
	59	unsigned int in_num,
	60	void *data);
	61
	62	void (kick)(struct virtqueue vq);
	63
	64	void (get_buf)(struct virtqueue vq, unsigned int len);
	65
18445c4d RR	66	void (disable_cb)(struct virtqueue vq);
18445c4d RR	67	bool (enable_cb)(struct virtqueue vq);
ec3d41c4 RR	68	};
	69
	70	/**
	71	* virtio_device - representation of a device using virtio
	72	* @index: unique position on the virtio bus
	73	* @dev: underlying device.
	74	* @id: the device type identification (used to match it with a driver).
	75	* @config: the configuration ops for this device.
	76	* @priv: private pointer for the driver's use.
	77	*/
	78	struct virtio_device
	79	{
	80	int index;
	81	struct device dev;
	82	struct virtio_device_id id;
	83	struct virtio_config_ops *config;
	84	void *priv;
	85	};
	86
	87	int register_virtio_device(struct virtio_device *dev);
	88	void unregister_virtio_device(struct virtio_device *dev);
	89
	90	/**
	91	* virtio_driver - operations for a virtio I/O driver
	92	* @driver: underlying device driver (populate name and owner).
	93	* @id_table: the ids serviced by this driver.
	94	* @probe: the function to call when a device is found. Returns a token for
	95	* remove, or PTR_ERR().
	96	* @remove: the function when a device is removed.
f957d1f0 RR	97	* @config_changed: optional function to call when the device configuration
f957d1f0 RR	98	* changes; may be called in interrupt context.
ec3d41c4 RR	99	*/
	100	struct virtio_driver {
	101	struct device_driver driver;
	102	const struct virtio_device_id *id_table;
	103	int (probe)(struct virtio_device dev);
	104	void (remove)(struct virtio_device dev);
f957d1f0	105	void (config_changed)(struct virtio_device dev);
ec3d41c4 RR	106	};
	107
	108	int register_virtio_driver(struct virtio_driver *drv);
	109	void unregister_virtio_driver(struct virtio_driver *drv);
	110	#endif /* _LINUX_VIRTIO_H */