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 #include <linux/gfp.h>
11 
12 /**
13  * virtqueue - a queue to register buffers for sending or receiving.
14  * @list: the chain of virtqueues for this device
15  * @callback: the function to call when buffers are consumed (can be NULL).
16  * @name: the name of this virtqueue (mainly for debugging)
17  * @vdev: the virtio device this queue was created for.
18  * @priv: a pointer for the virtqueue implementation to use.
19  */
20 struct virtqueue {
21 	struct list_head list;
22 	void (*callback)(struct virtqueue *vq);
23 	const char *name;
24 	struct virtio_device *vdev;
25 	void *priv;
26 };
27 
28 int virtqueue_add_buf(struct virtqueue *vq,
29 		      struct scatterlist sg[],
30 		      unsigned int out_num,
31 		      unsigned int in_num,
32 		      void *data,
33 		      gfp_t gfp);
34 
35 void virtqueue_kick(struct virtqueue *vq);
36 
37 bool virtqueue_kick_prepare(struct virtqueue *vq);
38 
39 void virtqueue_notify(struct virtqueue *vq);
40 
41 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
42 
43 void virtqueue_disable_cb(struct virtqueue *vq);
44 
45 bool virtqueue_enable_cb(struct virtqueue *vq);
46 
47 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
48 
49 bool virtqueue_poll(struct virtqueue *vq, unsigned);
50 
51 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
52 
53 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
54 
55 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
56 
57 /**
58  * virtio_device - representation of a device using virtio
59  * @index: unique position on the virtio bus
60  * @dev: underlying device.
61  * @id: the device type identification (used to match it with a driver).
62  * @config: the configuration ops for this device.
63  * @vqs: the list of virtqueues for this device.
64  * @features: the features supported by both driver and device.
65  * @priv: private pointer for the driver's use.
66  */
67 struct virtio_device {
68 	int index;
69 	struct device dev;
70 	struct virtio_device_id id;
71 	struct virtio_config_ops *config;
72 	struct list_head vqs;
73 	/* Note that this is a Linux set_bit-style bitmap. */
74 	unsigned long features[1];
75 	void *priv;
76 };
77 
78 #define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
79 int register_virtio_device(struct virtio_device *dev);
80 void unregister_virtio_device(struct virtio_device *dev);
81 
82 /**
83  * virtio_driver - operations for a virtio I/O driver
84  * @driver: underlying device driver (populate name and owner).
85  * @id_table: the ids serviced by this driver.
86  * @feature_table: an array of feature numbers supported by this driver.
87  * @feature_table_size: number of entries in the feature table array.
88  * @probe: the function to call when a device is found.  Returns 0 or -errno.
89  * @remove: the function to call when a device is removed.
90  * @config_changed: optional function to call when the device configuration
91  *    changes; may be called in interrupt context.
92  */
93 struct virtio_driver {
94 	struct device_driver driver;
95 	const struct virtio_device_id *id_table;
96 	const unsigned int *feature_table;
97 	unsigned int feature_table_size;
98 	int (*probe)(struct virtio_device *dev);
99 	void (*remove)(struct virtio_device *dev);
100 	void (*config_changed)(struct virtio_device *dev);
101 #ifdef CONFIG_PM
102 	int (*freeze)(struct virtio_device *dev);
103 	int (*restore)(struct virtio_device *dev);
104 #endif
105 };
106 
107 int register_virtio_driver(struct virtio_driver *drv);
108 void unregister_virtio_driver(struct virtio_driver *drv);
109 #endif /* _LINUX_VIRTIO_H */
110